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PIC18F6390/6490/8390/8490 Data Sheet
64/80-Pin Flash Microcontrollers with LCD Driver and nanoWatt Technology
(c) 2007 Microchip Technology Inc.
DS39629C
Note the following details of the code protection feature on Microchip devices: * * * Microchip products meet the specification contained in their particular Microchip Data Sheet. Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. Microchip is willing to work with the customer who is concerned about the integrity of their code. Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable."
* *
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Trademarks The Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, KEELOQ logo, microID, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, rfPIC and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. AmpLab, FilterLab, Linear Active Thermistor, Migratable Memory, MXDEV, MXLAB, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, PICkit, PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Smart Serial, SmartTel, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. (c) 2007, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper.
Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company's quality system processes and procedures are for its PIC(R) MCUs and dsPIC(R) DSCs, KEELOQ(R) code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001:2000 certified.
DS39629C-page ii
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
64/80-Pin Flash Microcontrollers with LCD Driver and nanoWatt Technology
LCD Driver Module Features:
* Direct Driving of LCD Panel * Up to 48 Segments: Software Selectable * Programmable LCD Timing module: - Multiple LCD timing sources available - Up to 4 commons: Static, 1/2, 1/3 or 1/4 multiplex - Static, 1/2 or 1/3 bias configuration * Can drive LCD Panel while in Sleep mode
Peripheral Highlights:
* * * * * High-Current Sink/Source 25 mA/25 mA Four External Interrupts Four Input Change Interrupts Four 8-Bit/16-Bit Timer/Counter modules Real-Time Clock (RTC) Software module: - Configurable 24-hour clock, calendar, automatic 100-year or 12800-year, day-of-week calculator - Uses Timer1 Up to 2 Capture/Compare/PWM (CCP) modules Master Synchronous Serial Port (MSSP) module supporting 3-Wire SPI (all 4 modes) and I2CTM Master and Slave modes Addressable USART module: - Supports RS-485 and RS-232 Enhanced Addressable USART module: - Supports RS-485, RS-232 and LIN 1.2 - Auto-wake-up on Start bit - Auto-Baud Detect 10-Bit, up to 12-Channel Analog-to-Digital (A/D) Converter module: - Auto-acquisition capability - Conversion available during Sleep Dual Analog Comparators with Input Multiplexing
Power-Managed Modes:
* * * * * * * * * Run: CPU On, Peripherals On Idle: CPU Off, Peripherals On Sleep: CPU Off, Peripherals Off Run mode Currents Down to 14.0 A Typical Idle mode Currents Down to 5.8 A Typical Sleep Current Down to 0.1 A Typical Timer1 Oscillator: 1.8 A, 32 kHz, 2V Watchdog Timer: 2.1 A Two-Speed Oscillator Start-up
* * * *
*
Flexible Oscillator Structure:
* Four Crystal modes: - LP: up to 200 kHz - XT: up to 4 MHz - HS: up to 40 MHz - HSPLL: 4-10 MHz (16-40 MHz internal) * 4x Phase Lock Loop (available for crystal and internal oscillators) * Two External RC modes, up to 4 MHz * Two External Clock modes, up to 40 MHz * Internal Oscillator Block: - 8 user-selectable frequencies, from 31 kHz to 8 MHz - Provides a complete range of clock speeds from 31 kHz to 32 MHz when used with PLL - User-tunable to compensate for frequency drift * Secondary Oscillator using Timer1 @ 32 kHz * Fail-Safe Clock Monitor: - Allows for safe shut down of device if primary or secondary clock fails
Program Memory Device Data Memory
*
Special Microcontroller Features:
* C Compiler Optimized Architecture: - Optional extended instruction set designed to optimize re-entrant code * 1000 Erase/Write Cycle Flash Program Memory Typical * Flash Retention: 100 Years Typical * Priority Levels for Interrupts * 8 x 8 Single-Cycle Hardware Multiplier * Extended Watchdog Timer (WDT): - Programmable period from 4 ms to 132s - 2% stability over VDD and temperature * In-Circuit Serial ProgrammingTM (ICSPTM) via Two Pins * In-Circuit Debug (ICD) via Two Pins * Wide Operating Voltage Range: 2.0V to 5.5V
Flash # Single-Word SRAM (bytes) Instructions (bytes) 8K 16K 8K 16K 4096 8192 4096 8192 768 768 768 768
I/O
LCD 10-Bit (pixel) A/D (ch) 128 128 192 192 12 12 12 12
CCP (PWM) 2 2 2 2
MSSP SPI Y Y Y Y Master I2CTM Y Y Y Y
EUSART/ AUSART
Comparators
Timers 8/16-Bit 1/3 1/3 1/3 1/3
PIC18F6390 PIC18F6490 PIC18F8390 PIC18F8490
50 50 66 66
1/1 1/1 1/1 1/1
2 2 2 2
(c) 2007 Microchip Technology Inc.
DS39629C-page 1
PIC18F6390/6490/8390/8490
Pin Diagrams
64-Pin TQFP
RE7/CCP2(1)/SEG31
RE4/COM1
RE5/COM2
RE6/COM3
RD1/SEG1
RD2/SEG2
RD3/SEG3
RD4/SEG4
RD5/SEG5
RD6/SEG6
RD0/SEG0
VDD
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
RD7/SEG7
LCDBIAS3
COM0
VSS
LCDBIAS2 LCDBIAS1 RG0/SEG30 RG1/TX2/CK2/SEG29 RG2/RX2/DT2/SEG28 RG3/SEG27 MCLR/VPP/RG5 RG4/SEG26 VSS VDD RF7/SS/SEG25 RF6/AN11/SEG24 RF5/AN10/CVREF/SEG23 RF4/AN9/SEG22 RF3/AN8/SEG21 RF2/AN7/C1OUT/SEG20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33
RB0/INT0 RB1/INT1/SEG8 RB2/INT2/SEG9 RB3/INT3/SEG10 RB4/KBI0/SEG11 RB5/KBI1 RB6/KBI2/PGC VSS OSC2/CLKO/RA6 OSC1/CLKI/RA7 VDD RB7/KBI3/PGD RC5/SDO/SEG12 RC4/SDI/SDA RC3/SCK/SCL RC2/CCP1/SEG13
PIC18F6390 PIC18F6490
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
RF1/AN6/C2OUT/SEG19
RF0/AN5/SEG18
RA2/AN2/VREF-/SEG16
RA5/AN4/HLVDIN/SEG15
AVSS RA3/AN3/VREF+/SEG17
Note 1: RE7 is the alternate pin for CCP2 multiplexing.
RA4/T0CKI/SEG14 RC1/T1OSI/CCP2(1)
RC0/T1OSO/T13CKI
RC7/RX1/DT1
RC6/TX1/CK1
RA1/AN1
RA0/AN0
AVDD
VSS
VDD
DS39629C-page 2
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
Pin Diagrams (Continued)
80-Pin TQFP
RH1/SEG46
RH0/SEG47
RE7/CCP2(1)/SEG31
RJ0/SEG32
80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 RH2/SEG45 RH3/SEG44 LCDBIAS2 LCDBIAS1 RG0/SEG30 RG1/TX2/CK2/SEG29 RG2/RX2/DT2/SEG28 RG3/SEG27 MCLR/VPP/RG5 RG4/SEG26 VSS VDD RF7/SS/SEG25 RF6/AN11/SEG24 RF5/AN10/CVREF/SEG23 RF4/AN9/SEG22 RF3/AN8/SEG21 RF2/AN7/C1OUT/SEG20 RH7/SEG43 RH6/SEG42 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 RJ2/SEG34 RJ3/SEG35 RB0/INT0 RB1/INT1/SEG8 RB2/INT2/SEG9 RB3/INT3/SEG10 RB4/KBI0/SEG11 RB5/KBI1 RB6/KBI2/PGC VSS OSC2/CLKO/RA6 OSC1/CLKI/RA7 VDD RB7/KBI3/PGD RC5/SDO/SEG12 RC4/SDI/SDA RC3/SCK/SCL RC2/CCP1/SEG13 RJ7/SEG36 RJ6/SEG37
PIC18F8390 PIC18F8490
RF1/AN6/C2OUT/SEG19
RF0/AN5/SEG18
RJ4/SEG39
AVSS RA3/AN3/VREF+/SEG17
RA2/AN2/VREF-/SEG16
RA4/T0CKI/SEG14 RC1/T1OSI/CCP2(1)
RA5/AN4/HLVDIN/SEG15
Note 1: RE7 is the alternate pin for CCP2 multiplexing.
(c) 2007 Microchip Technology Inc.
RC0/T1OSO/T13CKI
RC7/RX1/DT1
RC6/TX1/CK1
RH5/SEG41
RH4/SEG40
RJ5/SEG38
RA1/AN1
RA0/AN0
AVDD
VSS
VDD
RJ1/SEG33
RE4/COM1
RE5/COM2
RE6/COM3
RD0/SEG0
RD1/SEG1
RD2/SEG2
RD3/SEG3
RD4/SEG4
RD5/SEG5
RD6/SEG6
RD7/SEG7
LCDBIAS3
COM0
VDD
VSS
DS39629C-page 3
PIC18F6390/6490/8390/8490
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 7 2.0 Oscillator Configurations ............................................................................................................................................................ 31 3.0 Power-Managed Modes ............................................................................................................................................................. 41 4.0 Reset .......................................................................................................................................................................................... 51 5.0 Memory Organization ................................................................................................................................................................. 65 6.0 Flash Program Memory .............................................................................................................................................................. 87 7.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 91 8.0 Interrupts .................................................................................................................................................................................... 93 9.0 I/O Ports ................................................................................................................................................................................... 109 10.0 Timer0 Module ......................................................................................................................................................................... 131 11.0 Timer1 Module ......................................................................................................................................................................... 135 12.0 Timer2 Module ......................................................................................................................................................................... 141 13.0 Timer3 Module ......................................................................................................................................................................... 143 14.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 147 15.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 157 16.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 197 17.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART) ........................................................... 217 18.0 10-Bit Analog-to-Digital Converter (A/D) Module ..................................................................................................................... 231 19.0 Comparator Module.................................................................................................................................................................. 241 20.0 Comparator Voltage Reference Module ................................................................................................................................... 247 21.0 High/Low-Voltage Detect (HLVD)............................................................................................................................................. 251 22.0 Liquid Crystal Display (LCD) Driver Module ............................................................................................................................. 257 23.0 Special Features of the CPU .................................................................................................................................................... 281 24.0 Instruction Set Summary .......................................................................................................................................................... 295 25.0 Development Support............................................................................................................................................................... 345 26.0 Electrical Characteristics .......................................................................................................................................................... 349 27.0 DC and AC Characteristics Graphs and Tables ....................................................................................................................... 387 28.0 Packaging Information.............................................................................................................................................................. 389 Appendix A: Revision History............................................................................................................................................................. 395 Appendix B: Device Differences......................................................................................................................................................... 395 Appendix C: Conversion Considerations ........................................................................................................................................... 396 Appendix D: Migration from Baseline to Enhanced Devices.............................................................................................................. 396 Appendix E: migration from Mid-Range to Enhanced Devices .......................................................................................................... 397 Appendix F: Migration from High-End to Enhanced Devices ............................................................................................................. 397 Index .................................................................................................................................................................................................. 399 The Microchip Web Site ..................................................................................................................................................................... 409 Customer Change Notification Service .............................................................................................................................................. 409 Customer Support .............................................................................................................................................................................. 409 Reader Response .............................................................................................................................................................................. 410 PIC18F6390/6490/8390/8490 Product Identification System ............................................................................................................ 411
DS39629C-page 4
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at docerrors@mail.microchip.com or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We welcome your feedback.
Most Current Data Sheet
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Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: * Microchip's Worldwide Web site; http://www.microchip.com * Your local Microchip sales office (see last page) * The Microchip Corporate Literature Center; U.S. FAX: (480) 792-7277 When contacting a sales office or the literature center, please specify which device, revision of silicon and data sheet (include literature number) you are using.
Customer Notification System
Register on our web site at www.microchip.com/cn to receive the most current information on all of our products.
(c) 2007 Microchip Technology Inc.
DS39629C-page 5
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 6
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
1.0 DEVICE OVERVIEW
1.1.2
This document contains device-specific information for the following devices: * PIC18F6390 * PIC18F6490 * PIC18F8390 * PIC18F8490
MULTIPLE OSCILLATOR OPTIONS AND FEATURES
All of the devices in the PIC18F6390/6490/8390/8490 family offer ten different oscillator options, allowing users a wide range of choices in developing application hardware. These include: * Four Crystal modes using crystals or ceramic resonators. * Two External Clock modes offering the option of using two pins (oscillator input and a divide-by-4 clock output) or one pin (oscillator input, with the second pin reassigned as general I/O). * Two External RC Oscillator modes with the same pin options as the External Clock modes. * An internal oscillator block which provides an 8 MHz clock (2% accuracy) and an INTRC source (approximately 31 kHz, stable over temperature and VDD), as well as a range of six user-selectable clock frequencies between 125 kHz to 4 MHz for a total of eight clock frequencies. This option frees the two oscillator pins for use as additional general purpose I/O. * A Phase Lock Loop (PLL) frequency multiplier, available to both the High-Speed Crystal and Internal Oscillator modes, which allows clock speeds of up to 40 MHz. Used with the internal oscillator, the PLL gives users a complete selection of clock speeds from 31 kHz to 32 MHz - all without using an external crystal or clock circuit. Besides its availability as a clock source, the internal oscillator block provides a stable reference source that gives the family additional features for robust operation: * Fail-Safe Clock Monitor: This option constantly monitors the main clock source against a reference signal provided by the internal oscillator. If a clock failure occurs, the controller is switched to the internal oscillator block, allowing for continued low-speed operation or a safe application shutdown. * Two-Speed Start-up: This option allows the internal oscillator to serve as the clock source from Power-on Reset or wake-up from Sleep mode until the primary clock source is available.
This family offers the advantages of all PIC18 microcontrollers - namely, high computational performance at an economical price. In addition to these features, the PIC18F6390/6490/8390/8490 family introduces design enhancements that make these microcontrollers a logical choice for many high-performance, power-sensitive applications.
1.1
1.1.1
New Core Features
nanoWatt TECHNOLOGY
All of the devices in the PIC18F6390/6490/8390/8490 family incorporate a range of features that can significantly reduce power consumption during operation. Key items include: * Alternate Run Modes: By clocking the controller from the Timer1 source or the internal oscillator block, power consumption during code execution can be reduced by as much as 90%. * Multiple Idle Modes: The controller can also run with its CPU core disabled, but the peripherals still active. In these states, power consumption can be reduced even further - to as little as 4% of normal operation requirements. * On-the-Fly Mode Switching: The power-managed modes are invoked by user code during operation, allowing the user to incorporate power-saving ideas into their application's software design. * Lower Consumption in Key Modules: The power requirements for both Timer1 and the Watchdog Timer have been reduced by up to 80%, with typical values of 1.1 A and 2.1 A, respectively.
(c) 2007 Microchip Technology Inc.
DS39629C-page 7
PIC18F6390/6490/8390/8490
1.2 Other Special Features 1.3
* Memory Endurance: The Flash cells for program memory are rated to last for approximately a thousand erase/write cycles. Data retention without refresh is conservatively estimated to be greater than 100 years. * Extended Instruction Set: The PIC18F6390/6490/8390/8490 family introduces an optional extension to the PIC18 instruction set, which adds 8 new instructions and an Indexed Addressing mode. This extension, enabled as a device configuration option, has been specifically designed to optimize re-entrant application code originally developed in high-level languages such as C. * Enhanced Addressable USART: This serial communication module is capable of standard RS-232 operation and provides support for the LIN bus protocol. Other enhancements include Automatic Baud Rate Detection and a 16-bit Baud Rate Generator for improved resolution. When the microcontroller is using the internal oscillator block, the EUSART provides stable operation for applications that talk to the outside world, without using an external crystal (or its accompanying power requirement). * 10-Bit A/D Converter: This module incorporates programmable acquisition time, allowing for a channel to be selected and a conversion to be initiated without waiting for a sampling period and thus, reduces code overhead. * Extended Watchdog Timer (WDT): This enhanced version incorporates a 16-bit prescaler, allowing a time-out range from 4 ms to over 10 minutes that is stable across operating voltage and temperature.
Details on Individual Family Members
Devices in the PIC18F6390/6490/8390/8490 family are available in 64-pin (PIC18F6X90) and 80-pin (PIC18F8X90) packages. Block diagrams for the two groups are shown in Figure 1-1 and Figure 1-2, respectively. The devices are differentiated from each other in three ways: 1. 2. I/O Ports: 7 bidirectional ports on 64-pin devices; 9 bidirectional ports on 80-pin devices. LCD Pixels: 128 (32 SEGs x 4 COMs) pixels can be driven by 64-pin devices; 192 (48 SEGs x 4 COMs) pixels can be driven by 80-pin devices. Flash Program Memory: 8 Kbytes for PIC18FX390 devices; 16 Kbytes for PIC18FX490.
3.
All other features for devices in this family are identical. These are summarized in Table 1-1. The pinouts for all devices are listed in Table 1-2 and Table 1-3. Like all Microchip PIC18 devices, members of the PIC18F6390/6490/8390/8490 family are available as both standard and low-voltage devices. Standard devices with Flash memory, designated with an "F" in the part number (such as PIC18F6390), accommodate an operating VDD range of 4.2V to 5.5V. Low-voltage parts, designated by "LF" (such as PIC18LF6490), function over an extended VDD range of 2.0V to 5.5V.
DS39629C-page 8
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-1: DEVICE FEATURES
Features Operating Frequency Program Memory (Bytes) Program Memory (Instructions) Data Memory (Bytes) Interrupt Sources I/O Ports Number of Pixels the LCD Driver can Drive Timers Capture/Compare/PWM Modules Serial Communications 10-Bit Analog-to-Digital Module Resets (and Delays) PIC18F6390 DC - 40 MHz 8K 4096 768 22 PIC18F6490 DC - 40 MHz 16K 8192 768 22 PIC18F8390 DC - 40 MHz 8K 4096 768 22 PIC18F8490 DC - 40 MHz 16K 8192 768 22
Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E, F, G F, G F, G, H, J F, G, H, J 128 (32 SEGs x 4 COMs) 4 2 128 (32 SEGs x 4 COMs) 4 2 192 (48 SEGs x 4 COMs) 4 2 192 (48 SEGs x 4 COMs) 4 2
MSSP, AUSART MSSP, AUSART MSSP, AUSART MSSP, AUSART Enhanced USART Enhanced USART Enhanced USART Enhanced USART 12 Input Channels 12 Input Channels 12 Input Channels 12 Input Channels POR, BOR, POR, BOR, POR, BOR, POR, BOR, RESET Instruction, RESET Instruction, RESET Instruction, RESET Instruction, Stack Full, Stack Full, Stack Full, Stack Full, Stack Underflow Stack Underflow Stack Underflow Stack Underflow (PWRT, OST), (PWRT, OST), (PWRT, OST), (PWRT, OST), MCLR (optional), MCLR (optional), MCLR (optional), MCLR (optional), WDT WDT WDT WDT Yes Yes 75 Instructions; 83 with Extended Instruction Set Enabled 64-Pin TQFP Yes Yes 75 Instructions; 83 with Extended Instruction Set Enabled 64-Pin TQFP Yes Yes 75 Instructions; 83 with Extended Instruction Set Enabled 80-Pin TQFP Yes Yes 75 Instructions; 83 with Extended Instruction Set Enabled 80-Pin TQFP
Programmable Low-Voltage Detect Programmable Brown-out Reset Instruction Set
Packages
(c) 2007 Microchip Technology Inc.
DS39629C-page 9
PIC18F6390/6490/8390/8490
FIGURE 1-1:
Table Pointer<21> inc/dec logic 21 20 8
PCLATU PCLATH
PIC18F6X90 (64-PIN) BLOCK DIAGRAM
Data Bus<8> Data Latch Data Memory (3.9 Kbytes) Address Latch 12 Data Address<12> 4 BSR 12 FSR0 FSR1 FSR2 inc/dec logic 4 Access Bank 12 PORTC PORTB PORTA RA0/AN0 RA1/AN1 RA2/AN2/VREF-/SEG16 RA3/AN3/VREF+/SEG17 RA4/T0CKI/SEG14 RA5/AN4/HLVDIN/SEG15 OSC2/CLKO(3)/RA6 OSC1/CLKI(3)/RA7 RB0/INT0 RB1/INT1/SEG8 RB2/INT2/SEG9 RB3/INT3/SEG10 RB4/KBI0/SEG11 RB5/KBI1 RB6/KBI2/PGC RB7/KBI3/PGD RC0/T1OSO/T13CKI RC1/T1OSI/CCP2(1) RC2/CCP1/SEG13 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO/SEG12 RC6/TX1/CK1 RC7/RX1/DT1
8
PCU PCH PCL Program Counter 31 Level Stack
Address Latch Program Memory (48/64 Kbytes) Data Latch 8 STKPTR
Table Latch
Instruction Bus <16>
ROM Latch
Address Decode
IR 8 PORTD
Instruction Decode and Control
State Machine Control Signals
PRODH PRODL 3 BITOP 8 8 x 8 Multiply 8 W 8 8 ALU<8> 8 PORTF 8 PORTE
RD7/SEG7:RD0/SEG0
OSC1(3) OSC2
(3)
Internal Oscillator Block INTRC Oscillator 8 MHz Oscillator Single-Supply Programming In-Circuit Debugger
Power-up Timer Oscillator Start-up Timer Power-on Reset Watchdog Timer Brown-out Reset Fail-Safe Clock Monitor
8
LCDBIAS1 LCDBIAS2 LCDBIAS3 COM0 RE4/COM1 RE5/COM2 RE6/COM3 RE7/CCP2(1)/SEG31 RF0/AN5/SEG18 RF1/AN6/C2OUT/SEG19 RF2/AN7/C1OUT/SEG20 RF3/AN8/SEG21 RF4/AN9/SEG22 RF5/AN10/CVREF/SEG23 RF6/AN11/SEG24 RF7/SS/SEG25 RG0/SEG30 RG1/TX2/CK2/SEG29 RG2/RX2/DT2/SEG28 RG3/SEG27 RG4/SEG26 MCLR/VPP/RG5(2)
T1OSI T1OSO MCLR(2) VDD, VSS
Precision Band Gap Reference
BOR HLVD
ADC 10-Bit
PORTG Timer0 Timer1 Timer2 Timer3
Comparators
CCP1
CCP2
MSSP
EUSART1
AUSART2
LCD Driver
Note
1: 2: 3:
CCP2 is multiplexed with RC1 when Configuration bit, CCP2MX, is set, or RE7 when CCP2MX is not set. RG5 is only available when MCLR functionality is disabled. OSC1/CLKI and OSC2/CLKO are only available in select oscillator modes and when these pins are not being used as digital I/O. Refer to Section 2.0 "Oscillator Configurations" for additional information.
DS39629C-page 10
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 1-2:
Table Pointer<21> inc/dec logic 21 20 8
PCLATU PCLATH
PIC18F8X90 (80-PIN) BLOCK DIAGRAM
Data Bus<8> Data Latch Data Memory (3.9 Kbytes) Address Latch PORTB 12 Data Address<12> 4 BSR 12 FSR0 FSR1 FSR2 inc/dec logic 4 Access Bank 12 PORTC PORTA RA0/AN0 RA1/AN1 RA2/AN2/VREF-/SEG16 RA3/AN3/VREF+/SEG17 RA4/T0CKI/SEG14 RA5/AN4/HLVDIN/SEG15 OSC2/CLKO(3)/RA6 OSC1/CLKI(3)/RA7 RB0/INT0 RB1/INT1/SEG8 RB2/INT2/SEG9 RB3/INT3/SEG10 RB4/KBI0/SEG11 RB5/KBI1 RB6/KBI2/PGC RB7/KBI3/PGD RC0/T1OSO/T13CKI RC1/T1OSI/CCP2(1) RC2/CCP1/SEG13 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO/SEG12 RC6/TX1/CK1 RC7/RX1/DT1
8
PCU PCH PCL Program Counter 31 Level Stack
Address Latch Program Memory (48/64 Kbytes) Data Latch 8 STKPTR
Table Latch
Instruction Bus <16>
ROM Latch
Address Decode PORTD 8
IR
RD7/SEG7:RD0/SEG0
Instruction Decode and Control
State Machine Control Signals PRODH PRODL 3 BITOP 8 8 x 8 Multiply 8 W 8 8 8 PORTE LCDBIAS1 LCDBIAS2 LCDBIAS3 COM0 RE4/COM1 RE5/COM2 RE6/COM3 RE7/CCP2(1)/SEG31 RF0/AN5/SEG18 RF1/AN6/C2OUT/SEG19 RF2/AN7/C1OUT/SEG20 RF3/AN8/SEG21 RF4/AN9/SEG22 RF5/AN10/CVREF/SEG23 RF6/AN11/SEG24 RF7/SS/SEG25 RG0/SEG30 RG1/TX2/CK2/SEG29 RG2/RX2/DT2/SEG28 RG3/SEG27 RG4/SEG26 MCLR/VPP/RG5(2)
OSC1(3) OSC2
(3)
Internal Oscillator Block INTRC Oscillator 8 MHz Oscillator Single-Supply Programming In-Circuit Debugger
Power-up Timer Oscillator Start-up Timer Power-on Reset Watchdog Timer Brown-out Reset Fail-Safe Clock Monitor
8 ALU<8> 8
PORTF
T1OSI T1OSO MCLR(2) VDD, VSS
Precision Band Gap Reference
PORTG
PORTH BOR HLVD ADC 10-Bit Timer0 Timer1 Timer2 Timer3 RH3/SEG47:RH0/SEG44 RH7/SEG40:RH4/SEG43 PORTJ RJ3/SEG35:RJ0/SEG32 Comparators CCP1 CCP2 LCD Driver MSSP EUSART1 AUSART2 RJ7/SEG36:RJ4/SEG39
Note
1: 2: 3:
CCP2 is multiplexed with RC1 when Configuration bit, CCP2MX, is set and RE7 when CCP2MX is not set. RG5 is only available when MCLR functionality is disabled. OSC1/CLKI and OSC2/CLKO are only available in select oscillator modes and when these pins are not being used as digital I/O. Refer to Section 2.0 "Oscillator Configurations" for additional information.
(c) 2007 Microchip Technology Inc.
DS39629C-page 11
PIC18F6390/6490/8390/8490
TABLE 1-2: PIC18F6X90 PINOUT I/O DESCRIPTIONS
Pin Number TQFP 7 I P I 39 I ST Pin Buffer Type Type Description Master Clear (input) or programming voltage (input). Master Clear (Reset) input. This pin is an active-low Reset to the device. Programming voltage input. Digital input. Pin Name MCLR/VPP/RG5 MCLR VPP RG5 OSC1/CLKI/RA7 OSC1
ST ST
CLKI
I
RA7 OSC2/CLKO/RA6 OSC2 CLKO 40
I/O O O
Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode, CMOS otherwise. CMOS External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) TTL General purpose I/O pin. -- -- Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. General purpose I/O pin.
RA6
I/O
TTL
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 12
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-2: PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTA is a bidirectional I/O port. RA0/AN0 RA0 AN0 RA1/AN1 RA1 AN1 RA2/AN2/VREF-/SEG16 RA2 AN2 VREFSEG16 RA3/AN3/VREF+/SEG17 RA3 AN3 VREF+ SEG17 RA4/T0CKI/SEG14 RA4 T0CKI SEG14 RA5/AN4/HLVDIN/SEG15 RA5 AN4 HLVDIN SEG15 RA6 RA7 24 I/O I 23 I/O I 22 I/O I I O 21 I/O I I O 28 I/O I O 27 I/O I I O TTL Analog Analog Analog Digital I/O. Analog input 4. Low-Voltage Detect input. SEG15 output for LCD. See the OSC2/CLKO/RA6 pin. See the OSC1/CLKI/RA7 pin. ST/OD ST Analog Digital I/O. Open-drain when configured as output. Timer0 external clock input. SEG14 output for LCD. TTL Analog Analog Analog Digital I/O. Analog input 3. A/D reference voltage (High) input. SEG17 output for LCD. TTL Analog Analog Analog Digital I/O. Analog input 2. A/D reference voltage (Low) input. SEG16 output for LCD. TTL Analog Digital I/O. Analog input 1. TTL Analog Digital I/O. Analog input 0. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
(c) 2007 Microchip Technology Inc.
DS39629C-page 13
PIC18F6390/6490/8390/8490
TABLE 1-2: PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTB is a bidirectional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/INT0 RB0 INT0 RB1/INT1/SEG8 RB1 INT1 SEG8 RB2/INT2/SEG9 RB2 INT2 SEG9 RB3/INT3/SEG10 RB3 INT3 SEG10 RB4/KBI0/SEG11 RB4 KBI0 SEG11 RB5/KBI1 RB5 KBI1 RB6/KBI2/PGC RB6 KBI2 PGC RB7/KBI3/PGD RB7 KBI3 PGD 48 I/O I 47 I/O I O 46 I/O I O 45 I/O I O 44 I/O I O 43 I/O I 42 I/O I I/O 37 I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSPTM programming clock pin. TTL TTL Digital I/O. Interrupt-on-change pin. TTL TTL Analog Digital I/O. Interrupt-on-change pin. SEG11 output for LCD. TTL ST Analog Digital I/O. External interrupt 3. SEG10 output for LCD. TTL ST Analog Digital I/O. External interrupt 2. SEG9 output for LCD. TTL ST Analog Digital I/O. External interrupt 1. SEG8 output for LCD. TTL ST Digital I/O. External interrupt 0. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 14
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-2: PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTC is a bidirectional I/O port. RC0/T1OSO/T13CKI RC0 T1OSO T13CKI RC1/T1OSI/CCP2 RC1 T1OSI CCP2(1) RC2/CCP1/SEG13 RC2 CCP1 SEG13 RC3/SCK/SCL RC3 SCK SCL RC4/SDI/SDA RC4 SDI SDA RC5/SDO/SEG12 RC5 SDO SEG12 RC6/TX1/CK1 RC6 TX1 CK1 RC7/RX1/DT1 RC7 RX1 DT1 30 I/O O I 29 I/O I I/O 33 I/O I/O O 34 I/O I/O I/O 35 I/O I I/O 36 I/O O O 31 I/O O I/O 32 I/O I I/O ST ST ST Digital I/O. EUSART1 asynchronous receive. EUSART1 synchronous data (see related TX1/CK1). ST -- ST Digital I/O. EUSART1 asynchronous transmit. EUSART1 synchronous clock (see related RX1/DT1). ST -- Analog Digital I/O. SPI data out. SEG12 output for LCD. ST ST ST Digital I/O. SPI data in. I2C data I/O. ST ST ST Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2CTM mode. ST ST Analog Digital I/O. Capture 1 input/Compare 1 output/PWM1 output. SEG13 output for LCD. ST CMOS ST Digital I/O. Timer1 oscillator input. Capture 2 input/Compare 2 output/PWM2 output. ST -- ST Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
(c) 2007 Microchip Technology Inc.
DS39629C-page 15
PIC18F6390/6490/8390/8490
TABLE 1-2: PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTD is a bidirectional I/O port. RD0/SEG0 RD0 SEG0 RD1/SEG1 RD1 SEG1 RD2/SEG2 RD2 SEG2 RD3/SEG3 RD3 SEG3 RD4/SEG4 RD4 SEG4 RD5/SEG5 RD5 SEG5 RD6/SEG6 RD6 SEG6 RD7/SEG7 RD7 SEG7 58 I/O O 55 I/O O 54 I/O O 53 I/O O 52 I/O O 51 I/O O 50 I/O O 49 I/O O ST Analog Digital I/O. SEG7 output for LCD. ST Analog Digital I/O. SEG6 output for LCD. ST Analog Digital I/O. SEG5 output for LCD. ST Analog Digital I/O. SEG4 output for LCD. ST Analog Digital I/O. SEG3 output for LCD. ST Analog Digital I/O. SEG2 output for LCD. ST Analog Digital I/O. SEG1 output for LCD. ST Analog Digital I/O. SEG0 output for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 16
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-2: PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTE is a bidirectional I/O port. LCDBIAS1 LCDBIAS1 LCDBIAS2 LCDBIAS2 LCDBIAS3 LCDBIAS3 COM0 COM0 RE4/COM1 RE4 COM1 RE5/COM2 RE5 COM2 RE6/COM3 RE6 COM3 RE7/CCP2/SEG31 RE7 CCP2(2) SEG31 2 I 1 I 64 I 63 O 62 I/O O 61 I/O O 60 I/O O 59 I/O I/O O ST ST Analog Digital I/O. Capture 2 input/Compare 2 output/PWM2 output. SEG31 output for LCD. ST Analog Digital I/O. COM3 output for LCD. ST Analog Digital I/O. COM2 output for LCD. ST Analog Digital I/O. COM1 output for LCD. Analog COM0 output for LCD. Analog BIAS3 input for LCD. Analog BIAS2 input for LCD. Analog BIAS1 input for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
(c) 2007 Microchip Technology Inc.
DS39629C-page 17
PIC18F6390/6490/8390/8490
TABLE 1-2: PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTF is a bidirectional I/O port. RF0/AN5/SEG18 RF0 AN5 SEG18 RF1/AN6/C2OUT/SEG19 RF1 AN6 C2OUT SEG19 RF2/AN7/C1OUT/SEG20 RF2 AN7 C1OUT SEG20 RF3/AN8/SEG21 RF3 AN8 SEG21 RF4/AN9/SEG22 RF4 AN9 SEG22 RF5/AN10/CVREF/SEG23 RF5 AN10 CVREF SEG23 RF6/AN11/SEG24 RF6 AN11 SEG24 RF7/SS/SEG25 RF7 SS SEG25 18 I/O I O 17 I/O I O O 16 I/O I O O 15 I/O I O 14 I/O I O 13 I/O I O O 12 I/O I O 11 I/O I O ST TTL Analog Digital I/O. SPI slave select input. SEG25 output for LCD. ST Analog Analog Digital I/O. Analog input 11. SEG24 output for LCD. ST Analog Analog Analog Digital I/O. Analog input 10. Comparator reference voltage output. SEG23 output for LCD. ST Analog Analog Digital I/O. Analog input 9. SEG22 output for LCD. ST Analog Analog Digital I/O. Analog input 8. SEG21 output for LCD. ST Analog -- Analog Digital I/O. Analog input 7. Comparator 1 output. SEG20 output for LCD. ST Analog -- Analog Digital I/O. Analog input 6. Comparator 2 output. SEG19 output for LCD. ST Analog Analog Digital I/O. Analog input 5. SEG18 output for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 18
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-2: PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTG is a bidirectional I/O port. RG0/SEG30 RG0 SEG30 RG1/TX2/CK2/SEG29 RG1 TX2 CK2 SEG29 RG2/RX2/DT2/SEG28 RG2 RX2 DT2 SEG28 RG3/SEG27 RG3 SEG27 RG4/SEG26 RG4 SEG26 RG5 VSS VDD AVSS AVDD 9, 25, 41, 56 10, 26, 38, 57 20 19 P P P P -- -- -- -- 3 I/O O 4 I/O O I/O O 5 I/O I I/O O 6 I/O O 8 I/O O ST Analog Digital I/O. SEG26 output for LCD. See MCLR/VPP/RG5 pin. Ground reference for logic and I/O pins. Positive supply for logic and I/O pins. Ground reference for analog modules. Positive supply for analog modules. ST Analog Digital I/O. SEG27 output for LCD. ST ST ST Analog Digital I/O. AUSART2 asynchronous receive. AUSART2 synchronous data (see related TX2/CK2). SEG28 output for LCD. ST -- ST Analog Digital I/O. AUSART2 asynchronous transmit. AUSART2 synchronous clock (see related RX2/DT2). SEG29 output for LCD. ST Analog Digital I/O. SEG30 output for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
(c) 2007 Microchip Technology Inc.
DS39629C-page 19
PIC18F6390/6490/8390/8490
TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS
Pin Number TQFP 9 I P I 49 I ST Pin Buffer Type Type Description Master Clear (input) or programming voltage (input). Master Clear (Reset) input. This pin is an active-low Reset to the device. Programming voltage input. Digital input.
Pin Name MCLR/VPP/RG5 MCLR VPP RG5 OSC1/CLKI/RA7 OSC1
ST ST
CLKI
I
RA7 OSC2/CLKO/RA6 OSC2 CLKO 50
I/O O O
Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode, CMOS otherwise. CMOS External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) TTL General purpose I/O pin. -- -- Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. General purpose I/O pin.
RA6
I/O
TTL
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 20
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTA is a bidirectional I/O port. RA0/AN0 RA0 AN0 RA1/AN1 RA1 AN1 RA2/AN2/VREF-/SEG16 RA2 AN2 VREFSEG16 RA3/AN3/VREF+/SEG17 RA3 AN3 VREF+ SEG17 RA4/T0CKI/SEG14 RA4 T0CKI SEG14 RA5/AN4/HLVDIN/SEG15 RA5 AN4 HLVDIN SEG15 RA6 RA7 30 I/O I 29 I/O I 28 I/O I I O 27 I/O I I O 34 I/O I O 33 I/O I I O TTL Analog Analog Analog Digital I/O. Analog input 4. Low-Voltage Detect input. SEG15 output for LCD. See the OSC2/CLKO/RA6 pin. See the OSC1/CLKI/RA7 pin. ST/OD ST Analog Digital I/O. Open-drain when configured as output. Timer0 external clock input. SEG14 output for LCD. TTL Analog Analog Analog Digital I/O. Analog input 3. A/D reference voltage (High) input. SEG17 output for LCD. TTL Analog Analog Analog Digital I/O. Analog input 2. A/D reference voltage (Low) input. SEG16 output for LCD. TTL Analog Digital I/O. Analog input 1. TTL Analog Digital I/O. Analog input 0. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
(c) 2007 Microchip Technology Inc.
DS39629C-page 21
PIC18F6390/6490/8390/8490
TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTB is a bidirectional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/INT0 RB0 INT0 RB1/INT1/SEG8 RB1 INT1 SEG8 RB2/INT2/SEG9 RB2 INT2 SEG9 RB3/INT3/SEG10 RB3 INT3 SEG10 RB4/KBI0/SEG11 RB4 KBI0 SEG11 RB5/KBI1 RB5 KBI1 RB6/KBI2/PGC RB6 KBI2 PGC RB7/KBI3/PGD RB7 KBI3 PGD 58 I/O I 57 I/O I O 56 I/O I O 55 I/O I O 54 I/O I O 53 I/O I 52 I/O I I/O 47 I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSPTM programming clock pin. TTL TTL Digital I/O. Interrupt-on-change pin. TTL TTL Analog Digital I/O. Interrupt-on-change pin. SEG11 output for LCD. TTL ST Analog Digital I/O. External interrupt 3. SEG10 output for LCD. TTL ST Analog Digital I/O. External interrupt 2. SEG9 output for LCD. TTL ST Analog Digital I/O. External interrupt 1. SEG8 output for LCD. TTL ST Digital I/O. External interrupt 0. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 22
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTC is a bidirectional I/O port. RC0/T1OSO/T13CKI RC0 T1OSO T13CKI RC1/T1OSI/CCP2 RC1 T1OSI CCP2(1) RC2/CCP1/SEG13 RC2 CCP1 SEG13 RC3/SCK/SCL RC3 SCK SCL RC4/SDI/SDA RC4 SDI SDA RC5/SDO/SEG12 RC5 SDO SEG12 RC6/TX1/CK1 RC6 TX1 CK1 RC7/RX1/DT1 RC7 RX1 DT1 36 I/O O I 35 I/O I I/O 43 I/O I/O O 44 I/O I/O I/O 45 I/O I I/O 46 I/O O O 37 I/O O I/O 38 I/O I I/O ST ST ST Digital I/O. EUSART1 asynchronous receive. EUSART1 synchronous data (see related TX1/CK1). ST -- ST Digital I/O. EUSART1 asynchronous transmit. EUSART1 synchronous clock (see related RX1/DT1). ST -- Analog Digital I/O. SPI data out. SEG12 output for LCD. ST ST ST Digital I/O. SPI data in. I2C data I/O. ST ST ST Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2CTM mode. ST ST Analog Digital I/O. Capture 1 input/Compare 1 output/PWM1 output. SEG13 output for LCD. ST CMOS ST Digital I/O. Timer1 oscillator input. Capture 2 input/Compare 2 output/PWM2 output. ST -- ST Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
(c) 2007 Microchip Technology Inc.
DS39629C-page 23
PIC18F6390/6490/8390/8490
TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTD is a bidirectional I/O port. RD0/SEG0 RD0 SEG0 RD1/SEG1 RD1 SEG1 RD2/SEG2 RD2 SEG2 RD3/SEG3 RD3 SEG3 RD4/SEG4 RD4 SEG4 RD5/SEG5 RD5 SEG5 RD6/SEG6 RD6 SEG6 RD7/SEG7 RD7 SEG7 72 I/O O 69 I/O O 68 I/O O 67 I/O O 66 I/O O 65 I/O O 64 I/O O 63 I/O O ST Analog Digital I/O. SEG7 output for LCD. ST Analog Digital I/O. SEG6 output for LCD. ST Analog Digital I/O. SEG5 output for LCD. ST Analog Digital I/O. SEG4 output for LCD. ST Analog Digital I/O. SEG3 output for LCD. ST Analog Digital I/O. SEG2 output for LCD. ST Analog Digital I/O. SEG1 output for LCD. ST Analog Digital I/O. SEG0 output for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 24
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTE is a bidirectional I/O port. LCDBIAS1 LCDBIAS1 LCDBIAS2 LCDBIAS2 LCDBIAS3 LCDBIAS3 COM0 COM0 RE4/COM1 RE4 COM1 RE5/COM2 RE5 COM2 RE6/COM3 RE6 COM3 RE7/CCP2/SEG31 RE7 CCP2(2) SEG31 4 I 3 I 78 I 77 O 76 I/O O 75 I/O O 74 I/O O 73 I/O I/O O ST ST Analog Digital I/O. Capture 2 input/Compare 2 output/PWM2 output. SEG31 output for LCD. ST Analog Digital I/O. COM3 output for LCD. ST Analog Digital I/O. COM2 output for LCD. ST Analog Digital I/O. COM1 output for LCD. Analog COM0 output for LCD. Analog BIAS3 input for LCD. Analog BIAS2 input for LCD. Analog BIAS1 input for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
(c) 2007 Microchip Technology Inc.
DS39629C-page 25
PIC18F6390/6490/8390/8490
TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTF is a bidirectional I/O port. RF0/AN5/SEG18 RF0 AN5 SEG18 RF1/AN6/C2OUT/SEG19 RF1 AN6 C2OUT SEG19 RF2/AN7/C1OUT/SEG20 RF2 AN7 C1OUT SEG20 RF3/AN8/SEG21 RF3 AN8 SEG21 RF4/AN9/SEG22 RF4 AN9 SEG22 RF5/AN10/CVREF/SEG23 RF5 AN10 CVREF SEG23 RF6/AN11/SEG24 RF6 AN11 SEG24 RF7/SS/SEG25 RF7 SS SEG25 24 I/O I O 23 I/O I O O 18 I/O I O O 17 I/O I O 16 I/O I O 15 I/O I O O 14 I/O I O 13 I/O I O ST TTL Analog Digital I/O. SPI slave select input. SEG25 output for LCD. ST Analog Analog Digital I/O. Analog input 11. SEG24 output for LCD. ST Analog Analog Analog Digital I/O. Analog input 10. Comparator reference voltage output. SEG23 output for LCD. ST Analog Analog Digital I/O. Analog input 9. SEG22 output for LCD. ST Analog Analog Digital I/O. Analog input 8. SEG21 output for LCD. ST Analog -- Analog Digital I/O. Analog input 7. Comparator 1 output. SEG20 output for LCD. ST Analog -- Analog Digital I/O. Analog input 6. Comparator 2 output. SEG19 output for LCD. ST Analog Analog Digital I/O. Analog input 5. SEG18 output for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
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TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTG is a bidirectional I/O port. RG0/SEG30 RG0 SEG30 RG1/TX2/CK2/SEG29 RG1 TX2 CK2 SEG29 RG2/RX2/DT2/SEG28 RG2 RX2 DT2 SEG28 RG3/SEG27 RG3 SEG27 RG4/SEG26 RG4 SEG26 RG5 5 I/O O 6 I/O O I/O O 7 I/O I I/O O 8 I/O O 10 I/O O ST Analog Digital I/O. SEG26 output for LCD. See MCLR/VPP/RG5 pin. ST Analog Digital I/O. SEG27 output for LCD. ST ST ST Analog Digital I/O. AUSART2 asynchronous receive. AUSART2 synchronous data (see related TX2/CK2). SEG28 output for LCD. ST -- ST Analog Digital I/O. AUSART2 asynchronous transmit. AUSART2 synchronous clock (see related RX2/DT2). SEG29 output for LCD. ST Analog Digital I/O. SEG30 output for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
(c) 2007 Microchip Technology Inc.
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TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTH is a bidirectional I/O port. RH0/SEG47 RH0 SEG47 RH1/SEG46 RH1 SEG46 RH2/SEG45 RH2 SEG45 RH3/SEG44 RH3 SEG44 RH4/SEG40 RH4 SEG40 RH5/SEG41 RH5 SEG41 RH6/SEG42 RH6 SEG42 RH7/SEG43 RH7 SEG43 79 I/O O 80 I/O O 1 I/O O 2 I/O O 22 I/O O 21 I/O O 20 I/O O 19 I/O O ST Analog Digital I/O. SEG43 output for LCD. ST Analog Digital I/O. SEG42 output for LCD. ST Analog Digital I/O. SEG41 output for LCD. ST Analog Digital I/O. SEG40 output for LCD. ST Analog Digital I/O. SEG44 output for LCD. ST Analog Digital I/O. SEG45 output for LCD. ST Analog Digital I/O. SEG46 output for LCD. ST Analog Digital I/O. SEG47 output for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
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TABLE 1-3: PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number TQFP Pin Buffer Type Type Description PORTJ is a bidirectional I/O port. RJ0/SEG32 RJ0 SEG32 RJ1/SEG33 RJ1 SEG33 RJ2/SEG34 RJ2 SEG34 RJ3/SEG35 RJ3 SEG35 RJ4/SEG39 RJ4 SEG39 RJ5/SEG38 RJ5 SEG38 RJ6/SEG37 RJ6 SEG37 RJ7/SEG36 RJ7 SEG36 VSS VDD AVSS AVDD 62 I/O O 61 I/O O 60 I/O O 59 I/O O 39 I/O O 40 I/O O 41 I/O O 42 I/O O 11, 31, 51, 70 12, 32, 48, 71 26 25 P P P P ST Analog -- -- -- -- Digital I/O. SEG36 output for LCD. Ground reference for logic and I/O pins. Positive supply for logic and I/O pins. Ground reference for analog modules. Positive supply for analog modules. ST Analog Digital I/O. SEG37 output for LCD. ST Analog Digital I/O SEG38 output for LCD. ST Analog Digital I/O. SEG39 output for LCD. ST Analog Digital I/O. SEG35 output for LCD. ST Analog Digital I/O. SEG34 output for LCD. ST Analog Digital I/O. SEG33 output for LCD. ST Analog Digital I/O. SEG32 output for LCD. Pin Name
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set. 2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
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NOTES:
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2.0
2.1
OSCILLATOR CONFIGURATIONS
Oscillator Types
FIGURE 2-1:
CRYSTAL/CERAMIC RESONATOR OPERATION (XT, LP, HS OR HSPLL CONFIGURATION)
OSC1 To Internal Logic Sleep
PIC18F6390/6490/8390/8490 devices can be operated in ten different oscillator modes. The user can program the Configuration bits, FOSC3:FOSC0, in Configuration Register 1H to select one of these ten modes: Low-Power Crystal Crystal/Resonator High-Speed Crystal/Resonator High-Speed Crystal/Resonator with PLL Enabled 5. RC External Resistor/Capacitor with FOSC/4 Output on RA6 6. RCIO External Resistor/Capacitor with I/O on RA6 7. INTIO1 Internal Oscillator with FOSC/4 Output on RA6 and I/O on RA7 8. INTIO2 Internal Oscillator with I/O on RA6 and RA7 9. EC External Clock with FOSC/4 Output 10. ECIO External Clock with I/O on RA6 1. 2. 3. 4. LP XT HS HSPLL
C1(1)
XTAL
RS(2) C2(1) Note 1: 2: 3: OSC2
RF(3)
PIC18FXXXX
See Table 2-1 and Table 2-2 for initial values of C1 and C2. A series resistor (RS) may be required for AT strip cut crystals. RF varies with the oscillator mode chosen.
TABLE 2-1:
CAPACITOR SELECTION FOR CERAMIC RESONATORS
Freq 455 kHz 2.0 MHz 4.0 MHz 8.0 MHz 16.0 MHz OSC1 56 pF 47 pF 33 pF 27 pF 22 pF OSC2 56 pF 47 pF 33 pF 27 pF 22 pF
Typical Capacitor Values Used: Mode XT
2.2
Crystal Oscillator/Ceramic Resonators
In XT, LP, HS or HSPLL Oscillator modes, a crystal or ceramic resonator is connected to the OSC1 and OSC2 pins to establish oscillation. Figure 2-1 shows the pin connections. The oscillator design requires the use of a parallel cut crystal. Note: Use of a series cut crystal may give a frequency out of the crystal manufacturer's specifications.
HS
Capacitor values are for design guidance only. These capacitors were tested with the resonators listed below for basic start-up and operation. These values are not optimized. Different capacitor values may be required to produce acceptable oscillator operation. The user should test the performance of the oscillator over the expected VDD and temperature range for the application. See the notes following Table 2-2 for additional information. Resonators Used: 455 kHz 2.0 MHz 16.0 MHz 4.0 MHz 8.0 MHz
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PIC18F6390/6490/8390/8490
TABLE 2-2: CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR
Crystal Freq 32 kHz 200 kHz XT HS 1 MHz 4 MHz 4 MHz 8 MHz 20 MHz Typical Capacitor Values Tested: C1 33 pF 15 pF 33 pF 27 pF 27 pF 22 pF 15 pF C2 33 pF 15 pF 33 pF 27 pF 27 pF 22 pF 15 pF
Clock from Ext. System Open OSC1
An external clock source may also be connected to the OSC1 pin in the HS mode, as shown in Figure 2-2.
Osc Type LP
FIGURE 2-2:
EXTERNAL CLOCK INPUT OPERATION (HS CONFIGURATION)
PIC18FXXXX
OSC2 (HS Mode)
2.3
External Clock Input
Capacitor values are for design guidance only. These capacitors were tested with the crystals listed below for basic start-up and operation. These values are not optimized. Different capacitor values may be required to produce acceptable oscillator operation. The user should test the performance of the oscillator over the expected VDD and temperature range for the application. See the notes following this table for additional information. Crystals Used: 32 kHz 200 kHz 1 MHz 4 MHz 8 MHz 20 MHz
The EC and ECIO Oscillator modes require an external clock source to be connected to the OSC1 pin. There is no oscillator start-up time required after a Power-on Reset or after an exit from Sleep mode. In the EC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. Figure 2-3 shows the pin connections for the EC Oscillator mode.
FIGURE 2-3:
EXTERNAL CLOCK INPUT OPERATION (EC CONFIGURATION)
OSC1/CLKI
Clock from Ext. System FOSC/4
PIC18FXXXX
OSC2/CLKO
Note 1: Higher capacitance increases the stability of oscillator, but also increases the start-up time. 2: When operating below 3V VDD, or when using certain ceramic resonators at any voltage, it may be necessary to use the HS mode or switch to a crystal oscillator. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: Rs may be required to avoid overdriving crystals with low drive level specification. 5: Always verify oscillator performance over the VDD and temperature range that is expected for the application.
The ECIO Oscillator mode functions like the EC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6). Figure 2-4 shows the pin connections for the ECIO Oscillator mode.
FIGURE 2-4:
EXTERNAL CLOCK INPUT OPERATION (ECIO CONFIGURATION)
OSC1/CLKI
Clock from Ext. System RA6
PIC18FXXXX
I/O (OSC2)
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2.4 RC Oscillator 2.5 PLL Frequency Multiplier
For timing insensitive applications, the "RC" and "RCIO" device options offer additional cost savings. The actual oscillator frequency is a function of several factors: * Supply voltage * Values of the external resistor (REXT) and capacitor (CEXT) * Operating temperature Given the same device, operating voltage and temperature and component values, there will also be unit-to-unit frequency variations. These are due to factors such as: * Normal manufacturing variation * Difference in lead frame capacitance between package types (especially for low CEXT values) * Variations within the tolerance of limits of REXT and CEXT In the RC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. Figure 2-5 shows how the R/C combination is connected. A Phase Locked Loop (PLL) circuit is provided as an option for users who want to use a lower frequency oscillator circuit, or to clock the device up to its highest rated frequency from a crystal oscillator. This may be useful for customers who are concerned with EMI due to high-frequency crystals, or users who require higher clock speeds from an internal oscillator.
2.5.1
HSPLL OSCILLATOR MODE
The HSPLL mode makes use of the HS mode oscillator for frequencies up to 10 MHz. A PLL then multiplies the oscillator output frequency by 4 to produce an internal clock frequency up to 40 MHz. The PLL is only available to the crystal oscillator when the FOSC3:FOSC0 Configuration bits are programmed for HSPLL mode (= 0110).
FIGURE 2-7:
PLL BLOCK DIAGRAM (HS MODE)
HS Oscillator Enable PLL Enable (from Configuration Register 1H) OSC2
HS Mode OSC1 Crystal Oscillator
FIGURE 2-5:
VDD REXT
RC OSCILLATOR MODE
FIN FOUT
Phase Comparator
OSC1 CEXT VSS FOSC/4 OSC2/CLKO
Internal Clock
Loop Filter
PIC18FXXXX
/4 VCO MUX SYSCLK
Recommended values: 3 k REXT 100 k CEXT > 20 pF
The RCIO Oscillator mode (Figure 2-6) functions like the RC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6).
2.5.2
PLL AND INTOSC
FIGURE 2-6:
VDD REXT
RCIO OSCILLATOR MODE
The PLL is also available to the internal oscillator block in selected oscillator modes. In this configuration, the PLL is enabled in software and generates a clock output of up to 32 MHz. The operation of INTOSC with the PLL is described in Section 2.6.4 "PLL in INTOSC Modes".
OSC1 CEXT VSS RA6 I/O (OSC2)
Internal Clock
PIC18FXXXX
Recommended values: 3 k REXT 100 k CEXT > 20 pF
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PIC18F6390/6490/8390/8490
2.6 Internal Oscillator Block
The PIC18F6390/6490/8390/8490 devices include an internal oscillator block, which generates two different clock signals; either can be used as the microcontroller's clock source. This may eliminate the need for external oscillator circuits on the OSC1 and/or OSC2 pins. The main output (INTOSC) is an 8 MHz clock source, which can be used to directly drive the device clock. It also drives a postscaler, which can provide a range of clock frequencies from 31 kHz to 4 MHz. The INTOSC output is enabled when a clock frequency from 125 kHz to 8 MHz is selected. The other clock source is the internal RC oscillator (INTRC), which provides a nominal 31 kHz output. INTRC is enabled if it is selected as the device clock source; it is also enabled automatically when any of the following are enabled: * * * * * Power-up Timer Fail-Safe Clock Monitor Watchdog Timer Two-Speed Start-up LCD with INTRC as its clock source When the OSCTUNE register is modified, the INTOSC and INTRC frequencies will begin shifting to the new frequency. The INTRC clock will reach the new frequency within 8 clock cycles (approximately 8 * 32 s = 256 s). The INTOSC clock will stabilize within 1 ms. Code execution continues during this shift. There is no indication that the shift has occurred. The OSCTUNE register also implements the INTSRC and PLLEN bits, which control certain features of the internal oscillator block. The INTSRC bit allows users to select which internal oscillator provides the clock source when the 31 kHz frequency option is selected. This is covered in greater detail in Section 2.7.1 "Oscillator Control Register". The PLLEN bit controls the operation of the frequency multiplier, PLL, in internal oscillator modes.
2.6.4
PLL IN INTOSC MODES
The 4x frequency multiplier can be used with the internal oscillator block to produce faster device clock speeds than are normally possible with an internal oscillator. When enabled, the PLL produces a clock speed of up to 32 MHz. Unlike HSPLL mode, the PLL is controlled through software. The control bit, PLLEN (OSCTUNE<6>), is used to enable or disable its operation. The PLL is available when the device is configured to use the internal oscillator block as its primary clock source (FOSC3:FOSC0 = 1001 or 1000). Additionally, the PLL will only function when the selected output frequency is either 4 MHz or 8 MHz (OSCCON<6:4> = 111 or 110). If both of these conditions are not met, the PLL is disabled. The PLLEN control bit is only functional in those internal oscillator modes where the PLL is available. In all other modes, it is forced to `0' and is effectively unavailable.
These features are discussed in greater detail in Section 23.0 "Special Features of the CPU". The clock source frequency (INTOSC direct, INTRC direct or INTOSC postscaler) is selected by configuring the IRCF bits of the OSCCON register (Register 2-2).
2.6.1
INTIO MODES
Using the internal oscillator as the clock source eliminates the need for up to two external oscillator pins, which can then be used for digital I/O. Two distinct configurations are available: * In INTIO1 mode, the OSC2 pin outputs FOSC/4, while OSC1 functions as RA7 for digital input and output. * In INTIO2 mode, OSC1 functions as RA7 and OSC2 functions as RA6, both for digital input and output.
2.6.5
INTOSC FREQUENCY DRIFT
2.6.2
INTOSC OUTPUT FREQUENCY
The internal oscillator block is calibrated at the factory to produce an INTOSC output frequency of 8.0 MHz. The INTRC oscillator operates independently of the INTOSC source. Any changes in INTOSC across voltage and temperature are not necessarily reflected by changes in INTRC and vice versa.
The factory calibrates the internal oscillator block output (INTOSC) for 8 MHz. However, this frequency may drift as VDD or temperature changes, which can affect the controller operation in a variety of ways. It is possible to adjust the INTOSC frequency by modifying the value in the OSTUNE register. This has no effect on the INTRC clock source frequency. Tuning the INTOSC source requires knowing when to make the adjustment, in which direction it should be made and in some cases, how large a change is needed. Three compensation techniques are discussed in Section 2.6.5.1 "Compensating with the AUSART", Section 2.6.5.2 "Compensating with the Timers" and Section 2.6.5.3 "Compensating with the Timers", but other techniques may be used.
2.6.3
OSCTUNE REGISTER
The internal oscillator's output has been calibrated at the factory, but can be adjusted in the user's application. This is done by writing to the OSCTUNE register (Register 2-1). The tuning sensitivity is constant throughout the tuning range.
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2.6.5.1 Compensating with the AUSART
An adjustment may be required when the AUSART begins to generate framing errors or receives data with errors while in Asynchronous mode. Framing errors indicate that the device clock frequency is too high. To adjust for this, decrement the value in OSTUNE to reduce the clock frequency. On the other hand, errors in data may suggest that the clock speed is too low. To compensate, increment OSTUNE to increase the clock frequency. is greater than expected, then the internal oscillator block is running too fast. To adjust for this, decrement the OSCTUNE register.
2.6.5.3
Compensating with the Timers
2.6.5.2
Compensating with the Timers
This technique compares device clock speed to some reference clock. Two timers may be used; one timer is clocked by the peripheral clock, while the other is clocked by a fixed reference source, such as the Timer1 oscillator. Both timers are cleared, but the timer clocked by the reference generates interrupts. When an interrupt occurs, the internally clocked timer is read and both timers are cleared. If the internally clocked timer value
A CCP module can use free-running Timer1 (or Timer3), clocked by the internal oscillator block and an external event with a known period (i.e., AC power frequency). The time of the first event is captured in the CCPRxH:CCPRxL registers and is recorded. When the second event causes a capture, the time of the first event is subtracted from the time of the second event. Since the period of the external event is known, the time difference between events can be calculated. If the measured time is much greater than the calculated time, then the internal oscillator block is running too fast. To compensate, decrement the OSTUNE register. If the measured time is much less than the calculated time, then the internal oscillator block is running too slow. To compensate, increment the OSTUNE register.
REGISTER 2-1:
R/W-0 INTSRC bit 7 Legend: R = Readable bit -n = Value at POR bit 7
OSCTUNE: OSCILLATOR TUNING REGISTER
U-0 -- R/W-0 TUN4 R/W-0 TUN3 R/W-0 TUN2 R/W-0 TUN1 R/W-0 TUN0 bit 0
R/W-0(1) PLLEN(1)
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
INTSRC: Internal Oscillator Low-Frequency Source Select bit 1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled) 0 = 31 kHz device clock derived directly from INTRC internal oscillator PLLEN: Frequency Multiplier PLL for INTOSC Enable bit(1) 1 = PLL enabled for INTOSC (4 MHz and 8 MHz only) 0 = PLL disabled Unimplemented: Read as `0' TUN4:TUN0: Frequency Tuning bits 01111 = Maximum frequency * * * * 00001 00000 = Center frequency. Oscillator module is running at the calibrated frequency. 11111 * * * * 10000 = Minimum frequency Available only in certain oscillator configurations; otherwise, this bit is unavailable and read as `0'. See Section 2.6.4 "PLL in INTOSC Modes" for details.
bit 6
bit 5 bit 4-0
Note 1:
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PIC18F6390/6490/8390/8490
2.7 Clock Sources and Oscillator Switching
The secondary oscillators are those external sources not connected to the OSC1 or OSC2 pins. These sources may continue to operate even after the controller is placed in a power-managed mode. PIC18F6390/6490/8390/8490 devices offer the Timer1 oscillator as a secondary oscillator. This oscillator, in all power-managed modes, is often the time base for functions such as a Real-Time Clock. Most often, a 32.768 kHz watch crystal is connected between the RC0/T1OSO/T13CKI and RC1/T1OSI pins. Like the LP Oscillator mode circuit, loading capacitors are also connected from each pin to ground. The Timer1 oscillator is discussed in greater detail in Section 11.3 "Timer1 Oscillator". In addition to being a primary clock source, the internal oscillator block is available as a power-managed mode clock source. The INTRC source is also used as the clock source for several special features, such as the WDT and Fail-Safe Clock Monitor. The clock sources for the PIC18F6390/6490/8390/8490 devices are shown in Figure 2-8. See Section 23.0 "Special Features of the CPU" for Configuration register details.
Like previous PIC18 devices, the PIC18F6390/6490/8390/8490 family includes a feature that allows the device clock source to be switched from the main oscillator to an alternate low-frequency clock source. PIC18F6390/6490/8390/8490 devices offer two alternate clock sources. When an alternate clock source is enabled, the various power-managed operating modes are available. Essentially, there are three clock sources for these devices: * Primary oscillators * Secondary oscillators * Internal oscillator block The primary oscillators include the External Crystal and Resonator modes, the External RC modes, the External Clock modes and the internal oscillator block. The particular mode is defined by the FOSC3:FOSC0 Configuration bits. The details of these modes are covered earlier in this chapter.
FIGURE 2-8:
PIC18F6390/6490/8390/8490 CLOCK DIAGRAM
PIC18F6X90/8X90
Primary Oscillator
OSC2 Sleep OSC1 Secondary Oscillator T1OSO T1OSCEN Enable Oscillator OSCCON<6:4> Internal Oscillator Block 8 MHz Source INTRC Source OSCTUNE<6> 4 x PLL
LP, XT, HS, RC, EC HSPLL, INTOSC/PLL T1OSC Peripherals
T1OSI
OSCCON<6:4> 8 MHz 4 MHz 2 MHz Postscaler 1 MHz 500 kHz 250 kHz 125 kHz 111 110 101 011 010 001 MUX 100
Internal Oscillator CPU
MUX
IDLEN Clock Control FOSC3:FOSC0 OSCCON<1:0>
8 MHz (INTOSC)
31 kHz (INTRC)
1 31 kHz 000 0 OSCTUNE<7>
Clock Source Option for Other Modules
WDT, PWRT, FSCM and Two-Speed Start-up
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PIC18F6390/6490/8390/8490
2.7.1 OSCILLATOR CONTROL REGISTER
The OSCCON register (Register 2-2) controls several aspects of the device clock's operation, both in full-power operation and in power-managed modes. The System Clock Select bits, SCS1:SCS0, select the clock source. The available clock sources are the primary clock (defined by the FOSC:FOSC0 Configuration bits), the secondary clock (Timer1 oscillator) and the internal oscillator block. The clock source changes immediately after one or more of the bits is written to, following a brief clock transition interval. The SCS bits are cleared on all forms of Reset. The Internal Oscillator Frequency Select bits, IRCF2:IRCF0, select the frequency output of the internal oscillator block to drive the device clock. The choices are the INTRC source, the INTOSC source (8 MHz) or one of the frequencies derived from the INTOSC postscaler (31.25 kHz to 4 MHz). If the internal oscillator block is supplying the device clock, changing the states of these bits will have an immediate change on the internal oscillator's output. When an output frequency of 31 kHz is selected (IRCF2:IRCF0 = 000), users may choose which internal oscillator acts as the source. This is done with the INTSRC bit in the OSCTUNE register (OSCTUNE<7>). Setting this bit selects INTOSC as a 31.25 kHz clock source by enabling the divide-by-256 output of the INTOSC postscaler. Clearing INTSRC selects INTRC (nominally 31 kHz) as the clock source. This option allows users to select the tunable and more precise INTOSC as a clock source, while maintaining power savings with a very low clock speed. Regardless of the setting of INTSRC, INTRC always remains the clock source for features such as the Watchdog Timer and the Fail-Safe Clock Monitor. The OSTS, IOFS and T1RUN bits indicate which clock source is currently providing the device clock. The OSTS bit indicates that the Oscillator Start-up Timer has timed out and the primary clock is providing the device clock in primary clock modes. The IOFS bit indicates when the internal oscillator block has stabilized and is providing the device clock in RC Clock modes. The T1RUN bit (T1CON<6>) indicates when the Timer1 oscillator is providing the device clock in secondary clock modes. In power-managed modes, only one of these three bits will be set at any time. If none of these bits are set, the INTRC is providing the clock, or the internal oscillator block has just started and is not yet stable. The IDLEN bit determines if the device goes into Sleep mode or one of the Idle modes when the SLEEP instruction is executed. The use of the flag and control bits in the OSCCON register is discussed in more detail in Section 3.0 "Power-Managed Modes". Note 1: The Timer1 oscillator must be enabled to select the secondary clock source. The Timer1 oscillator is enabled by setting the T1OSCEN bit in the Timer1 Control register (T1CON<3>). If the Timer1 oscillator is not enabled, then any attempt to select a secondary clock source when executing a SLEEP instruction will be ignored. 2: It is recommended that the Timer1 oscillator be operating and stable before executing the SLEEP instruction, or a very long delay may occur while the Timer1 oscillator starts.
2.7.2
OSCILLATOR TRANSITIONS
PIC18F6390/6490/8390/8490 devices contain circuitry to prevent clock "glitches" when switching between clock sources. A short pause in the device clock occurs during the clock switch. The length of this pause is the sum of two cycles of the old clock source and three to four cycles of the new clock source. This formula assumes that the new clock source is stable. Clock transitions are discussed in greater detail in Section 3.1.2 "Entering Power-Managed Modes".
(c) 2007 Microchip Technology Inc.
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PIC18F6390/6490/8390/8490
REGISTER 2-2:
R/W-0 IDLEN bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
OSCCON: OSCILLATOR CONTROL REGISTER
R/W-1 IRCF2 R/W-0 IRCF1 R/W-0 IRCF0 R(1) OSTS R-0 IOFS R/W-0 SCS1 R/W-0 SCS0 bit 0
IDLEN: Idle Enable bit 1 = Device enters Idle mode on SLEEP instruction 0 = Device enters Sleep mode on SLEEP instruction IRCF2:IRCF0: Internal Oscillator Frequency Select bits 111 = 8 MHz (INTOSC drives clock directly) 110 = 4 MHz 101 = 2 MHz 100 = 1 MHz(3) 011 = 500 kHz 010 = 250 kHz 001 = 125 kHz 000 = 31 kHz (from either INTOSC/256 or INTRC directly)(2) OSTS: Oscillator Start-up Timer Time-out Status bit(1) 1 = Oscillator Start-up Timer time-out has expired; primary oscillator is running 0 = Oscillator Start-up Timer time-out is running; primary oscillator is not ready IOFS: INTOSC Frequency Stable bit 1 = INTOSC frequency is stable 0 = INTOSC frequency is not stable SCS1:SCS0: System Clock Select bits 1x = Internal oscillator block 01 = Timer1 oscillator 00 = Primary oscillator Depends on state of the IESO Configuration bit. Source selected by the INTSRC bit (OSCTUNE<7>), see Section 2.6.3 "OSCTUNE Register". Default output frequency of INTOSC on Reset.
bit 6-4
bit 3
bit 2
bit 1-0
Note 1: 2: 3:
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2.8 Effects of Power-Managed Modes on the Various Clock Sources 2.9 Power-up Delays
Power-up delays are controlled by two timers, so that no external Reset circuitry is required for most applications. The delays ensure that the device is kept in Reset until the device power supply is stable under normal circumstances and the primary clock is operating and stable. For additional information on power-up delays, see Section 4.5 "Device Reset Timers". The first timer is the Power-up Timer (PWRT), which provides a fixed delay on power-up (parameter 33, Table 26-10). It is enabled by clearing (= 0) the PWRTEN Configuration bit. The second timer is the Oscillator Start-up Timer (OST), intended to keep the chip in Reset until the crystal oscillator is stable (LP, XT and HS modes). The OST does this by counting 1024 oscillator cycles before allowing the oscillator to clock the device. When the HSPLL Oscillator mode is selected, the device is kept in Reset for an additional 2 ms, following the HS mode OST delay, so the PLL can lock to the incoming clock frequency. There is a delay of interval TCSD (parameter 38, Table 26-10) following POR while the controller becomes ready to execute instructions. This delay runs concurrently with any other delays. This may be the only delay that occurs when any of the EC, RC or INTIO modes are used as the primary clock source.
When PRI_IDLE mode is selected, the designated primary oscillator continues to run without interruption. For all other power-managed modes, the oscillator using the OSC1 pin is disabled. The OSC1 pin (and OSC2 pin, if used by the oscillator) will stop oscillating. In secondary clock modes (SEC_RUN and SEC_IDLE), the Timer1 oscillator is operating and providing the device clock. The Timer1 oscillator may also run in all power-managed modes if required to clock Timer1 or Timer3. In internal oscillator modes (RC_RUN and RC_IDLE), the internal oscillator block provides the device clock source. The 31 kHz INTRC output can be used directly to provide the clock and may be enabled to support various special features, regardless of the power-managed mode (see Section 23.2 "Watchdog Timer (WDT)" through Section 23.4 "Fail-Safe Clock Monitor" for more information on WDT, Fail-Safe Clock Monitor and Two-Speed Start-up). The INTOSC output at 8 MHz may be used directly to clock the device, or may be divided down by the postscaler. The INTOSC output is disabled if the clock is provided directly from the INTRC output. If the Sleep mode is selected, all clock sources are stopped. Since all the transistor switching currents have been stopped, Sleep mode achieves the lowest current consumption of the device (only leakage currents). Enabling any on-chip feature that will operate during Sleep will increase the current consumed during Sleep. The INTRC is required to support WDT operation. The Timer1 oscillator may be operating to support a Real-Time Clock. Other features may be operating that do not require a device clock source (i.e., MSSP slave, INTx pins and others). Peripherals that may add significant current consumption are listed in Section 26.2 "DC Characteristics: Power-Down and Supply Current".
TABLE 2-3:
RC, INTIO1 RCIO, INTIO2 ECIO EC LP, XT and HS Note:
OSC1 AND OSC2 PIN STATES IN SLEEP MODE
OSC1 Pin Floating, external resistor should pull high Floating, external resistor should pull high Floating, pulled by external clock Floating, pulled by external clock Feedback inverter disabled at quiescent voltage level OSC2 Pin At logic low (clock/4 output) Configured as PORTA, bit 6 Configured as PORTA, bit 6 At logic low (clock/4 output) Feedback inverter disabled at quiescent voltage level
Oscillator Mode
See Table 4-2 in Section 4.0 "Reset" for time-outs due to Sleep and MCLR Reset.
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NOTES:
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3.0 POWER-MANAGED MODES
3.1.1 CLOCK SOURCES
PIC18F6390/6490/8390/8490 devices offer a total of seven operating modes for more efficient power management. These modes provide a variety of options for selective power conservation in applications where resources may be limited (i.e., battery-powered devices). There are three categories of power-managed modes: * Sleep mode * Idle modes * Run modes These categories define which portions of the device are clocked and sometimes, what speed. The Run and Idle modes may use any of the three available clock sources (primary, secondary or INTOSC multiplexer); the Sleep mode does not use a clock source. The power-managed modes include several power-saving features. One of these is the clock switching feature, offered in other PIC18 devices, allowing the controller to use the Timer1 oscillator in place of the primary oscillator. Also included is the Sleep mode, offered by all PIC(R) devices, where all device clocks are stopped. The SCS1:SCS0 bits allow the selection of one of three clock sources for power-managed modes. They are: * the primary clock, as defined by the FOSC3:FOSC0 Configuration bits * the secondary clock (the Timer1 oscillator) * the internal oscillator block (for RC modes)
3.1.2
ENTERING POWER-MANAGED MODES
Entering power-managed Run mode, or switching from one power-managed mode to another, begins by loading the OSCCON register. The SCS1:SCS0 bits select the clock source and determine which Run or Idle mode is being used. Changing these bits causes an immediate switch to the new clock source, assuming that it is running. The switch may also be subject to clock transition delays. These are discussed in Section 3.1.3 "Clock Transitions and Status Indicators" and subsequent sections. Entry to the power-managed Idle or Sleep modes is triggered by the execution of a SLEEP instruction. The actual mode that results depends on the status of the IDLEN bit. Depending on the current mode and the mode being switched to, a change to a power-managed mode does not always require setting all of these bits. Many transitions may be done by changing the oscillator select bits, or changing the IDLEN bit prior to issuing a SLEEP instruction. If the IDLEN bit is already configured correctly, it may only be necessary to perform a SLEEP instruction to switch to the desired mode.
3.1
Selecting Power-Managed Modes
Selecting a power-managed mode requires deciding if the CPU is to be clocked or not and selecting a clock source. The IDLEN bit controls CPU clocking, while the SCS1:SCS0 bits select a clock source. The individual modes, bit settings, clock sources and affected modules are summarized in Table 3-1.
TABLE 3-1:
Mode Sleep PRI_RUN SEC_RUN RC_RUN PRI_IDLE SEC_IDLE RC_IDLE Note 1: 2:
POWER-MANAGED MODES
OSCCON<7,1:0> IDLEN(1) 0 N/A N/A N/A 1 1 1 SCS1:SCS0 N/A 00 01 1x 00 01 1x Module Clocking CPU Off Clocked Clocked Clocked Off Off Off Peripherals Off Clocked Clocked Clocked Clocked Clocked Clocked Available Clock and Oscillator Source None - All clocks are disabled Primary - LP, XT, HS, HSPLL, RC, EC, INTRC(2): This is the normal, full-power execution mode. Secondary - Timer1 Oscillator Internal Oscillator Block(2) Primary - LP, XT, HS, HSPLL, RC, EC Secondary - Timer1 Oscillator Internal Oscillator Block(2)
IDLEN reflects its value when the SLEEP instruction is executed. Includes INTOSC and INTOSC postscaler, as well as the INTRC source.
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3.1.3 CLOCK TRANSITIONS AND STATUS INDICATORS
3.2
Run Modes
The length of the transition between clock sources is the sum of two cycles of the old clock source and three to four cycles of the new clock source. This formula assumes that the new clock source is stable. Three bits indicate the current clock source and its status. They are: * OSTS (OSCCON<3>) * IOFS (OSCCON<2>) * T1RUN (T1CON<6>) In general, only one of these bits will be set while in a given power-managed mode. When the OSTS bit is set, the primary clock is providing the device clock. When the IOFS bit is set, the INTOSC output provides a stable, 8 MHz clock source to a divider that actually drives the device clock. When the T1RUN bit is set, the Timer1 oscillator provides the clock. If none of these bits are set, then either the INTRC clock source clocks the device, or the INTOSC source is not yet stable. If the internal oscillator block is configured as the primary clock source by the FOSC3:FOSC0 Configuration bits, then both the OSTS and IOFS bits may be set when in PRI_RUN or PRI_IDLE modes. This indicates that the primary clock (INTOSC output) is generating a stable 8 MHz output. Entering another power-managed RC mode at the same frequency would clear the OSTS bit. Note 1: Caution should be used when modifying a single IRCF bit. If VDD is less than 3V, it is possible to select a higher clock speed than is supported by the low VDD. Improper device operation may result if the VDD/FOSC specifications are violated. 2: Executing a SLEEP instruction does not necessarily place the device into Sleep mode. It acts as the trigger to place the controller into either the Sleep mode or one of the Idle modes, depending on the setting of the IDLEN bit.
In the Run modes, clocks to both the core and peripherals are active. The difference between these modes is the clock source.
3.2.1
PRI_RUN MODE
The PRI_RUN mode is the normal, full-power execution mode of the microcontroller. This is also the default mode upon a device Reset unless Two-Speed Start-up is enabled (see Section 23.3 "Two-Speed Start-up" for details). In this mode, the OSTS bit is set. The IOFS bit may be set if the internal oscillator block is the primary clock source (see Section 2.7.1 "Oscillator Control Register").
3.2.2
SEC_RUN MODE
The SEC_RUN mode is the compatible mode to the "clock switching" feature offered in other PIC18 devices. In this mode, the CPU and peripherals are clocked from the Timer1 oscillator. This gives users the option of lower power consumption while still using a high-accuracy clock source. SEC_RUN mode is entered by setting the SCS1:SCS0 bits to `01'. The device clock source is switched to the Timer1 oscillator (see Figure 3-1), the primary oscillator is shut down, the T1RUN bit (T1CON<6>) is set and the OSTS bit is cleared. Note: The Timer1 oscillator should already be running prior to entering SEC_RUN mode. If the T1OSCEN bit is not set when the SCS1:SCS0 bits are set to `01', entry to SEC_RUN mode will not occur. If the Timer1 oscillator is enabled, but not yet running, peripheral clocks will be delayed until the oscillator has started. In such situations, initial oscillator operation is far from stable and unpredictable operation may result.
3.1.4
MULTIPLE SLEEP COMMANDS
The power-managed mode that is invoked with the SLEEP instruction is determined by the setting of the IDLEN bit at the time the instruction is executed. If another SLEEP instruction is executed, the device will enter the power-managed mode specified by IDLEN at that time. If IDLEN has changed, the device will enter the new power-managed mode specified by the new setting.
On transitions from SEC_RUN mode to PRI_RUN, the peripherals and CPU continue to be clocked from the Timer1 oscillator while the primary clock is started. When the primary clock becomes ready, a clock switch back to the primary clock occurs (see Figure 3-2). When the clock switch is complete, the T1RUN bit is cleared, the OSTS bit is set and the primary clock provides the clock. The IDLEN and SCS bits are not affected by the wake-up; the Timer1 oscillator continues to run.
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FIGURE 3-1: TRANSITION TIMING FOR ENTRY TO SEC_RUN MODE
Q1 Q2 Q3 Q4 Q1 T1OSI OSC1 CPU Clock Peripheral Clock Program Counter PC PC + 2 PC + 4 1 2 3 Clock Transition n-1 n Q2 Q3 Q4 Q1 Q2 Q3
FIGURE 3-2:
TRANSITION TIMING FROM SEC_RUN MODE TO PRI_RUN MODE (HSPLL)
Q1 T1OSI OSC1 TOST(1) TPLL(1) 1 n-1 Clock Transition 2 n Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3
PLL Clock Output CPU Clock Peripheral Clock Program Counter SCS1:SCS0 bits Changed PC OSTS bit Set
PC + 2
PC + 4
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
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3.2.3 RC_RUN MODE
In RC_RUN mode, the CPU and peripherals are clocked from the internal oscillator block using the INTOSC multiplexer and the primary clock is shut down. When using the INTRC source, this mode provides the best power conservation of all the Run modes, while still executing code. It works well for user applications which are not highly timing-sensitive, or do not require high-speed clocks at all times. If the primary clock source is the internal oscillator block (either INTRC or INTOSC), there are no distinguishable differences between PRI_RUN and RC_RUN modes during execution. However, a clock switch delay will occur during entry to and exit from RC_RUN mode. Therefore, if the primary clock source is the internal oscillator block, the use of RC_RUN mode is not recommended. This mode is entered by setting the SCS1 bit to `1'. Although it is ignored, it is recommended that the SCS0 bit also be cleared; this is to maintain software compatibility with future devices. When the clock source is switched to the INTOSC multiplexer (see Figure 3-3), the primary oscillator is shut down and the OSTS bit is cleared. The IRCF bits may be modified at any time to immediately change the clock speed. Note: Caution should be used when modifying a single IRCF bit. If VDD is less than 3V, it is possible to select a higher clock speed than is supported by the low VDD. Improper device operation may result if the VDD/FOSC specifications are violated. If the IRCF bits and the INTSRC bit are all clear, the INTOSC output is not enabled and the IOFS bit will remain clear; there will be no indication of the current clock source. The INTRC source provides the device clocks. If the IRCF bits are changed from all clear (thus enabling the INTOSC output), or if INTSRC is set, the IOFS bit becomes set after the INTOSC output becomes stable. Clocks to the device continue while the INTOSC source stabilizes after an interval of TIOBST. If the IRCF bits were previously at a non-zero value, or if INTSRC was set before setting SCS1 and the INTOSC source was already stable, the IOFS bit will remain set. On transitions from RC_RUN mode to PRI_RUN, the device continues to be clocked from the INTOSC multiplexer while the primary clock is started. When the primary clock becomes ready, a clock switch to the primary clock occurs (see Figure 3-4). When the clock switch is complete, the IOFS bit is cleared, the OSTS bit is set and the primary clock provides the device clock. The IDLEN and SCS bits are not affected by the switch. The INTRC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled.
FIGURE 3-3:
INTRC OSC1 CPU Clock Peripheral Clock Program Counter
TRANSITION TIMING TO RC_RUN MODE
Q1 Q2 Q3 Q4 Q1 1 2 3 Clock Transition n-1 n Q2 Q3 Q4 Q1 Q2 Q3
PC
PC + 2
PC + 4
FIGURE 3-4:
INTOSC Multiplexer OSC1
TRANSITION TIMING FROM RC_RUN MODE TO PRI_RUN MODE
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3
TOST(1) PLL Clock Output CPU Clock Peripheral Clock Program Counter SCS1:SCS0 bits Changed PC
TPLL(1)
1
2
n-1 n
Clock Transition
PC + 2 OSTS bit Set
PC + 4
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
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3.3 Sleep Mode 3.4 Idle Modes
The power-managed Sleep mode in the PIC18F6390/6490/8390/8490 devices is identical to the legacy Sleep mode offered in all other PIC devices. It is entered by clearing the IDLEN bit (the default state on device Reset) and executing the SLEEP instruction. This shuts down the selected oscillator (see Figure 3-5). All clock source status bits are cleared. Entering the Sleep mode from any other mode does not require a clock switch. This is because no clocks are needed once the controller has entered Sleep. If the WDT is selected, the INTRC source will continue to operate. If the Timer1 oscillator is enabled, it will also continue to run. When a wake event occurs in Sleep mode (by interrupt, Reset or WDT time-out), the device will not be clocked until the primary clock source becomes ready (see Figure 3-6), or it will be clocked from the internal oscillator block if either the Two-Speed Start-up or the Fail-Safe Clock Monitor are enabled (see Section 23.0 "Special Features of the CPU"). In either case, the OSTS bit is set when the primary clock provides the device clocks. The IDLEN and SCS bits are not affected by the wake-up. The Idle modes allow the controller's CPU to be selectively shut down while the peripherals continue to operate. Selecting a particular Idle mode allows users to further manage power consumption. If the IDLEN bit is set to a `1' when a SLEEP instruction is executed, the peripherals will be clocked from the clock source selected using the SCS1:SCS0 bits; however, the CPU will not be clocked. The clock source status bits are not affected. Setting IDLEN and executing SLEEP provides a quick method of switching from a given Run mode to its corresponding Idle mode. If the WDT is selected, the INTRC source will continue to operate. If the Timer1 oscillator is enabled, it will also continue to run. Since the CPU is not executing instructions, the only exits from any of the Idle modes are by interrupt, WDT time-out or a Reset. When a wake event occurs, CPU execution is delayed by an interval of TCSD (parameter 38, Table 26-10) while it becomes ready to execute code. When the CPU begins executing code, it resumes with the same clock source for the current Idle mode. For example, when waking from RC_IDLE mode, the internal oscillator block will clock the CPU and peripherals (in other words, RC_RUN mode). The IDLEN and SCS bits are not affected by the wake-up. While in any Idle mode or the Sleep mode, a WDT time-out will result in a WDT wake-up to the Run mode currently specified by the SCS1:SCS0 bits.
FIGURE 3-5:
OSC1 CPU Clock Peripheral Clock Sleep Program Counter PC
TRANSITION TIMING FOR ENTRY TO SLEEP MODE
Q1 Q2 Q3 Q4 Q1
PC + 2
FIGURE 3-6:
OSC1 PLL Clock Output CPU Clock Peripheral Clock Program Counter
TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
TOST(1)
TPLL(1)
PC Wake Event OSTS bit Set
PC + 2
PC + 4
PC + 6
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
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3.4.1 PRI_IDLE MODE
This mode is unique among the three low-power Idle modes, in that it does not disable the primary device clock. For timing-sensitive applications, this allows for the fastest resumption of device operation with its more accurate primary clock source, since the clock source does not have to "warm up" or transition from another oscillator. PRI_IDLE mode is entered from PRI_RUN mode by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set IDLEN first, then clear the SCS bits and execute SLEEP. Although the CPU is disabled, the peripherals continue to be clocked from the primary clock source specified by the FOSC3:FOSC0 Configuration bits. The OSTS bit remains set (see Figure 3-7). When a wake event occurs, the CPU is clocked from the primary clock source. A delay of interval TCSD is required between the wake event and when code execution starts. This is required to allow the CPU to become ready to execute instructions. After the wake-up, the OSTS bit remains set. The IDLEN and SCS bits are not affected by the wake-up (see Figure 3-8).
FIGURE 3-7:
TRANSITION TIMING FOR ENTRY TO PRI_IDLE MODE
Q1 Q2 Q3 Q4 Q1
OSC1 CPU Clock Peripheral Clock Program Counter PC PC + 2
FIGURE 3-8:
Q1 OSC1 CPU Clock Peripheral Clock Program Counter
TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE
Q2 Q3 Q4
TCSD
PC
Wake Event
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3.4.2 SEC_IDLE MODE 3.4.3 RC_IDLE MODE
In SEC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the Timer1 oscillator. This mode is entered from SEC_RUN by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set IDLEN first, then set SCS1:SCS0 to `01' and execute SLEEP. When the clock source is switched to the Timer1 oscillator, the primary oscillator is shut down, the OSTS bit is cleared and the T1RUN bit is set. When a wake event occurs, the peripherals continue to be clocked from the Timer1 oscillator. After an interval of TCSD following the wake event, the CPU begins executing code being clocked by the Timer1 oscillator. The IDLEN and SCS bits are not affected by the wake-up; the Timer1 oscillator continues to run (see Figure 3-8). Note: The Timer1 oscillator should already be running prior to entering SEC_IDLE mode. If the T1OSCEN bit is not set when the SLEEP instruction is executed, the SLEEP instruction will be ignored and entry to SEC_IDLE mode will not occur. If the Timer1 oscillator is enabled, but not yet running, peripheral clocks will be delayed until the oscillator has started. In such situations, initial oscillator operation is far from stable and unpredictable operation may result. In RC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the internal oscillator block using the INTOSC multiplexer. This mode allows for controllable power conservation during Idle periods. From RC_RUN, this mode is entered by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, first set IDLEN, then set the SCS1 bit and execute SLEEP. Although its value is ignored, it is recommended that SCS0 also be cleared; this is to maintain software compatibility with future devices. The INTOSC multiplexer may be used to select a higher clock frequency by modifying the IRCF bits before executing the SLEEP instruction. When the clock source is switched to the INTOSC multiplexer, the primary oscillator is shut down and the OSTS bit is cleared. If the IRCF bits are set to any non-zero value, or the INTSRC bit is set, the INTOSC output is enabled. The IOFS bit becomes set after the INTOSC output becomes stable after an interval of TIOBST (parameter 39, Table 26-10). Clocks to the peripherals continue while the INTOSC source stabilizes. If the IRCF bits were previously at a non-zero value, or INTSRC was set before the SLEEP instruction was executed and the INTOSC source was already stable, the IOFS bit will remain set. If the IRCF bits and INTSRC are all clear, the INTOSC output will not be enabled; the IOFS bit will remain clear and there will be no indication of the current clock source. When a wake event occurs, the peripherals continue to be clocked from the INTOSC multiplexer. After a delay of TCSD following the wake event, the CPU begins executing code being clocked by the INTOSC multiplexer. The IDLEN and SCS bits are not affected by the wake-up. The INTRC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled.
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3.5 Exiting Idle and Sleep Modes
3.5.3 EXIT BY RESET
An exit from Sleep mode or any of the Idle modes is triggered by an interrupt, a Reset or a WDT time-out. This section discusses the triggers that cause exits from power-managed modes. The clocking subsystem actions are discussed in each of the power-managed modes (see Section 3.2 "Run Modes" through Section 3.4 "Idle Modes"). Normally, the device is held in Reset by the Oscillator Start-up Timer (OST) until the primary clock becomes ready. At that time, the OSTS bit is set and the device begins executing code. If the internal oscillator block is the new clock source, the IOFS bit is set instead. The exit delay time from Reset to the start of code execution depends on both the clock sources before and after the wake-up and the type of oscillator if the new clock source is the primary clock. Exit delays are summarized in Table 3-2. Code execution can begin before the primary clock becomes ready. If either the Two-Speed Start-up (see Section 23.3 "Two-Speed Start-up") or Fail-Safe Clock Monitor (see Section 23.4 "Fail-Safe Clock Monitor") is enabled, the device may begin execution as soon as the Reset source has cleared. Execution is clocked by the INTOSC multiplexer driven by the internal oscillator block. Execution is clocked by the internal oscillator block until either the primary clock becomes ready, or a power-managed mode is entered before the primary clock becomes ready; the primary clock is then shut down.
3.5.1
EXIT BY INTERRUPT
Any of the available interrupt sources can cause the device to exit from an Idle or Sleep mode to a Run mode. To enable this functionality, an interrupt source must be enabled by setting its enable bit in one of the INTCON or PIE registers. The exit sequence is initiated when the corresponding interrupt flag bit is set. On all exits from Idle or Sleep modes by interrupt, code execution branches to the interrupt vector if the GIE/GIEH bit (INTCON<7>) is set. Otherwise, code execution continues or resumes without branching (see Section 8.0 "Interrupts"). A fixed delay of interval, TCSD, following the wake event, is required when leaving Sleep and Idle modes. This delay is required for the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay.
3.5.4
EXIT WITHOUT AN OSCILLATOR START-UP DELAY
3.5.2
EXIT BY WDT TIME-OUT
Certain exits from power-managed modes do not invoke the OST at all. There are two cases: * PRI_IDLE mode, where the primary clock source is not stopped; and * the primary clock source is not any of the LP, XT, HS or HSPLL modes. In these instances, the primary clock source either does not require an oscillator start-up delay since it is already running (PRI_IDLE), or normally does not require an oscillator start-up delay (RC, EC and INTIO Oscillator modes). However, a fixed delay of interval, TCSD, following the wake event, is still required when leaving Sleep and Idle modes to allow the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay.
A WDT time-out will cause different actions depending on which power-managed mode the device is in when the time-out occurs. If the device is not executing code (all Idle modes and Sleep mode), the time-out will result in an exit from the power-managed mode (see Section 3.2 "Run Modes" and Section 3.3 "Sleep Mode"). If the device is executing code (all Run modes), the time-out will result in a WDT Reset (see Section 23.2 "Watchdog Timer (WDT)"). The WDT timer and postscaler are cleared by executing a SLEEP or CLRWDT instruction, losing a currently selected clock source (if the Fail-Safe Clock Monitor is enabled) and modifying the IRCF bits in the OSCCON register if the internal oscillator block is the device clock source.
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TABLE 3-2: EXIT DELAY ON WAKE-UP BY RESET FROM SLEEP MODE OR ANY IDLE MODE (BY CLOCK SOURCES)
Clock Source after Wake-up LP, XT, HS Primary Device Clock (PRI_IDLE mode) HSPLL EC, RC, INTRC(1) INTOSC(3) LP, XT, HS T1OSC or INTRC(1) HSPLL EC, RC, INTRC(1) INTOSC
(3)
Clock Source before Wake-up
Exit Delay
Clock Ready Status Bit (OSCCON) OSTS
TCSD(2)
-- IOFS
TOST(4) TOST + trc(4) TCSD(2) TIOBST
(5)
OSTS -- IOFS OSTS -- IOFS OSTS -- IOFS
LP, XT, HS INTOSC(3) HSPLL EC, RC, INTRC(1) INTOSC None (Sleep mode) Note 1: 2: 3: 4: 5:
(3)
TOST(5) TOST + trc(4) TCSD(2) None TOST(4) TOST + trc(4) TCSD(2) TIOBST(5)
LP, XT, HS HSPLL EC, RC, INTRC(1) INTOSC(3)
In this instance, refers specifically to the 31 kHz INTRC clock source. TCSD (parameter 38) is a required delay when waking from Sleep and all Idle modes and runs concurrently with any other required delays (see Section 3.4 "Idle Modes"). Includes both the INTOSC 8 MHz source and postscaler derived frequencies. TOST is the Oscillator Start-up Timer (parameter 32). trc is the PLL Lock-out Timer (parameter F12); it is also designated as TPLL. Execution continues during TIOBST (parameter 39), the INTOSC stabilization period.
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4.0 RESET
4.1 RCON Register
The PIC18F6390/6490/8390/8490 devices differentiate between various kinds of Reset: a) b) c) d) e) f) g) h) Power-on Reset (POR) MCLR Reset during normal operation MCLR Reset during power-managed modes Watchdog Timer (WDT) Reset (during execution) Programmable Brown-out Reset (BOR) RESET Instruction Stack Full Reset Stack Underflow Reset Device Reset events are tracked through the RCON register (Register 4-1). The lower five bits of the register indicate that a specific Reset event has occurred. In most cases, these bits can only be set by the event and must be cleared by the application after the event. The state of these flag bits, taken together, can be read to indicate the type of Reset that just occurred. This is described in more detail in Section 4.6 "Reset State of Registers". The RCON register also has control bits for setting interrupt priority (IPEN) and software control of the BOR (SBOREN). Interrupt priority is discussed in Section 8.0 "Interrupts". BOR is covered in Section 4.4 "Brown-out Reset (BOR)".
This section discusses Resets generated by MCLR, POR and BOR and covers the operation of the various start-up timers. Stack Reset events are covered in Section 5.1.2.4 "Stack Full and Underflow Resets". WDT Resets are covered in Section 23.2 "Watchdog Timer (WDT)". A simplified block diagram of the on-chip Reset circuit is shown in Figure 4-1.
FIGURE 4-1:
RESET Instruction Stack Pointer
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
Stack Full/Underflow Reset
External Reset MCLR MCLRE ( )_IDLE Sleep WDT Time-out VDD Rise Detect VDD Brown-out Reset BOREN OST/PWRT OST OSC1 32 s INTRC(1) PWRT 65.5 ms 1024 Cycles R Q 10-Bit Ripple Counter Chip_Reset POR Pulse
S
11-Bit Ripple Counter Enable PWRT Enable OST(2)
Note 1: 2:
This is the INTRC source from the internal oscillator block and is separate from the RC oscillator of the CLKI pin. See Table 4-2 for time-out situations.
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REGISTER 4-1:
R/W-0 IPEN bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
RCON: RESET CONTROL REGISTER
R/W-1(1) SBOREN U-0 -- R/W-1 RI R-1 TO R-1 PD R/W-0 POR R/W-0 BOR bit 0
IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode) SBOREN: BOR Software Enable bit(1) If BOREN1:BOREN0 = 01: 1 = BOR is enabled 0 = BOR is disabled If BOREN1:BOREN0 = 00, 10 or 11: Bit is disabled and read as `0'. Unimplemented: Read as `0' RI: RESET Instruction Flag bit 1 = The RESET instruction was not executed (set by firmware only) 0 = The RESET instruction was executed causing a device Reset (must be set in software after a Brown-out Reset occurs) TO: Watchdog Time-out Flag bit 1 = Set by power-up, CLRWDT instruction or SLEEP instruction 0 = A WDT time-out occurred PD: Power-Down Detection Flag bit 1 = Set by power-up or by the CLRWDT instruction 0 = Set by execution of the SLEEP instruction POR: Power-on Reset Status bit 1 = A Power-on Reset has not occurred (set by firmware only) 0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs) BOR: Brown-out Reset Status bit 1 = A Brown-out Reset has not occurred (set by firmware only) 0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs) If SBOREN is enabled, its Reset state is `1'; otherwise, it is `0'.
bit 6
bit 5 bit 4
bit 3
bit 2
bit 1
bit 0
Note 1:
Note 1: It is recommended that the POR bit be set after a Power-on Reset has been detected, so that subsequent Power-on Resets may be detected. 2: Brown-out Reset is said to have occurred when BOR is `0' and POR is `1' (assuming that POR was set to `1' by software immediately after a Power-on Reset).
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4.2 Master Clear (MCLR)
FIGURE 4-2:
The MCLR pin provides a method for triggering a hard external Reset of the device. A Reset is generated by holding the pin low. PIC18 Extended MCU devices have a noise filter in the MCLR Reset path which detects and ignores small pulses. The MCLR pin is not driven low by any internal Resets, including the WDT. In PIC18F6390/6490/8390/8490 devices, the MCLR input can be disabled with the MCLRE Configuration bit. When MCLR is disabled, the pin becomes a digital input. See Section 9.7 "PORTG, TRISG and LATG Registers" for more information.
EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP)
VDD
VDD D
R R1 C MCLR
PIC18FXXXX
Note 1:
4.3
Power-on Reset (POR)
2:
A Power-on Reset pulse is generated on-chip whenever VDD rises above a certain threshold. This allows the device to start in the initialized state when VDD is adequate for operation. To take advantage of the POR circuitry, tie the MCLR pin through a resistor (1 k to 10 k) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset delay. A minimum rise rate for VDD is specified (parameter D004). For a slow rise time, see Figure 4-2. When the device starts normal operation (i.e., exits the Reset condition), device operating parameters (voltage, frequency, temperature, etc.) must be met to ensure operation. If these conditions are not met, the device must be held in Reset until the operating conditions are met. POR events are captured by the POR bit (RCON<1>). The state of the bit is set to `0' whenever a Power-on Reset occurs; it does not change for any other Reset event. POR is not reset to `1' by any hardware event. To capture multiple events, the user manually resets the bit to `1' in software following any Power-on Reset.
External Power-on Reset circuit is required only if the VDD power-up slope is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. R < 40 k is recommended to make sure that the voltage drop across R does not violate the device's electrical specification. R1 1 k will limit any current flowing into MCLR from external capacitor C, in the event of MCLR/VPP pin breakdown, due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS).
3:
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4.4 Brown-out Reset (BOR)
PIC18F6390/6490/8390/8490 devices implement a BOR circuit that provides the user with a number of configuration and power-saving options. The BOR is controlled by the BORV1:BORV0 and BOREN1:BOREN0 Configuration bits. There are a total of four BOR configurations, which are summarized in Table 4-1. The BOR threshold is set by the BORV1:BORV0 bits. If BOR is enabled (any values of BOREN1:BOREN0 except `00'), any drop of VDD below VBOR (parameter D005) for greater than TBOR (parameter 35) will reset the device. A Reset may or may not occur if VDD falls below VBOR for less than TBOR. The chip will remain in Brown-out Reset until VDD rises above VBOR. If the Power-up Timer is enabled, it will be invoked after VDD rises above VBOR; it then will keep the chip in Reset for an additional time delay, TPWRT (parameter 33). If VDD drops below VBOR while the Power-up Timer is running, the chip will go back into a Brown-out Reset and the Power-up Timer will be initialized. Once VDD rises above VBOR, the Power-up Timer will execute the additional time delay. BOR and the Power-up Timer (PWRT) are independently configured. Enabling the BOR Reset does not automatically enable the PWRT. Placing the BOR under software control gives the user the additional flexibility of tailoring the application to its environment without having to reprogram the device to change the BOR configuration. It also allows the user to tailor device power consumption in software by eliminating the incremental current that the BOR consumes. While the BOR current is typically very small, it may have some impact in low-power applications. Note: Even when BOR is under software control, the BOR Reset voltage level is still set by the BORV1:BORV0 Configuration bits. It cannot be changed in software.
4.4.2
DETECTING BOR
When BOR is enabled, the BOR bit always resets to `0' on any BOR or POR event. This makes it difficult to determine if a BOR event has occurred just by reading the state of BOR alone. A more reliable method is to simultaneously check the state of both POR and BOR. This assumes that the POR bit is reset to `1' in software immediately after any POR event. IF BOR is `0' while POR is `1', it can be reliably assumed that a BOR event has occurred.
4.4.3
DISABLING BOR IN SLEEP MODE
4.4.1
SOFTWARE ENABLED BOR
When BOREN1:BOREN0 = 01, the BOR can be enabled or disabled by the user in software. This is done with the control bit, SBOREN (RCON<6>). Setting SBOREN enables the BOR to function as previously described. Clearing SBOREN disables the BOR entirely. The SBOREN bit operates only in this mode; otherwise it is read as `0'.
When BOREN1:BOREN0 = 10, the BOR remains under hardware control and operates as previously described. Whenever the device enters Sleep mode, however, the BOR is automatically disabled. When the device returns to any other operating mode, BOR is automatically re-enabled. This mode allows for applications to recover from brown-out situations while actively executing code, when the device requires BOR protection the most. At the same time, it saves additional power in Sleep mode by eliminating the small incremental BOR current.
TABLE 4-1:
BOR CONFIGURATIONS
Status of SBOREN (RCON<6>) Unavailable Available Unavailable Unavailable BOR Operation BOR is disabled; must be enabled by reprogramming the Configuration bits. BOR is enabled in software; operation controlled by SBOREN. BOR is enabled in hardware and active during the Run and Idle modes, disabled during Sleep mode. BOR is enabled in hardware; must be disabled by reprogramming the Configuration bits.
BOR Configuration BOREN1 0 0 1 1 BOREN0 0 1 0 1
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4.5 Device Reset Timers
4.5.3 PLL LOCK TIME-OUT
PIC18F6390/6490/8390/8490 devices incorporate three separate on-chip timers that help regulate the Power-on Reset process. Their main function is to ensure that the device clock is stable before code is executed. These timers are: * Power-up Timer (PWRT) * Oscillator Start-up Timer (OST) * PLL Lock Time-out With the PLL enabled in its PLL mode, the time-out sequence following a Power-on Reset is slightly different from other oscillator modes. A separate timer is used to provide a fixed time-out that is sufficient for the PLL to lock to the main oscillator frequency. This PLL lock time-out (TPLL) is typically 2 ms and follows the oscillator start-up time-out.
4.5.4
1. 2.
TIME-OUT SEQUENCE
4.5.1
POWER-UP TIMER (PWRT)
On power-up, the time-out sequence is as follows: After the POR pulse has cleared, PWRT time-out is invoked (if enabled). Then, the OST is activated.
The Power-up Timer (PWRT) of PIC18F6390/6490/8390/8490 devices is an 11-bit counter which uses the INTRC source as the clock input. This yields an approximate time interval of 2048 x 32 s = 65.6 ms. While the PWRT is counting, the device is held in Reset. The power-up time delay depends on the INTRC clock and will vary from chip-to-chip due to temperature and process variation. See DC parameter 33 for details. The PWRT is enabled by clearing the PWRTEN Configuration bit.
The total time-out will vary based on oscillator configuration and the status of the PWRT. Figure 4-3, Figure 4-4, Figure 4-5, Figure 4-6 and Figure 4-7 all depict time-out sequences on power-up, with the Power-up Timer enabled and the device operating in HS Oscillator mode. Figures 4-3 through 4-6 also apply to devices operating in XT or LP modes. For devices in RC mode and with the PWRT disabled, on the other hand, there will be no time-out at all. Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, all time-outs will expire. Bringing MCLR high will begin execution immediately (Figure 4-5). This is useful for testing purposes, or to synchronize more than one PIC18FXXXX device operating in parallel.
4.5.2
OSCILLATOR START-UP TIMER (OST)
The Oscillator Start-up Timer (OST) provides a 1024 oscillator cycle (from OSC1 input) delay after the PWRT delay is over (parameter 33). This ensures that the crystal oscillator or resonator has started and is stabilized. The OST time-out is invoked only for XT, LP, HS and HSPLL modes and only on Power-on Reset, or on exit from most power-managed modes.
TABLE 4-2:
TIME-OUT IN VARIOUS SITUATIONS
Power-up(2) and Brown-out PWRTEN = 0 66 ms(1) + 1024 TOSC + 2 66 ms(1) 66 66 ms(1) ms(1) ms(2) 66 ms(1) + 1024 TOSC PWRTEN = 1 1024 TOSC + 2 ms(2) 1024 TOSC -- -- -- Exit from Power-Managed Mode 1024 TOSC + 2 ms(2) 1024 TOSC -- -- --
Oscillator Configuration HSPLL HS, XT, LP EC, ECIO RC, RCIO INTIO1, INTIO2
Note 1: 66 ms (65.5 ms) is the nominal Power-up Timer (PWRT) delay. 2: 2 ms is the nominal time required for the PLL to lock.
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FIGURE 4-3:
VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT OST TIME-OUT INTERNAL RESET TOST
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT)
FIGURE 4-4:
VDD MCLR INTERNAL POR
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1
TPWRT TOST
PWRT TIME-OUT OST TIME-OUT INTERNAL RESET
FIGURE 4-5:
VDD MCLR INTERNAL POR
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2
TPWRT PWRT TIME-OUT OST TIME-OUT INTERNAL RESET
TOST
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FIGURE 4-6: SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT)
5V VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET 0V 1V
FIGURE 4-7:
TIME-OUT SEQUENCE ON POR w/PLL ENABLED (MCLR TIED TO VDD)
VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT OST TIME-OUT TOST TPLL
PLL TIME-OUT INTERNAL RESET Note: TOST = 1024 clock cycles. TPLL 2 ms max. First three stages of the PWRT timer.
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4.6 Reset State of Registers
Most registers are unaffected by a Reset. Their status is unknown on POR and unchanged by all other Resets. The other registers are forced to a "Reset state" depending on the type of Reset that occurred. Most registers are not affected by a WDT wake-up, since this is viewed as the resumption of normal operation. Status bits from the RCON register, RI, TO, PD, POR and BOR, are set or cleared differently in different Reset situations, as indicated in Table 4-3. These bits are used in software to determine the nature of the Reset. Table 4-4 describes the Reset states for all of the Special Function Registers. These are categorized by Power-on and Brown-out Resets, Master Clear and WDT Resets and WDT wake-ups.
TABLE 4-3:
STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR RCON REGISTER
Program Counter 0000h 0000h 0000h 0000h 0000h RCON Register SBOREN 1 u(2) u(2) u(2) u(2) RI 1 0 1 u u TO 1 u 1 1 1 PD 1 u 1 u 0 STKPTR Register POR BOR STKFUL 0 u u u u 0 u 0 u u 0 u u u u STKUNF 0 u u u u
Condition Power-on Reset RESET Instruction Brown-out Reset MCLR Reset during power-managed Run modes MCLR Reset during power-managed Idle modes and Sleep WDT time-out during full power or power-managed Run modes MCLR during full-power execution Stack Full Reset (STVREN = 1) Stack Underflow Reset (STVREN = 1) Stack Underflow Error (not an actual Reset, STVREN = 0) WDT time-out during power-managed Idle or Sleep modes Interrupt exit from power-managed modes
0000h 0000h 0000h 0000h 0000h PC + 2(1)
u(2) u(2) u(2) u(2) u(2) u(2)
u u u u u u
0 u u u u 0
u u u u u 0
u u u u u u
u u u u u u
u u 1 u u u
u u u 1 1 u
PC + 2(1)
u(2)
u
u
0
u
u
u
u
Legend: u = unchanged Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the interrupt vector (008h or 0018h). 2: Reset state is `1' for POR and unchanged for all other Resets when software BOR is enabled (BOREN1:BOREN0 Configuration bits = 01 and SBOREN = 1); otherwise, the Reset state is `0'.
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TABLE 4-4:
Register
INITIALIZATION CONDITIONS FOR ALL REGISTERS
Applicable Devices 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 Power-on Reset, Brown-out Reset ---0 0000 0000 0000 0000 0000 00-0 0000 ---0 0000 0000 0000 0000 0000 --00 0000 0000 0000 0000 0000 0000 0000 xxxx xxxx xxxx xxxx 0000 000x 1111 1111 1100 0000 N/A N/A N/A N/A N/A ---- xxxx xxxx xxxx xxxx xxxx N/A N/A N/A N/A N/A MCLR Resets WDT Reset RESET Instruction Stack Resets ---0 0000 0000 0000 0000 0000 00-0 0000 ---0 0000 0000 0000 0000 0000 --00 0000 0000 0000 0000 0000 0000 0000 uuuu uuuu uuuu uuuu 0000 000u 1111 1111 1100 0000 N/A N/A N/A N/A N/A ---- uuuu uuuu uuuu uuuu uuuu N/A N/A N/A N/A N/A Wake-up via WDT or Interrupt ---0 uuuu(3) uuuu uuuu(3) uuuu uuuu(3) uu-u uuuu(3) ---u uuuu uuuu uuuu PC + 2(2) --uu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu(1) uuuu uuuu(1) uuuu uuuu(1) N/A N/A N/A N/A N/A ---- uuuu uuuu uuuu uuuu uuuu N/A N/A N/A N/A N/A
TOSU TOSH TOSL STKPTR PCLATU PCLATH PCL TBLPTRU TBLPTRH TBLPTRL TABLAT PRODH PRODL INTCON INTCON2 INTCON3 INDF0 POSTINC0 POSTDEC0 PREINC0 PLUSW0 FSR0H FSR0L WREG INDF1 POSTINC1 POSTDEC1 PREINC1 PLUSW1
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read `0'. 6: These registers are cleared on POR and unchanged on BOR.
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TABLE 4-4:
Register
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Applicable Devices 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 Power-on Reset, Brown-out Reset ---- xxxx xxxx xxxx ---- 0000 N/A N/A N/A N/A N/A ---- xxxx xxxx xxxx ---x xxxx 0000 0000 xxxx xxxx 1111 1111 0100 q000 0-00 0101 ---- ---0 0q-1 11q0 xxxx xxxx xxxx xxxx 0000 0000 0000 0000 1111 1111 -000 0000 xxxx xxxx 0000 0000 0000 0000 0000 0000 0000 0000 MCLR Resets WDT Reset RESET Instruction Stack Resets ---- uuuu uuuu uuuu ---- 0000 N/A N/A N/A N/A N/A ---- uuuu uuuu uuuu ---u uuuu 0000 0000 uuuu uuuu 1111 1111 0100 00q0 0-00 0101 ---- ---0 0q-q qquu uuuu uuuu uuuu uuuu u0uu uuuu 0000 0000 1111 1111 -000 0000 uuuu uuuu 0000 0000 0000 0000 0000 0000 0000 0000 Wake-up via WDT or Interrupt ---- uuuu uuuu uuuu ---- uuuu N/A N/A N/A N/A N/A ---- uuuu uuuu uuuu ---u uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuqu u-uu uuuu ---- ---u uq-u qquu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu 1111 1111 -uuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
FSR1H FSR1L BSR INDF2 POSTINC2 POSTDEC2 PREINC2 PLUSW2 FSR2H FSR2L STATUS TMR0H TMR0L T0CON OSCCON HLVDCON WDTCON RCON(4) TMR1H TMR1L T1CON TMR2 PR2 T2CON SSPBUF SSPADD SSPSTAT SSPCON1 SSPCON2
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read `0'. 6: These registers are cleared on POR and unchanged on BOR.
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TABLE 4-4:
Register
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Applicable Devices 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 Power-on Reset, Brown-out Reset xxxx xxxx xxxx xxxx --00 0000 --00 0000 0-00 0000 xxxx xxxx xxxx xxxx --00 0000 xxxx xxxx xxxx xxxx --00 0000 000- 0000 0000 0111 xxxx xxxx xxxx xxxx 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 0000 000x -111 ----000 ----000 ---11-- 1111 00-- 0000 00-- 0000 -111 1111 -000 0000 -000 0000 00-0 0000 MCLR Resets WDT Reset RESET Instruction Stack Resets uuuu uuuu uuuu uuuu --00 0000 --00 0000 0-00 0000 uuuu uuuu uuuu uuuu --00 0000 uuuu uuuu uuuu uuuu --00 0000 000- 0000 0000 0111 uuuu uuuu uuuu uuuu uuuu uuuu 0000 0000 0000 0000 0000 0000 0000 0010 0000 000x -111 ----000 ----000 ---11-- 1111 00-- 0000 00-- 0000 -111 1111 -000 0000 -000 0000 00-0 0000 Wake-up via WDT or Interrupt uuuu uuuu uuuu uuuu --uu uuuu --uu uuuu u-uu uuuu uuuu uuuu uuuu uuuu --uu uuuu uuuu uuuu uuuu uuuu --uu uuuu uuu- uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu -uuu ----uuu ----(1) -uuu ---uu-- uuuu uu-- uuuu(1) uu-- uuuu -uuu uuuu -uuu uuuu(1) -uuu uuuu uu-u uuuu
ADRESH ADRESL ADCON0 ADCON1 ADCON2 CCPR1H CCPR1L CCP1CON CCPR2H CCPR2L CCP2CON CVRCON CMCON TMR3H TMR3L T3CON SPBRG1 RCREG1 TXREG1 TXSTA1 RCSTA1 IPR3 PIR3 PIE3 IPR2 PIR2 PIE2 IPR1 PIR1 PIE1 OSCTUNE
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read `0'. 6: These registers are cleared on POR and unchanged on BOR.
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TABLE 4-4:
Register
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Applicable Devices 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 Power-on Reset, Brown-out Reset 1111 1111 1111 1111 ---1 1111 1111 1111 1111 ---1111 1111 1111 1111 1111 1111 1111 1111(5) xxxx xxxx xxxx xxxx ---x xxxx xxxx xxxx xxxx ---xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx(5) xxxx xxxx xxxx xxxx --xx xxxx xxxx xxxx xxxx ---xxxx xxxx xxxx xxxx xxxx xxxx xx0x 0000 0000 0000 01-0 0-00
(5)
MCLR Resets WDT Reset RESET Instruction Stack Resets 1111 1111 1111 1111 ---1 1111 1111 1111 1111 ---1111 1111 1111 1111 1111 1111 1111 1111(5) uuuu uuuu uuuu uuuu ---u uuuu uuuu uuuu uuuu ---uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu(5) uuuu uuuu uuuu uuuu --uu uuuu uuuu uuuu uuuu ---uuuu uuuu uuuu uuuu uuuu uuuu uu0u 0000 0000 0000 01-0 0-00
(5)
Wake-up via WDT or Interrupt uuuu uuuu uuuu uuuu ---u uuuu uuuu uuuu uuuu ---uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu(5) uuuu uuuu uuuu uuuu ---u uuuu uuuu uuuu uuuu ---uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu(5) uuuu uuuu uuuu uuuu --uu uuuu uuuu uuuu uuuu ---uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu(5) uuuu uuuu uu-u u-uu
TRISJ TRISH TRISG TRISF TRISE TRISD TRISC TRISB TRISA LATJ LATH LATG LATF LATE LATD LATC LATB LATA(5) PORTJ PORTH PORTG PORTF PORTE PORTD PORTC PORTB PORTA
(5) (5)
SPBRGH1 BAUDCON1
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read `0'. 6: These registers are cleared on POR and unchanged on BOR.
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TABLE 4-4:
Register LCDDATA23 LCDDATA22 LCDDATA21 LCDDATA20 LCDDATA19 LCDDATA18 LCDDATA17 LCDDATA16 LCDDATA15 LCDDATA14 LCDDATA13 LCDDATA12 LCDDATA11 SPBRG2 RCREG2 TXREG2 TXSTA2 RCSTA2 LCDDATA10 LCDDATA9 LCDDATA8 LCDDATA7 LCDDATA6 LCDDATA5 LCDDATA4 LCDDATA3 LCDDATA2 LCDDATA1 LCDDATA0
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Applicable Devices 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 Power-on Reset, Brown-out Reset xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 0000 0000 0000 0000 0000 0000 0000 -010 0000 000x xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx MCLR Resets WDT Reset RESET Instruction Stack Resets 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 -010 0000 000x 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 Wake-up via WDT or Interrupt uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu -uuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read `0'. 6: These registers are cleared on POR and unchanged on BOR.
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TABLE 4-4:
Register
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Applicable Devices 6X90 6X90 6X90 6X90 6X90 6X90 6X90 6X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 8X90 Power-on Reset, Brown-out Reset 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 000- 0000 0000 0000 MCLR Resets WDT Reset RESET Instruction Stack Resets 0000 0000(6) 0000 0000(6) 0000 0000 0000
(6)
Wake-up via WDT or Interrupt uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuu- uuuu uuuu uuuu
LCDSE5 LCDSE4 LCDSE3 LCDSE2 LCDSE1 LCDSE0 LCDCON LCDPS
0000 0000(6) 0000(6) 0000 0000(6) 000- 0000 0000 0000
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 4-3 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read `0'. 6: These registers are cleared on POR and unchanged on BOR.
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5.0 MEMORY ORGANIZATION
5.1 Program Memory Organization
There are two types of memory in PIC18 Flash microcontroller devices: * Program Memory * Data RAM As Harvard architecture devices, the data and program memories use separate busses; this allows for concurrent access of the two memory spaces. Additional detailed information on the operation of the Flash program memory is provided in Section 6.0 "Flash Program Memory". PIC18 microcontrollers implement a 21-bit program counter, which is capable of addressing a 2-Mbyte program memory space. Accessing a location between the upper boundary of the physically implemented memory and the 2-Mbyte address will return all `0's (a NOP instruction). The PIC18FX390 have 8 Kbytes of Flash memory and can store up to 4,096 single-word instructions and the PIC18FX490 have 16 Kbytes of Flash memory and can store up to 8,192 single-word instructions. PIC18 devices have two interrupt vectors. The Reset vector address is at 0000h and the interrupt vector addresses are at 0008h and 0018h. The program memory maps for PIC18F6390/6490/8390/8490 devices are shown in Figure 5-1.
FIGURE 5-1:
PROGRAM MEMORY MAP AND STACK FOR PIC18F6390/6490/8390/8490 DEVICES
PIC18F6390/8390 PIC18F6490/8490 PC<20:0> 21 CALL,RCALL,RETURN RETFIE,RETLW Stack Level 1
* * *
PC<20:0> 21 CALL,RCALL,RETURN RETFIE,RETLW Stack Level 1
* * *
Stack Level 31 Reset Vector 0000h
Stack Level 31 Reset Vector 0000h
High-Priority Interrupt Vector 0008h Low-Priority Interrupt Vector 0018h On-Chip Program Memory 1FFFh 2000h User Memory Space
High-Priority Interrupt Vector 0008h Low-Priority Interrupt Vector 0018h On-Chip Program Memory 3FFFh 4000h
Read `0'
Read `0'
1FFFFFh
1FFFFFh
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User Memory Space
PIC18F6390/6490/8390/8490
5.1.1 PROGRAM COUNTER
The Program Counter (PC) specifies the address of the instruction to fetch for execution. The PC is 21 bits wide and is contained in three separate 8-bit registers. The low byte, known as the PCL register, is both readable and writable. The high byte, or PCH register, contains the PC<15:8> bits; it is not directly readable or writable. Updates to the PCH register are performed through the PCLATH register. The upper byte is called PCU. This register contains the PC<20:16> bits; it is also not directly readable or writable. Updates to the PCU register are performed through the PCLATU register. The contents of PCLATH and PCLATU are transferred to the program counter by any operation that writes PCL. Similarly, the upper two bytes of the program counter are transferred to PCLATH and PCLATU by an operation that reads PCL. This is useful for computed offsets to the PC (see Section 5.1.4.1 "Computed GOTO"). The PC addresses bytes in the program memory. To prevent the PC from becoming misaligned with word instructions, the Least Significant bit of PCL is fixed to a value of `0'. The PC increments by 2 to address sequential instructions in the program memory. The CALL, RCALL, GOTO and program branch instructions write to the program counter directly. For these instructions, the contents of PCLATH and PCLATU are not transferred to the program counter. The stack operates as a 31-word by 21-bit RAM and a 5-bit Stack Pointer. The stack space is not part of either program or data space. The Stack Pointer is readable and writable and the address on the top of the stack is readable and writable through the top-of-stack Special Function Registers. Data can also be pushed to, or popped from the stack using these registers. A CALL type instruction causes a push onto the stack; the Stack Pointer is first incremented and the location pointed to by the Stack Pointer is written with the contents of the PC (already pointing to the instruction following the CALL). A RETURN type instruction causes a pop from the stack; the contents of the location pointed to by the STKPTR register are transferred to the PC and then the Stack Pointer is decremented. The Stack Pointer is initialized to `00000' after all Resets. There is no RAM associated with the location corresponding to a Stack Pointer value of `00000'; this is only a Reset value. Status bits indicate if the stack is full, has overflowed or has underflowed.
5.1.2.1
Top-of-Stack Access
5.1.2
RETURN ADDRESS STACK
The return address stack allows any combination of up to 31 program calls and interrupts to occur. The PC is pushed onto the stack when a CALL or RCALL instruction is executed, or an interrupt is Acknowledged. The PC value is pulled off the stack on a RETURN, RETLW or a RETFIE instruction. PCLATU and PCLATH are not affected by any of the RETURN or CALL instructions.
Only the top of the return address stack (TOS) is readable and writable. A set of three registers, TOSU:TOSH:TOSL, hold the contents of the stack location pointed to by the lower five bits of the STKPTR register (Figure 5-2). This allows users to implement a software stack if necessary. After a CALL, RCALL or interrupt, the software can read the pushed value by reading the TOSU:TOSH:TOSL registers. These values can be placed on a user-defined software stack. At return time, the software can return these values to TOSU:TOSH:TOSL and do a return. The user must disable the global interrupt enable bits while accessing the stack to prevent inadvertent stack corruption.
FIGURE 5-2:
RETURN ADDRESS STACK AND ASSOCIATED REGISTERS
Return Address Stack <20:0> 11111 11110 11101
Top-of-Stack Registers TOSU 00h TOSH 1Ah TOSL 34h Top-of-Stack 001A34h 000D58h
Stack Pointer STKPTR<4:0> 00010
00011 00010 00001 00000
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5.1.2.2 Return Stack Pointer (STKPTR)
The STKPTR register (Register 5-1) contains the Stack Pointer value, the STKFUL (Stack Full) status bit and the STKUNF (Stack Underflow) status bits. The value of the Stack Pointer can be 0 through 31. The Stack Pointer increments before values are pushed onto the stack and decrements after values are popped off the stack. On Reset, the Stack Pointer value will be zero. The user may read and write the Stack Pointer value. This feature can be used by a Real-Time Operating System (RTOS) for return stack maintenance. After the PC is pushed onto the stack 31 times (without popping any values off the stack), the STKFUL bit is set. The STKFUL bit is cleared by software or by a POR. The action that takes place when the stack becomes full depends on the state of the STVREN (Stack Overflow Reset Enable) Configuration bit. (Refer to Section 23.1 "Configuration Bits" for a description of the device Configuration bits.) If STVREN is set (default), the 31st push will push the (PC + 2) value onto the stack, set the STKFUL bit and reset the device. The STKFUL bit will remain set and the Stack Pointer will be set to zero. If STVREN is cleared, the STKFUL bit will be set on the 31st push and the Stack Pointer will increment to 31. Any additional pushes will not overwrite the 31st push and STKPTR will remain at 31. When the stack has been popped enough times to unload the stack, the next pop will return a value of zero to the PC and sets the STKUNF bit, while the Stack Pointer remains at zero. The STKUNF bit will remain set until cleared by software, or until a POR occurs. Note: Returning a value of zero to the PC on an underflow has the effect of vectoring the program to the Reset vector where the stack conditions can be verified and appropriate actions can be taken. This is not the same as a Reset, as the contents of the SFRs are not affected.
5.1.2.3
PUSH and POP Instructions
Since the Top-of-Stack is readable and writable, the ability to push values onto the stack and pull values off the stack, without disturbing normal program execution, is a desirable feature. The PIC18 instruction set includes two instructions, PUSH and POP, that permit the TOS to be manipulated under software control. TOSU, TOSH and TOSL can be modified to place data or a return address on the stack. The PUSH instruction places the current PC value onto the stack. This increments the Stack Pointer and loads the current PC value onto the stack. The POP instruction discards the current TOS by decrementing the Stack Pointer. The previous value pushed onto the stack then becomes the TOS value.
REGISTER 5-1:
R/C-0 STKFUL(1) bit 7 Legend: R = Readable bit -n = Value at POR bit 7
STKPTR: STACK POINTER REGISTER
R/C-0 U-0 -- R/W-0 SP4 R/W-0 SP3 R/W-0 SP2 R/W-0 SP1 R/W-0 SP0 bit 0 C = Clearable only bit W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
STKUNF(1)
STKFUL: Stack Full Flag bit(1) 1 = Stack became full or overflowed 0 = Stack has not become full or overflowed STKUNF: Stack Underflow Flag bit(1) 1 = Stack underflow occurred 0 = Stack underflow did not occur Unimplemented: Read as `0' SP4:SP0: Stack Pointer Location bits Bit 7 and bit 6 are cleared by user software or by a POR.
bit 6
bit 5 bit 4-0 Note 1:
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5.1.2.4 Stack Full and Underflow Resets 5.1.4
Device Resets on stack overflow and stack underflow conditions are enabled by setting the STVREN bit in Configuration Register 4L. When STVREN is set, a full or underflow will set the appropriate STKFUL or STKUNF bit and then cause a device Reset. When STVREN is cleared, a full or underflow condition will set the appropriate STKFUL or STKUNF bit, but not cause a device Reset. The STKFUL or STKUNF bits are cleared by the user software or a Power-on Reset.
LOOK-UP TABLES IN PROGRAM MEMORY
There may be programming situations that require the creation of data structures, or look-up tables, in program memory. For PIC18 devices, look-up tables can be implemented in two ways: * Computed GOTO * Table Reads
5.1.4.1
Computed GOTO
5.1.3
FAST REGISTER STACK
A Fast Register Stack is provided for the STATUS, WREG and BSR registers, to provide a "fast return" option for interrupts. This stack is only one level deep and is neither readable nor writable. It is loaded with the current value of the corresponding register when the processor vectors for an interrupt. All interrupt sources will push values into the stack registers. The values in the registers are then loaded back into the working registers if the RETFIE, FAST instruction is used to return from the interrupt. If both low and high-priority interrupts are enabled, the stack registers cannot be used reliably to return from low-priority interrupts. If a high-priority interrupt occurs while servicing a low-priority interrupt, the Stack register values stored by the low-priority interrupt will be overwritten. In these cases, users must save the key registers in software during a low-priority interrupt. If interrupt priority is not used, all interrupts may use the Fast Register Stack for returns from interrupt. If no interrupts are used, the Fast Register Stack can be used to restore the STATUS, WREG and BSR registers at the end of a subroutine call. To use the Fast Register Stack for a subroutine call, a CALL label, FAST instruction must be executed to save the STATUS, WREG and BSR registers to the Fast Register Stack. A RETURN, FAST instruction is then executed to restore these registers from the Fast Register Stack. Example 5-1 shows a source code example that uses the Fast Register Stack during a subroutine call and return.
A computed GOTO is accomplished by adding an offset to the program counter. An example is shown in Example 5-2. A look-up table can be formed with an ADDWF PCL instruction and a group of RETLW nn instructions. The W register is loaded with an offset into the table before executing a call to that table. The first instruction of the called routine is the ADDWF PCL instruction. The next instruction executed will be one of the RETLW nn instructions that returns the value `nn' to the calling function. The offset value (in WREG) specifies the number of bytes that the program counter should advance and should be multiples of 2 (LSb = 0). In this method, only one data byte may be stored in each instruction location and room on the return address stack is required.
EXAMPLE 5-2:
MOVF CALL nn00h ADDWF RETLW RETLW RETLW . . .
COMPUTED GOTO USING AN OFFSET VALUE
OFFSET, W TABLE PCL nnh nnh nnh
ORG TABLE
5.1.4.2
Table Reads
EXAMPLE 5-1:
CALL SUB1, FAST * * SUB1 * * RETURN FAST
FAST REGISTER STACK CODE EXAMPLE
;STATUS, WREG, BSR ;SAVED IN FAST REGISTER ;STACK
A better method of storing data in program memory allows two bytes of data to be stored in each instruction location. Look-up table data may be stored two bytes per program word while programming. The Table Pointer register (TBLPTR) specifies the byte address and the Table Latch register (TABLAT) contains the data that is read from the program memory. Data is transferred from program memory one byte at a time. Table read operation is Section 6.1 "Table Reads". discussed further in
;RESTORE VALUES SAVED ;IN FAST REGISTER STACK
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5.2
5.2.1
PIC18 Instruction Cycle
CLOCKING SCHEME
5.2.2
INSTRUCTION FLOW/PIPELINING
The microcontroller clock input, whether from an internal or external source, is internally divided by four to generate four non-overlapping quadrature clocks (Q1, Q2, Q3 and Q4). Internally, the program counter is incremented on every Q1; the instruction is fetched from the program memory and latched into the Instruction Register (IR) during Q4. The instruction is decoded and executed during the following Q1 through Q4. The clocks and instruction execution flow are shown in Figure 5-3.
An "Instruction Cycle" consists of four Q cycles, Q1 through Q4. The instruction fetch and execute are pipelined in such a manner that a fetch takes one instruction cycle, while the decode and execute take another instruction cycle. However, due to the pipelining, each instruction effectively executes in one cycle. If an instruction causes the program counter to change (e.g., GOTO), then two cycles are required to complete the instruction (Example 5-3). A fetch cycle begins with the Program Counter (PC) incrementing in Q1. In the execution cycle, the fetched instruction is latched into the Instruction Register (IR) in cycle Q1. This instruction is then decoded and executed during the Q2, Q3 and Q4 cycles. Data memory is read during Q2 (operand read) and written during Q4 (destination write).
FIGURE 5-3:
OSC1 Q1 Q2 Q3 Q4 PC OSC2/CLKO (RC mode)
CLOCK/INSTRUCTION CYCLE
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Internal Phase Clock
PC
PC + 2
PC + 4
Execute INST (PC - 2) Fetch INST (PC)
Execute INST (PC) Fetch INST (PC + 2)
Execute INST (PC + 2) Fetch INST (PC + 4)
EXAMPLE 5-3:
INSTRUCTION PIPELINE FLOW
TCY0 TCY1 Execute 1 Fetch 2 Execute 2 Fetch 3 Execute 3 Fetch 4 Flush (NOP) Fetch SUB_1 Execute SUB_1 TCY2 TCY3 TCY4 TCY5
1. MOVLW 55h 2. MOVWF PORTB 3. BRA 4. BSF SUB_1
Fetch 1
PORTA, BIT3 (Forced NOP)
5. Instruction @ address SUB_1
All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction is "flushed" from the pipeline, while the new instruction is being fetched and then executed.
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5.2.3 INSTRUCTIONS IN PROGRAM MEMORY
The program memory is addressed in bytes. Instructions are stored as two bytes or four bytes in program memory. The Least Significant Byte of an instruction word is always stored in a program memory location with an even address (LSB = 0). To maintain alignment with instruction boundaries, the PC increments in steps of 2 and the LSB will always read `0' (see Section 5.1.1 "Program Counter"). Figure 5-4 shows an example of how instruction words are stored in the program memory. The CALL and GOTO instructions have the absolute program memory address embedded into the instruction. Since instructions are always stored on word boundaries, the data contained in the instruction is a word address. The word address is written to PC<20:1>, which accesses the desired byte address in program memory. Instruction #2 in Figure 5-4 shows how the instruction, GOTO 0006h, is encoded in the program memory. Program branch instructions, which encode a relative address offset, operate in the same manner. The offset value stored in a branch instruction represents the number of single-word instructions that the PC will be offset by. Section 24.0 "Instruction Set Summary" provides further details of the instruction set.
5.2.4
TWO-WORD INSTRUCTIONS
The standard PIC18 instruction set has four two-word instructions: CALL, MOVFF, GOTO and LSFR. In all cases, the second word of the instructions always has `1111' as its four Most Significant bits; the other 12 bits are literal data, usually a data memory address. The use of `1111' in the 4 MSbs of an instruction specifies a special form of NOP. If the instruction is executed in proper sequence - immediately after the first word - the data in the second word is accessed and used by the instruction sequence. If the first word is skipped for some reason and the second word is executed by itself, a NOP is executed instead. This is necessary for cases when the two-word instruction is preceded by a conditional instruction that changes the PC. Example 5-4 shows how this works. Note: See Section 5.5 "Program Memory and the Extended Instruction Set" for information on two-word instructions in the extended instruction set.
FIGURE 5-4:
INSTRUCTIONS IN PROGRAM MEMORY
LSB = 1 Program Memory Byte Locations LSB = 0 Word Address 000000h 000002h 000004h 000006h 000008h 00000Ah 00000Ch 00000Eh 000010h 000012h 000014h
Instruction 1: Instruction 2: Instruction 3:
MOVLW GOTO MOVFF
055h 0006h 123h, 456h
0Fh EFh F0h C1h F4h
55h 03h 00h 23h 56h
EXAMPLE 5-4:
CASE 1: Object Code
TWO-WORD INSTRUCTIONS
Source Code TSTFSZ MOVFF ADDWF Source Code TSTFSZ MOVFF ADDWF REG1 REG1, REG2 REG3 ; is RAM location 0? ; Yes, execute this word ; 2nd word of instruction ; continue code REG1 REG1, REG2 REG3 ; is RAM location 0? ; No, skip this word ; Execute this word as a NOP ; continue code
0110 0110 0000 0000 1100 0001 0010 0011 1111 0100 0101 0110 0010 0100 0000 0000 CASE 2: Object Code 0110 0110 0000 0000 1100 0001 0010 0011 1111 0100 0101 0110 0010 0100 0000 0000
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5.3
Note:
Data Memory Organization
The operation of some aspects of data memory are changed when the PIC18 extended instruction set is enabled. See Section 5.6 "Data Memory and the Extended Instruction Set" for more information.
5.3.1
BANK SELECT REGISTER
The data memory in PIC18 devices is implemented as static RAM. Each register in the data memory has a 12-bit address, allowing up to 4096 bytes of data memory. The memory space is divided into as many as 16 banks that contain 256 bytes each; PIC18F6390/6490/8390/8490 devices implement only 4 banks. Figure 5-5 shows the data memory organization for the PIC18F6390/6490/8390/8490 devices. The data memory contains Special Function Registers (SFRs) and General Purpose Registers (GPRs). The SFRs are used for control and status of the controller and peripheral functions, while GPRs are used for data storage and scratchpad operations in the user's application. Any read of an unimplemented location will read as `0's. The instruction set and architecture allow operations across all banks. The entire data memory may be accessed by Direct, Indirect or Indexed Addressing modes. Addressing modes are discussed later in this section. To ensure that commonly used registers (SFRs and select GPRs) can be accessed in a single cycle, PIC18 devices implement an Access Bank. This is a 256-byte memory space that provides fast access to SFRs and the lower portion of GPR Bank 0 without using the BSR. Section 5.3.2 "Access Bank" provides a detailed description of the Access RAM.
Large areas of data memory require an efficient addressing scheme to make rapid access to any address possible. Ideally, this means that an entire address does not need to be provided for each read or write operation. For PIC18 devices, this is accomplished with a RAM banking scheme. This divides the memory space into 16 contiguous banks of 256 bytes. Depending on the instruction, each location can be addressed directly by its full 12-bit address, or an 8-bit low-order address and a 4-bit Bank Pointer. Most instructions in the PIC18 instruction set make use of the Bank Pointer, known as the Bank Select Register (BSR). This SFR holds the 4 Most Significant bits of a location's address; the instruction itself includes the 8 Least Significant bits. Only the four lower bits of the BSR are implemented (BSR3:BSR0). The upper four bits are unused; they will always read `0' and cannot be written to. The BSR can be loaded directly by using the MOVLB instruction. The value of the BSR indicates the bank in data memory; the 8 bits in the instruction show the location in the bank and can be thought of as an offset from the bank's lower boundary. The relationship between the BSR's value and the bank division in data memory is shown in Figure 5-6. Since up to 16 registers may share the same low-order address, the user must always be careful to ensure that the proper bank is selected before performing a data read or write. For example, writing what should be program data to an 8-bit address of F9h, while the BSR is 0Fh will end up resetting the program counter. While any bank can be selected, only those banks that are actually implemented can be read or written to. Writes to unimplemented banks are ignored, while reads from unimplemented banks will return `0's. Even so, the STATUS register will still be affected as if the operation was successful. The data memory map in Figure 5-5 indicates which banks are implemented. In the core PIC18 instruction set, only the MOVFF instruction fully specifies the 12-bit address of the source and target registers. This instruction ignores the BSR completely when it executes. All other instructions include only the low-order address as an operand and must use either the BSR or the Access Bank to locate their target registers.
(c) 2007 Microchip Technology Inc.
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FIGURE 5-5:
BSR<3:0> 00h = 0000 = 0001 = 0010 Bank 0 FFh 00h Bank 1 Bank 2 FFh 00h GPR FFh 2FFh 300h
DATA MEMORY MAP FOR PIC18F6390/6490/8390/8490 DEVICES
Data Memory Map Access RAM GPR GPR 1FFh 200h 000h 05Fh 060h 0FFh 100h
When a = 0: The BSR is ignored and the Access Bank is used. The first 128 bytes are general purpose RAM (from Bank 0). The second 128 bytes are Special Function Registers (from Bank 15). When a = 1: The BSR specifies the bank used by the instruction.
= 0011
Bank 3
Access Bank 5Fh Access RAM High 60h (SFRs) FFh Access RAM Low 00h
to
Unused Read as 00h
= 1110
Bank 14
= 1111
00h Bank 15 FFh
Unimplemented SFR
EFFh F00h F58h F60h FFFh
Banked SFRs
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PIC18F6390/6490/8390/8490
FIGURE 5-6:
7 0 0 0
USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING)
BSR(1) 0 0 0 1 0 0 000h 100h Bank 1 200h 300h Bank 2
Data Memory
00h Bank 0 FFh 00h FFh 00h FFh 00h
7 1 1 1 1
From Opcode(2) 1 1 1 1 1 1 1 1
0 1
Bank Select(2)
Bank 3 through Bank 13
E00h Bank 14 F00h FFFh Note 1: 2: Bank 15
FFh 00h FFh 00h FFh
The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to the registers of the Access Bank. The MOVFF instruction embeds the entire 12-bit address in the instruction.
5.3.2
ACCESS BANK
While the use of the BSR with an embedded 8-bit address allows users to address the entire range of data memory, it also means that the user must always ensure that the correct bank is selected. Otherwise, data may be read from or written to the wrong location. This can be disastrous if a GPR is the intended target of an operation but an SFR is written to instead. Verifying and/or changing the BSR for each read or write to data memory can become very inefficient. To streamline access for the most commonly used data memory locations, the data memory is configured with an Access Bank, which allows users to access a mapped block of memory without specifying a BSR. The Access Bank consists of the first 96 bytes of memory (00h-5Fh) in Bank 0 and the last 160 bytes of memory (60h-FFh) in Block 15. The lower half is known as the "Access RAM" and is composed of GPRs. This upper half is where the device's SFRs are mapped. These two areas are mapped contiguously in the Access Bank and can be addressed in a linear fashion by an 8-bit address (Figure 5-5). The Access Bank is used by core PIC18 instructions that include the Access RAM bit (the `a' parameter in the instruction). When `a' is equal to `1', the instruction uses the BSR and the 8-bit address included in the opcode for the data memory address. When `a' is `0', however, the instruction is forced to use the Access Bank address map; the current value of the BSR is ignored entirely.
Using this "forced" addressing allows the instruction to operate on a data address in a single cycle without updating the BSR first. For 8-bit addresses of 80h and above, this means that users can evaluate and operate on SFRs more efficiently. The Access RAM below 60h is a good place for data values that the user might need to access rapidly, such as immediate computational results or common program variables. Access RAM also allows for faster and more code efficient context saving and switching of variables. The mapping of the Access Bank is slightly different when the extended instruction set is enabled (XINST Configuration bit = 1). This is discussed in more detail in Section 5.6.3 "Mapping the Access Bank in Indexed Literal Offset Mode".
5.3.3
GENERAL PURPOSE REGISTER FILE
PIC18 devices may have banked memory in the GPR area. This is data RAM, which is available for use by all instructions. GPRs start at the bottom of Bank 0 (address 000h) and grow upwards towards the bottom of the SFR area. GPRs are not initialized by a Power-on Reset and are unchanged on all other Resets.
(c) 2007 Microchip Technology Inc.
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5.3.4 SPECIAL FUNCTION REGISTERS
The Special Function Registers (SFRs) are registers used by the CPU and peripheral modules for controlling the desired operation of the device. These registers are implemented as static RAM. SFRs start at the top of data memory (FFFh) and extend downward to occupy three-quarters of Bank 15 (from F40h to FFFh). A list of these registers is given in Table 5-1 and Table 5-2. The SFRs can be classified into two sets: those associated with the "core" device functionality (ALU, Resets and interrupts) and those related to the peripheral functions. The Reset and Interrupt registers are described in their respective chapters, while the ALU's STATUS register is described later in this section. Registers related to the operation of the peripheral features are described in the chapter for that peripheral. The SFRs are typically distributed among the peripherals whose functions they control. Unused SFR locations are unimplemented and read as `0's.
TABLE 5-1:
Address FFFh FFEh FFDh FFCh FFBh FFAh FF9h FF8h FF7h FF6h FF5h FF4h FF3h FF2h FF1h FF0h FEFh FEEh FECh FEBh FEAh FE9h FE8h FE7h FE6h FE4h FE3h FE2h FE1h FE0h Note 1: 2: 3: 4:
SPECIAL FUNCTION REGISTER MAP FOR PIC18F6390/6490/8390/8490 DEVICES
Name TOSU TOSH TOSL STKPTR PCLATU PCLATH PCL TBLPTRU TBLPTRH TBLPTRL TABLAT PRODH PRODL INTCON INTCON2 INTCON3 INDF0(1) POSTINC0(1) PREINC0(1) PLUSW0(1) FSR0H FSR0L WREG INDF1(1) POSTINC1
(1)
Address FDFh FDEh FDCh FDBh FDAh FD9h FD8h FD7h FD6h FD5h FD4h FD3h FD2h FD1h FD0h FCFh FCEh FCDh FCCh FCBh FCAh FC9h FC8h FC7h FC6h FC5h FC4h FC3h FC2h FC1h FC0h
Name INDF2(1) POSTINC2
(1)
Address FBFh FBEh FBDh FBCh FBBh FBAh FB9h FB8h FB7h FB6h FB5h FB4h FB3h FB2h FB1h FB0h FAFh FAEh FADh FACh FABh FAAh FA9h FA8h FA7h FA6h FA5h FA4h FA3h FA2h FA1h FA0h
Name CCPR1H CCPR1L CCP1CON CCPR2H CCPR2L CCP2CON -- -- --
(2) (2)
Address F9Fh F9Eh F9Dh F9Ch F9Bh F9Ah F99h F98h F97h F96h F95h F94h F93h F92h F91h F90h F8Fh F8Eh F8Dh F8Ch F8Bh F8Ah F89h F88h F87h F86h F85h F84h F83h F82h F81h F80h
Name IPR1 PIR1 PIE1 MEMCON(3) OSCTUNE TRISJ(3) TRISH(3) TRISG TRISF TRISE TRISD TRISC TRISB TRISA LATJ(3) LATH(3) LATG LATF LATE LATD LATC LATB LATA PORTJ(3) PORTH(3) PORTG PORTF PORTE PORTD PORTC PORTB PORTA
FDDh POSTDEC2(1) PREINC2(1) PLUSW2(1) FSR2H FSR2L STATUS TMR0H TMR0L T0CON --(2) OSCCON HLVDCON WDTCON RCON TMR1H TMR1L T1CON TMR2 PR2 T2CON SSPBUF SSPADD SSPSTAT SSPCON1 SSPCON2 ADRESH ADRESL ADCON0 ADCON1 ADCON2
--(2)
(2)
CVRCON CMCON TMR3H TMR3L T3CON --(2) SPBRG1 RCREG1 TXREG1 TXSTA1 RCSTA1 --
(2)
FEDh POSTDEC0(1)
--(2) --(2) --(2) --
(2)
FE5h POSTDEC1(1) PREINC1(1) PLUSW1(1) FSR1H FSR1L BSR
IPR3 PIR3 PIE3 IPR2 PIR2 PIE2
This is not a physical register. Unimplemented registers are read as `0'. This register is not available on 64-pin devices. This register is implemented but unused on 64-pin devices.
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TABLE 5-1:
Address F7Fh F7Eh F7Dh F7Bh F7Ah F79h F78h F77h
SPECIAL FUNCTION REGISTER MAP FOR PIC18F6390/6490/8390/8490 DEVICES (CONTINUED)
Name SPBRGH1 BAUDCON1 --(2)
(4)
Address F6Fh F6Eh F6Dh F6Ch F6Bh F69h F68h F67h F66h F65h F64h F63h F62h F61h F60h
Name SPBRG2 RCREG2 TXREG2 TXSTA2 RCSTA2
(4)
Address F5Fh F5Eh F5Dh F5Ch F5Bh F5Ah F59h F58h F57h F56h F55h F54h F53h F52h F51h F50h
Name LCDSE5 LCDSE4
(3) (3)
Address F4Fh F4Eh F4Dh F4Ch F4Bh F4Ah F49h F48h F47h F46h F45h F44h F43h F42h F41h F40h
Name --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2) --(2)
LCDSE3 LCDSE2 LCDSE1 LCDSE0 LCDCON LCDPS -- -- -- --
(2) (2)
F7Ch LCDDATA23
LCDDATA22(4) LCDDATA21 LCDDATA20 LCDDATA19 LCDDATA18
(4)
F6Ah LCDDATA10
LCDDATA9 LCDDATA8 LCDDATA7 LCDDATA6 LCDDATA5(4) LCDDATA4
(4)
F76h LCDDATA17 F74h F73h F72h F71h
F75h LCDDATA16(4) LCDDATA15 LCDDATA14 LCDDATA13 LCDDATA12
(4)
--(2)
(2) (2)
LCDDATA3 LCDDATA2 LCDDATA1 LCDDATA0
--(2) --(2) --
(2)
F70h LCDDATA11 Note 1: 2: 3: 4:
This is not a physical register. Unimplemented registers are read as `0'. This register is not available on 64-pin devices. This register is implemented but unused on 64-pin devices.
(c) 2007 Microchip Technology Inc.
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TABLE 5-2:
File Name TOSU TOSH TOSL STKPTR PCLATU PCLATH PCL TBLPTRU TBLPTRH TBLPTRL TABLAT PRODH PRODL INTCON INTCON2 INTCON3 INDF0 POSTINC0 POSTDEC0 PREINC0 PLUSW0 FSR0H FSR0L WREG INDF1 POSTINC1 POSTDEC1 PREINC1 PLUSW1 FSR1H FSR1L BSR INDF2 POSTINC2 POSTDEC2 PREINC2 PLUSW2 FSR2H FSR2L STATUS Legend: Note 1: 2: 3: 4: 5: 6:
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY
Bit 7 -- Bit 6 -- Bit 5 -- Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR ---0 0000 0000 0000 0000 0000 Return Stack Pointer Holding Register for PC<20:16> 00-0 0000 ---0 0000 0000 0000 0000 0000 bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 0000 0000 0000 0000 0000 0000 xxxx xxxx xxxx xxxx TMR0IE INTEDG1 INT3IE INT0IE INTEDG2 INT2IE RBIE INTEDG3 INT1IE TMR0IF TMR0IP INT3IF INT0IF INT3IP INT2IF RBIF RBIP INT1IF 0000 000x 1111 1111 1100 0000 N/A N/A N/A N/A N/A ---- xxxx xxxx xxxx xxxx xxxx N/A N/A N/A N/A N/A ---- xxxx xxxx xxxx Bank Select Register ---- 0000 N/A N/A N/A N/A N/A ---- xxxx xxxx xxxx OV Z DC C ---x xxxx Details on page: 59, 66 59, 66 59, 66 59, 67 59, 66 59, 66 59, 66 59, 88 59, 88 59, 88 59, 88 59, 91 59, 91 59, 95 59, 96 59, 97 59, 82 59, 83 59, 83 59, 83 59, 83 59, 82 59, 82 59 59, 82 59, 83 59, 83 59, 83 59, 83 60, 82 60, 82 60, 71 60, 82 60, 83 60, 83 60, 83 60, 83 60, 82 60, 82 60, 80
Top-of-Stack Upper Byte (TOS<20:16>)
Top-of-Stack High Byte (TOS<15:8>) Top-of-Stack Low Byte (TOS<7:0>) STKFUL -- STKUNF -- -- --
Holding Register for PC<15:8> PC Low Byte (PC<7:0>) -- -- Program Memory Table Pointer High Byte (TBLPTR<15:8>) Program Memory Table Pointer Low Byte (TBLPTR<7:0>) Program Memory Table Latch Product Register High Byte Product Register Low Byte GIE/GIEH RBPU INT2IP PEIE/GIEL INTEDG0 INT1IP
Uses contents of FSR0 to address data memory - value of FSR0 not changed (not a physical register) Uses contents of FSR0 to address data memory - value of FSR0 post-incremented (not a physical register) Uses contents of FSR0 to address data memory - value of FSR0 post-decremented (not a physical register) Uses contents of FSR0 to address data memory - value of FSR0 pre-incremented (not a physical register) Uses contents of FSR0 to address data memory - value of FSR0 pre-incremented (not a physical register), value of FSR0 offset by W -- Working Register Uses contents of FSR1 to address data memory - value of FSR1 not changed (not a physical register) Uses contents of FSR1 to address data memory - value of FSR1 post-incremented (not a physical register) Uses contents of FSR1 to address data memory - value of FSR1 post-decremented (not a physical register) Uses contents of FSR1 to address data memory - value of FSR1 pre-incremented (not a physical register) Uses contents of FSR1 to address data memory - value of FSR1 pre-incremented (not a physical register), value of FSR1 offset by W -- -- -- -- -- -- -- -- Indirect Data Memory Address Pointer 1 High Byte Indirect Data Memory Address Pointer 1 Low Byte Uses contents of FSR2 to address data memory - value of FSR2 not changed (not a physical register) Uses contents of FSR2 to address data memory - value of FSR2 post-incremented (not a physical register) Uses contents of FSR2 to address data memory - value of FSR2 post-decremented (not a physical register) Uses contents of FSR2 to address data memory - value of FSR2 pre-incremented (not a physical register) Uses contents of FSR2 to address data memory - value of FSR2 pre-incremented (not a physical register), value of FSR2 offset by W -- -- -- -- -- -- -- N Indirect Data Memory Address Pointer 2 High Byte Indirect Data Memory Address Pointer 2 Low Byte -- -- -- Indirect Data Memory Address Pointer 0 High Byte Indirect Data Memory Address Pointer 0 Low Byte
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as `0'. See Section 4.4 "Brown-out Reset (BOR)". These registers and/or bits are not implemented on 64-pin devices; read as `0'. The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as `0'. See Section 2.6.4 "PLL in INTOSC Modes". The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as `0'. This bit is read-only. RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as `0'. These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.
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TABLE 5-2:
File Name TMR0H TMR0L T0CON OSCCON HLVDCON WDTCON RCON TMR1H TMR1L T1CON TMR2 PR2 T2CON SSPBUF SSPADD SSPSTAT SSPCON1 SSPCON2 ADRESH ADRESL ADCON0 ADCON1 ADCON2 CCPR1H CCPR1L CCP1CON CCPR2H CCPR2L CCP2CON CVRCON CMCON TMR3H TMR3L T3CON Legend: Note 1: 2: 3: 4: 5: 6:
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY (CONTINUED)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR 0000 0000 xxxx xxxx T0CS IRCF1 IRVST --
(1)
Details on page: 60, 132 60, 132 60, 131 38, 60 60, 251 60, 288 52, 60, 107 60, 137 60, 137 60, 135 60, 141 60, 141 60, 141 60, 158, 166 60, 166 60, 158, 167 60, 159, 168 60, 169 61, 240 61, 240 61, 231 61, 232 61, 233 61, 152, 155 61, 152, 155 61, 147 61, 152, 155 61, 152, 155 61, 147 61, 247 61, 241 61, 145 61, 145 61, 143
Timer0 Register High Byte Timer0 Register Low Byte TMR0ON IDLEN VDIRMAG -- IPEN T08BIT IRCF2 -- -- SBOREN T0SE IRCF0 HLVDEN -- RI PSA OSTS HLVDL3 -- TO T0PS2 IOFS HLVDL2 -- PD T0PS1 SCS1 HLVDL1 -- POR T0PS0 SCS0 HLVDL0 SWDTEN BOR
1111 1111 0100 q000 0-00 0101 --- ---0 0q-1 11q0 xxxx xxxx xxxx xxxx
--
Timer1 Register High Byte Timer1 Register Low Byte RD16 Timer2 Register Timer2 Period Register -- T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 MSSP Receive Buffer/Transmit Register MSSP Address Register in I2CTM Slave Mode. MSSP Baud Rate Reload Register in I2C Master Mode. SMP WCOL GCEN CKE SSPOV ACKSTAT D/A SSPEN ACKDT P CKP ACKEN S SSPM3 RCEN R/W SSPM2 PEN UA SSPM1 RSEN BF SSPM0 SEN T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
0000 0000 0000 0000 1111 1111 -000 0000 xxxx xxxx 0000 0000 0000 0000 0000 0000 0000 0000 xxxx xxxx xxxx xxxx
A/D Result Register High Byte A/D Result Register Low Byte -- -- ADFM -- -- -- CHS3 VCFG1 ACQT2 CHS2 VCFG0 ACQT1 CHS1 PCFG3 ACQT0 CHS0 PCFG2 ADCS2 GO/DONE PCFG1 ADCS1 ADON PCFG0 ADCS0
--00 0000 --00 0000 0-00 0000 xxxx xxxx xxxx xxxx
Capture/Compare/PWM Register 1 High Byte Capture/Compare/PWM Register 1 Low Byte -- -- DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0
--00 0000 xxxx xxxx xxxx xxxx
Capture/Compare/PWM Register 2 High Byte Capture/Compare/PWM Register 2 Low Byte -- CVREN C2OUT -- CVROE C1OUT DC2B1 CVRR C2INV DC2B0 CVRSS C1INV CCP2M3 CVR3 CIS CCP2M2 CVR2 CM2 CCP2M1 CVR1 CM1 CCP2M0 CVR0 CM0
--00 0000 0000 0000 0000 0111 xxxx xxxx xxxx xxxx
Timer3 Register High Byte Timer3 Register Low Byte RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON
0000 0000
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as `0'. See Section 4.4 "Brown-out Reset (BOR)". These registers and/or bits are not implemented on 64-pin devices; read as `0'. The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as `0'. See Section 2.6.4 "PLL in INTOSC Modes". The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as `0'. This bit is read-only. RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as `0'. These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.
(c) 2007 Microchip Technology Inc.
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TABLE 5-2:
File Name SPBRG1 RCREG1 TXREG1 TXSTA1 RCSTA1 IPR3 PIR3 PIE3 IPR2 PIR2 PIE2 IPR1 PIR1 PIE1 OSCTUNE TRISJ(2) TRISH(2) TRISG TRISF TRISE TRISD TRISC TRISB TRISA LATJ(2) LATH(2) LATG LATF LATE LATD LATC LATB LATA PORTJ(2) PORTH(2) PORTG PORTF PORTE PORTD PORTC PORTB PORTA Legend: Note 1: 2: 3: 4: 5: 6:
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY (CONTINUED)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR 0000 0000 0000 0000 0000 0000 TXEN SREN RC2IP RC2IF RC2IE -- -- -- RC1IP RC1IF RC1IE -- SYNC CREN TX2IP TX2IF TX2IE -- -- -- TX1IP TX1IF TX1IE TUN4 SENDB ADDEN -- -- -- BCLIP BCLIF BCLIE SSPIP SSPIF SSPIE TUN3 BRGH FERR -- -- -- HLVDIP HLVDIF HLVDIE CCP1IP CCP1IF CCP1IE TUN2 TRMT OERR -- -- -- TMR3IP TMR3IF TMR3IE TMR2IP TMR2IF TMR2IE TUN1 TX9D RX9D -- -- -- CCP2IP CCP2IF CCP2IE TMR1IP TMR1IF TMR1IE TUN0 0000 0010 0000 000x -111 ----000 ----000 ---11-- 1111 00-- 0000 00-- 0000 -111 1111 -000 0000 -000 0000 00-0 0000 1111 1111 1111 1111 -- PORTG Data Direction Register -- -- -- -- ---1 1111 1111 1111 1111 ---1111 1111 1111 1111 1111 1111 1111 1111 xxxx xxxx xxxx xxxx -- LATG Data Output Register -- -- -- -- ---x xxxx xxxx xxxx xxxx ---xxxx xxxx xxxx xxxx xxxx xxxx LATA Data Output Register xxxx xxxx xxxx xxxx xxxx xxxx --xx xxxx xxxx xxxx -- -- -- -- xxxx ---xxxx xxxx xxxx xxxx xxxx xxxx xx0x 0000 Details on page: 61, 201 61, 208 61, 206 61, 198 61, 199 61, 106 61, 100 61, 103 61, 105 61, 99 61, 102 61, 104 61, 98 61, 101 35, 61 62, 130 62, 128 62, 126 62, 124 62, 121 62, 119 62, 117 62, 114 62, 111 62, 130 62, 128 62, 126 62, 124 62, 121 62, 119 62, 117 62, 114 62, 111 62, 130 62, 128 62, 126 62, 124 62, 121 62, 119 62, 117 62, 114 62, 111
EUSART1 Baud Rate Generator Register Low Byte EUSART1 Receive Register EUSART1 Transmit Register CSRC SPEN -- -- -- OSCFIP OSCFIF OSCFIE -- -- -- INTSRC TX9 RX9 LCDIP LCDIF LCDIE CMIP CMIF CMIE ADIP ADIF ADIE PLLEN(3)
PORTJ Data Direction Register PORTH Data Direction Register -- -- PORTF Data Direction Register PORTE Data Direction Register PORTD Data Direction Register PORTC Data Direction Register PORTB Data Direction Register TRISA7(5) TRISA6(5) PORTA Data Direction Register LATJ Data Output Register LATH Data Output Register -- -- LATF Data Output Register LATE Data Output Register LATD Data Output Register LATC Data Output Register LATB Data Output Register LATA7(5) LATA6(5) Read PORTJ pins, Write PORTJ Data Latch Read PORTH pins, Write PORTH Data Latch -- -- RG5(4) Read PORTG pins <4:0>, Write PORTG Data Latch <4:0> Read PORTF pins, Write PORTF Data Latch Read PORTE pins, Write PORTE Data Latch Read PORTD pins, Write PORTD Data Latch Read PORTC pins, Write PORTC Data Latch Read PORTB pins, Write PORTB Data Latch RA7(5) RA6(5) Read PORTA pins, Write PORTA Data Latch
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as `0'. See Section 4.4 "Brown-out Reset (BOR)". These registers and/or bits are not implemented on 64-pin devices; read as `0'. The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as `0'. See Section 2.6.4 "PLL in INTOSC Modes". The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as `0'. This bit is read-only. RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as `0'. These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.
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TABLE 5-2:
File Name SPBRGH1 BAUDCON1 LCDDATA23(6) LCDDATA22(6) LCDDATA21 LCDDATA20 LCDDATA19 LCDDATA18 LCDDATA17(6) LCDDATA16(6) LCDDATA15 LCDDATA14 LCDDATA13 LCDDATA12 LCDDATA11(6) SPBRG2 RCREG2 TXREG2 TXSTA2 RCSTA2 LCDDATA10(6) LCDDATA9 LCDDATA8 LCDDATA7 LCDDATA6 LCDDATA5(6) LCDDATA4(6) LCDDATA3 LCDDATA2 LCDDATA1 LCDDATA0 LCDSE5(2) LCDSE4(2) LCDSE3 LCDSE2 LCDSE1 LCDSE0 LCDCON LCDPS Legend: Note 1: 2: 3: 4: 5: 6:
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY (CONTINUED)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR 0000 0000 BRG16 S43C3 S35C3 S27C3 S19C3 S11C3 S03C3 S43C2 S35C2 S27C2 S19C2 S11C2 S03C2 S43C1 -- S42C3 S34C3 S26C3 S18C3 S10C3 S02C3 S42C2 S34C2 S26C2 S18C2 S10C2 S02C2 S42C1 WUE S41C3 S33C3 S25C3 S17C3 S09C3 S01C3 S41C2 S33C2 S25C2 S17C2 S09C2 S01C2 S41C1 ABDEN S40C3 S32C3 S24C3 S16C3 S08C3 S00C3 S40C2 S32C2 S24C2 S16C2 S08C2 S00C2 S40C1 01-0 0-00 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 0000 0000 0000 0000 0000 0000 TXEN SREN S37C1 S29C1 S21C1 S13C1 S05C1 S45C0 S37C0 S29C0 S21C0 S13C0 S05C0 SE45 SE37 SE29 SE21 SE13 SE5 WERR LCDA SYNC CREN S36C1 S28C1 S20C1 S12C1 S04C1 S44C0 S36C0 S28C0 S20C0 S12C0 S04C0 SE44 SE36 SE28 SE20 SE12 SE4 -- WA -- ADDEN S35C1 S27C1 S19C1 S11C1 S03C1 S43C0 S35C0 S27C0 S19C0 S11C0 S03C0 SE43 SE35 SE27 SE19 SE11 SE3 CS1 LP3 BRGH FERR S34C1 S26C1 S18C1 S10C1 S02C1 S42C0 S34C0 S26C0 S18C0 S10C0 S02C0 SE42 SE34 SE26 SE18 SE10 SE2 CS0 LP2 TRMT OERR S33C1 S25C1 S17C1 S09C1 S01C1 S41C0 S33C0 S25C0 S17C0 S09C0 S01C0 SE41 SE33 SE25 SE17 SE9 SE1 LMUX1 LP1 TX9D RX9D S32C1 S24C1 S16C1 S08C1 S00C1 S40C0 S32C0 S24C0 S16C0 S08C0 S00C0 SE40 SE32 SE24 SE16 SE8 SE0 LMUX0 LP0 0000 -010 0000 000x xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 000- 0000 0000 0000 Details on page: 62, 201 62, 200 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 220 63, 224 63, 222 63, 218 63, 219 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 63, 261 64, 261 64, 260 64, 260 64, 260 64, 260 64, 260 64, 258 64, 259
EUSART1 Baud Rate Generator Register High Byte ABDOVF S47C3 S39C3 S31C3 S23C3 S15C3 S07C3 S47C2 S39C2 S31C2 S23C2 S15C2 S07C2 S47C1 RCIDL S46C3 S38C3 S30C3 S22C3 S14C3 S06C3 S46C2 S38C2 S30C2 S22C2 S14C2 S06C2 S46C1 -- S45C3 S37C3 S29C3 S21C3 S13C3 S05C3 S45C2 S37C2 S29C2 S21C2 S13C2 S05C2 S45C1 SCKP S44C3 S36C3 S28C3 S20C3 S12C3 S04C3 S44C2 S36C2 S28C2 S20C2 S12C2 S04C2 S44C1
AUSART2 Baud Rate Generator Register AUSART2 Receive Register AUSART2 Transmit Register CSRC SPEN S39C1 S31C1 S23C1 S15C1 S07C1 S47C0 S39C0 S31C0 S23C0 S15C0 S07C0 SE47 SE39 SE31 SE23 SE15 SE7 LCDEN WFT TX9 RX9 S38C1 S30C1 S22C1 S14C1 S06C1 S46C0 S38C0 S30C0 S22C0 S14C0 S06C0 SE46 SE38 SE30 SE22 SE14 SE6 SLPEN BIASMD
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as `0'. See Section 4.4 "Brown-out Reset (BOR)". These registers and/or bits are not implemented on 64-pin devices; read as `0'. The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as `0'. See Section 2.6.4 "PLL in INTOSC Modes". The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as `0'. This bit is read-only. RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as `0'. These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.
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5.3.5 STATUS REGISTER
The STATUS register, shown in Register 5-2, contains the arithmetic status of the ALU. As with any other SFR, it can be the operand for any instruction. If the STATUS register is the destination for an instruction that affects the Z, DC, C, OV or N bits, the results of the instruction are not written; instead, the status is updated according to the instruction performed. Therefore, the result of an instruction with the STATUS register as its destination may be different than intended. As an example, CLRF STATUS will set the Z bit and leave the remaining Status bits unchanged (`000u u1uu'). It is recommended that only BCF, BSF, SWAPF, MOVFF and MOVWF instructions are used to alter the STATUS register, because these instructions do not affect the Z, C, DC, OV or N bits in the STATUS register. For other instructions that do not affect Status bits, see the instruction set summaries in Table 24-2 and Table 24-3. Note: The C and DC bits operate as a borrow and digit borrow bit respectively, in subtraction.
REGISTER 5-2:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7-5 bit 4
STATUS REGISTER
U-0 -- U-0 -- R/W-x N R/W-x OV R/W-x Z R/W-x DC(1) R/W-x C(2) bit 0
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
Unimplemented: Read as `0' N: Negative bit This bit is used for signed arithmetic (2's complement). It indicates whether the result was negative (ALU MSB = 1). 1 = Result was negative 0 = Result was positive OV: Overflow bit This bit is used for signed arithmetic (2's complement). It indicates an overflow of the 7-bit magnitude which causes the sign bit (bit 7) to change state. 1 = Overflow occurred for signed arithmetic (in this arithmetic operation) 0 = No overflow occurred Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The result of an arithmetic or logic operation is not zero DC: Digit carry/borrow bit(1) For ADDWF, ADDLW, SUBLW and SUBWF instructions: 1 = A carry-out from the 4th low-order bit of the result occurred 0 = No carry-out from the 4th low-order bit of the result C: Carry/borrow bit(2) For ADDWF, ADDLW, SUBLW and SUBWF instructions: 1 = A carry-out from the Most Significant bit of the result occurred 0 = No carry-out from the Most Significant bit of the result occurred For borrow, the polarity is reversed. A subtraction is executed by adding the 2's complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register. For borrow, the polarity is reversed. A subtraction is executed by adding the 2's complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the source register.
bit 3
bit 2
bit 1
bit 0
Note 1: 2:
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5.4
Note:
Data Addressing Modes
The execution of some instructions in the core PIC18 instruction set are changed when the PIC18 extended instruction set is enabled. See Section 5.6 "Data Memory and the Extended Instruction Set" for more information.
Purpose Register File"), or a location in the Access Bank (Section 5.3.2 "Access Bank") as the data source for the instruction. The Access RAM bit `a' determines how the address is interpreted. When `a' is `1', the contents of the BSR (Section 5.3.1 "Bank Select Register") are used with the address to determine the complete 12-bit address of the register. When `a' is `0', the address is interpreted as being a register in the Access Bank. Addressing that uses the Access RAM is sometimes also known as Direct Forced Addressing mode. A few instructions, such as MOVFF, include the entire 12-bit address (either source or destination) in their op codes. In those cases, the BSR is ignored entirely. The destination of the operation's results is determined by the destination bit `d'. When `d' is `1', the results are stored back in the source register, overwriting its original contents. When `d' is `0', the results are stored in the W register. Instructions without the `d' argument have a destination that is implicit in the instruction; their destination is either the target register being operated on, or the W register.
While the program memory can be addressed in only one way - through the program counter - information in the data memory space can be addressed in several ways. For most instructions, the addressing mode is fixed. Other instructions may use up to three modes, depending on which operands are used and whether or not the extended instruction set is enabled. The addressing modes are: * * * * Inherent Literal Direct Indirect
An additional addressing mode, Indexed Literal Offset, is available when the extended instruction set is enabled (XINST Configuration bit = 1). Its operation is discussed in greater detail in Section 5.6.1 "Indexed Addressing With Literal Offset".
5.4.3
INDIRECT ADDRESSING
5.4.1
INHERENT AND LITERAL ADDRESSING
Many PIC18 control instructions do not need any argument at all; they either perform an operation that globally affects the device, or they operate implicitly on one register. This addressing mode is known as Inherent Addressing. Examples include SLEEP, RESET and DAW. Other instructions work in a similar way but require an additional explicit argument in the opcode. This is known as Literal Addressing mode, because they require some literal value as an argument. Examples include ADDLW and MOVLW, which respectively add or move a literal value to the W register. Other examples include CALL and GOTO, which include a 20-bit program memory address.
Indirect Addressing allows the user to access a location in data memory without giving a fixed address in the instruction. This is done by using File Select Registers (FSRs) as pointers to the locations to be read or written to. Since the FSRs are themselves located in RAM as Special Function Registers, they can also be directly manipulated under program control. This makes FSRs very useful in implementing data structures, such as tables and arrays in data memory. The registers for Indirect Addressing are also implemented with Indirect File Operands (INDFs) that permit automatic manipulation of the pointer value with auto-incrementing, auto-decrementing or offsetting with another value. This allows for efficient code using loops, such as the example of clearing an entire RAM bank in Example 5-5. It also enables users to perform Indexed Addressing and other Stack Pointer operations for program memory in data memory.
5.4.2
DIRECT ADDRESSING
EXAMPLE 5-5:
Direct Addressing specifies all or part of the source and/or destination address of the operation within the opcode itself. The options are specified by the arguments accompanying the instruction. In the core PIC18 instruction set, bit-oriented and byte-oriented instructions use some version of Direct Addressing by default. All of these instructions include some 8-bit literal address as their Least Significant Byte. This address specifies either a register address in one of the banks of data RAM (Section 5.3.3 "General
HOW TO CLEAR RAM (BANK 1) USING INDIRECT ADDRESSING
FSR0, 100h ; POSTINC0 ; Clear INDF ; register then ; inc pointer FSR0H, 1 ; All done with ; Bank1? NEXT ; NO, clear next ; YES, continue
NEXT
LFSR CLRF
BTFSS BRA CONTINUE
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5.4.3.1 FSR Registers and the INDF Operand
At the core of Indirect Addressing are three sets of registers: FSR0, FSR1 and FSR2. Each represents a pair of 8-bit registers, FSRnH and FSRnL. The four upper bits of the FSRnH register are not used, so each FSR pair holds a 12-bit value. This represents a value that can address the entire range of the data memory in a linear fashion. The FSR register pairs, then, serve as pointers to data memory locations. Indirect Addressing is accomplished with a set of Indirect File Operands, INDF0 through INDF2. These can be thought of as "virtual" registers: they are mapped in the SFR space but are not physically implemented. Reading or writing to a particular INDF register actually accesses its corresponding FSR register pair. A read from INDF1, for example, reads the data at the address indicated by FSR1H:FSR1L. Instructions that use the INDF registers as operands actually use the contents of their corresponding FSR as a pointer to the instruction's target. The INDF operand is just a convenient way of using the pointer. Because Indirect Addressing uses a full 12-bit address, data RAM banking is not necessary. Thus, the current contents of the BSR and the Access RAM bit have no effect on determining the target address.
FIGURE 5-7:
INDIRECT ADDRESSING
000h ADDWF, INDF1, 1 Bank 0 100h 200h Bank 1 Bank 2
Using an instruction with one of the Indirect Addressing registers as the operand....
...uses the 12-bit address stored in the FSR pair associated with that register....
FSR1H:FSR1L 7 0 7 0
300h
xxxx1111
11001100
Bank 3 through Bank 13
...to determine the data memory location to be used in that operation. In this case, the FSR1 pair contains FCCh. This means the contents of location FCCh will be added to that of the W register and stored back in FCCh. E00h Bank 14 F00h FFFh Bank 15
Data Memory
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5.4.3.2 FSR Registers and POSTINC, POSTDEC, PREINC and PLUSW 5.4.3.3 Operations by FSRs on FSRs
In addition to the INDF operand, each FSR register pair also has four additional indirect operands. Like INDF, these are "virtual" registers that cannot be indirectly read or written to. Accessing these registers actually accesses the associated FSR register pair, but also performs a specific action on its stored value. They are: * POSTDEC: accesses the FSR value, then automatically decrements it by `1' afterwards * POSTINC: accesses the FSR value, then automatically increments it by `1' afterwards * PREINC: increments the FSR value by `1', then uses it in the operation * PLUSW: adds the signed value of the W register (range of -127 to 128) to that of the FSR and uses the new value in the operation. In this context, accessing an INDF register uses the value in the FSR registers without changing them. Similarly, accessing a PLUSW register gives the FSR value offset by the value in the W register; neither value is actually changed in the operation. Accessing the other virtual registers changes the value of the FSR registers. Operations on the FSRs with POSTDEC, POSTINC and PREINC affect the entire register pair; that is, rollovers of the FSRnL register from FFh to 00h carry over to the FSRnH register. On the other hand, results of these operations do not change the value of any flags in the STATUS register (e.g., Z, N, OV, etc.). The PLUSW register can be used to implement a form of Indexed Addressing in the data memory space. By manipulating the value in the W register, users can reach addresses that are fixed offsets from pointer addresses. In some applications, this can be used to implement some powerful program control structure, such as software stacks, inside of data memory. Indirect Addressing operations that target other FSRs or virtual registers represent special cases. For example, using an FSR to point to one of the virtual registers will not result in successful operations. As a specific case, assume that FSR0H:FSR0L contains FE7h, the address of INDF1. Attempts to read the value of the INDF1, using INDF0 as an operand, will return 00h. Attempts to write to INDF1, using INDF0 as the operand, will result in a NOP. On the other hand, using the virtual registers to write to an FSR pair may not occur as planned. In these cases, the value will be written to the FSR pair, but without any incrementing or decrementing. Thus, writing to INDF2 or POSTDEC2 will write the same value to the FSR2H:FSR2L. Since the FSRs are physical registers mapped in the SFR space, they can be manipulated through all direct operations. Users should proceed cautiously when working on these registers, particularly if their code uses Indirect Addressing. Similarly, operations by Indirect Addressing are generally permitted on all other SFRs. Users should exercise the appropriate caution that they do not inadvertently change settings that might affect the operation of the device.
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5.5 Program Memory and the Extended Instruction Set
When using the extended instruction set, this addressing mode requires the following: * The use of the Access Bank is forced (`a' = 0); and * The file address argument is less than or equal to 5Fh. Under these conditions, the file address of the instruction is not interpreted as the lower byte of an address (used with the BSR in Direct Addressing), or as an 8-bit address in the Access Bank. Instead, the value is interpreted as an offset value to an Address Pointer specified by FSR2. The offset and the contents of FSR2 are added to obtain the target address of the operation.
The operation of program memory is unaffected by the use of the extended instruction set. Enabling the extended instruction set adds five additional two-word commands to the existing PIC18 instruction set: ADDFSR, CALLW, MOVSF, MOVSS and SUBFSR. These instructions are executed as described in Section 5.2.4 "Two-Word Instructions".
5.6
Data Memory and the Extended Instruction Set
Enabling the PIC18 extended instruction set (XINST Configuration bit = 1) significantly changes certain aspects of data memory and its addressing. Specifically, the use of the Access Bank for many of the core PIC18 instructions is different; this is due to the introduction of a new addressing mode for the data memory space. This mode also alters the behavior of Indirect Addressing using FSR2 and its associated operands. What does not change is just as important. The size of the data memory space is unchanged, as well as its linear addressing. The SFR map remains the same. Core PIC18 instructions can still operate in both Direct and Indirect Addressing mode; inherent and literal instructions do not change at all. Indirect Addressing with FSR0 and FSR1 also remains unchanged.
5.6.2
INSTRUCTIONS AFFECTED BY INDEXED LITERAL OFFSET MODE
Any of the core PIC18 instructions that can use Direct Addressing are potentially affected by the Indexed Literal Offset Addressing mode. This includes all byte-oriented and bit-oriented instructions, or almost one-half of the standard PIC18 instruction set. Instructions that only use Inherent or Literal Addressing modes are unaffected. Additionally, byte-oriented and bit-oriented instructions are not affected if they use the Access Bank (Access RAM bit is `1'), or include a file address of 60h or above. Instructions meeting these criteria will continue to execute as before. A comparison of the different possible addressing modes when the extended instruction set is enabled is shown in Figure 5-8. Those who desire to use byte-oriented or bit-oriented instructions in the Indexed Literal Offset mode should note the changes to assembler syntax for this mode. This is described in more detail in Section 24.2.1 "Extended Instruction Syntax".
5.6.1
INDEXED ADDRESSING WITH LITERAL OFFSET
Enabling the PIC18 extended instruction set changes the behavior of Indirect Addressing using the FSR2 register pair and its associated file operands. Under the proper conditions, instructions that use the Access Bank - that is, most bit-oriented and byte-oriented instructions - can invoke a form of Indexed Addressing using an offset specified in the instruction. This special addressing mode is known as Indexed Addressing with Literal Offset, or Indexed Literal Offset mode.
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FIGURE 5-8: COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND BYTE-ORIENTED INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED)
EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff)
When a = 0 and f 60h: The instruction executes in Direct Forced mode. `f' is interpreted as a location in the Access RAM between 060h and FFFh. This is the same as locations F60h to FFFh (Bank 15) of data memory. Locations below 060h are not available in this addressing mode.
000h 060h Bank 0 100h Bank 1 through Bank 14 00h 60h Valid range for `f' Access RAM Bank 15 F40h SFRs FFFh Data Memory FFh
F00h
When a = 0 and f 5Fh: The instruction executes in Indexed Literal Offset mode. `f' is interpreted as an offset to the address value in FSR2. The two are added together to obtain the address of the target register for the instruction. The address can be anywhere in the data memory space. Note that in this mode, the correct syntax is now: ADDWF [k], d where `k' is the same as `f'.
000h Bank 0 060h 100h Bank 1 through Bank 14 FSR2H F00h Bank 15 F40h SFRs FFFh Data Memory FSR2L 001001da ffffffff
When a = 1 (all values of f): The instruction executes in Direct mode (also known as Direct Long mode). `f' is interpreted as a location in one of the 16 banks of the data memory space. The bank is designated by the Bank Select Register (BSR). The address can be in any implemented bank in the data memory space.
000h Bank 0 060h 100h Bank 1 through Bank 14
BSR 00000000
001001da ffffffff
F00h Bank 15 F40h SFRs FFFh Data Memory
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5.6.3 MAPPING THE ACCESS BANK IN INDEXED LITERAL OFFSET MODE
The use of Indexed Literal Offset Addressing mode effectively changes how the lower part of Access RAM (00h to 5Fh) is mapped. Rather than containing just the contents of the bottom part of Bank 0, this mode maps the contents from Bank 0 and a user-defined "window" that can be located anywhere in the data memory space. The value of FSR2 establishes the lower boundary of the addresses mapped into the window, while the upper boundary is defined by FSR2 plus 95 (5Fh). Addresses in the Access RAM above 5Fh are mapped as previously described (see Section 5.3.2 "Access Bank"). An example of Access Bank remapping in this addressing mode is shown in Figure 5-9. Remapping of the Access Bank applies only to operations using the Indexed Literal Offset mode. Operations that use the BSR (Access RAM bit is `1') will continue to use Direct Addressing as before. Any indirect or indexed operation that explicitly uses any of the indirect file operands (including FSR2) will continue to operate as standard Indirect Addressing. Any instruction that uses the Access Bank, but includes a register address of greater than 05Fh, will use Direct Addressing and the normal Access Bank map.
5.6.4
BSR IN INDEXED LITERAL OFFSET MODE
Although the Access Bank is remapped when the extended instruction set is enabled, the operation of the BSR remains unchanged. Direct Addressing, using the BSR to select the data memory bank, operates in the same manner as previously described.
FIGURE 5-9:
Example Situation:
REMAPPING THE ACCESS BANK WITH INDEXED LITERAL OFFSET ADDRESSING
000h 05Fh Not Accessible Bank 0 100h 120h 17Fh 200h Window Bank 1 Bank 1 "Window" 5Fh 60h Bank 2 through Bank 14
ADDWF f, d, a
FSR2H:FSR2L = 120h Locations in the region from the FSR2 Pointer (120h) to the pointer plus 05Fh (17Fh) are mapped to the bottom of the Access RAM (000h-05Fh). Special File Registers at F60h through FFFh are mapped to 60h through FFh, as usual. Bank 0 addresses below 5Fh are not available in this mode. They can still be addressed by using the BSR.
00h
SFRs FFh
Access Bank
F00h Bank 15 F60h FFFh SFRs
Data Memory
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6.0 FLASH PROGRAM MEMORY
In PIC18F6390/6490/8390/8490 devices, the program memory is implemented as read-only Flash memory. It is readable over the entire VDD range during normal operation. A read from program memory is executed on one byte at a time. Table reads work with byte entities. A table block containing data, rather than program instructions, is not required to be word-aligned. Therefore, a table block can start and end at any byte address. Because the program memory cannot be written to or erased under normal operation, the TBLWT operation is not discussed here. Note 1: Although it cannot be used in PIC18F6390/6490/8390/8490 devices in normal operation, the TBLWT instruction is still implemented in the instruction set. Executing the instruction takes two instruction cycles, but effectively results in a NOP. 2: The TBLWT instruction is available only in programming modes and is used during In-Circuit Serial ProgrammingTM (ICSPTM).
6.1
Table Reads
For PIC18 devices, there are two operations that allow the processor to move bytes between the program memory space and the data RAM: table read (TBLRD) and table write (TBLWT). Table read operations retrieve data from program memory and place it into the data RAM space. Figure 6-1 shows the operation of a table read with program memory and data RAM. The program memory space is 16 bits wide, while the data RAM space is 8 bits wide. Table reads and table writes move data between these two memory spaces through an 8-bit register, TABLAT.
FIGURE 6-1:
TABLE READ OPERATION
Instruction: TBLRD*
Table Pointer(1) TBLPTRU TBLPTRH TBLPTRL
Program Memory Table Latch (8-bit) TABLAT
Program Memory (TBLPTR)
Note 1: Table Pointer register points to a byte in program memory.
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6.2 Control Registers
TABLE 6-1:
Two control registers are used in conjunction with the TBLRD instruction: the TABLAT register and the TBLPTR register set.
TABLE POINTER OPERATIONS WITH TBLRD INSTRUCTIONS
Operation on Table Pointer TBLPTR is not modified TBLPTR is incremented after the read TBLPTR is decremented after the read TBLPTR is incremented before the read
Example TBLRD* TBLRD*+ TBLRD*TBLRD+*
6.2.1
TABLE LATCH REGISTER (TABLAT)
The Table Latch (TABLAT) is an 8-bit register mapped into the SFR space. The Table Latch register is used to hold 8-bit data during data transfers between program memory and data RAM.
6.2.2
TABLE POINTER REGISTER (TBLPTR)
6.3
Reading the Flash Program Memory
The Table Pointer register (TBLPTR) addresses a byte within the program memory. It is comprised of three SFR registers: Table Pointer Upper Byte, Table Pointer High Byte and Table Pointer Low Byte (TBLPTRU:TBLPTRH:TBLPTRL). Only the lower six bits of TBLPTRU are used with TBLPTRH and TBLPTRL to form a 22-bit wide pointer. The contents of TBLPTR indicates a location in program memory space. The low-order 21 bits allow the device to address the full 2 Mbytes of program memory space. The 22nd bit allows access to the configuration space, including the device ID, user ID locations and the Configuration bits. The TBLPTR register set is updated when executing a TBLRD in one of four ways, based on the instruction's arguments. These are detailed in Table 6-1. These operations on the TBLPTR only affect the low-order 21 bits. When a TBLRD is executed, all 22 bits of the TBLPTR determine which byte is read from program memory into TABLAT.
The TBLRD instruction is used to retrieve data from program memory and places it into data RAM. Table reads from program memory are performed one byte at a time. TBLPTR points to a byte address in program space. Executing TBLRD places the byte pointed to into TABLAT. In addition, TBLPTR can be modified automatically for the next table read operation. The internal program memory is typically organized by words. The Least Significant bit of the address selects between the high and low bytes of the word. Figure 6-2 shows the interface between the internal program memory and the TABLAT. A typical method for reading data from program memory is shown in Example 6-1.
FIGURE 6-2:
READS FROM FLASH PROGRAM MEMORY
Program Memory
(Even Byte Address) (Odd Byte Address)
TBLPTR = xxxxx1 Instruction Register (IR) FETCH TBLRD
TBLPTR = xxxxx0 TABLAT Read Register
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EXAMPLE 6-1:
MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF READ_WORD TBLRD*+ MOVF MOVWF TBLRD*+ MOVF MOVWF TABLAT, W WORD_EVEN TABLAT, W WORD_ODD ; read into TABLAT and increment ; get data ; read into TABLAT and increment ; get data
READING A FLASH PROGRAM MEMORY WORD
CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; Load TBLPTR with the base ; address of the word
TABLE 6-2:
Name TBLPTRU TBLPTRH TBLPTRL TABLAT
REGISTERS ASSOCIATED WITH READING PROGRAM FLASH MEMORY
Bit 7 -- Bit 6 -- Bit 5 bit 21 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page 59 59 59 59
Program Memory Table Pointer Upper Byte (TBLPTR<20:16>)
Program Memory Table Pointer High Byte (TBLPTR<15:8>) Program Memory Table Pointer Low Byte (TBLPTR<7:0>) Program Memory Table Latch
Legend: -- = unimplemented, read as `0'. Shaded cells are not used during Flash access.
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NOTES:
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7.0
7.1
8 x 8 HARDWARE MULTIPLIER
Introduction
EXAMPLE 7-1:
MOVF MULWF ARG1, W ARG2
8 x 8 UNSIGNED MULTIPLY ROUTINE
; ; ARG1 * ARG2 -> ; PRODH:PRODL
All PIC18 devices include an 8 x 8 hardware multiplier as part of the ALU. The multiplier performs an unsigned operation and yields a 16-bit result that is stored in the product register pair PRODH:PRODL. The multiplier's operation does not affect any flags in the STATUS register. Making multiplication a hardware operation allows it to be completed in a single instruction cycle. This has the advantages of higher computational throughput and reduced code size for multiplication algorithms and allows the PIC18 devices to be used in many applications previously reserved for digital signal processors. A comparison of various hardware and software multiply operations, along with the savings in memory and execution time, is shown in Table 7-1.
EXAMPLE 7-2:
MOVF MULWF BTFSC SUBWF MOVF BTFSC SUBWF ARG1, W ARG2 ARG2, SB PRODH, F ARG2, W ARG1, SB PRODH, F
8 x 8 SIGNED MULTIPLY ROUTINE
; ; ; ; ; ARG1 * ARG2 -> PRODH:PRODL Test Sign Bit PRODH = PRODH - ARG1
; Test Sign Bit ; PRODH = PRODH ; - ARG2
7.2
Operation
Example 7-1 shows the instruction sequence for an 8 x 8 unsigned multiplication. Only one instruction is required when one of the arguments is already loaded in the WREG register. Example 7-2 shows the sequence to do an 8 x 8 signed multiplication. To account for the signed bits of the arguments, each argument's Most Significant bit (MSb) is tested and the appropriate subtractions are done.
TABLE 7-1:
Routine
PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS
Multiply Method Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Program Memory (Words) 13 1 33 6 21 28 52 35 Cycles (Max) 69 1 91 6 242 28 254 40 Time @ 40 MHz 6.9 s 100 ns 9.1 s 600 ns 24.2 s 2.8 s 25.4 s 4.0 s @ 10 MHz 27.6 s 400 ns 36.4 s 2.4 s 96.8 s 11.2 s 102.6 s 16.0 s @ 4 MHz 69 s 1 s 91 s 6 s 242 s 28 s 254 s 40 s
8 x 8 unsigned 8 x 8 signed 16 x 16 unsigned 16 x 16 signed
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Example 7-3 shows the sequence to do a 16 x 16 unsigned multiplication. Equation 7-1 shows the algorithm that is used. The 32-bit result is stored in four registers (RES3:RES0).
EQUATION 7-2:
16 x 16 SIGNED MULTIPLICATION ALGORITHM
EQUATION 7-1:
16 x 16 UNSIGNED MULTIPLICATION ALGORITHM
ARG1H:ARG1L * ARG2H:ARG2L (ARG1H * ARG2H * 216) + (ARG1H * ARG2L * 28) + (ARG1L * ARG2H * 28) + (ARG1L * ARG2L)
RES3:RES0
= =
RES3:RES0= ARG1H:ARG1L * ARG2H:ARG2L = (ARG1H * ARG2H * 216) + (ARG1H * ARG2L * 28) + (ARG1L * ARG2H * 28) + (ARG1L * ARG2L) + (-1 * ARG2H<7> * ARG1H:ARG1L * 216) + (-1 * ARG1H<7> * ARG2H:ARG2L * 216)
EXAMPLE 7-4:
MOVF MULWF MOVFF MOVFF ; MOVF MULWF MOVFF MOVFF
16 x 16 SIGNED MULTIPLY ROUTINE
; ARG1L * ARG2L -> ; PRODH:PRODL ; ;
EXAMPLE 7-3:
MOVF MULWF MOVFF MOVFF ; MOVF MULWF MOVFF MOVFF ; MOVF MULWF MOVF ADDWF MOVF ADDWFC CLRF ADDWFC ; MOVF MULWF MOVF ADDWF MOVF ADDWFC CLRF ADDWFC
16 x 16 UNSIGNED MULTIPLY ROUTINE
; ARG1L * ARG2L-> ; PRODH:PRODL ; ;
ARG1L, W ARG2L PRODH, RES1 PRODL, RES0 ARG1H, W ARG2H PRODH, RES3 PRODL, RES2 ARG1L, W ARG2H PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F ARG1H, W ARG2L PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F ARG2H, 7 SIGN_ARG1 ARG1L, W RES2 ARG1H, W RES3
ARG1L, W ARG2L PRODH, RES1 PRODL, RES0 ARG1H, W ARG2H PRODH, RES3 PRODL, RES2 ARG1L, W ARG2H PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F ARG1H, W ARG2L PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F
; ARG1H * ARG2H -> ; PRODH:PRODL ; ;
; ARG1H * ARG2H-> ; PRODH:PRODL ; ;
; MOVF MULWF MOVF ADDWF MOVF ADDWFC CLRF ADDWFC ; MOVF MULWF MOVF ADDWF MOVF ADDWFC CLRF ADDWFC ; BTFSS BRA MOVF SUBWF MOVF SUBWFB ; SIGN_ARG1 BTFSS BRA MOVF SUBWF MOVF SUBWFB ; CONT_CODE : ; ARG2H:ARG2L neg? ; no, check ARG1 ; ; ; ; ; ; ; ; ; ; ; ; ARG1H * ARG2L -> PRODH:PRODL Add cross products ; ; ; ; ; ; ; ; ARG1L * ARG2H -> PRODH:PRODL Add cross products
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
ARG1L * ARG2H-> PRODH:PRODL Add cross products
ARG1H * ARG2L-> PRODH:PRODL Add cross products
Example 7-4 shows the sequence to do a 16 x 16 signed multiply. Equation 7-2 shows the algorithm used. The 32-bit result is stored in four registers (RES3:RES0). To account for the signed bits of the arguments, the MSb for each argument pair is tested and the appropriate subtractions are done.
ARG1H, 7 CONT_CODE ARG2L, W RES2 ARG2H, W RES3
; ARG1H:ARG1L neg? ; no, done ; ; ;
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8.0 INTERRUPTS
The PIC18F6390/6490/8390/8490 devices have multiple interrupt sources and an interrupt priority feature that allows most interrupt sources to be assigned a high-priority level or a low-priority level. The highpriority interrupt vector is at 0008h and the low-priority interrupt vector is at 0018h. High-priority interrupt events will interrupt any low-priority interrupts that may be in progress. There are thirteen registers which are used to control interrupt operation. These registers are: * * * * * * * RCON INTCON INTCON2 INTCON3 PIR1, PIR2, PIR3 PIE1, PIE2, PIE3 IPR1, IPR2, IPR3 When the IPEN bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with PIC(R) mid-range devices. In Compatibility mode, the interrupt priority bits for each source have no effect. INTCON<6> is the PEIE bit, which enables/disables all peripheral interrupt sources. INTCON<7> is the GIE bit, which enables/disables all interrupt sources. All interrupts branch to address 0008h in Compatibility mode. When an interrupt is responded to, the global interrupt enable bit is cleared to disable further interrupts. If the IPEN bit is cleared, this is the GIE bit. If interrupt priority levels are used, this will be either the GIEH or GIEL bit. High-priority interrupt sources can interrupt a lowpriority interrupt. Low-priority interrupts are not processed while high-priority interrupts are in progress. The return address is pushed onto the stack and the PC is loaded with the interrupt vector address (0008h or 0018h). Once in the Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt flag bits must be cleared in software before re-enabling interrupts to avoid recursive interrupts. The "return from interrupt" instruction, RETFIE, exits the interrupt routine and sets the GIE bit (GIEH or GIEL if priority levels are used), which re-enables interrupts. For external interrupt events, such as the INTx pins or the PORTB input change interrupt, the interrupt latency will be three to four instruction cycles. The exact latency is the same for one or two-cycle instructions. Individual interrupt flag bits are set, regardless of the status of their corresponding enable bit or the GIE bit. Note: Do not use the MOVFF instruction to modify any of the interrupt control registers while any interrupt is enabled. Doing so may cause erratic microcontroller behavior.
It is recommended that the Microchip header files supplied with MPLAB(R) IDE be used for the symbolic bit names in these registers. This allows the assembler/ compiler to automatically take care of the placement of these bits within the specified register. In general, interrupt sources have three bits to control their operation. They are: * Flag bit to indicate that an interrupt event occurred * Enable bit that allows program execution to branch to the interrupt vector address when the flag bit is set * Priority bit to select high priority or low priority The interrupt priority feature is enabled by setting the IPEN bit (RCON<7>). When interrupt priority is enabled, there are two bits which enable interrupts globally. Setting the GIEH bit (INTCON<7>) enables all interrupts that have the priority bit set (high priority). Setting the GIEL bit (INTCON<6>) enables all interrupts that have the priority bit cleared (low priority). When the interrupt flag, enable bit and appropriate global interrupt enable bit are set, the interrupt will vector immediately to address 0008h or 0018h, depending on the priority bit setting. Individual interrupts can be disabled through their corresponding enable bits.
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FIGURE 8-1: PIC18F6X90/8X90 INTERRUPT LOGIC
TMR0IF TMR0IE TMR0IP RBIF RBIE RBIP INT0IF INT0IE INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP INT3IF INT3IE INT3IP Wake-up if in Idle or Sleep modes
PIR1<6:0> PIE1<6:0> IPR1<6:0> PIR2<7:6, 3:0> PIE2<7:6, 3:0> IPR2<7:6, 3:0> PIR3<6:4> PIE3<6:4> IPR3<6:4>
Interrupt to CPU Vector to Location 0008h
GIE/GIEH
IPEN IPEN PEIE/GIEL IPEN
High-Priority Interrupt Generation Low-Priority Interrupt Generation
PIR1<6:0> PIE1<6:0> IPR1<6:0> PIR2<7:6, 3:0> PIE2<7:6, 3:0> IPR2<7:6, 3:0> PIR3<6:4> PIE3<6:4> IPR3<6:4>
TMR0IF TMR0IE TMR0IP RBIF RBIE RBIP INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP INT3IF INT3IE INT3IP
IPEN
Interrupt to CPU Vector to Location 0018h
GIEH/GIE GIEL/PEIE
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8.1 INTCON Registers
Note: The INTCON registers are readable and writable registers which contain various enable, priority and flag bits. Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.
REGISTER 8-1:
R/W-0 GIE/GIEH bit 7 Legend: R = Readable bit -n = Value at POR bit 7
INTCON: INTERRUPT CONTROL REGISTER
R/W-0 R/W-0 TMR0IE R/W-0 INT0IE R/W-0 RBIE R/W-0 TMR0IF R/W-0 INT0IF R/W-x RBIF(1) bit 0
PEIE/GIEL
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
GIE/GIEH: Global Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked interrupts 0 = Disables all interrupts When IPEN = 1: 1 = Enables all high-priority interrupts 0 = Disables all interrupts PEIE/GIEL: Peripheral Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked peripheral interrupts 0 = Disables all peripheral interrupts When IPEN = 1: 1 = Enables all low-priority peripheral interrupts 0 = Disables all low-priority peripheral interrupts TMR0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 overflow interrupt 0 = Disables the TMR0 overflow interrupt INT0IE: INT0 External Interrupt Enable bit 1 = Enables the INT0 external interrupt 0 = Disables the INT0 external interrupt RBIE: RB Port Change Interrupt Enable bit 1 = Enables the RB port change interrupt 0 = Disables the RB port change interrupt TMR0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared in software) 0 = TMR0 register did not overflow INT0IF: INT0 External Interrupt Flag bit 1 = The INT0 external interrupt occurred (must be cleared in software) 0 = The INT0 external interrupt did not occur RBIF: RB Port Change Interrupt Flag bit(1) 1 = At least one of the RB7:RB4 pins changed state (must be cleared in software) 0 = None of the RB7:RB4 pins have changed state A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and allow the bit to be cleared.
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note 1:
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REGISTER 8-2:
R/W-1 RBPU bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
INTCON2: INTERRUPT CONTROL REGISTER 2
R/W-1 R/W-1 INTEDG1 R/W-1 INTEDG2 R/W-1 INTEDG3 R/W-1 TMR0IP R/W-1 INT3IP R/W-1 RBIP bit 0
INTEDG0
RBPU: PORTB Pull-up Enable bit 1 = All PORTB pull-ups are disabled 0 = PORTB pull-ups are enabled by individual port latch values INTEDG0: External Interrupt 0 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge INTEDG1: External Interrupt 1 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge INTEDG2: External Interrupt 2 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge INTEDG3: External Interrupt 3 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge TMR0IP: TMR0 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority INT3IP: INT3 External Interrupt Priority bit 1 = High priority 0 = Low priority RBIP: RB Port Change Interrupt Priority bit 1 = High priority 0 = Low priority Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note:
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REGISTER 8-3:
R/W-1 INT2IP bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
INTCON3: INTERRUPT CONTROL REGISTER 3
R/W-1 INT1IP R/W-0 INT3IE R/W-0 INT2IE R/W-0 INT1IE R/W-0 INT3IF R/W-0 INT2IF R/W-0 INT1IF bit 0
INT2IP: INT2 External Interrupt Priority bit 1 = High priority 0 = Low priority INT1IP: INT1 External Interrupt Priority bit 1 = High priority 0 = Low priority INT3IE: INT3 External Interrupt Enable bit 1 = Enables the INT3 external interrupt 0 = Disables the INT3 external interrupt INT2IE: INT2 External Interrupt Enable bit 1 = Enables the INT2 external interrupt 0 = Disables the INT2 external interrupt INT1IE: INT1 External Interrupt Enable bit 1 = Enables the INT1 external interrupt 0 = Disables the INT1 external interrupt INT3IF: INT3 External Interrupt Flag bit 1 = The INT3 external interrupt occurred (must be cleared in software) 0 = The INT3 external interrupt did not occur INT2IF: INT2 External Interrupt Flag bit 1 = The INT2 external interrupt occurred (must be cleared in software) 0 = The INT2 external interrupt did not occur INT1IF: INT1 External Interrupt Flag bit 1 = The INT1 external interrupt occurred (must be cleared in software) 0 = The INT1 external interrupt did not occur Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note:
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8.2 PIR Registers
The PIR registers contain the individual flag bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are three Peripheral Interrupt Request (Flag) registers (PIR1, PIR2, PIR3). Note 1: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global interrupt enable bit, GIE (INTCON<7>). 2: User software should ensure the appropriate interrupt flag bits are cleared prior to enabling an interrupt and after servicing that interrupt.
REGISTER 8-4:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7 bit 6
PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1
R/W-0 ADIF R-0 RC1IF R-0 TX1IF R/W-0 SSPIF R/W-0 CCP1IF R/W-0 TMR2IF R/W-0 TMR1IF bit 0
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
Unimplemented: Read as `0' ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed (must be cleared in software) 0 = The A/D conversion is not complete RC1IF: EUSART Receive Interrupt Flag bit 1 = The EUSART receive buffer, RCREG1, is full (cleared when RCREG1 is read) 0 = The EUSART receive buffer is empty TX1IF: EUSART Transmit Interrupt Flag bit 1 = The EUSART transmit buffer, TXREG1, is empty (cleared when TXREG1 is written) 0 = The EUSART transmit buffer is full SSPIF: Master Synchronous Serial Port Interrupt Flag bit 1 = The transmission/reception is complete (must be cleared in software) 0 = Waiting to transmit/receive CCP1IF: CCP1 Interrupt Flag bit Capture mode: 1 = A TMR1/TMR3 register capture occurred (must be cleared in software) 0 = No TMR1/TMR3 register capture occurred Compare mode: 1 = A TMR1/TMR3 register compare match occurred (must be cleared in software) 0 = No TMR1/TMR3 register compare match occurred PWM mode: Unused in this mode. TMR2IF: TMR2 to PR2 Match Interrupt Flag bit 1 = TMR2 to PR2 match occurred (must be cleared in software) 0 = No TMR2 to PR2 match occurred TMR1IF: TMR1 Overflow Interrupt Flag bit 1 = TMR1 register overflowed (must be cleared in software) 0 = TMR1 register did not overflow
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
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REGISTER 8-5:
R/W-0 OSCFIF bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2
R/W-0 CMIF U-0 -- U-0 -- R/W-0 BCLIF R/W-0 HLVDIF R/W-0 TMR3IF R/W-0 CCP2IF bit 0
OSCFIF: Oscillator Fail Interrupt Flag bit 1 = Device oscillator failed, clock input has changed to INTOSC (must be cleared in software) 0 = Device clock operating CMIF: Comparator Interrupt Flag bit 1 = Comparator input has changed (must be cleared in software) 0 = Comparator input has not changed Unimplemented: Read as `0' BCLIF: Bus Collision Interrupt Flag bit 1 = A bus collision occurred (must be cleared in software) 0 = No bus collision occurred HLVDIF: High/Low-Voltage Detect Interrupt Flag bit 1 = A low-voltage condition occurred (must be cleared in software) 0 = The device voltage is above the Low-Voltage Detect trip point TMR3IF: TMR3 Overflow Interrupt Flag bit 1 = TMR3 register overflowed (must be cleared in software) 0 = TMR3 register did not overflow CCP2IF: CCP2 Interrupt Flag bit Capture mode: 1 = A TMR1/TMR3 register capture occurred (must be cleared in software) 0 = No TMR1/TMR3 register capture occurred Compare mode: 1 = A TMR1/TMR3 register compare match occurred (must be cleared in software) 0 = No TMR1/TMR3 register compare match occurred PWM mode: Unused in this mode.
bit 6
bit 5-4 bit 3
bit 2
bit 1
bit 0
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REGISTER 8-6:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7 bit 6 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
PIR3: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 3
R/W-0 LCDIF R-0 RC2IF R/W-0 TX2IF U-0 -- U-0 -- U-0 -- U-0 -- bit 0
Unimplemented: Read as `0' LCDIF: LCD Interrupt Flag bit (valid when Type-B waveform with Non-Static mode is selected) 1 = LCD data of all COMs is output (must be cleared in software) 0 = LCD data of all COMs is not yet output RC2IF: AUSART Receive Interrupt Flag bit 1 = The AUSART receive buffer, RCREG2, is full (cleared when RCREG2 is read) 0 = The AUSART receive buffer is empty TX2IF: AUSART Transmit Interrupt Flag bit 1 = The AUSART transmit buffer, TXREG2, is empty (cleared when TXREG2 is written) 0 = The AUSART transmit buffer is full Unimplemented: Read as `0'
bit 5
bit 4
bit 3-0
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8.3 PIE Registers
The PIE registers contain the individual enable bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are three Peripheral Interrupt Enable registers (PIE1, PIE2, PIE3). When IPEN = 0, the PEIE bit must be set to enable any of these peripheral interrupts.
REGISTER 8-7:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7 bit 6
PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1
R/W-0 ADIE R/W-0 RC1IE R/W-0 TX1IE R/W-0 SSPIE R/W-0 CCP1IE R/W-0 TMR2IE R/W-0 TMR1IE bit 0
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
Unimplemented: Read as `0' ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D interrupt 0 = Disables the A/D interrupt RC1IE: EUSART Receive Interrupt Enable bit 1 = Enables the EUSART receive interrupt 0 = Disables the EUSART receive interrupt TX1IE: EUSART Transmit Interrupt Enable bit 1 = Enables the EUSART transmit interrupt 0 = Disables the EUSART transmit interrupt SSPIE: Master Synchronous Serial Port Interrupt Enable bit 1 = Enables the MSSP interrupt 0 = Disables the MSSP interrupt CCP1IE: CCP1 Interrupt Enable bit 1 = Enables the CCP1 interrupt 0 = Disables the CCP1 interrupt TMR2IE: TMR2 to PR2 Match Interrupt Enable bit 1 = Enables the TMR2 to PR2 match interrupt 0 = Disables the TMR2 to PR2 match interrupt TMR1IE: TMR1 Overflow Interrupt Enable bit 1 = Enables the TMR1 overflow interrupt 0 = Disables the TMR1 overflow interrupt
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
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REGISTER 8-8:
R/W-0 OSCFIE bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2
R/W-0 CMIE U-0 -- U-0 -- R/W-0 BCLIE R/W-0 HLVDIE R/W-0 TMR3IE R/W-0 CCP2IE bit 0
OSCFIE: Oscillator Fail Interrupt Enable bit 1 = Enabled 0 = Disabled CMIE: Comparator Interrupt Enable bit 1 = Enabled 0 = Disabled Unimplemented: Read as `0' BCL1IE: Bus Collision Interrupt Enable bit 1 = Enabled 0 = Disabled HLVDIE: High/Low-Voltage Detect Interrupt Enable bit 1 = Enabled 0 = Disabled TMR3IE: TMR3 Overflow Interrupt Enable bit 1 = Enabled 0 = Disabled CCP2IE: CCP2 Interrupt Enable bit 1 = Enabled 0 = Disabled
bit 6
bit 5-4 bit 3
bit 2
bit 1
bit 0
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REGISTER 8-9:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7 bit 6 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
PIE3: PERIPHERAL INTERRUPT ENABLE REGISTER 3
R/W-0 LCDIE R-0 RC2IE R-0 TX2IE U-0 -- U-0 -- U-0 -- U-0 -- bit 0
Unimplemented: Read as `0' LCDIE: LCD Interrupt Enable bit (valid when Type-B waveform with Non-Static mode is selected) 1 = Enabled 0 = Disabled RC2IE: AUSART Receive Interrupt Enable bit 1 = Enabled 0 = Disabled TX2IE: AUSART Transmit Interrupt Enable bit 1 = Enabled 0 = Disabled Unimplemented: Read as `0'
bit 5
bit 4
bit 3-0
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8.4 IPR Registers
The IPR registers contain the individual priority bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are three Peripheral Interrupt Priority registers (IPR1, IPR2, IPR3). Using the priority bits requires that the Interrupt Priority Enable (IPEN) bit be set.
REGISTER 8-10:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7 bit 6
IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1
R/W-1 RC1IP R/W-1 TX1IP R/W-1 SSPIP R/W-1 CCP1IP R/W-1 TMR2IP R/W-1 TMR1IP bit 0 ADIP
R/W-1
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
Unimplemented: Read as `0' ADIP: A/D Converter Interrupt Priority bit 1 = High priority 0 = Low priority RC1IP: EUSART Receive Interrupt Priority bit 1 = High priority 0 = Low priority TX1IP: EUSART Transmit Interrupt Priority bit 1 = High priority 0 = Low priority
bit 5
bit 4
bit 3
SSPIP: Master Synchronous Serial Port Interrupt Priority bit 1 = High priority 0 = Low priority CCP1IP: CCP1 Interrupt Priority bit 1 = High priority 0 = Low priority TMR2IP: TMR2 to PR2 Match Interrupt Priority bit 1 = High priority 0 = Low priority TMR1IP: TMR1 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority
bit 2
bit 1
bit 0
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REGISTER 8-11:
R/W-1 OSCFIP bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2
U-0 -- U-0 -- R/W-1 BCLIP R/W-1 HLVDIP R/W-1 TMR3IP R/W-1 CCP2IP bit 0
R/W-1 CMIP
OSCFIP: Oscillator Fail Interrupt Priority bit 1 = High priority 0 = Low priority CMIP: Comparator Interrupt Priority bit 1 = High priority 0 = Low priority Unimplemented: Read as `0' BCLIP: Bus Collision Interrupt Priority bit 1 = High priority 0 = Low priority HLVDIP: High/Low-Voltage Detect Interrupt Priority bit 1 = High priority 0 = Low priority TMR3IP: TMR3 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority CCP2IP: CCP2 Interrupt Priority bit 1 = High priority 0 = Low priority
bit 6
bit 5-4 bit 3
bit 2
bit 1
bit 0
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REGISTER 8-12:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7 bit 6 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
IPR3: PERIPHERAL INTERRUPT PRIORITY REGISTER 3
R/W-1 RC2IP R/W-1 TX2IP U-0 -- U-0 -- U-0 -- U-0 -- bit 0
R/W-1 LCDIP
Unimplemented: Read as `0' LCDIP: LCD Interrupt Priority bit (valid when Type-B waveform with Non-Static mode is selected) 1 = High priority 0 = Low priority RC2IP: AUSART Receive Interrupt Priority bit 1 = High priority 0 = Low priority TX2IP: AUSART Transmit Interrupt Priority bit 1 = High priority 0 = Low priority Unimplemented: Read as `0'
bit 5
bit 4
bit 3-0
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8.5 RCON Register
The RCON register contains bits used to determine the cause of the last Reset or wake-up from Idle or Sleep modes. RCON also contains the bit that enables interrupt priorities (IPEN).
REGISTER 8-13:
R/W-0 IPEN bit 7 Legend: R = Readable bit -n = Value at POR bit 7
RCON: RESET CONTROL REGISTER
U-0 -- R/W-1 RI R-1 TO R-1 PD R/W-0 POR R/W-0 BOR bit 0
R/W-1 SBOREN
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode) SBOREN: Software BOR Enable bit For details of bit operation and Reset state, see Register 4-1. Unimplemented: Read as `0' RI: RESET Instruction Flag bit For details of bit operation, see Register 4-1. TO: Watchdog Timer Time-out Flag bit For details of bit operation, see Register 4-1. PD: Power-Down Detection Flag bit For details of bit operation, see Register 4-1. POR: Power-on Reset Status bit For details of bit operation, see Register 4-1. BOR: Brown-out Reset Status bit For details of bit operation, see Register 4-1.
bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
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8.6 INTx Pin Interrupts 8.7 TMR0 Interrupt
External interrupts on the RB0/INT0, RB1/INT1, RB2/ INT2 and RB3/INT3 pins are edge-triggered. If the corresponding INTEDGx bit in the INTCON2 register is set (= 1), the interrupt is triggered by a rising edge; if the bit is clear, the trigger is on the falling edge. When a valid edge appears on the RBx/INTx pin, the corresponding flag bit INTxIF is set. This interrupt can be disabled by clearing the corresponding enable bit, INTxIE. The interrupt flag bit must be cleared in software in the Interrupt Service Routine before re-enabling the interrupt. All external interrupts (INT0, INT1, INT2 and INT3) can wake-up the processor from the power-managed modes if bit INTxIE was set prior to going into the power-managed modes. If the Global Interrupt Enable bit, GIE, is set, the processor will branch to the interrupt vector following wake-up. Interrupt priority for INT1, INT2 and INT3 is determined by the value contained in the interrupt priority bits, INT1IP (INTCON3<6>), INT2IP (INTCON3<7>) and INT3IP (INTCON2<1>). There is no priority bit associated with INT0. It is always a high-priority interrupt source. In 8-bit mode (which is the default), an overflow in the TMR0 register (FFh 00h) will set flag bit, TMR0IF. In 16-bit mode, an overflow in the TMR0H:TMR0L register pair (FFFFh 0000h) will set TMR0IF. The interrupt can be enabled/disabled by setting/clearing enable bit, TMR0IE (INTCON<5>). Interrupt priority for Timer0 is determined by the value contained in the interrupt priority bit, TMR0IP (INTCON2<2>). See Section 10.0 "Timer0 Module" for further details on the Timer0 module.
8.8
PORTB Interrupt-on-Change
An input change on PORTB<7:4> sets flag bit, RBIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit, RBIE (INTCON<3>). Interrupt priority for PORTB interrupt-on-change is determined by the value contained in the interrupt priority bit, RBIP (INTCON2<0>).
8.9
Context Saving During Interrupts
During interrupts, the return PC address is saved on the stack. Additionally, the WREG, STATUS and BSR registers are saved on the fast return stack. If a fast return from interrupt is not used (see Section 5.3 "Data Memory Organization"), the user may need to save the WREG, STATUS and BSR registers on entry to the Interrupt Service Routine. Depending on the user's application, other registers may also need to be saved. Example 8-1 saves and restores the WREG, STATUS and BSR registers during an Interrupt Service Routine.
EXAMPLE 8-1:
SAVING STATUS, WREG AND BSR REGISTERS IN RAM
; W_TEMP is in virtual bank ; STATUS_TEMP located anywhere ; BSR_TMEP located anywhere
MOVWF W_TEMP MOVFF STATUS, STATUS_TEMP MOVFF BSR, BSR_TEMP ; ; USER ISR CODE ; MOVFF BSR_TEMP, BSR MOVF W_TEMP, W MOVFF STATUS_TEMP, STATUS
; Restore BSR ; Restore WREG ; Restore STATUS
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9.0 I/O PORTS
9.1
Depending on the device selected and features enabled, there are up to nine ports available. Some pins of the I/O ports are multiplexed with an alternate function from the peripheral features on the device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. Each port has three registers for its operation. These registers are: * TRIS register (data direction register) * PORT register (reads the levels on the pins of the device) * LAT register (output latch) The Data Latch (LAT register) is useful for read-modify-write operations on the value that the I/O pins are driving. A simplified model of a generic I/O port, without the interfaces to other peripherals, is shown in Figure 9-1.
PORTA, TRISA and LATA Registers
PORTA is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISA. Setting a TRISA bit (= 1) will make the corresponding PORTA pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output (i.e., put the contents of the output latch on the selected pin). Reading the PORTA register reads the status of the pins, whereas writing to it will write to the port latch. The Data Latch register (LATA) is also memory mapped. Read-modify-write operations on the LATA register read and write the latched output value for PORTA. The RA4 pin is multiplexed with the Timer0 module clock input and the LCD segment drive to become the RA4/T0CKI/SEG14 pin. Pins RA6 and RA7 are multiplexed with the main oscillator pins; they are enabled as oscillator or I/O pins by the selection of the main oscillator in the Configuration register (see Section 23.1 "Configuration Bits" for details). When they are not used as port pins, RA6 and RA7 and their associated TRIS and LAT bits are read as `0'. The other PORTA pins are multiplexed with analog inputs and the analog VREF+ and VREF- inputs. The operation of pins RA3:RA0 and RA5 as A/D converter inputs is selected by clearing or setting the control bits in the ADCON1 register (A/D Control Register 1). The RA4/T0CKI/SEG14 pin is a Schmitt Trigger input and an open-drain output. All other PORTA pins have TTL input levels and full CMOS output drivers. The TRISA register controls the direction of the PORTA pins, even when they are being used as analog inputs. The user must ensure the bits in the TRISA register are maintained set when using them as analog inputs. RA5:RA2 are also multiplexed with LCD segment drives controlled by bits in the LCDSE1 and LCDSE2 registers. I/O port functions are only available when the segments are disabled.
FIGURE 9-1:
GENERIC I/O PORT OPERATION
RD LAT Data Bus WR LAT or PORT
D CK
Q I/O pin(1)
Data Latch D WR TRIS CK TRIS Latch Input Buffer Q
RD TRIS
Q
D EN EN
EXAMPLE 9-1:
CLRF ; ; ; LATA ; ; ; 07h ; ADCON1 ; 07h ; CMCON ; 0CFh ; ; ; TRISA ; ; PORTA
INITIALIZING PORTA
Initialize PORTA by clearing output data latches Alternate method to clear output data latches Configure A/D for digital inputs Configure comparators for digital input Value used to initialize data direction Set RA<3:0> as inputs RA<5:4> as outputs
RD PORT
Note 1:
I/O pins have diode protection to VDD and VSS.
CLRF
MOVLW MOVWF MOVWF MOVWF MOVLW
MOVWF
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TABLE 9-1:
Pin Name RA0/AN0
PORTA FUNCTIONS
Function RA0 AN0 TRIS Setting 0 1 1 0 1 AN1 1 0 1 AN2 VREFSEG16 1 1 x 0 1 AN3 VREF+ SEG17 1 1 x 0 1 T0CKI SEG14 x 0 1 AN4 HLVDIN SEG15 1 1 x x x 0 1 x x 0 1 I/O O I I O I I O I I I O O I I I O O I I O O I I I O O O O I I I O I Buffer DIG TTL ANA DIG TTL ANA DIG TTL ANA ANA ANA DIG TTL ANA ANA ANA DIG ST ST ANA DIG TTL ANA ANA ANA ANA DIG DIG TTL ANA ANA DIG TTL Description LATA<0> data output. Not affected by analog pin setting. PORTA<0> data input. Reads `0' on POR. A/D input channel 0. Default configuration on POR. LATA<1> data output. Not affected by analog pin setting. PORTA<1> data input. Reads `0' on POR. A/D input channel 1. Default configuration on POR. LATA<2> data output. Not affected by analog pin setting; disabled when LCD segment enabled. PORTA<2> data input. Reads `0' on POR. A/D input channel 2. Default configuration on POR. A/D low reference voltage input. Segment 16 analog output for LCD. LATA<3> data output. Output is unaffected by analog pin setting; disabled when LCD segment enabled. PORTA<3> data input. Reads `0' on POR. A/D input channel 3. Default configuration on POR. A/D high reference voltage input. Segment 17 analog output for LCD. Disables all other digital outputs. LATA<4> data output; disabled when LCD segment enabled. PORTA<4> data input. Timer0 clock input. Segment 14 analog output for LCD. LATA<5> data output. Not affected by analog pin setting; disabled when LCD segment enabled. PORTA<5> data input. Reads `0' on POR. A/D input channel 5. Default configuration on POR. High/Low-Voltage Detect external trip point input. Segment 15 analog output for LCD. Main oscillator feedback output connection (XT, HS and LP modes). System cycle clock output (FOSC/4) in all oscillator modes except RCIO, INTIO2 and ECIO. LATA<6> data output. Enabled in RCIO, INTIO2 and ECIO modes only. PORTA<6> data input. Enabled in RCIO, INTIO2 and ECIO modes only. Main oscillator input connection, all modes except INTIO. Main clock input connection, all modes except INTIO. LATA<7> data output. Available only in INTIO modes; otherwise reads as `0'. PORTA<7> data input. Available only in INTIO modes; otherwise reads as `0'.
RA1/AN1
RA1
RA2/AN2/VREF-/ SEG16
RA2
RA3/AN3/VREF+/ SEG17
RA3
RA4/T0CKI/ SEG14
RA4
RA5/AN4/ HLVDIN/SEG15
RA5
OSC2/CLKO/RA6
OSC2 CLKO RA6
OSC1/CLKI/RA7
OSC1 CLKI RA7
Legend:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option).
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TABLE 9-2:
Name PORTA LATA TRISA ADCON1 LCDSE1 LCDSE2
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Bit 7 RA7(1) LATA7 -- SE15 SE23
(1)
Bit 6 RA6(1)
Bit 5 RA5
Bit 4 RA4
Bit 3 RA3
Bit 2 RA2
Bit 1 RA1
Bit 0 RA0
Reset Values on Page 62 62 62
LATA6(1) LATA Data Output Register -- SE14 SE22 VCFG1 SE13 SE21 VCFG0 SE12 SE20 PCFG3 SE11 SE19 PCFG2 SE10 SE18 PCFG1 SE9 SE17 PCFG0 SE8 SE16
TRISA7(1) TRISA6(1) PORTA Data Direction Register
61 64 64
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by PORTA. Note 1: RA7:RA6 and their associated latch and data direction bits are enabled as I/O pins based on oscillator configuration; otherwise, they are read as `0'.
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9.2 PORTB, TRISB and LATB Registers
Four of the PORTB pins (RB7:RB4) have an interrupt-on-change feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB7:RB4 pin configured as an output is excluded from the interrupt-on-change comparison). The input pins (of RB7:RB4) are compared with the old value latched on the last read of PORTB. The "mismatch" outputs of RB7:RB4 are ORed together to generate the RB Port Change Interrupt with Flag bit, RBIF (INTCON<0>). This interrupt can wake the device from power-managed modes. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) Any read or write of PORTB (except with the MOVFF (ANY), PORTB instruction). This will end the mismatch condition. Clear flag bit, RBIF.
PORTB is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISB bit (= 0) will make the corresponding PORTB pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATB) is also memory mapped. Read-modify-write operations on the LATB register read and write the latched output value for PORTB.
EXAMPLE 9-2:
CLRF PORTB ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTB
Initialize PORTB by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RB<3:0> as inputs RB<5:4> as outputs RB<7:6> as inputs
b)
CLRF
LATB
A mismatch condition will continue to set flag bit, RBIF. Reading PORTB will end the mismatch condition and allow flag bit RBIF to be cleared. The interrupt-on-change feature is recommended for wake-up on key depression operation and operations where PORTB is only used for the interrupt-on-change feature. Polling of PORTB is not recommended while using the interrupt-on-change feature. RB4:RB1 are also multiplexed with LCD segment drives controlled by bits in the LCDSE1 register. I/O port functions are only available when the segments are disabled.
MOVLW
0CFh
MOVWF
TRISB
Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is performed by clearing bit RBPU (INTCON2<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset.
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TABLE 9-3:
Pin Name RB0/INT0
PORTB FUNCTIONS
Function RB0 INT0 TRIS Setting 0 1 1 0 1 INT1 SEG8 1 x 0 1 INT2 SEG9 1 x 0 1 INT3 SEG10 1 x 0 1 KBI0 SEG11 1 x 0 1 KBI1 1 0 1 KBI2 PGC 1 x 0 1 KBI3 PGD 1 x x I/O O I I O I I O O I I O O I I O O I I O O I I O I I I O I I O I Buffer DIG TTL ST DIG TTL ST ANA DIG TTL ST ANA DIG TTL ST ANA DIG TTL TTL ANA DIG TTL TTL DIG TTL TTL ST DIG TTL TTL DIG ST LATB<0> data output. PORTB<0> data input; programmable weak pull-up. External interrupt 0 input. LATB<1> data output; disabled when LCD segment enabled. PORTB<1> data input; weak pull-up when RBPU bit is cleared. External interrupt 1 input. Segment 8 analog output for LCD. Disables digital output. LATB<2> data output; disabled when LCD segment enabled. PORTB<2> data input; weak pull-up when RBPU bit is cleared. External interrupt 2 input. Segment 9 analog output for LCD LATB<3> data output; disabled when LCD segment enabled. PORTB<3> data input; weak pull-up when RBPU bit is cleared. External interrupt 3 input. Segment 10 analog output for LCD. LATB<4> data output; disabled when LCD segment enabled. PORTB<4> data input; weak pull-up when RBPU bit is cleared. Interrupt-on-pin change. Segment 11 analog output for LCD. LATB<5> data output; disabled when LCD segment enabled. PORTB<5> data input; weak pull-up when RBPU bit is cleared. Interrupt-on-pin change. LATB<6> data output; unavailable when ICD or ICSPTM enabled. PORTB<6> data input; unavailable when ICD or ICSP enabled. Interrupt-on-pin change; unavailable when ICD or ICSP enabled. Serial execution (ICSP) clock input for ICSP and ICD operation.(1) LATB<7> data output; unavailable when ICD or ICSP enabled. PORTB<7> data input; unavailable when ICD or ICSP enabled. Interrupt-on-pin change; unavailable when ICD or ICSP enabled. Serial execution data output for ICSP and ICD operation.(1) Serial execution data input for ICSP and ICD operation.(1) Description
RB1/INT1/SEG8
RB1
RB2/INT2/SEG9
RB2
RB3/INT3/ SEG10
RB3
RB4/KBI0/ SEG11
RB4
RB5/KBI1
RB5
RB6/KBI2/PGC
RB6
RB7/KBI3/PGD
RB7
Legend: Note 1:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). All other pin functions are disabled when ICSP or ICD are enabled.
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TABLE 9-4:
Name PORTB LATB TRISB INTCON INTCON2 INTCON3 LCDSE1
SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
Bit 7 RB7 Bit 6 RB6 Bit 5 RB5 Bit 4 RB4 Bit 3 RB3 Bit 2 RB2 Bit 1 RB1 Bit 0 RB0 Reset Values on Page 62 62 62 INT0IE INT2IE SE12 RBIE INT1IE SE11 TMR0IF INT3IF SE10 INT0IF INT3IP INT2IF SE9 RBIF RBIP INT1IF SE8 59 59 59 64
LATB Data Output Register PORTB Data Direction Register GIE/GIEH PEIE/GIEL RBPU INT2IP SE15 INT1IP SE14 TMR0IE INT3IE SE13 INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP
Legend: Shaded cells are not used by PORTB.
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9.3 PORTC, TRISC and LATC Registers
Note: On a Power-on Reset, these pins are configured as digital inputs.
PORTC is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISC. Setting a TRISC bit (= 1) will make the corresponding PORTC pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISC bit (= 0) will make the corresponding PORTC pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATC) is also memory mapped. Read-modify-write operations on the LATC register read and write the latched output value for PORTC. PORTC is multiplexed with several peripheral functions (Table 9-5). The pins have Schmitt Trigger input buffers. RC1 is normally configured by Configuration bit, CCP2MX, as the default peripheral pin of the CCP2 module (default/erased state, CCP2MX = 1). When enabling peripheral functions, care should be taken in defining TRIS bits for each PORTC pin. Some peripherals override the TRIS bit to make a pin an output, while other peripherals override the TRIS bit to make a pin an input. The user should refer to the corresponding peripheral section for the correct TRIS bit settings.
The contents of the TRISC register are affected by peripheral overrides. Reading TRISC always returns the current contents, even though a peripheral device may be overriding one or more of the pins. RC2 and RC5 are also multiplexed with LCD segment drives controlled by bits in the LCDSE1 register. I/O port functions are only available when the segments are disabled.
EXAMPLE 9-3:
CLRF PORTC ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTC
Initialize PORTC by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RC<3:0> as inputs RC<5:4> as outputs RC<7:6> as inputs
CLRF
LATC
MOVLW
0CFh
MOVWF
TRISC
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TABLE 9-5:
Pin Name RC0/T1OSO/ T13CKI/
PORTC FUNCTIONS
Function RC0 T1OSO T13CKI TRIS Setting 0 1 x x 0 1 T1OSI CCP2(1) x 0 1 0 1 CCP1 SEG13 0 1 x 0 1 SCK SCL 0 1 0 1 0 1 SDI SDA 1 1 1 0 1 SDO SEG12 0 x 0 1 TX1 CK1 1 1 1 I/O O I O I O I I O I O I O I O O I O I O I O I I O I O I O O O I O O I O I I O I Buffer DIG ST ANA ST DIG ST ANA DIG ST DIG ST DIG ST ANA DIG ST DIG ST DIG ST DIG ST ST DIG ST DIG ST DIG ANA DIG ST DIG DIG ST DIG ST ST DIG ST Description LATC<0> data output; disabled when Timer1 oscillator is used. PORTC<0> data input; disabled when Timer1 oscillator is used. Timer1 oscillator output. Timer1/Timer3 clock input. LATC<1> data output; disabled when Timer1 oscillator is used. PORTC<1> data input; disabled when Timer1 oscillator is used. Timer1 oscillator input. CCP2 compare output or PWM output; takes priority over digital I/O data. CCP2 capture input. LATC<2> data output; disabled when LCD segment enabled. PORTC<2> data input. CCP1 compare output or PWM output; takes priority over digital I/O data. CCP1 capture input. Segment 13 analog output for LCD. LATC<3> data output. PORTC<3> data input. SPI clock output (MSSP module); takes priority over port data. SPI clock input (MSSP module). I2CTM clock output (MSSP module); takes priority over port data. I2C clock input (MSSP module); input type depends on module setting. LATC<4> data output. PORTC<4> data input. SPI data input (MSSP module). I2C data output (MSSP module); takes priority over port data. I2C data input (MSSP module); input type depends on module setting. LATC<5> data output; disabled when LCD segment enabled. PORTC<5> data input. SPI data output (MSSP module); takes priority over port data. Segment 12 analog output for LCD. LATC<6> data output. PORTC<6> data input. Synchronous serial data output (EUSART module); takes priority over port data. Synchronous serial data input (EUSART module). User must configure as an input. Synchronous serial clock input (EUSART module). LATC<7> data output. PORTC<7> data input. Asynchronous serial receive data input (EUSART module). Synchronous serial data output (EUSART module); takes priority over port data. Synchronous serial data input (EUSART module). User must configure as an input.
RC1/T1OSI/ CCP2
RC1
RC2/CCP1/ SEG13
RC2
RC3/SCK/SCL
RC3
RC4/SDI/SDA
RC4
RC5/SDO/ SEG12
RC5
RC6/TX1/CK1
RC6
RC7/RX1/DT1
RC7 RX1 DT1
0 1 1 1 1
Legend: Note 1:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). Default assignment for CCP2 (CCP2MX Configuration bit = 1).
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TABLE 9-6:
Name PORTC LATC TRISC LCDSE1
SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
Bit 7 RC7 Bit 6 RC6 Bit 5 RC5 Bit 4 RC4 Bit 3 RC3 Bit 2 RC2 Bit 1 RC1 Bit 0 RC0 Reset Values on Page 62 62 62 SE12 SE11 SE10 SE9 SE8 64
LATC Data Output Register PORTC Data Direction Register SE15 SE14 SE13
Legend: Shaded cells are not used by PORTC.
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9.4 PORTD, TRISD and LATD Registers
PORTD is also multiplexed with LCD segment drives controlled by the LCDSE0 register. I/O port functions are only available when the segments are disabled.
PORTD is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISD. Setting a TRISD bit (= 1) will make the corresponding PORTD pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISD bit (= 0) will make the corresponding PORTD pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATD) is also memory mapped. Read-modify-write operations on the LATD register read and write the latched output value for PORTD. All pins on PORTD are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. Note: On a Power-on Reset, these pins are configured as digital inputs.
EXAMPLE 9-4:
CLRF PORTD ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTD
Initialize PORTD by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RD<3:0> as inputs RD<5:4> as outputs RD<7:6> as inputs
CLRF
LATD
MOVLW
0CFh
MOVWF
TRISD
TABLE 9-7:
Pin Name RD0/SEG0
PORTD FUNCTIONS
Function RD0 SEG0 TRIS Setting 0 1 x 0 1 SEG1 x 0 1 SEG2 x 0 1 SEG3 x 0 1 SEG4 x 0 1 SEG5 x 0 1 SEG6 x 0 1 SEG7 x I/O O I O O I O O I O O I O O I O O I O O I O O I O Buffer DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA Description LATD<0> data output; disabled when LCD segment enabled. PORTD<0> data input. Segment 0 analog output for LCD. LATD<1> data output; disabled when LCD segment enabled. PORTD<1> data input. Segment 1 analog output for LCD. LATD<2> data output; disabled when LCD segment enabled. PORTD<2> data input. Segment 2 analog output for LCD. LATD<3> data output; disabled when LCD segment enabled. PORTD<3> data input. Segment 3 analog output for LCD. LATD<4> data output; disabled when LCD segment enabled. PORTD<4> data input. Segment 4 analog output for LCD module. LATD<5> data output; disabled when LCD segment enabled. PORTD<5> data input. Segment 5 analog output for LCD. LATD<6> data output; disabled when LCD segment enabled. PORTD<6> data input. Segment 6 analog output for LCD. LATD<7> data output; disabled when LCD segment enabled. PORTD<7> data input. Segment 7 analog output for LCD.
RD1/SEG1
RD1
RD2/SEG2
RD2
RD3/SEG3
RD3
RD4/SEG4
RD4
RD5/SEG5
RD5
RD6/SEG6
RD6
RD7/SEG7
RD7
Legend:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option).
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TABLE 9-8:
Name PORTD LATD TRISD LCDSE0
SUMMARY OF REGISTERS ASSOCIATED WITH PORTD
Bit 7 RD7 Bit 6 RD6 Bit 5 RD5 Bit 4 RD4 Bit 3 RD3 Bit 2 RD2 Bit 1 RD1 Bit 0 RD0 Reset Values on Page 62 62 62 SE4 SE3 SE2 SE1 SE0 64
LATD Data Output Register PORTD Data Direction Register SE7 SE6 SE5
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9.5 PORTE, TRISE and LATE Registers
RE7 also can be configured as the alternate peripheral pin for the CCP2 module. This is done by clearing the CCP2MX Configuration bit.
PORTE is a 4-bit wide, bidirectional port. The corresponding Data Direction register is TRISE. Setting a TRISE bit (= 1) will make the corresponding PORTE pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISE bit (= 0) will make the corresponding PORTE pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATE) is also memory mapped. Read-modify-write operations on the LATE register read and write the latched output value for PORTE. All pins on PORTE are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. Note: On a Power-on Reset, these pins are configured as digital inputs.
TABLE 9-9:
PORTE PINS AVAILABLE IN DIFFERENT LCD DRIVE CONFIGURATIONS
Active LCD Commons COM0 COM0, COM1 COM0, COM1 and COM2 All (COM0 through COM3) PORTE Available for I/O RE6, RE5, RE4 RE6, RE5 RE6 None
LCDCON <1:0> 00 01 10 11
EXAMPLE 9-5:
CLRF CLRF MOVLW MOVWF PORTE LATE 30h TRISE ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTE
Initialize PORTE by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RE<5:4> as inputs RE<7:6> as outputs
Pins RE6:RE4 are multiplexed with three of the LCD common drives. I/O port functions are only available on those PORTE pins, depending on which commons are active. The configuration is determined by the LMUX1:LMUX0 control bits (LCDCON<1:0>). The availability is summarized in Table 9-9. RE7 is also multiplexed with LCD segment drive (SEG31) controlled by the LCDSE3<7> bit. I/O port function is only available when the segment is disabled. Note: The pins corresponding to RE2:RE0 of other PIC18F parts have the function of LCDBIAS3:LCDBIAS1 and the pin corresponding to RE3 of other PIC18F parts has the function of COM0. These four pins cannot be used as digital I/O.
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TABLE 9-10:
Pad Name RE4/COM1
PORTE FUNCTIONS
TRIS Setting 0 1 COM1 x 0 1 COM2 x 0 1 COM3 x 0 1 CCP2(1) SEG31 0 1 x I/O O I O O I O O I O O I O I O Buffer DIG ST ANA DIG ST ANA DIG ST ANA DIG ST DIG ST ANA Description LATE<4> data output; disabled when LCD common enabled. PORTE<4> data input. Common 1 analog output for LCD. LATE<5> data output; disabled when LCD common enabled. PORTE<5> data input. Common 2 analog output for LCD. LATE<6> data output; disabled when LCD segment enabled. PORTE<6> data input. Common 3 analog output for LCD. LATE<7> data output; disabled when LCD segment enabled. PORTE<7> data input. CCP2 compare output and CCP2 PWM output; takes priority over port data. CCP2 capture input. Segment 31 analog output for LCD.
Function RE4
RE5/COM2
RE5
RE6/COM3
RE6
RE7/CCP2/ SEG31
RE7
Legend: Note 1:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). Alternate assignment for CCP2 when the CCP2MX Configuration bit = 0.
TABLE 9-11:
Name PORTE LATE TRISE LCDCON LCDSE3
SUMMARY OF REGISTERS ASSOCIATED WITH PORTE
Bit 7 RE7 Bit 6 RE6 Bit 5 RE5 Bit 4 RE4 Bit 3 -- -- -- -- SE28 CS1 SE27 Bit 2 -- -- -- CS0 SE26 Bit 1 -- -- -- LMUX1 SE25 Bit 0 -- -- -- LMUX0 SE24 Reset Values on Page 62 62 62 64 64
LATE Data Output Register PORTE Data Direction Register LCDEN SE31 SLPEN SE30 WERR SE29
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by PORTE.
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9.6 PORTF, LATF and TRISF Registers
EXAMPLE 9-6:
CLRF ; ; ; LATF ; ; ; 0x07 ; CMCON ; 0x0F ; ADCON1 ; 0xCF ; ; ; TRISF ; ; ; PORTF
INITIALIZING PORTF
Initialize PORTF by clearing output data latches Alternate method to clear output data latches Turn off comparators Set PORTF as digital I/O Value used to initialize data direction Set RF3:RF0 as inputs RF5:RF4 as outputs RF7:RF6 as inputs
PORTF is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISF. Setting a TRISF bit (= 1) will make the corresponding PORTF pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISF bit (= 0) will make the corresponding PORTF pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATF) is also memory mapped. Read-modify-write operations on the LATF register read and write the latched output value for PORTF. All pins on PORTF are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. PORTF is multiplexed with several analog peripheral functions, including the A/D converter inputs and comparator inputs, outputs and voltage reference. Note 1: On a Power-on Reset, the RF6:RF0 pins are configured as inputs and read as `0'. 2: To configure PORTF as digital I/O, turn off comparators and set ADCON1 value. PORTF is also multiplexed with LCD segment drives controlled by bits in the LCDSE2 and LCDSE3 registers. I/O port functions are only available when the segments are disabled.
CLRF
MOVLW MOVWF MOVLW MOVWF MOVLW
MOVWF
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TABLE 9-12:
Pin Name RF0/AN5/ SEG18
PORTF FUNCTIONS
Function RF0 TRIS Setting 0 1 AN5 SEG18 1 x 0 1 AN6 C2OUT SEG19 1 0 x 0 1 AN7 C1OUT SEG20 1 0 x 0 1 AN8 SEG21 1 x 0 1 AN9 SEG22 1 x 0 1 AN10 CVREF SEG23 1 0 x 0 1 AN11 SEG24 1 x 0 1 SS SEG25 1 x I/O O I I O O I I O O O I I O O O I I O O I I O O I I O O O I I O O I I O Buffer DIG ST ANA ANA DIG ST ANA DIG ANA DIG ST ANA TTL ANA DIG ST ANA ANA DIG ST ANA ANA DIG ST ANA ANA ANA DIG ST ANA ANA DIG ST TTL ANA Description LATF<0> data output. Output is unaffected by analog input; disabled when LCD segment is enabled. PORTF<0> data input. Reads `0' on POR. A/D input channel 5. Default configuration on POR. Segment 18 analog output for LCD. LATF<1> data output. Output is unaffected by analog input; disabled when LCD segment is enabled. PORTF<1> data input. Reads `0' on POR. A/D input channel 6. Default configuration on POR. Comparator 2 output; takes priority over port data. Segment 19 analog output for LCD. LATF<2> data output. Output is unaffected by analog input; disabled when LCD segment is enabled. PORTF<2> data input. Reads `0' on POR. A/D input channel 7. Default configuration on POR. Comparator 1 output; takes priority over port data. Segment 20 analog output for LCD. LATF<3> data output. Output is unaffected by analog input; disabled when LCD segment is enabled. PORTF<3> data input. Reads `0' on POR. A/D input channel 8 and Comparator C2+ input. Default input configuration on POR; not affected by analog output. Segment 21 analog output for LCD. LATF<4> data output. Output is unaffected by analog input; disabled when LCD segment is enabled. PORTF<4> data input. Reads `0' on POR. A/D input channel 9 and Comparator C2- input. Default input configuration on POR; does not affect digital output. Segment 22 analog output for LCD. LATF<5> data output. Output unaffected by analog input; disabled when either LCD segment or CVREF is enabled. PORTF<5> data input. Reads `0' on POR. A/D input channel 10 and Comparator C1+ input. Default input configuration on POR. Comparator voltage reference output. Enabling this feature disables digital I/O. Segment 23 analog output for LCD. LATF<6> data output. Output is unaffected by analog input; disabled when LCD segment is enabled. PORTF<6> data input. Reads `0' on POR. A/D input channel 11 and Comparator C1- input. Default input configuration on POR; does not affect digital output. Segment 24 analog output for LCD. LATF<7> data output; disabled when LCD segment is enabled. PORTF<7> data input. Slave select input for MSSP module. Segment 25 analog output for LCD.
RF1/AN6/ C2OUT/SEG19
RF1
RF2/AN7/ C1OUT/SEG20
RF2
RF3/AN8/ SEG21
RF3
RF4/AN9/ SEG22
RF4
RF5/AN10/ CVREF/SEG23
RF5
RF6/AN11/ SEG24
RF6
RF7/SS/SEG25
RF7
Legend:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option).
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TABLE 9-13:
Name TRISF PORTF LATF ADCON1 CMCON CVRCON LCDSE2 LCDSE3
SUMMARY OF REGISTERS ASSOCIATED WITH PORTF
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page 62 62 62 VCFG0 C1INV CVRSS SE20 SE28 PCFG3 CIS CVR3 SE19 SE27 PCFG2 CM2 CVR2 SE18 SE26 PCFG1 CM1 CVR1 SE17 SE25 PCFG0 CM0 CVR0 SE16 SE24 61 61 61 64 64
PORTF Data Direction Register Read PORTF Data Latch/Write PORTF Data Latch LATF Data Output Register -- C2OUT CVREN SE23 SE31 -- C1OUT CVROE SE22 SE30 VCFG1 C2INV CVRR SE21 SE29
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by PORTF.
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9.7 PORTG, TRISG and LATG Registers
PORTG<4:0> are also multiplexed with LCD segment drives controlled by bits in the LCDSE3 register. I/O port functions are only available when the segments are disabled. The sixth pin of PORTG (MCLR/VPP/RG5) is an input only pin. Its operation is controlled by the MCLRE Configuration bit. When selected as a port pin (MCLRE = 0), it functions as a digital input only pin; as such, it does not have TRIS or LAT bits associated with its operation. Otherwise, it functions as the device's Master Clear input. In either configuration, RG5 also functions as the programming voltage input during programming. Note: On a Power-on Reset, RG5 is enabled as a digital input only if Master Clear functionality is disabled. All other 5 pins are configured as digital inputs.
PORTG is a 6-bit wide, bidirectional port. The corresponding Data Direction register is TRISG. Setting a TRISG bit (= 1) will make the corresponding PORTG pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISG bit (= 0) will make the corresponding PORTG pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATG) is also memory mapped. Read-modify-write operations on the LATG register read and write the latched output value for PORTG. PORTG is multiplexed with both USART and LCD functions (Table 9-14). PORTG pins have Schmitt Trigger input buffers. When enabling peripheral functions, care should be taken in defining TRIS bits for each PORTG pin. Some peripherals override the TRIS bit to make a pin an output, while other peripherals override the TRIS bit to make a pin an input. The user should refer to the corresponding peripheral section for the correct TRIS bit settings. The pin override value is not loaded into the TRIS register. This allows read-modify-write of the TRIS register without concern due to peripheral overrides.
EXAMPLE 9-7:
CLRF PORTG ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTG
Initialize PORTG by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RG1:RG0 as outputs RG2 as input RG4:RG3 as inputs
CLRF
LATG
MOVLW
0x04
MOVWF
TRISG
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TABLE 9-14:
Pin Name RG0/SEG30
PORTG FUNCTIONS
Function RG0 SEG30 TRIS Setting 0 1 x 0 1 TX2 CK2 1 1 1 SEG29 x 0 1 RX2 DT2 1 1 1 SEG28 x 0 1 SEG27 0 0 1 SEG26 x --(1) --(1) --(1) I/O O I O O I O O I O O I I O I O O I O O I O I I I Buffer DIG ST ANA DIG ST DIG DIG ST ANA DIG ST ST DIG ST ANA DIG ST ANA DIG ST ANA ST ANA ST Description LATG<0> data output; disabled when LCD segment enabled. PORTG<0> data input. Segment 30 analog output for LCD. LATG<1> data output; disabled when LCD segment enabled. PORTG<1> data input. Synchronous serial data output (AUSART module); takes priority over port data. Synchronous serial data input (AUSART module). User must configure as an input. Synchronous serial clock input (AUSART module). Segment 29 analog output for LCD. LATG<2> data output; disabled when LCD segment enabled. PORTG<2> data input. Asynchronous serial receive data input (AUSART module). Synchronous serial data output (AUSART module); takes priority over port data. Synchronous serial data input (AUSART module). User must configure as an input. Segment 28 analog output for LCD. LATG<3> data output; disabled when LCD segment enabled. PORTG<3> data input. Segment 27 analog output for LCD. LATG<4> data output; disabled when LCD segment enabled. PORTG<4> data input. Segment 26 analog output for LCD. External Master Clear input; enabled when MCLRE Configuration bit is set. High-voltage detection; used for ICSPTM mode entry detection. Always available, regardless of pin mode. PORTG<5> data input; enabled when MCLRE Configuration bit is clear.
RG1/TX2/CK2/ SEG29
RG1
RG2/RX2/DT2/ SEG28
RG2
RG3/SEG27
RG3
RG4/SEG26
RG4
MCLR/VPP/RG5
MCLR VPP RG5
Legend: Note 1:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). RG5 does not have a corresponding TRISG bit.
TABLE 9-15:
Name PORTG LATG TRISG LCDSE3
SUMMARY OF REGISTERS ASSOCIATED WITH PORTG
Bit 7 -- -- -- SE31 Bit 6 -- -- -- SE30 Bit 5 RG5(1) -- -- SE29 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page 62 62 62 SE25 SE24 64
Read PORTG pin/Write PORTG Data Latch LATG Data Output Register PORTG Data Direction Register SE28 SE27 SE26
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by PORTG. Note 1: RG5 is available as an input only when MCLR is disabled.
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9.8
Note:
PORTH, LATH and TRISH Registers
PORTH is available only on 80-pin devices.
EXAMPLE 9-8:
CLRF PORTH
INITIALIZING PORTH
; ; ; ; ; ; ; ; ; ; ; ; Initialize PORTH by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RH3:RH0 as inputs RH5:RH4 as outputs RH7:RH6 as inputs
CLRF
LATH
PORTH is an 8-bit wide, bidirectional I/O port. The corresponding Data Direction register is TRISH. Setting a TRISH bit (= 1) will make the corresponding PORTH pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISH bit (= 0) will make the corresponding PORTH pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATH) is also memory mapped. Read-modify-write operations on the LATH register read and write the latched output value for PORTH. All pins on PORTH are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. Note: On a Power-on Reset, these pins are configured as digital inputs.
MOVLW
0CFh
MOVWF
TRISH
PORTH is also multiplexed with LCD segment drives controlled by the LCDSE5 register. I/O port functions are only available when the segments are disabled.
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TABLE 9-16:
Pin Name RH0/SEG47
PORTH FUNCTIONS
Function RH0 SEG47 TRIS Setting 0 1 x 0 1 SEG46 x 0 1 SEG45 x 0 1 SEG44 x 0 1 SEG40 x 0 1 SEG41 x 0 1 SEG42 x 0 1 SEG43 x I/O O I O O I O O I O O I O O I O O I O O I O O I O Buffer DIG-4 ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA Description LATH<0> data output; disabled when LCD segment enabled. PORTH<0> data input. Segment 47 analog output for LCD. LATH<1> data output; disabled when LCD segment enabled. PORTH<1> data input. Segment 46 analog output for LCD. LATH<2> data output; disabled when LCD segment enabled. PORTH<2> data input. Segment 45 analog output for LCD. LATH<3> data output; disabled when LCD segment enabled. PORTH<3> data input. Segment 44 analog output for LCD. LATH<4> data output; disabled when LCD segment enabled. PORTH<4> data input. Segment 40 analog output for LCD LATH<5> data output; disabled when LCD segment enabled. PORTH<5> data input. Segment 41 analog output for LCD. LATH<6> data output; disabled when LCD segment enabled. PORTH<6> data input. Segment 42 analog output for LCD. LATH<7> data output; disabled when LCD segment enabled. PORTH<7> data input. Segment 43 analog output for LCD.
RH1/SEG46
RH1
RH2/SEG45
RH2
RH3/SEG44
RH3
RH4/SEG40
RH4
RH5/SEG41
RH5
RH6/SEG42
RH6
RH7/SEG43
RH7
Legend:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option).
TABLE 9-17:
Name TRISH PORTH LATH LCDSE5
SUMMARY OF REGISTERS ASSOCIATED WITH PORTH
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page 62 62 62 SE44 SE43 SE42 SE41 SE40 64
PORTH Data Direction Register Read PORTH pin/Write PORTH Data Latch LATH Data Output Register SE47 SE46 SE45
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9.9
Note:
PORTJ, TRISJ and LATJ Registers
PORTJ is available only on 80-pin devices.
EXAMPLE 9-9:
CLRF PORTJ ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTJ
Initialize PORTG by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RJ3:RJ0 as inputs RJ5:RJ4 as output RJ7:RJ6 as inputs
PORTJ is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISJ. Setting a TRISJ bit (= 1) will make the corresponding PORTJ pin an input (i.e., put the corresponding output driver in a high-impedance mode). Clearing a TRISJ bit (= 0) will make the corresponding PORTJ pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATJ) is also memory mapped. Read-modify-write operations on the LATJ register read and write the latched output value for PORTJ. All pins on PORTJ are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. Note: On a Power-on Reset, these pins are configured as digital inputs.
CLRF
LATJ
MOVLW 0xCF
MOVWF TRISJ
PORTJ is also multiplexed with LCD segment drives controlled by the LCDSE4 register. I/O port functions are only available when the segments are disabled.
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TABLE 9-18:
Pin Name RJ0/SEG32
PORTJ FUNCTIONS
Function RJ0 SEG32 TRIS Setting 0 1 x 0 1 SEG33 x 0 1 SEG34 x 0 1 SEG35 x 0 1 SEG39 x 0 1 SEG38 x 0 1 SEG37 x 0 1 SEG36 x I/O O I O O I O O I O O I O O I O O I O O I O O I O Buffer DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA DIG ST ANA Description LATJ<0> data output; disabled when LCD segment enabled. PORTJ<0> data input. Segment 32 analog output for LCD. LATJ<1> data output; disabled when LCD segment enabled. PORTJ<1> data input. Segment 33 analog output for LCD. LATJ<2> data output; disabled when LCD segment enabled. PORTJ<2> data input. Segment 34 analog output for LCD. LATJ<3> data output; disabled when LCD segment enabled. PORTJ<3> data input. Segment 35 analog output for LCD. LATJ<4> data output; disabled when LCD segment enabled. PORTJ<4> data input. Segment 39 analog output for LCD. LATJ<5> data output; disabled when LCD segment enabled. PORTJ<5> data input. Segment 38 analog output for LCD. LATJ<6> data output; disabled when LCD segment enabled. PORTJ<6> data input. Segment 37 analog output for LCD. LATJ<7> data output; disabled when LCD segment enabled. PORTJ<7> data input. Segment 36 analog output for LCD.
RJ1/SEG33
RJ1
RJ2/SEG34
RJ2
RJ3/SEG35
RJ3
RJ4/SEG39
RJ4
RJ5/SEG38
RJ5
RJ6/SEG37
RJ6
RJ7/SEG36
RJ7
Legend:
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option).
TABLE 9-19:
Name PORTJ LATJ TRISJ LCDSE4
SUMMARY OF REGISTERS ASSOCIATED WITH PORTJ
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page 62 62 62 SE36 SE35 SE34 SE33 SE32 64
Read PORTJ pin/Write PORTJ Data Latch LATJ Data Output Register PORTJ Data Direction Register SE39 SE38 SE37
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10.0 TIMER0 MODULE
The Timer0 module incorporates the following features: * Software selectable operation as a timer or counter in both 8-bit or 16-bit modes * Readable and writable registers * Dedicated 8-bit software programmable prescaler * Selectable clock source (internal or external) * Edge select for external clock * Interrupt-on-overflow The T0CON register (Register 10-1) controls all aspects of the module's operation, including the prescale selection. It is both readable and writable. A simplified block diagram of the Timer0 module in 8-bit mode is shown in Figure 10-1. Figure 10-2 shows a simplified block diagram of the Timer0 module in 16-bit mode.
REGISTER 10-1:
R/W-1 TMR0ON bit 7 Legend: R = Readable bit -n = Value at POR bit 7
T0CON: TIMER0 CONTROL REGISTER
R/W-1 T0CS R/W-1 T0SE R/W-1 PSA R/W-1 T0PS2 R/W-1 T0PS1 R/W-1 T0PS0 bit 0
R/W-1 T08BIT
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
TMR0ON: Timer0 On/Off Control bit 1 = Enables Timer0 0 = Stops Timer0 T08BIT: Timer0 8-Bit/16-Bit Control bit 1 = Timer0 is configured as an 8-bit timer/counter 0 = Timer0 is configured as a 16-bit timer/counter T0CS: Timer0 Clock Source Select bit 1 = Transition on T0CKI pin 0 = Internal instruction cycle clock (CLKO) T0SE: Timer0 Source Edge Select bit 1 = Increment on high-to-low transition on T0CKI pin 0 = Increment on low-to-high transition on T0CKI pin PSA: Timer0 Prescaler Assignment bit 1 = TImer0 prescaler is not assigned. Timer0 clock input bypasses prescaler. 0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output. T0PS2:T0PS0: Timer0 Prescaler Select bits 111 = 1:256 Prescale value 110 = 1:128 Prescale value 101 = 1:64 Prescale value 100 = 1:32 Prescale value 011 = 1:16 Prescale value 010 = 1:8 Prescale value 001 = 1:4 Prescale value 000 = 1:2 Prescale value
bit 6
bit 5
bit 4
bit 3
bit 2-0
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10.1 Timer0 Operation
Timer0 can operate as either a timer or a counter; the mode is selected by clearing the T0CS bit (T0CON<5>). In Timer mode (T0CS = 0), the module increments on every clock by default, unless a different prescaler value is selected (see Section 10.3 "Prescaler"). If the TMR0 register is written to, the increment is inhibited for the following two instruction cycles. The user can work around this by writing an adjusted value to the TMR0 register. The Counter mode is selected by setting the T0CS bit (= 1). In Counter mode, Timer0 increments either on every rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0 Source Edge Select bit, T0SE (T0CON<4>); clearing this bit selects the rising edge. Restrictions on the external clock input are discussed below. An external clock source can be used to drive Timer0; however, it must meet certain requirements to ensure that the external clock can be synchronized with the internal phase clock (TOSC). There is a delay between synchronization and the onset of incrementing the timer/counter.
10.2
Timer0 Reads and Writes in 16-Bit Mode
TMR0H is not the actual high byte of Timer0 in 16-bit mode; it is actually a buffered version of the real high byte of Timer0, which is not directly readable nor writable (refer to Figure 10-2). TMR0H is updated with the contents of the high byte of Timer0 during a read of TMR0L. This provides the ability to read all 16 bits of Timer0, without having to verify that the read of the high and low byte were valid, due to a rollover between successive reads of the high and low byte. Similarly, a write to the high byte of Timer0 must also take place through the TMR0H Buffer register. The high byte is updated with the contents of TMR0H when a write occurs to TMR0L. This allows all 16 bits of Timer0 to be updated at once.
FIGURE 10-1:
TIMER0 BLOCK DIAGRAM (8-BIT MODE)
FOSC/4 0 1 1 Sync with Internal Clocks (2 TCY Delay) 8 TMR0L Set TMR0IF on Overflow
T0CKI pin T0SE T0CS T0PS2:T0PS0 PSA
Programmable Prescaler 3
0
8 Internal Data Bus
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.
FIGURE 10-2:
FOSC/4
TIMER0 BLOCK DIAGRAM (16-BIT MODE)
0 1 1 Sync with Internal Clocks (2 TCY Delay) TMR0L TMR0 High Byte 8 Set TMR0IF on Overflow Read TMR0L Write TMR0L 8 8 TMR0H 8 Internal Data Bus
T0CKI pin T0SE T0CS T0PS2:T0PS0 PSA
Programmable Prescaler 3
0
8
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.
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10.3 Prescaler
10.3.1
An 8-bit counter is available as a prescaler for the Timer0 module. The prescaler is not directly readable or writable; its value is set by the PSA and T0PS2:T0PS0 bits (T0CON<3:0>), which determine the prescaler assignment and prescale ratio. Clearing the PSA bit assigns the prescaler to the Timer0 module. When it is assigned, prescale values from 1:2 through 1:256 in power-of-2 increments are selectable. When assigned to the Timer0 module, all instructions writing to the TMR0 register (e.g., CLRF TMR0, MOVWF TMR0, BSF TMR0, etc.) clear the prescaler count. Note: Writing to TMR0 when the prescaler is assigned to Timer0 will clear the prescaler count, but will not change the prescaler assignment.
SWITCHING PRESCALER ASSIGNMENT
The prescaler assignment is fully under software control and can be changed "on-the-fly" during program execution.
10.4
Timer0 Interrupt
The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h in 8-bit mode, or from FFFFh to 0000h in 16-bit mode. This overflow sets the TMR0IF flag bit. The interrupt can be masked by clearing the TMR0IE bit (INTCON<5>). Before re-enabling the interrupt, the TMR0IF bit must be cleared in software by the Interrupt Service Routine. Since Timer0 is shut down in Sleep mode, the TMR0 interrupt cannot awaken the processor from Sleep.
TABLE 10-1:
Name TMR0L TMR0H INTCON T0CON TRISA
REGISTERS ASSOCIATED WITH TIMER0
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page 60 60 INT0IE T0SE RBIE PSA TMR0IF T0PS2 INT0IF T0PS1 RBIF T0PS0 59 60 62 T0CS
Timer0 Register Low Byte Timer0 Register High Byte GIE/GIEH PEIE/GIEL TMR0IE TMR0ON T08BIT PORTA Data Direction Register
Legend: Shaded cells are not used by Timer0.
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11.0 TIMER1 MODULE
The Timer1 timer/counter module incorporates these features: * Software selectable operation as a 16-bit timer or counter * Readable and writable 8-bit registers (TMR1H and TMR1L) * Selectable clock source (internal or external) with device clock or Timer1 oscillator internal options * Interrupt-on-overflow * Reset on CCP Special Event Trigger * Device clock status flag (T1RUN) A simplified block diagram of the Timer1 module is shown in Figure 11-1. A block diagram of the module's operation in Read/Write mode is shown in Figure 11-2. The module incorporates its own low-power oscillator to provide an additional clocking option. The Timer1 oscillator can also be used as a low-power clock source for the microcontroller in power-managed operation. Timer1 can also be used to provide Real-Time Clock (RTC) functionality to applications with only a minimal addition of external components and code overhead. Timer1 is controlled through the T1CON Control register (Register 11-1). It also contains the Timer1 Oscillator Enable bit (T1OSCEN). Timer1 can be enabled or disabled by setting or clearing control bit, TMR1ON (T1CON<0>).
REGISTER 11-1:
R/W-0 RD16 bit 7 Legend: R = Readable bit -n = Value at POR bit 7
T1CON: TIMER1 CONTROL REGISTER
R-0 R/W-0 T1CKPS1 R/W-0 T1CKPS0 R/W-0 T1OSCEN R/W-0 T1SYNC R/W-0 TMR1CS R/W-0 TMR1ON bit 0
T1RUN
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
RD16: 16-Bit Read/Write Mode Enable bit 1 = Enables register read/write of TImer1 in one 16-bit operation 0 = Enables register read/write of Timer1 in two 8-bit operations T1RUN: Timer1 System Clock Status bit 1 = Device clock is derived from Timer1 oscillator 0 = Device clock is derived from another source T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value T1OSCEN: Timer1 Oscillator Enable bit 1 = Timer1 oscillator is enabled 0 = Timer1 oscillator is shut off The oscillator inverter and feedback resistor are turned off to eliminate power drain. T1SYNC: Timer1 External Clock Input Synchronization Select bit When TMR1CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR1CS = 0: This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0. TMR1CS: Timer1 Clock Source Select bit 1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge) 0 = Internal clock (FOSC/4) TMR1ON: Timer1 On bit 1 = Enables Timer1 0 = Stops Timer1
bit 6
bit 5-4
bit 3
bit 2
bit 1
bit 0
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11.1 Timer1 Operation
Timer1 can operate in one of these modes: * Timer * Synchronous Counter * Asynchronous Counter The operating mode is determined by the clock select bit, TMR1CS (T1CON<1>). When TMR1CS is cleared (= 0), Timer1 increments on every internal instruction cycle (FOSC/4). When the bit is set, Timer1 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. When Timer1 is enabled, the RC1/T1OSI and RC0/T1OSO/T13CKI pins become inputs. This means the values of TRISC<1:0> are ignored and the pins are read as `0'.
FIGURE 11-1:
TIMER1 BLOCK DIAGRAM
Timer1 Oscillator On/Off 1 FOSC/4 Internal Clock T1OSCEN T1SYNC TMR1ON
(1)
1 Prescaler 1, 2, 4, 8 2 Synchronize Detect 0
T1OSO/T13CKI
T1OSI
0 Sleep Input Timer1 On/Off
TMR1CS
T1CKPS1:T1CKPS0
Clear TMR1 (CCP Special Event Trigger)
TMR1L
TMR1 High Byte
Set TMR1IF on Overflow
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
FIGURE 11-2:
TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
Timer1 Oscillator 1
T1OSO/T13CKI FOSC/4 Internal Clock T1OSCEN(1) T1CKPS1:T1CKPS0 T1SYNC TMR1ON TMR1CS
1
Prescaler 1, 2, 4, 8 2
Synchronize Detect 0
T1OSI
0 Sleep Input Timer1 On/Off
Clear TMR1 (CCP Special Event Trigger)
TMR1L
TMR1 High Byte 8
Set TMR1IF on Overflow
Read TMR1L Write TMR1L 8 8 TMR1H 8 8 Internal Data Bus
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
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11.2 Timer1 16-Bit Read/Write Mode
Timer1 can be configured for 16-bit reads and writes (see Figure 11-2). When the RD16 control bit (T1CON<7>) is set, the address for TMR1H is mapped to a buffer register for the high byte of Timer1. A read from TMR1L will load the contents of the high byte of Timer1 into the Timer1 High Byte Buffer register. This provides the user with the ability to accurately read all 16 bits of Timer1 without having to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover between reads. A write to the high byte of Timer1 must also take place through the TMR1H Buffer register. The Timer1 high byte is updated with the contents of TMR1H when a write occurs to TMR1L. This allows a user to write all 16 bits to both the high and low bytes of Timer1 at once. The high byte of Timer1 is not directly readable or writable in this mode. All reads and writes must take place through the Timer1 High Byte Buffer register. Writes to TMR1H do not clear the Timer1 prescaler. The prescaler is only cleared on writes to TMR1L.
TABLE 11-1: CAPACITOR SELECTION FOR THE TIMER1 OSCILLATOR(2,3,4)
Osc Type LP Freq 32 kHz 27 C1 pF(1) C2 27 pF(1)
Note 1: Microchip suggests these values as a starting point in validating the oscillator circuit. 2: Higher capacitance increases the stability of the oscillator, but also increases the start-up time. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: Capacitor values are for design guidance only.
11.3.1
USING TIMER1 AS A CLOCK SOURCE
11.3
Timer1 Oscillator
An on-chip crystal oscillator circuit is incorporated between pins T1OSI (input) and T1OSO (amplifier output). It is enabled by setting the Timer1 Oscillator Enable bit, T1OSCEN (T1CON<3>). The oscillator is a low-power circuit rated for 32 kHz crystals. It will continue to run during all power-managed modes. The circuit for a typical LP oscillator is shown in Figure 11-3. Table 11-1 shows the capacitor selection for the Timer1 oscillator. The user must provide a software time delay to ensure proper start-up of the Timer1 oscillator.
The Timer1 oscillator is also available as a clock source in power-managed modes. By setting the clock select bits, SCS1:SCS0 (OSCCON<1:0>), to `01', the device switches to SEC_RUN mode; both the CPU and peripherals are clocked from the Timer1 oscillator. If the IDLEN bit (OSCCON<7>) is cleared and a SLEEP instruction is executed, the device enters SEC_IDLE mode. Additional details are available in Section 3.0 "Power-Managed Modes". Whenever the Timer1 oscillator is providing the clock source, the Timer1 system clock status flag, T1RUN (T1CON<6>), is set. This can be used to determine the controller's current clocking mode. It can also indicate the clock source being currently used by the Fail-Safe Clock Monitor. If the Clock Monitor is enabled and the Timer1 oscillator fails while providing the clock, polling the T1RUN bit will indicate whether the clock is being provided by the Timer1 oscillator or another source.
FIGURE 11-3:
EXTERNAL COMPONENTS FOR THE TIMER1 LP OSCILLATOR
PIC18FXXXX
T1OSI XTAL 32.768 kHz T1OSO
C1 33 pF
11.3.2
LOW-POWER TIMER1 OPTION
C2 33 pF Note: See the Notes with Table 11-1 for additional information about capacitor selection.
The Timer1 oscillator can operate at two distinct levels of power consumption based on device configuration. When the LPT1OSC Configuration bit is set, the Timer1 oscillator operates in a low-power mode. When LPT1OSC is not set, Timer1 operates at a higher power level. Power consumption for a particular mode is relatively constant, regardless of the device's operating mode. The default Timer1 configuration is the higher power mode. As the Low-Power Timer1 mode tends to be more sensitive to interference, high noise environments may cause some oscillator instability. The low-power option is therefore best suited for low noise applications where power conservation is an important design consideration.
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11.3.3 TIMER1 OSCILLATOR LAYOUT CONSIDERATIONS
11.5
Resetting Timer1 Using the CCP Special Event Trigger
The Timer1 oscillator circuit draws very little power during operation. Due to the low-power nature of the oscillator, it may also be sensitive to rapidly changing signals in close proximity. The oscillator circuit, shown in Figure 11-3, should be located as close as possible to the microcontroller. There should be no circuits passing within the oscillator circuit boundaries other than VSS or VDD. If a high-speed circuit must be located near the oscillator (such as the CCP1 pin in Output Compare or PWM mode, or the primary oscillator using the OSC2 pin), a grounded guard ring around the oscillator circuit, as shown in Figure 11-4, may be helpful when used on a single sided PCB or in addition to a ground plane.
If either of the CCP modules is configured in Compare mode to generate a Special Event Trigger (CCP1M3:CCP1M0 or CCP2M3:CCP2M0 = 1011), this signal will reset Timer1. The trigger from CCP2 will also start an A/D conversion if the A/D module is enabled (see Section 14.3.4 "Special Event Trigger" for more information.). The module must be configured as either a timer or a synchronous counter to take advantage of this feature. When used this way, the CCPRH:CCPRL register pair effectively becomes a period register for Timer1. If Timer1 is running in Asynchronous Counter mode, this Reset operation may not work. In the event that a write to Timer1 coincides with a Special Event Trigger, the write operation will take precedence. Note: The Special Event Triggers from the CCP2 module will not set the TMR1IF interrupt flag bit (PIR1<0>).
FIGURE 11-4:
OSCILLATOR CIRCUIT WITH GROUNDED GUARD RING
VDD VSS OSC1 OSC2
11.6
Using Timer1 as a Real-Time Clock
RC0 RC1
RC2 Note: Not drawn to scale.
Adding an external LP oscillator to Timer1 (such as the one described in Section 11.3 "Timer1 Oscillator", above) gives users the option to include RTC functionality to their applications. This is accomplished with an inexpensive watch crystal to provide an accurate time base and several lines of application code to calculate the time. When operating in Sleep mode and using a battery or supercapacitor as a power source, it can completely eliminate the need for a separate RTC device and battery backup. The application code routine, RTCisr, shown in Example 11-1, demonstrates a simple method to increment a counter at one-second intervals using an Interrupt Service Routine. Incrementing the TMR1 register pair to overflow, triggers the interrupt and calls the routine, which increments the seconds counter by one; additional counters for minutes and hours are incremented as the previous counter overflows. Since the register pair is 16 bits wide, counting up to overflow the register directly from a 32.768 kHz clock would take 2 seconds. To force the overflow at the required one-second intervals, it is necessary to preload it. The simplest method is to set the Most Significant bit of TMR1H with a BSF instruction. Note that the TMR1L register is never preloaded or altered; doing so may introduce cumulative error over many cycles. For this method to be accurate, Timer1 must operate in Asynchronous mode and the Timer1 overflow interrupt must be enabled (PIE1<0> = 1), as shown in the routine, RTCinit. The Timer1 oscillator must also be enabled and running at all times.
11.4
Timer1 Interrupt
The TMR1 register pair (TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The Timer1 interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit, TMR1IF (PIR1<0>). This interrupt can be enabled or disabled by setting or clearing the Timer1 Interrupt Enable bit, TMR1IE (PIE1<0>).
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EXAMPLE 11-1:
RTCinit MOVLW MOVWF CLRF MOVLW MOVWF CLRF CLRF MOVLW MOVWF BSF RETURN RTCisr BSF BCF INCF MOVLW CPFSGT RETURN CLRF INCF MOVLW CPFSGT RETURN CLRF INCF MOVLW CPFSGT RETURN MOVLW MOVWF RETURN TMR1H, 7 PIR1, TMR1IF secs, F .59 secs secs mins, F .59 mins mins hours, F .23 hours .01 hours ; ; ; ; ; ; ; ; ; ; ; ; Preload for 1 sec overflow Clear interrupt flag Increment seconds 60 seconds elapsed? No, done Clear seconds Increment minutes 60 minutes elapsed? No, done clear minutes Increment hours 24 hours elapsed? 80h TMR1H TMR1L b'00001111' T1OSC secs mins .12 hours PIE1, TMR1IE ; Preload TMR1 register pair ; for 1 second overflow ; Configure for external clock, ; Asynchronous operation, external oscillator ; Initialize timekeeping registers ;
IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
; Enable Timer1 interrupt
; No, done ; Reset hours to 1 ; Done
TABLE 11-2:
Name INTCON PIR1 PIE1 IPR1 TMR1L TMR1H T1CON
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Bit 7 Bit 6 Bit 5 TMR0IE RC1IF RC1IE RC1IP Bit 4 INT0IE TX1IF TX1IE TX1IP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Reset Values on Page 59 61 61 61 60 60 TMR1CS TMR1ON 60
GIE/GIEH PEIE/GIEL -- -- -- ADIF ADIE ADIP
Timer1 Register Low Byte Timer1 Register High Byte RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the Timer1 module.
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12.0 TIMER2 MODULE
12.1 Timer2 Operation
The Timer2 timer module incorporates the following features: * 8-bit Timer and Period registers (TMR2 and PR2, respectively) * Readable and writable (both registers) * Software programmable prescaler (1:1, 1:4 and 1:16) * Software programmable postscaler (1:1 through 1:16) * Interrupt on TMR2 to PR2 match * Optional use as the shift clock for the MSSP module The module is controlled through the T2CON register (Register 12-1), which enables or disables the timer and configures the prescaler and postscaler. Timer2 can be shut off by clearing control bit, TMR2ON (T2CON<2>), to minimize power consumption. A simplified block diagram of the module is shown in Figure 12-1. In normal operation, TMR2 is incremented from 00h on each clock (FOSC/4). A 2-bit counter/prescaler on the clock input gives direct input, divide-by-4 and divide-by-16 prescale options; these are selected by the prescaler control bits, T2CKPS1:T2CKPS0 (T2CON<1:0>). The value of TMR2 is compared to that of the Period register, PR2, on each clock cycle. When the two values match, the comparator generates a match signal as the timer output. This signal also resets the value of TMR2 to 00h on the next cycle and drives the output counter/postscaler (see Section 12.2 "Timer2 Interrupt"). The TMR2 and PR2 registers are both directly readable and writable. The TMR2 register is cleared on any device Reset, while the PR2 register initializes at FFh. Both the prescaler and postscaler counters are cleared on the following events: * a write to the TMR2 register * a write to the T2CON register * any device Reset (Power-on Reset, MCLR Reset, Watchdog Timer Reset, or Brown-out Reset) TMR2 is not cleared when T2CON is written.
REGISTER 12-1:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7 bit 6-3
T2CON: TIMER2 CONTROL REGISTER
R/W-0 T2OUTPS2 R/W-0 T2OUTPS1 R/W-0 T2OUTPS0 R/W-0 TMR2ON R/W-0 T2CKPS1 R/W-0 T2CKPS0 bit 0
R/W-0 T2OUTPS3
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
Unimplemented: Read as `0' T2OUTPS3:T2OUTPS0: Timer2 Output Postscale Select bits 0000 = 1:1 Postscale 0001 = 1:2 Postscale * * * 1111 = 1:16 Postscale TMR2ON: Timer2 On bit 1 = Timer2 is on 0 = Timer2 is off T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits 00 = Prescaler is 1 01 = Prescaler is 4 1x = Prescaler is 16
bit 2
bit 1-0
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12.2 Timer2 Interrupt 12.3 TMR2 Output
Timer2 also can generate an optional device interrupt. The Timer2 output signal (TMR2 to PR2 match) provides the input for the 4-bit output counter/postscaler. This counter generates the TMR2 match interrupt flag which is latched in TMR2IF (PIR1<1>). The interrupt is enabled by setting the TMR2 Match Interrupt Enable bit, TMR2IE (PIE1<1>). A range of 16 postscale options (from 1:1 through 1:16 inclusive) can be selected with the postscaler control bits, T2OUTPS3:T2OUTPS0 (T2CON<6:3>). The unscaled output of TMR2 is available primarily to the CCP modules, where it is used as a time base for operations in PWM mode. Timer2 can be optionally used as the shift clock source for the MSSP module operating in SPI mode. Additional information is provided in Section 15.0 "Master Synchronous Serial Port (MSSP) Module".
FIGURE 12-1:
TIMER2 BLOCK DIAGRAM
4 2 TMR2/PR2 Match Comparator 8 PR2 8 1:1 to 1:16 Postscaler
T2OUTPS3:T2OUTPS0 T2CKPS1:T2CKPS0
Set TMR2IF TMR2 Output (to PWM or MSSP)
FOSC/4
1:1, 1:4, 1:16 Prescaler
Reset TMR2 8
Internal Data Bus
TABLE 12-1:
Name
REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Bit 6 Bit 5 TMR0IE RC1IF RC1IE RC1IP Bit 4 INT0IE TX1IF TX1IE TX1IP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Reset Values on Page 59 61 61 61 60 60 60
Bit 7
INTCON GIE/GIEH PEIE/GIEL PIR1 PIE1 IPR1 TMR2 T2CON PR2 -- -- -- -- ADIF ADIE ADIP
Timer2 Register T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 Timer2 Period Register
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the Timer2 module.
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13.0 TIMER3 MODULE
The Timer3 timer/counter module incorporates these features: * Software selectable operation as a 16-bit timer or counter * Readable and writable 8-bit registers (TMR3H and TMR3L) * Selectable clock source (internal or external), with device clock or Timer1 oscillator internal options * Interrupt-on-overflow * Module Reset on CCP Special Event Trigger A simplified block diagram of the Timer3 module is shown in Figure 13-1. A block diagram of the module's operation in Read/Write mode is shown in Figure 13-2. The Timer3 module is controlled through the T3CON register (Register 13-1). It also selects the clock source options for the CCP modules (see Section 14.1.1 "CCP Modules and Timer Resources" for more information).
REGISTER 13-1:
R/W-0 RD16 bit 7 Legend: R = Readable bit -n = Value at POR bit 7
T3CON: TIMER3 CONTROL REGISTER
R/W-0 T3CKPS1 R/W-0 T3CKPS0 R/W-0 T3CCP1 R/W-0 T3SYNC R/W-0 TMR3CS R/W-0 TMR3ON bit 0
R/W-0 T3CCP2
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
RD16: 16-Bit Read/Write Mode Enable bit 1 = Enables register read/write of Timer3 in one 16-bit operation 0 = Enables register read/write of Timer3 in two 8-bit operations T3CCP2:T3CCP1: Timer3 and Timer1 to CCPx Enable bits 1x = Timer3 is the capture/compare clock source for the CCPx modules 01 = Timer3 is the capture/compare clock source for the CCP2 module; Timer1 is the capture/compare clock source for the CCP1 module 00 = Timer1 is the capture/compare clock source for the CCPx modules T3CKPS1:T3CKPS0: Timer3 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value T3SYNC: Timer3 External Clock Input Synchronization Control bit (Not usable if the device clock comes from Timer1/Timer3.) When TMR3CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR3CS = 0: This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0. TMR3CS: Timer3 Clock Source Select bit 1 = External clock input from Timer1 oscillator or T13CKI (on the rising edge after the first falling edge) 0 = Internal clock (FOSC/4) TMR3ON: Timer3 On bit 1 = Enables Timer3 0 = Stops Timer3
bit 6,3
bit 5-4
bit 2
bit 1
bit 0
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13.1 Timer3 Operation
Timer3 can operate in one of three modes: * Timer * Synchronous counter * Asynchronous counter The operating mode is determined by the clock select bit, TMR3CS (T3CON<1>). When TMR3CS is cleared (= 0), Timer3 increments on every internal instruction cycle (FOSC/4). When the bit is set, Timer3 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. As with Timer1, the RC1/T1OSI and RC0/T1OSO/T13CKI pins become inputs when the Timer1 oscillator is enabled. This means the values of TRISC<1:0> are ignored and the pins are read as `0'.
FIGURE 13-1:
TIMER3 BLOCK DIAGRAM
Timer1 Oscillator 1
T1OSO/T13CKI FOSC/4 Internal Clock T1OSCEN T3SYNC TMR3ON
(1)
1
Prescaler 1, 2, 4, 8 2
Synchronize Detect 0
T1OSI
0 Sleep Input Timer3 On/Off
TMR3CS
T3CKPS1:T3CKPS0
CCP Special Event Trigger T3CCPx
Clear TMR3
TMR3L
TMR3 High Byte
Set TMR3IF on Overflow
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
FIGURE 13-2:
TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
Timer1 Oscillator Timer1 Clock Input 1 1 FOSC/4 Internal Clock T1OSCEN T3CKPS1:T3CKPS0 T3SYNC TMR3ON
(1)
T1OSO/T13CKI
Prescaler 1, 2, 4, 8 2
Synchronize Detect 0
T1OSI
0 Sleep Input Timer3 On/Off
TMR3CS
CCP Special Event Trigger T3CCPx
Clear TMR3
TMR3L
TMR3 High Byte 8
Set TMR3IF on Overflow
Read TMR3L Write TMR3L 8 8 TMR3H 8 8 Internal Data Bus Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
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13.2 Timer3 16-Bit Read/Write Mode 13.4 Timer3 Interrupt
Timer3 can be configured for 16-bit reads and writes (see Figure 13-2). When the RD16 control bit (T3CON<7>) is set, the address for TMR3H is mapped to a buffer register for the high byte of Timer3. A read from TMR3L will load the contents of the high byte of Timer3 into the Timer3 High Byte Buffer register. This provides the user with the ability to accurately read all 16 bits of Timer1 without having to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover between reads. A write to the high byte of Timer3 must also take place through the TMR3H Buffer register. The Timer3 high byte is updated with the contents of TMR3H when a write occurs to TMR3L. This allows a user to write all 16 bits to both the high and low bytes of Timer3 at once. The high byte of Timer3 is not directly readable or writable in this mode. All reads and writes must take place through the Timer3 High Byte Buffer register. Writes to TMR3H do not clear the Timer3 prescaler. The prescaler is only cleared on writes to TMR3L. The TMR3 register pair (TMR3H:TMR3L) increments from 0000h to FFFFh and overflows to 0000h. The Timer3 interrupt, if enabled, is generated on overflow and is latched in interrupt flag bit, TMR3IF (PIR2<1>). This interrupt can be enabled or disabled by setting or clearing the Timer3 Interrupt Enable bit, TMR3IE (PIE2<1>).
13.5
Resetting Timer3 Using the CCP Special Event Trigger
If either of the CCP modules is configured in Compare mode to generate a Special Event Trigger (CCP1M3:CCP1M0 or CCP2M3:CCP2M0 = 1011), this signal will reset Timer1. The trigger from CCP2 will also start an A/D conversion if the A/D module is enabled (see Section 14.3.4 "Special Event Trigger" for more information.). The module must be configured as either a timer or synchronous counter to take advantage of this feature. When used this way, the CCPR2H:CCPR2L register pair effectively becomes a Period register for Timer3. If Timer3 is running in Asynchronous Counter mode, the Reset operation may not work. In the event that a write to Timer3 coincides with a Special Event Trigger from a CCP module, the write will take precedence. Note: The Special Event Triggers from the CCP2 module will not set the TMR3IF interrupt flag bit (PIR2<1>).
13.3
Using the Timer1 Oscillator as the Timer3 Clock Source
The Timer1 internal oscillator may be used as the clock source for Timer3. The Timer1 oscillator is enabled by setting the T1OSCEN (T1CON<3>) bit. To use it as the Timer3 clock source, the TMR3CS bit must also be set. As previously noted, this also configures Timer3 to increment on every rising edge of the oscillator source. The Timer1 oscillator is described in Section 11.0 "Timer1 Module".
TABLE 13-1:
Name INTCON PIR2 PIE2 IPR2 TMR3L TMR3H T1CON T3CON
REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER
Bit 7 Bit 6 Bit 5 TMR0IE -- -- -- Bit 4 INT0IE -- -- -- Bit 3 RBIE BCLIF BCLIE BCLIP Bit 2 TMR0IF HLVDIF HLVDIE HLVDIP Bit 1 INT0IF TMR3IF TMR3IE TMR3IP Bit 0 RBIF CCP2IF CCP2IE CCP2IP Reset Values on Page 59 61 61 61 61 61 TMR1CS TMR3CS TMR1ON TMR3ON 60 61 T3CCP1 T3SYNC
GIE/GIEH PEIE/GIEL OSCFIF OSCFIE OSCFIP CMIF CMIE CMIP
Timer3 Register Low Byte Timer3 Register High Byte RD16 RD16 T1RUN T3CCP2 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC T3CKPS1 T3CKPS0
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the Timer3 module.
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14.0 CAPTURE/COMPARE/PWM (CCP) MODULES
Each CCP module contains a 16-bit register which can operate as a 16-bit Capture register, a 16-bit Compare register or a PWM Master/Slave Duty Cycle register. For the sake of clarity, all CCP module operation in the following sections is described with respect to CCP2, but is equally applicable to CCP1.
PIC18F6390/6490/8390/8490 devices have two CCP (Capture/Compare/PWM) modules, designated CCP1 and CCP2. Both modules implement standard capture, compare and Pulse-Width Modulation (PWM) modes.
REGISTER 14-1:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7-6 bit 5-4 U-0 --
CCPxCON: CCPx CONTROL REGISTER
R/W-0 DCxB1 R/W-0 DCxB0 R/W-0 CCPxM3 R/W-0 CCPxM2 R/W-0 CCPxM1 R/W-0 CCPxM0 bit 0
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
Unimplemented: Read as `0' DCxB1:DCxB0: PWM Duty Cycle bit 1 and bit 0 for CCPx Module Capture mode: Unused. Compare mode: Unused. PWM mode: These bits are the two Least Significant bits (bit 1 and bit 0) of the 10-bit PWM duty cycle. The eight Most Significant bits (DCxB9:DCxB2) of the duty cycle are found in CCPRxL. CCPxM3:CCPxM0: CCPx Module Mode Select bits 0000 = Capture/Compare/PWM disabled (resets CCPx module) 0001 = Reserved 0010 = Compare mode, toggle output on match (CCPxIF bit is set) 0011 = Reserved 0100 = Capture mode, every falling edge 0101 = Capture mode, every rising edge 0110 = Capture mode, every 4th rising edge 0111 = Capture mode, every 16th rising edge 1000 = Compare mode: initialize CCPx pin low; on compare match, force CCPx pin high (CCPxIF bit is set) 1001 = Compare mode: initialize CCPx pin high; on compare match, force CCPx pin low (CCPxIF bit is set) 1010 = Compare mode: generate software interrupt on compare match (CCPxIF bit is set, CCPx pin reflects I/O state) 1011 = Compare mode: trigger special event, reset timer, start A/D conversion on CCPx match (CCPxIF bit is set)(1) 11xx = PWM mode CCPxM3:CCPxM0 = 1011 will only reset the timer and not start the A/D conversion on the CCPx match.
bit 3-0
Note 1:
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14.1 CCP Module Configuration
Each Capture/Compare/PWM module is associated with a control register (generically, CCPxCON) and a data register (CCPRx). The data register in turn is comprised of two 8-bit registers: CCPRxL (low byte) and CCPRxH (high byte). All registers are both readable and writable. The assignment of a particular timer to a module is determined by the Timer to CCP enable bits in the T3CON register (Register 13-1). Both modules may be active at any given time and may share the same timer resource if they are configured to operate in the same mode (capture/compare or PWM) at the same time. The interactions between the two modules are summarized in Table 14-2. Depending on the configuration selected, up to four timers may be active at once, with modules in the same configuration (capture/compare or PWM) sharing timer resources. The possible configurations are shown in Figure 14-1.
14.1.1
CCP MODULES AND TIMER RESOURCES
The CCP modules utilize Timers 1, 2 or 3, depending on the mode selected. Timer1 and Timer3 are available to modules in Capture or Compare modes, while Timer2 is available for modules in PWM mode.
14.1.2
CCP2 PIN ASSIGNMENT
TABLE 14-1:
CCP MODE - TIMER RESOURCE
Timer Resource Timer1 or Timer3 Timer1 or Timer3 Timer2
CCP Mode Capture Compare PWM
The pin assignment for CCP2 (capture input, compare and PWM output) can change based on device configuration. The CCP2MX Configuration bit determines which pin CCP2 is multiplexed to. By default, it is assigned to RC1 (CCP2MX = 1). If the Configuration bit is cleared, CCP2 is multiplexed with RE7. Changing the pin assignment of CCP2 does not automatically change any requirements for configuring the port pin. Users must always verify that the appropriate TRIS register is configured correctly for CCP2 operation, regardless of where it is located.
FIGURE 14-1:
CCP AND TIMER INTERCONNECT CONFIGURATIONS
T3CCP<2:1> = 01 TMR1 TMR3 T3CCP<2:1> = 1x TMR1 TMR3
T3CCP<2:1> = 00 TMR1 TMR3
CCP1 CCP2
CCP1 CCP2
CCP1 CCP2
TMR2 Timer1 is used for all capture and compare operations for all CCP modules. Timer2 is used for PWM operations for all CCP modules. Modules may share either timer resource as a common time base.
TMR2 Timer1 is used for capture and compare operations for CCP1 and Timer 3 is used for CCP2. Both the modules use Timer2 as a common time base if they are in PWM modes.
TMR2 Timer3 is used for all capture and compare operations for all CCP modules. Timer2 is used for PWM operations for all CCP modules. Modules may share either timer resource as a common time base.
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TABLE 14-2:
Capture Capture
INTERACTIONS BETWEEN CCP1 AND CCP2 FOR TIMER RESOURCES
Interaction Each module can use TMR1 or TMR3 as the time base. The time base can be different for each CCP. CCP2 can be configured for the Special Event Trigger to reset TMR1 or TMR3 (depending upon which time base is used). Automatic A/D conversions on trigger event can also be done. Operation of CCP1 could be affected if it is using the same timer as a time base. CCP1 can be configured for the Special Event Trigger to reset TMR1 or TMR3 (depending upon which time base is used). Operation of CCP2 could be affected if it is using the same timer as a time base. Either module can be configured for the Special Event Trigger to reset the time base. Automatic A/D conversions on CCP2 trigger event can be done. Conflicts may occur if both modules are using the same time base. None None None None Both PWMs will have the same frequency and update rate (TMR2 interrupt). Capture Compare
CCP1 Mode CCP2 Mode
Compare
Capture
Compare
Compare
Capture Compare PWM* PWM* PWM* *
PWM* PWM* Capture Compare PWM
Includes standard and Enhanced PWM operation.
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14.2 Capture Mode
14.2.3 SOFTWARE INTERRUPT
In Capture mode, the CCPR2H:CCPR2L register pair captures the 16-bit value of the TMR1 or TMR3 registers when an event occurs on the CCP2 pin (RC1 or RE7, depending on device configuration). An event is defined as one of the following: * * * * every falling edge every rising edge every 4th rising edge every 16th rising edge When the Capture mode is changed, a false capture interrupt may be generated. The user should keep bit CCP2IE (PIE2<0>) clear to avoid false interrupts and should clear the flag bit, CCP2IF, following any such change in operating mode.
14.2.4
CCP PRESCALER
The event is selected by the mode select bits, CCP2M3:CCP2M0 (CCP2CON<3:0>). When a capture is made, the interrupt request flag bit, CCP2IF (PIR2<0>), is set; it must be cleared in software. If another capture occurs before the value in register CCPR2 is read, the old captured value is overwritten by the new captured value.
There are four prescaler settings in Capture mode; they are specified as part of the operating mode selected by the mode select bits (CCP2M3:CCP2M0). Whenever the CCP module is turned off, or the CCP module is not in Capture mode, the prescaler counter is cleared. This means that any Reset will clear the prescaler counter. Switching from one capture prescaler to another may generate an interrupt. Also, the prescaler counter will not be cleared; therefore, the first capture may be from a non-zero prescaler. Example 14-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter and will not generate the "false" interrupt.
14.2.1
CCP PIN CONFIGURATION
In Capture mode, the appropriate CCPx pin should be configured as an input by setting the corresponding TRIS direction bit. Note: If RC1/CCP2 or RE7/CCP2 is configured as an output, a write to the port can cause a capture condition.
EXAMPLE 14-1:
CLRF MOVLW
CHANGING BETWEEN CAPTURE PRESCALERS
14.2.2
TIMER1/TIMER3 MODE SELECTION
MOVWF
The timers that are to be used with the capture feature (Timer1 and/or Timer3) must be running in Timer mode or Synchronized Counter mode. In Asynchronous Counter mode, the capture operation may not work. The timer to be used with each CCP module is selected in the T3CON register (see Section 14.1.1 "CCP Modules and Timer Resources").
CCP2CON ; Turn CCP module off NEW_CAPT_PS ; Load WREG with the ; new prescaler mode ; value and CCP ON CCP2CON ; Load CCP2CON with ; this value
FIGURE 14-2:
CAPTURE MODE OPERATION BLOCK DIAGRAM
Set CCP1IF T3CCP2 TMR3H TMR3 Enable CCPR1H TMR1 Enable TMR1H Set CCP2IF TMR3H TMR3 Enable CCPR2H TMR1 Enable T3CCP2 T3CCP1 TMR1H TMR1L CCPR2L TMR3L TMR1L CCPR1L TMR3L
CCP1 pin Prescaler / 1, 4, 16 and Edge Detect T3CCP2 CCP1CON<3:0> Q1:Q4 CCP2CON<3:0> 4 4 4 T3CCP1 T3CCP2
CCP2 pin Prescaler / 1, 4, 16 and Edge Detect
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14.3 Compare Mode
14.3.3 SOFTWARE INTERRUPT MODE
In Compare mode, the 16-bit CCPR2 register value is constantly compared against either the TMR1 or TMR3 register pair value. When a match occurs, the CCP2 pin can be: * * * * driven high driven low toggled (high-to-low or low-to-high) remain unchanged (that is, reflects the state of the I/O latch) When the Generate Software Interrupt mode is chosen (CCP2M3:CCP2M0 = 1010), the CCP2 pin is not affected. Only a CCP interrupt is generated if enabled and the CCP2IE bit is set.
14.3.4
SPECIAL EVENT TRIGGER
The action on the pin is based on the value of the mode select bits (CCP2M3:CCP2M0). At the same time, the interrupt flag bit, CCP2IF, is set.
Both CCP modules are equipped with a Special Event Trigger. This is an internal hardware signal generated in Compare mode to trigger actions by other modules. The Special Event Trigger is enabled by selecting the Compare Special Event Trigger mode (CCP2M3:CCP2M0 = 1011). For either CCP module, the Special Event Trigger resets the Timer register pair for whichever timer resource is currently assigned as the module's time base. This allows the CCPRx registers to serve as a programmable Period register for either timer. The Special Event Trigger for CCP2 can also start an A/D conversion. In order to do this, the A/D converter must already be enabled. Note: The Special Event Trigger of CCP1 only resets Timer1/Timer3 and cannot start an A/D conversion even when the A/D converter is enabled.
14.3.1
CCP PIN CONFIGURATION
The user must configure the CCPx pin as an output by clearing the appropriate TRIS bit. Note: Clearing the CCP2CON register will force the RC1 or RE7 compare output latch (depending on device configuration) to the default low level. This is not the PORTC or PORTE I/O data latch.
14.3.2
TIMER1/TIMER3 MODE SELECTION
Timer1 and/or Timer3 must be running in Timer mode, or Synchronized Counter mode, if the CCP module is using the compare feature. In Asynchronous Counter mode, the compare operation may not work.
FIGURE 14-3:
COMPARE MODE OPERATION BLOCK DIAGRAM
Set CCP1IF Special Event Trigger (Timer1 Reset) CCP1 pin Comparator Compare Match Output Logic 4 CCP1CON<3:0> S R TRIS Output Enable Q
CCPR1H
CCPR1L
0
TMR1H
TMR1L
0
1
TMR3H T3CCP1
TMR3L
1 T3CCP2
Special Event Trigger (Timer1/Timer3 Reset, A/D Trigger)
Set CCP2IF Comparator Compare Match Output Logic 4 CCP2CON<3:0> S R Q
CCP2 pin
CCPR2H
CCPR2L
TRIS Output Enable
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TABLE 14-3:
Name INTCON RCON PIR1 PIE1 IPR1 PIR2 PIE2 IPR2 TRISC TRISE TMR1L TMR1H T1CON TMR3H TMR3L T3CON CCPR1L CCPR1H CCP1CON CCPR2L CCPR2H CCP2CON
REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3
Bit 7 Bit 6 Bit 5 Bit 4 INT0IE RI TX1IF TX1IE TX1IP -- -- -- Bit 3 RBIE TO SSPIF SSPIE SSPIP BCLIF BCLIE BCLIP -- Bit 2 TMR0IF PD CCP1IF CCP1IE CCP1IP HLVDIF HLVDIE HLVDIP -- Bit 1 INT0IF POR TMR2IF TMR2IE TMR2IP TMR3IF TMR3IE TMR3IP -- Bit 0 RBIF BOR TMR1IF TMR1IE TMR1IP CCP2IF CCP2IE CCP2IP -- Reset Values on Page 59 60 61 61 61 61 61 61 62 62 60 60 TMR1CS TMR1ON 60 61 61 T3CCP1 T3SYNC TMR3CS TMR3ON 61 61 61 CCP1M3 CCP1M2 CCP1M1 CCP1M0 61 61 61 CCP2M3 CCP2M2 CCP2M1 CCP2M0 61
GIE/GIEH PEIE/GIEL TMR0IE IPEN -- -- -- OSCFIF OSCFIE OSCFIP SBOREN ADIF ADIE ADIP CMIF CMIE CMIP -- RC1IF RC1IE RC1IP -- -- --
PORTC Data Direction Register PORTE Data Direction Register Timer1 Register Low Byte Timer1 Register High Byte RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC Timer3 Register High Byte Timer3 Register Low Byte RD16 T3CCP2 T3CKPS1 T3CKPS0 Capture/Compare/PWM Register 1 Low Byte Capture/Compare/PWM Register 1 High Byte -- -- DC1B1 DC1B0 Capture/Compare/PWM Register 2 Low Byte Capture/Compare/PWM Register 2 High Byte -- -- DC2B1 DC2B0
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by capture/compare, Timer1 or Timer3.
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14.4 PWM Mode
In Pulse-Width Modulation (PWM) mode, the CCP2 pin produces up to a 10-bit resolution PWM output. Since the CCP2 pin is multiplexed with a PORTC or PORTE data latch, the appropriate TRIS bit must be cleared to make the CCP2 pin an output. Note: Clearing the CCP2CON register will force the RC1 or RE7 output latch (depending on device configuration) to the default low level. This is not the PORTC or PORTE I/O data latch. A PWM output (Figure 14-5) has a time base (period) and a time that the output stays high (duty cycle). The frequency of the PWM is the inverse of the period (1/period).
FIGURE 14-5:
Period
PWM OUTPUT
Duty Cycle TMR2 = PR2 TMR2 = Duty Cycle TMR2 = PR2
Figure 14-4 shows a simplified block diagram of the CCP2 module in PWM mode. For a step-by-step procedure on how to set up the CCP module for PWM operation, see Section 14.4.3 "Setup for PWM Operation".
14.4.1
PWM PERIOD
FIGURE 14-4:
Duty Cycle Registers CCPR2L
SIMPLIFIED PWM BLOCK DIAGRAM
CCP2CON<5:4>
The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the following formula:
EQUATION 14-1:
PWM Period = (PR2) + 1] * 4 * TOSC * (TMR2 Prescale Value)
CCPR2H (Slave) R Q CCP2 TMR2 (Note 1) S TRISC<2> Clear Timer, CCP2 pin and latch D.C.
PWM frequency is defined as 1/[PWM period]. When TMR2 is equal to PR2, the following three events occur on the next increment cycle: * TMR2 is cleared * The CCP2 pin is set (exception: if PWM duty cycle = 0%, the CCP2 pin will not be set) * The PWM duty cycle is latched from CCPR2L into CCPR2H Note: The Timer2 postscalers (see Section 12.0 "Timer2 Module") are not used in the determination of the PWM frequency. The postscaler could be used to have a servo update rate at a different frequency than the PWM output.
Comparator
Comparator
PR2
Note 1: The 8-bit TMR2 value is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler, to create the 10-bit time base.
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14.4.2 PWM DUTY CYCLE
The PWM duty cycle is specified by writing to the CCPR2L register and to the CCP2CON<5:4> bits. Up to 10-bit resolution is available. The CCPR2L contains the eight MSbs and the CCP2CON<5:4> bits contain the two LSbs. This 10-bit value is represented by CCPR2L:CCP2CON<5:4>. The following equation is used to calculate the PWM duty cycle in time: The CCPR2H register and a 2-bit internal latch are used to double-buffer the PWM duty cycle. This double-buffering is essential for glitchless PWM operation. When the CCPR2H and 2-bit latch match TMR2, concatenated with an internal 2-bit Q clock or 2 bits of the TMR2 prescaler, the CCP2 pin is cleared. The maximum PWM resolution (bits) for a given PWM frequency is given by the equation:
EQUATION 14-2:
PWM Duty Cycle = (CCPR2L:CCP2CON<5:4>) * TOSC * (TMR2 Prescale Value) CCPR2L and CCP2CON<5:4> can be written to at any time, but the duty cycle value is not latched into CCPR2H until after a match between PR2 and TMR2 occurs (i.e., the period is complete). In PWM mode, CCPR2H is a read-only register.
EQUATION 14-3:
FOSC log --------------- FPWM PWM Resolution (max) = -----------------------------bits log ( 2 ) Note: If the PWM duty cycle value is longer than the PWM period, the CCP2 pin will not be cleared.
TABLE 14-4:
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
2.44 kHz 16 FFh 14 9.77 kHz 4 FFh 12 39.06 kHz 1 FFh 10 156.25 kHz 1 3Fh 8 312.50 kHz 1 1Fh 7 416.67 kHz 1 17h 6.58
PWM Frequency Timer Prescaler (1, 4, 16) PR2 Value Maximum Resolution (bits)
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14.4.3 SETUP FOR PWM OPERATION
3. 4. 5. The following steps should be taken when configuring the CCP2 module for PWM operation: 1. 2. Set the PWM period by writing to the PR2 register. Set the PWM duty cycle by writing to the CCPR2L register and CCP2CON<5:4> bits. Make the CCP2 pin an output by clearing the appropriate TRIS bit. Set the TMR2 prescale value, then enable Timer2 by writing to T2CON. Configure the CCP2 module for PWM operation.
TABLE 14-5:
Name INTCON RCON PIR1 PIE1 IPR1 TRISC TRISE TMR2 PR2 T2CON CCPR1L CCPR1H CCP1CON CCPR2L CCPR2H CCP2CON
REGISTERS ASSOCIATED WITH PWM AND TIMER2
Bit 7 Bit 6 Bit 5 TMR0IE -- RC1IF RC1IE RC1IP Bit 4 INT0IE RI TX1IF TX1IE TX1IP Bit 3 RBIE TO SSPIF SSPIE SSPIP -- Bit 2 TMR0IF PD CCP1IF CCP1IE CCP1IP -- Bit 1 INT0IF POR TMR2IF TMR2IE TMR2IP -- Bit 0 RBIF BOR TMR1IF TMR1IE TMR1IP -- Reset Values on Page 59 60 61 61 61 62 62 60 60 60 61 61 CCP1M3 CCP1M2 CCP1M1 CCP1M0 61 61 61 CCP2M3 CCP2M2 CCP2M1 CCP2M0 61
GIE/GIEH PEIE/GIEL IPEN -- -- -- SBOREN ADIF ADIE ADIP
PORTC Data Direction Register PORTE Data Direction Register Timer2 Register Timer2 Period Register -- T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 Capture/Compare/PWM Register 1 Low Byte Capture/Compare/PWM Register 1 High Byte -- -- DC1B1 DC1B0 Capture/Compare/PWM Register 2 Low Byte Capture/Compare/PWM Register 2 High Byte -- -- DC2B1 DC2B0
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by PWM or Timer2.
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15.0 MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE
Master SSP (MSSP) Module Overview 15.3 SPI Mode
The SPI mode allows 8 bits of data to be synchronously transmitted and received simultaneously. All four modes of SPI are supported. To accomplish communication, typically three pins are used: * Serial Data Out (SDO) - RC5/SDO/SEG12 * Serial Data In (SDI) - RC4/SDI/SDA * Serial Clock (SCK) - RC3/SCK/SCL Additionally, a fourth pin may be used when in a Slave mode of operation: * Slave Select (SS) - RF7/SS/SEG25 Figure 15-1 shows the block diagram of the MSSP module when operating in SPI mode.
15.1
The Master Synchronous Serial Port (MSSP) module is a serial interface, useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be serial EEPROMs, shift registers, display drivers, A/D converters, etc. The MSSP module can operate in one of two modes: * Serial Peripheral Interface (SPI) * Inter-Integrated Circuit (I2C) - Full Master mode - Slave mode (with general address call) The I2C interface supports the following modes in hardware: * Master mode * Multi-Master mode * Slave mode
FIGURE 15-1:
MSSP BLOCK DIAGRAM (SPI MODE)
Internal Data Bus Read SSPBUF reg Write
15.2
Control Registers
RC4/SDI/SDA SSPSR reg RC5/SDO/SEG12 bit 0 Shift Clock
The MSSP module has three associated registers. These include a status register (SSPSTAT) and two control registers (SSPCON1 and SSPCON2). The use of these registers and their individual Configuration bits differ significantly depending on whether the MSSP module is operated in SPI or I2C mode. Additional details are provided under the individual sections.
RF7/SS/ SEG25
SS Control Enable Edge Select 2 Clock Select SSPM3:SSPM0 SMP:CKE 4 TMR2 Output 2 2
RC3/SCK/ SCL
(
)
Edge Select
Prescaler TOSC 4, 16, 64
Data to TXx/RXx in SSPSR TRIS bit
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15.3.1 REGISTERS
The MSSP module has four registers for SPI mode operation. These are: * * * * MSSP Control Register 1 (SSPCON1) MSSP Status Register (SSPSTAT) Serial Receive/Transmit Buffer Register (SSPBUF) MSSP Shift Register (SSPSR) - Not directly accessible SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. In receive operations, SSPSR and SSPBUF together create a double-buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set. During transmission, the SSPBUF is not doublebuffered. A write to SSPBUF will write to both SSPBUF and SSPSR.
SSPCON1 and SSPSTAT are the control and status registers in SPI mode operation. The SSPCON1 register is readable and writable. The lower 6 bits of the SSPSTAT are read-only. The upper 2 bits of the SSPSTAT are read/write.
REGISTER 15-1:
R/W-0 SMP bit 7 Legend: R = Readable bit -n = Value at POR bit 7
SSPSTAT: MSSP STATUS REGISTER (SPI MODE)
R-0 D/A R-0 P R-0 S R-0 R/W R-0 UA R-0 BF bit 0 CKE
R/W-0
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
SMP: Sample bit SPI Master mode: 1 = Input data sampled at end of data output time 0 = Input data sampled at middle of data output time SPI Slave mode: SMP must be cleared when SPI is used in Slave mode. CKE: SPI Clock Edge Select bit When CKP = 0: 1 = Data transmitted on rising edge of SCK 0 = Data transmitted on falling edge of SCK When CKP = 1: 1 = Data transmitted on falling edge of SCK 0 = Data transmitted on rising edge of SCK D/A: Data/Address bit Used in I2CTM mode only. P: Stop bit Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared. S: Start bit Used in I2C mode only. R/W: Read/Write Information bit Used in I2C mode only. UA: Update Address bit Used in I2C mode only. BF: Buffer Full Status bit (Receive mode only) 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty
bit 6
bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
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REGISTER 15-2:
R/W-0 WCOL bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
SSPCON1: MSSP CONTROL REGISTER 1 (SPI MODE)
R/W-0 SSPEN(2) R/W-0 CKP R/W-0 SSPM3(3) R/W-0 SSPM2(3) R/W-0 SSPM1(3) R/W-0 SSPM0(3) bit 0
R/W-0 SSPOV(1)
WCOL: Write Collision Detect bit (Transmit mode only) 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision SSPOV: Receive Overflow Indicator bit(1) SPI Slave mode: 1 = A new byte is received while the SSPBUF register is still holding the previous data. In case of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode. The user must read the SSPBUF, even if only transmitting data, to avoid setting overflow (must be cleared in software). 0 = No overflow SSPEN: Synchronous Serial Port Enable bit(2) 1 = Enables serial port and configures SCK, SDO, SDI and SS as serial port pins 0 = Disables serial port and configures these pins as I/O port pins CKP: Clock Polarity Select bit 1 = Idle state for clock is a high level 0 = Idle state for clock is a low level SSPM3:SSPM0: Master Synchronous Serial Port Mode Select bits(3) 0101 = SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin 0100 = SPI Slave mode, clock = SCK pin, SS pin control enabled 0011 = SPI Master mode, clock = TMR2 output/2 0010 = SPI Master mode, clock = FOSC/64 0001 = SPI Master mode, clock = FOSC/16 0000 = SPI Master mode, clock = FOSC/4 In Master mode, the overflow bit is not set, since each new reception (and transmission) is initiated by writing to the SSPBUF register. When enabled, these pins must be properly configured as inputs or outputs. Bit combinations not specifically listed here are either reserved or implemented in I2CTM mode only.
bit 6
bit 5
bit 4
bit 3-0
Note 1: 2: 3:
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15.3.2 OPERATION
When initializing the SPI, several options need to be specified. This is done by programming the appropriate control bits (SSPCON1<5:0> and SSPSTAT<7:6>). These control bits allow the following to be specified: * * * * Master mode (SCK is the clock output) Slave mode (SCK is the clock input) Clock Polarity (Idle state of SCK) Data Input Sample Phase (middle or end of data output time) * Clock Edge (output data on rising/falling edge of SCK) * Clock Rate (Master mode only) * Slave Select mode (Slave mode only) The MSSP consists of a Transmit/Receive Shift register (SSPSR) and a Buffer register (SSPBUF). The SSPSR shifts the data in and out of the device, MSb first. The SSPBUF holds the data that was written to the SSPSR until the received data is ready. Once the 8 bits of data have been received, that byte is moved to the SSPBUF register. Then, the Buffer Full detect bit, BF (SSPSTAT<0>), and the interrupt flag bit, SSPIF, are set. This double-buffering of the received data (SSPBUF) allows the next byte to start reception before reading the data that was just received. Any write to the SSPBUF register during transmission/reception of data will be ignored and the Write Collision Detect bit, WCOL (SSPCON1<7>), will be set. User software must clear the WCOL bit so that it can be determined if the following write(s) to the SSPBUF register completed successfully. When the application software is expecting to receive valid data, the SSPBUF should be read before the next byte of data to transfer is written to the SSPBUF. The Buffer Full bit, BF (SSPSTAT<0>), indicates when SSPBUF has been loaded with the received data (transmission is complete). When the SSPBUF is read, the BF bit is cleared. This data may be irrelevant if the SPI is only a transmitter. Generally, the MSSP interrupt is used to determine when the transmission/reception has completed. The SSPBUF must be read and/or written. If the interrupt method is not going to be used, then software polling can be done to ensure that a write collision does not occur. Example 15-1 shows the loading of the SSPBUF (SSPSR) for data transmission. The SSPSR is not directly readable or writable and can only be accessed by addressing the SSPBUF register. Additionally, the MSSP Status register (SSPSTAT) indicates the various status conditions.
EXAMPLE 15-1:
LOOP BTFSS BRA MOVF MOVWF MOVF MOVWF
LOADING THE SSPBUF (SSPSR) REGISTER
SSPSTAT, BF LOOP SSPBUF, W RXDATA TXDATA, W SSPBUF ;Has data been received (transmit complete)? ;No ;WREG reg = contents of SSPBUF ;Save in user RAM, if data is meaningful ;W reg = contents of TXDATA ;New data to xmit
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15.3.3 ENABLING SPI I/O 15.3.4 TYPICAL CONNECTION
To enable the serial port, MSSP Enable bit, SSPEN (SSPCON1<5>), must be set. To reset or reconfigure SPI mode, clear the SSPEN bit, reinitialize the SSPCONx registers and then set the SSPEN bit. This configures the SDI, SDO, SCK and SS pins as serial port pins. For the pins to behave as the serial port function, some must have their data direction bits (in the TRIS register) appropriately programmed as follows: * SDI is automatically controlled by the SPI module * SDO must have TRISC<5> bit cleared * SCK (Master mode) must have TRISC<3> bit cleared * SCK (Slave mode) must have TRISC<3> bit set * SS must have TRISF<7> bit set Any serial port function that is not desired may be overridden by programming the corresponding Data Direction (TRIS) register to the opposite value. Figure 15-2 shows a typical connection between two microcontrollers. The master controller (Processor 1) initiates the data transfer by sending the SCK signal. Data is shifted out of both shift registers on their programmed clock edge and latched on the opposite edge of the clock. Both processors should be programmed to the same Clock Polarity (CKP), then both controllers would send and receive data at the same time. Whether the data is meaningful (or dummy data) depends on the application software. This leads to three scenarios for data transmission: * Master sends data - Slave sends dummy data * Master sends data - Slave sends data * Master sends dummy data - Slave sends data
FIGURE 15-2:
SPI MASTER/SLAVE CONNECTION
SPI Master (SSPM3:SSPM0 = 00xx) SDO SDI
SPI Slave (SSPM3:SSPM0 = 010x)
Serial Input Buffer (SSPBUF)
Serial Input Buffer (SSPBUF)
Shift Register (SSPSR) MSb LSb
SDI
SDO
Shift Register (SSPSR) MSb LSb
SCK PROCESSOR 1
Serial Clock
SCK PROCESSOR 2
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15.3.5 MASTER MODE
The master can initiate the data transfer at any time because it controls the SCK. The master determines when the slave (Processor 2, Figure 15-2) is to broadcast data by the software protocol. In Master mode, the data is transmitted/received as soon as the SSPBUF register is written to. If the SPI is only going to receive, the SDO output could be disabled (programmed as an input). The SSPSR register will continue to shift in the signal present on the SDI pin at the programmed clock rate. As each byte is received, it will be loaded into the SSPBUF register as if a normal received byte (interrupts and status bits appropriately set). This could be useful in receiver applications as a "Line Activity Monitor" mode. The clock polarity is selected by appropriately programming the CKP bit (SSPCON1<4>). This then, would give waveforms for SPI communication, as shown in Figure 15-3, Figure 15-5 and Figure 15-6, where the MSB is transmitted first. In Master mode, the SPI clock rate (bit rate) is user programmable to be one of the following: * * * * FOSC/4 (or TCY) FOSC/16 (or 4 * TCY) FOSC/64 (or 16 * TCY) Timer2 output/2
This allows a maximum data rate (at 40 MHz) of 10.00 Mbps. Figure 15-3 shows the waveforms for Master mode. When the CKE bit is set, the SDO data is valid before there is a clock edge on SCK. The change of the input sample is shown based on the state of the SMP bit. The time when the SSPBUF is loaded with the received data is shown.
FIGURE 15-3:
Write to SSPBUF SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) SDO (CKE = 0) SDO (CKE = 1) SDI (SMP = 0) Input Sample (SMP = 0) SDI (SMP = 1) Input Sample (SMP = 1) SSPIF SSPSR to SSPBUF
SPI MODE WAVEFORM (MASTER MODE)
4 Clock Modes
bit 7 bit 7
bit 6 bit 6
bit 5 bit 5
bit 4 bit 4
bit 3 bit 3
bit 2 bit 2
bit 1 bit 1
bit 0 bit 0
bit 7
bit 0
bit 7
bit 0
Next Q4 Cycle after Q2
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15.3.6 SLAVE MODE
In Slave mode, the data is transmitted and received as the external clock pulses appear on SCK. When the last bit is latched, the SSPIF interrupt flag bit is set. While in Slave mode, the external clock is supplied by the external clock source on the SCK pin. This external clock must meet the minimum high and low times as specified in the electrical specifications. While in Sleep mode, the slave can transmit/receive data. When a byte is received, the device will wake-up from Sleep. even if in the middle of a transmitted byte and becomes a floating output. External pull-up/pull-down resistors may be desirable depending on the application. Note 1: When the SPI is in Slave mode with SS pin control enabled (SSPCON<3:0> = 0100), the SPI module will reset if the SS pin is set to VDD. 2: If the SPI is used in Slave mode with CKE set, then the SS pin control must be enabled. When the SPI module resets, the bit counter is forced to `0'. This can be done by either forcing the SS pin to a high level or clearing the SSPEN bit. To emulate two-wire communication, the SDO pin can be connected to the SDI pin. When the SPI needs to operate as a receiver, the SDO pin can be configured as an input. This disables transmissions from the SDO. The SDI can always be left as an input (SDI function) since it cannot create a bus conflict.
15.3.7
SLAVE SELECT SYNCHRONIZATION
The SS pin allows a Synchronous Slave mode. The SPI must be in Slave mode with SS pin control enabled (SSPCON1<3:0> = 04h). The pin must not be driven low for the SS pin to function as an input. The data latch must be high. When the SS pin is low, transmission and reception are enabled and the SDO pin is driven. When the SS pin goes high, the SDO pin is no longer driven,
FIGURE 15-4:
SS
SLAVE SYNCHRONIZATION WAVEFORM
SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0)
Write to SSPBUF
SDO
bit 7
bit 6
bit 7
bit 0
SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF
bit 0 bit 7 bit 7
Next Q4 Cycle after Q2
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FIGURE 15-5:
SS Optional SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
bit 7
bit 0
Next Q4 Cycle after Q2
FIGURE 15-6:
SS Not Optional SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) Write to SSPBUF SDO SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
bit 7
bit 0
Next Q4 Cycle after Q2
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15.3.8 SLEEP OPERATION 15.3.9 EFFECTS OF A RESET
In SPI Master mode, module clocks may be operating at a different speed than when in Full-Power mode; in the case of Sleep mode, all clocks are halted. In most power-managed modes, a clock is provided to the peripherals. That clock should be from the primary clock source, the secondary clock (Timer1 oscillator at 32.768 kHz) or the INTOSC source. See Section 2.7 "Clock Sources and Oscillator Switching" for additional information. In most cases, the speed that the master clocks SPI data is not important; however, this should be evaluated for each system. If MSSP interrupts are enabled, they can wake the controller from Sleep mode, or one of the Idle modes, when the master completes sending data. If an exit from Sleep or Idle mode is not desired, MSSP interrupts should be disabled. If the Sleep mode is selected, all module clocks are halted and the transmission/reception will remain in that state until the devices wakes. After the device returns to Run mode, the module will resume transmitting and receiving data. In SPI Slave mode, the SPI Transmit/Receive Shift register operates asynchronously to the device. This allows the device to be placed in any power-managed mode and data to be shifted into the SPI Transmit/ Receive Shift register. When all 8 bits have been received, the MSSP interrupt flag bit will be set and if enabled, will wake the device. A Reset disables the MSSP module and terminates the current transfer.
15.3.10
BUS MODE COMPATIBILITY
Table 15-1 shows the compatibility between the standard SPI modes and the states of the CKP and CKE control bits.
TABLE 15-1:
SPI BUS MODES
Control Bits State CKP 0 0 1 1 CKE 1 0 1 0
Standard SPI Mode Terminology 0, 0 0, 1 1, 0 1, 1
There is also an SMP bit which controls when the data is sampled.
TABLE 15-2:
Name INTCON PIR1 PIE1 IPR1 TRISC TRISF SSPBUF SSPCON1 SSPSTAT
REGISTERS ASSOCIATED WITH SPI OPERATION
Bit 7 Bit 6 Bit 5 Bit 4 INT0IE TX1IF TX1IE TX1IP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Reset Values on Page 59 61 61 61 62 62 60 SSPM3 S SSPM2 R/W SSPM1 UA SSPM0 BF 60 60 CKP P
GIE/GIEH PEIE/GIEL TMR0IE -- -- -- ADIF ADIE ADIP RC1IF RC1IE RC1IP
PORTC Data Direction Register PORTF Data Direction Register MSSP Receive Buffer/Transmit Register WCOL SMP SSPOV CKE SSPEN D/A
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the MSSP in SPI mode.
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15.4 I2C Mode
15.4.1 REGISTERS
The MSSP module in I 2C mode fully implements all master and slave functions (including general call support) and provides interrupts on Start and Stop bits in hardware to determine a free bus (multi-master function). The MSSP module implements the standard mode specifications, as well as 7-bit and 10-bit addressing. Two pins are used for data transfer: * Serial clock (SCL) - RC3/SCK/SCL * Serial data (SDA) - RC4/SDI/SDA The user must configure these pins as inputs by setting the TRISC<4:3> bits. The MSSP module has six registers for I2C operation. These are: MSSP Control Register 1 (SSPCON1) MSSP Control Register 2 (SSPCON2) MSSP Status Register (SSPSTAT) Serial Receive/Transmit Buffer Register (SSPBUF) * MSSP Shift Register (SSPSR) - Not directly accessible * MSSP Address Register (SSPADD) SSPCON1, SSPCON2 and SSPSTAT are the control and status registers in I2C mode operation. The SSPCON1 and SSPCON2 registers are readable and writable. The lower 6 bits of the SSPSTAT are read-only. The upper 2 bits of the SSPSTAT are read/write. SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to, or read from. SSPADD register holds the slave device address when the MSSP is configured in I2C Slave mode. When the MSSP is configured in Master mode, the lower 7 bits of SSPADD act as the Baud Rate Generator reload value. In receive operations, SSPSR and SSPBUF together create a double-buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set.
Addr Match
* * * *
FIGURE 15-7:
MSSP BLOCK DIAGRAM (I2CTM MODE)
Internal Data Bus Read SSPBUF reg Shift Clock SSPSR reg Write
RC3/SCK/SCL
RC4/ SDI/ SDA
MSb
LSb
Match Detect
SSPADD reg Start and Stop bit Detect Set, Reset S, P bits (SSPSTAT reg)
During transmission, the SSPBUF is not doublebuffered. A write to SSPBUF will write to both SSPBUF and SSPSR.
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REGISTER 15-3:
R/W-0 SMP bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
SSPSTAT: MSSP STATUS REGISTER (I2CTM MODE)
R-0 D/A R-0 P(1) R-0 S(1) R-0 R/W(2,3) R-0 UA R-0 BF bit 0 CKE
R/W-0
SMP: Slew Rate Control bit In Master or Slave mode: 1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz) 0 = Slew rate control enabled for High-Speed mode (400 kHz) CKE: SMBus Select bit In Master or Slave mode: 1 = Enable SMBus specific inputs 0 = Disable SMBus specific inputs D/A: Data/Address bit In Master mode: Reserved. In Slave mode: 1 = Indicates that the last byte received or transmitted was data 0 = Indicates that the last byte received or transmitted was address P: Stop bit(1) 1 = Indicates that a Stop bit has been detected last 0 = Stop bit was not detected last S: Start bit(1) 1 = Indicates that a Start bit has been detected last 0 = Start bit was not detected last R/W: Read/Write Information bit(2,3) In Slave mode: 1 = Read 0 = Write In Master mode: 1 = Transmit is in progress 0 = Transmit is not in progress UA: Update Address bit (10-Bit Slave mode only) 1 = Indicates that the user needs to update the address in the SSPADD register 0 = Address does not need to be updated BF: Buffer Full Status bit In Transmit mode: 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty In Receive mode: 1 = Data transmit in progress (does not include the ACK and Stop bits), SSPBUF is full 0 = Data transmit complete (does not include the ACK and Stop bits), SSPBUF is empty This bit is cleared on Reset and when SSPEN is cleared. This bit holds the R/W bit information following the last address match. This bit is only valid from the address match to the next Start bit, Stop bit or not ACK bit. ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSP is in Idle mode.
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note 1: 2: 3:
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REGISTER 15-4:
R/W-0 WCOL bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
SSPCON1: MSSP CONTROL REGISTER 1 (I2CTM MODE)
R/W-0 SSPEN
(1)
R/W-0 SSPOV
R/W-0 CKP
R/W-0 SSPM3
(2)
R/W-0 SSPM2
(2)
R/W-0 SSPM1
(2)
R/W-0 SSPM0(2) bit 0
WCOL: Write Collision Detect bit In Master Transmit mode: 1 = A write to the SSPxBUF register was attempted while the I2C conditions were not valid for a transmission to be started (must be cleared in software) 0 = No collision In Slave Transmit mode: 1 = The SSPxBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision In Receive mode (Master or Slave modes): This is a "don't care" bit. SSPOV: Receive Overflow Indicator bit In Receive mode: 1 = A byte is received while the SSPxBUF register is still holding the previous byte (must be cleared in software) 0 = No overflow In Transmit mode: This is a "don't care" bit in Transmit mode. SSPEN: Synchronous Serial Port Enable bit(1) 1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins 0 = Disables serial port and configures these pins as I/O port pins CKP: SCK Release Control bit In Slave mode: 1 = Releases clock 0 = Holds clock low (clock stretch), used to ensure data setup time In Master mode: Unused in this mode. SSPM3:SSPM0: Synchronous Serial Port Mode Select bits(2) 1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled 1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled 1011 = I2C Firmware Controlled Master mode (Slave Idle) 1000 = I2C Master mode, clock = FOSC/(4 * (SSPADD + 1)) 0111 = I2C Slave mode, 10-bit address 0110 = I2C Slave mode, 7-bit address When enabled, the SDA and SCL pins must be configured as inputs. Bit combinations not specifically listed here are either reserved or implemented in SPI mode only.
bit 6
bit 5
bit 4
bit 3-0
Note 1: 2:
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REGISTER 15-5:
R/W-0 GCEN bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
SSPCON2: MSSP CONTROL REGISTER 2 (I2CTM MODE)
R/W-0 ACKDT(1) R/W-0 ACKEN(2) R/W-0 RCEN(2) R/W-0 PEN(2) R/W-0 RSEN(2) R/W-0 SEN(2) bit 0
R/W-0 ACKSTAT
GCEN: General Call Enable bit (Slave mode only) 1 = Enable interrupt when a general call address (0000h) is received in the SSPSR 0 = General call address disabled ACKSTAT: Acknowledge Status bit (Master Transmit mode only) 1 = Acknowledge was not received from slave 0 = Acknowledge was received from slave ACKDT: Acknowledge Data bit (Master Receive mode only)(1) 1 = Not Acknowledge 0 = Acknowledge ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)(2) 1 = Initiate Acknowledge sequence on SDA and SCL pins and transmit ACKDT data bit. Automatically cleared by hardware. 0 = Acknowledge sequence Idle RCEN: Receive Enable bit (Master mode only)(2) 1 = Enables Receive mode for I2C 0 = Receive Idle PEN: Stop Condition Enable bit (Master mode only)(2) 1 = Initiate Stop condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Stop condition Idle RSEN: Repeated Start Condition Enable bit (Master mode only)(2) 1 = Initiate Repeated Start condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Repeated Start condition Idle SEN: Start Condition Enable/Stretch Enable bit(2) In Master mode: 1 = Initiate Start condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Start condition Idle In Slave mode: 1 = Clock stretching is enabled for both slave transmit and slave receive (stretch enabled) 0 = Clock stretching is disabled Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive. If the I2C module is not in the Idle mode, these bits may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled).
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note 1: 2:
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15.4.2 OPERATION 15.4.3.1 Addressing
The MSSP module functions are enabled by setting MSSP Enable bit, SSPEN (SSPCON1<5>). The SSPCON1 register allows control of the I 2C operation. Four mode selection bits (SSPCON1<3:0>) allow one of the following I 2C modes to be selected: * * * * I2C Master mode, clock = (FOSC/4) x (SSPADD + 1) I 2C Slave mode (7-bit address) I 2C Slave mode (10-bit address) I 2C Slave mode (7-bit address) with Start and Stop bit interrupts enabled * I 2C Slave mode (10-bit address) with Start and Stop bit interrupts enabled * I 2C Firmware Controlled Master mode, slave is Idle Once the MSSP module has been enabled, it waits for a Start condition to occur. Following the Start condition, the 8 bits are shifted into the SSPSR register. All incoming bits are sampled with the rising edge of the clock (SCL) line. The value of register SSPSR<7:1> is compared to the value of the SSPADD register. The address is compared on the falling edge of the eighth clock (SCL) pulse. If the addresses match and the BF and SSPOV bits are clear, the following events occur: 1. 2. 3. 4. The SSPSR register value is loaded into the SSPBUF register. The Buffer Full bit, BF, is set. An ACK pulse is generated. MSSP Interrupt Flag bit, SSPIF (PIR1<3>), is set (interrupt is generated, if enabled) on the falling edge of the ninth SCL pulse.
Selection of any I 2C mode with the SSPEN bit set, forces the SCL and SDA pins to be open-drain, provided these pins are programmed to inputs by setting the appropriate TRISC bits. To ensure proper operation of the module, pull-up resistors must be provided externally to the SCL and SDA pins.
15.4.3
SLAVE MODE
In Slave mode, the SCL and SDA pins must be configured as inputs (TRISC<4:3> set). The MSSP module will override the input state with the output data when required (slave-transmitter). The I 2C Slave mode hardware will always generate an interrupt on an address match. Through the mode select bits, the user can also choose to interrupt on Start and Stop bits When an address is matched, or the data transfer after an address match is received, the hardware automatically will generate the Acknowledge (ACK) pulse and load the SSPBUF register with the received value currently in the SSPSR register. Any combination of the following conditions will cause the MSSP module not to give this ACK pulse: * The Buffer Full bit, BF (SSPSTAT<0>), was set before the transfer was received. * The overflow bit, SSPOV (SSPCON1<6>), was set before the transfer was received. In this case, the SSPSR register value is not loaded into the SSPBUF, but the SSPIF bit (PIR1<3>) is set. The BF bit is cleared by reading the SSPBUF register, while bit SSPOV is cleared through software. The SCL clock input must have a minimum high and low time for proper operation. The high and low times of the I2C specification, as well as the requirement of the MSSP module, are shown in timing parameter #100 and parameter #101.
In 10-Bit Addressing mode, two address bytes need to be received by the slave. The five Most Significant bits (MSbs) of the first address byte specify if this is a 10-bit address. Bit R/W (SSPSTAT<2>) must specify a write so the slave device will receive the second address byte. For a 10-bit address, the first byte would equal `11110 A9 A8 0', where `A9' and `A8' are the two MSbs of the address. The sequence of events for 10-Bit Addressing mode is as follows, with steps 7 through 9 for the slave-transmitter: 1. 2. Receive first (high) byte of address (bits SSPIF, BF and UA (SSPSTAT<1>) are set). Update the SSPADD register with second (low) byte of address (clears bit UA and releases the SCL line). Read the SSPBUF register (clears bit, BF) and clear flag bit, SSPIF. Receive second (low) byte of address (bits SSPIF, BF and UA are set). Update the SSPADD register with the first (high) byte of address. If match releases SCL line, this will clear bit, UA. Read the SSPBUF register (clears bit, BF) and clear flag bit, SSPIF. Receive Repeated Start condition. Receive first (high) byte of address (SSPIF and BF bits are set). Read the SSPBUF register (clears bit, BF) and clear flag bit, SSPIF.
3. 4. 5.
6. 7. 8. 9.
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15.4.3.2 Reception 15.4.3.3 Transmission
When the R/W bit of the address byte is clear and an address match occurs, the R/W bit of the SSPSTAT register is cleared. The received address is loaded into the SSPBUF register and the SDA line is held low (ACK). When the address byte overflow condition exists, then the no Acknowledge (ACK) pulse is given. An overflow condition is defined as either bit BF (SSPSTAT<0>) is set, or bit SSPOV (SSPCON1<6>) is set. An MSSP interrupt is generated for each data transfer byte. Flag bit, SSPIF (PIR1<3>), must be cleared in software. The SSPSTAT register is used to determine the status of the byte. If SEN is enabled (SSPCON2<0> = 1), RC3/SCK/SCL will be held low (clock stretch) following each data transfer. The clock must be released by setting bit CKP (SSPCON1<4>). See Section 15.4.4 "Clock Stretching" for more detail. When the R/W bit of the incoming address byte is set and an address match occurs, the R/W bit of the SSPSTAT register is set. The received address is loaded into the SSPBUF register. The ACK pulse will be sent on the ninth bit and pin RC3/SCK/SCL is held low regardless of SEN (see Section 15.4.4 "Clock Stretching" for more detail). By stretching the clock, the master will be unable to assert another clock pulse until the slave is done preparing the transmit data. The transmit data must be loaded into the SSPBUF register which also loads the SSPSR register. Then, pin RC3/ SCK/SCL should be enabled by setting bit, CKP (SSPCON1<4>). The 8 data bits are shifted out on the falling edge of the SCL input. This ensures that the SDA signal is valid during the SCL high time (Figure 15-9). The ACK pulse from the master-receiver is latched on the rising edge of the ninth SCL input pulse. If the SDA line is high (not ACK), then the data transfer is complete. In this case, when the ACK is latched by the slave, the slave logic is reset and the slave monitors for another occurrence of the Start bit. If the SDA line was low (ACK), the next transmit data must be loaded into the SSPBUF register. Again, pin RC3/SCK/SCL must be enabled by setting bit CKP. An MSSP interrupt is generated for each data transfer byte. The SSPIF bit must be cleared in software and the SSPSTAT register is used to determine the status of the byte. The SSPIF bit is set on the falling edge of the ninth clock pulse.
(c) 2007 Microchip Technology Inc.
DS39629C-page 171
FIGURE 15-8:
DS39629C-page 172
Receiving Address A5 A4 A3 A2 A1 ACK D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 R/W = 0 Receiving Data ACK Receiving Data D1 D0 ACK 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 P Bus master terminates transfer Cleared in software SSPBUF is read SSPOV is set because SSPBUF is still full. ACK is not sent.
SDA
A7
A6
SCL
S
1
2
SSPIF (PIR1<3>)
PIC18F6390/6490/8390/8490
BF (SSPSTAT<0>)
SSPOV (SSPCON1<6>)
CKP (SSPCON1<4>)
I2CTM SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)
(c) 2007 Microchip Technology Inc.
(CKP does not reset to `0' when SEN = 0)
FIGURE 15-9:
(c) 2007 Microchip Technology Inc.
R/W = 1 ACK D1 D0 D4 D3 D5 D7 D6 D2 A1 D3 D2 ACK D5 D4 D7 D6 Transmitting Data Transmitting Data D1 D0 ACK A4 A2 A3 4 SCL held low while CPU responds to SSPIF 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 P Cleared in software SSPBUF is written in software Clear by reading From SSPIF ISR Cleared in software SSPBUF is written in software From SSPIF ISR CKP is set in software CKP is set in software
Receiving Address
SDA
A7
A6
A5
SCL
S
1
2
3
Data in sampled
SSPIF (PIR1<3>)
BF (SSPSTAT<0>)
I2CTM SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)
PIC18F6390/6490/8390/8490
CKP (SSPCON1<4>)
DS39629C-page 173
FIGURE 15-10:
DS39629C-page 174
Clock is held low until update of SSPADD has taken place R/W = 0 A8 D3 D2 ACK A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 ACK D7 D6 D5 D4 A0 ACK D1 D0 Receive Second Byte of Address Receive Data Byte Receive Data Byte ACK Clock is held low until update of SSPADD has taken place 0 A9 5 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 6 7 8 9 P Bus master terminates transfer Cleared in software Cleared in software Cleared in software Dummy read of SSPBUF to clear BF flag SSPOV is set because SSPBUF is still full. ACK is not sent. Cleared by hardware when SSPADD is updated with low byte of address UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address
Receive First Byte of Address
SDA
1
1
1
1
SCL
S
1
2
3
4
SSPIF (PIR1<3>)
Cleared in software
BF (SSPSTAT<0>)
SSPBUF is written with contents of SSPSR
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SSPOV (SSPCON1<6>)
UA (SSPSTAT<1>)
UA is set indicating that the SSPADD needs to be updated
CKP (SSPCON1<4>)
I2CTM SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)
(c) 2007 Microchip Technology Inc.
(CKP does not reset to `0' when SEN = 0)
FIGURE 15-11:
Bus master terminates transfer Clock is held low until CKP is set to `1' R/W=1 ACK Transmitting Data Byte D7 D6 D5 D4 D3 D2 D1 D0 ACK
(c) 2007 Microchip Technology Inc.
Clock is held low until update of SSPADD has taken place R/W = 0 Receive Second Byte of Address Receive First Byte of Address ACK 1 1 1 1 0 A9 A8 ACK A7 A6 A5 A4 A3 A2 A1 A0 Clock is held low until update of SSPADD has taken place 1 0 A9 A8 4 Sr 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 P Cleared in software Cleared in software Cleared in software Dummy read of SSPBUF to clear BF flag Dummy read of SSPBUF to clear BF flag Write of SSPBUF BF flag is clear initiates transmit at the end of the third address sequence Completion of data transmission clears BF flag Cleared by hardware when SSPADD is updated with low byte of address UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address. CKP is set in software CKP is automatically cleared in hardware, holding SCL low
Receive First Byte of Address
SDA
1
1
1
SCL
S
1
2
3
SSPIF (PIR1<3>)
BF (SSPSTAT<0>)
SSPBUF is written with contents of SSPSR
UA (SSPSTAT<1>)
UA is set indicating that the SSPADD needs to be updated
I2CTM SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)
PIC18F6390/6490/8390/8490
CKP (SSPCON1<4>)
DS39629C-page 175
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15.4.4 CLOCK STRETCHING 15.4.4.3
Both 7 and 10-Bit Slave modes implement automatic clock stretching during a transmit sequence. The SEN bit (SSPCON2<0>) allows clock stretching to be enabled during receives. Setting SEN will cause the SCL pin to be held low at the end of each data receive sequence.
Clock Stretching for 7-Bit Slave Transmit Mode
7-Bit Slave Transmit mode implements clock stretching by clearing the CKP bit after the falling edge of the ninth clock, if the BF bit is clear. This occurs regardless of the state of the SEN bit. The user's ISR must set the CKP bit before transmission is allowed to continue. By holding the SCL line low, the user has time to service the ISR and load the contents of the SSPBUF before the master device can initiate another transmit sequence (see Figure 15-9). Note 1: If the user loads the contents of SSPBUF, setting the BF bit before the falling edge of the ninth clock, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software regardless of the state of the BF bit.
15.4.4.1
Clock Stretching for 7-Bit Slave Receive Mode (SEN = 1)
In 7-Bit Slave Receive mode, on the falling edge of the ninth clock at the end of the ACK sequence, if the BF bit is set, the CKP bit in the SSPCON1 register is automatically cleared, forcing the SCL output to be held low. The CKP being cleared to `0' will assert the SCL line low. The CKP bit must be set in the user's ISR before reception is allowed to continue. By holding the SCL line low, the user has time to service the ISR and read the contents of the SSPBUF before the master device can initiate another receive sequence. This will prevent buffer overruns from occurring (see Figure 15-13). Note 1: If the user reads the contents of the SSPBUF before the falling edge of the ninth clock, thus clearing the BF bit, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software regardless of the state of the BF bit. The user should be careful to clear the BF bit in the ISR before the next receive sequence in order to prevent an overflow condition.
15.4.4.4
Clock Stretching for 10-Bit Slave Transmit Mode
In 10-Bit Slave Transmit mode, clock stretching is controlled during the first two address sequences by the state of the UA bit, just as it is in 10-Bit Slave Receive mode. The first two addresses are followed by a third address sequence which contains the highorder bits of the 10-bit address and the R/W bit set to `1'. After the third address sequence is performed, the UA bit is not set, the module is now configured in Transmit mode and clock stretching is controlled by the BF flag as in 7-Bit Slave Transmit mode (see Figure 15-11).
15.4.4.2
Clock Stretching for 10-Bit Slave Receive Mode (SEN = 1)
In 10-Bit Slave Receive mode during the address sequence, clock stretching automatically takes place but CKP is not cleared. During this time, if the UA bit is set after the ninth clock, clock stretching is initiated. The UA bit is set after receiving the upper byte of the 10-bit address and following the receive of the second byte of the 10-bit address with the R/W bit cleared to `0'. The release of the clock line occurs upon updating SSPADD. Clock stretching will occur on each data receive sequence as described in 7-bit mode. Note: If the user polls the UA bit and clears it by updating the SSPADD register before the falling edge of the ninth clock occurs and if the user hasn't cleared the BF bit by reading the SSPBUF register before that time, then the CKP bit will still NOT be asserted low. Clock stretching on the basis of the state of the BF bit only occurs during a data sequence, not an address sequence.
DS39629C-page 176
(c) 2007 Microchip Technology Inc.
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15.4.4.5 Clock Synchronization and the CKP bit
When the CKP bit is cleared, the SCL output is forced to `0'. However, setting the CKP bit will not assert the SCL output low until the SCL output is already sampled low. Therefore, the CKP bit will not assert the SCL line until an external I2C master device has already asserted the SCL line. The SCL output will remain low until the CKP bit is set and all other devices on the I2C bus have deasserted SCL. This ensures that a write to the CKP bit will not violate the minimum high time requirement for SCL (see Figure 15-12).
FIGURE 15-12:
CLOCK SYNCHRONIZATION TIMING
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
SDA
DX
DX - 1
SCL
CKP
Master device asserts clock Master device deasserts clock
WR SSPCON
(c) 2007 Microchip Technology Inc.
DS39629C-page 177
FIGURE 15-13:
DS39629C-page 178
Clock is not held low because buffer full bit is clear prior to falling edge of 9th clock Clock is held low until CKP is set to `1' ACK Receiving Data D7 D6 D5 D4 D3 D2 D1 D0 D2 D1 D0 Receiving Address A5 A4 A3 A2 A1 ACK D7 D6 D5 D4 D3 R/W = 0 Receiving Data Clock is not held low because ACK = 1 ACK 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 P Bus master terminates transfer Cleared in software SSPBUF is read SSPOV is set because SSPBUF is still full. ACK is not sent.
SDA
A7
A6
SCL
S
1
2
SSPIF (PIR1<3>)
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BF (SSPSTAT<0>)
SSPOV (SSPCON1<6>)
CKP (SSPON1<4>) CKP written to `1' in software BF is set after falling edge of the 9th clock, CKP is reset to `0' and clock stretching occurs
I2CTM SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)
(c) 2007 Microchip Technology Inc.
If BF is cleared prior to the falling edge of the 9th clock, CKP will not be reset to `0' and no clock stretching will occur
FIGURE 15-14:
Clock is held low until update of SSPADD has taken place Clock is held low until CKP is set to `1' Receive Data Byte D1 D7 D6 D5 D4 D0 ACK D3 D2 D1 D0 R/W = 0 ACK A7 A6 A5 A4 A3 A2 A1 A0 ACK D7 D6 D5 D4 D3 D2 Receive Second Byte of Address Receive Data Byte
Clock is held low until update of SSPADD has taken place
Clock is not held low because ACK = 1 ACK
Receive First Byte of Address A9 A8
(c) 2007 Microchip Technology Inc.
6 1 2 3 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 4 5 6 7 8 9 P Cleared in software Cleared in software Cleared in software Bus master terminates transfer Dummy read of SSPBUF to clear BF flag Dummy read of SSPBUF to clear BF flag SSPOV is set because SSPBUF is still full. ACK is not sent. Cleared by hardware when SSPADD is updated with low byte of address after falling edge of ninth clock UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address after falling edge of ninth clock Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA and UA will remain set. Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA and UA will remain set. CKP written to `1' in software
SDA
1
1
1
1
0
SCL
S
1
2
3
4
5
SSPIF (PIR1<3>)
Cleared in software
BF (SSPSTAT<0>)
SSPBUF is written with contents of SSPSR
SSPOV (SSPCON1<6>)
UA (SSPSTAT<1>)
UA is set indicating that the SSPADD needs to be updated
I2CTM SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESS)
PIC18F6390/6490/8390/8490
CKP (SSPCON1<4>)
DS39629C-page 179
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15.4.5 GENERAL CALL ADDRESS SUPPORT
The addressing procedure for the I2C bus is such that the first byte after the Start condition usually determines which device will be the slave addressed by the master. The exception is the general call address which can address all devices. When this address is used, all devices should, in theory, respond with an Acknowledge. The general call address is one of eight addresses reserved for specific purposes by the I2C protocol. It consists of all `0's with R/W = 0. The general call address is recognized when the General Call Enable bit (GCEN) is enabled (SSPCON2<7> set). Following a Start bit detect, 8 bits are shifted into the SSPSR and the address is compared against the SSPADD. It is also compared to the general call address and fixed in hardware. If the general call address matches, the SSPSR is transferred to the SSPBUF, the BF flag bit is set (eighth bit) and on the falling edge of the ninth bit (ACK bit), the SSPIF interrupt flag bit is set. When the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the SSPBUF. The value can be used to determine if the address was device specific or a general call address. In 10-bit mode, the SSPADD is required to be updated for the second half of the address to match and the UA bit is set (SSPSTAT<1>). If the general call address is sampled when the GCEN bit is set, while the slave is configured in 10-Bit Addressing mode, then the second half of the address is not necessary, the UA bit will not be set and the slave will begin receiving data after the Acknowledge (Figure 15-15).
FIGURE 15-15:
SLAVE MODE GENERAL CALL ADDRESS SEQUENCE (7 OR 10-BIT ADDRESSING MODE)
Address is compared to General Call Address after ACK, set interrupt R/W = 0 ACK D7 Receiving Data D6 D5 D4 D3 D2 D1 D0 ACK
SDA SCL S SSPIF BF (SSPSTAT<0>)
General Call Address
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
Cleared in software SSPBUF is read SSPOV (SSPCON1<6>) GCEN (SSPCON2<7>) `1' `0'
DS39629C-page 180
(c) 2007 Microchip Technology Inc.
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15.4.6 MASTER MODE
Note: Master mode is enabled by setting and clearing the appropriate SSPM bits in SSPCON1 and by setting the SSPEN bit. In Master mode, the SCL and SDA lines are manipulated by the MSSP hardware. Master mode of operation is supported by interrupt generation on the detection of the Start and Stop conditions. The Stop (P) and Start (S) bits are cleared from a Reset or when the MSSP module is disabled. Control of the I 2C bus may be taken when the P bit is set or the bus is Idle, with both the S and P bits clear. In Firmware Controlled Master mode, user code conducts all I 2C bus operations based on Start and Stop bit conditions. Once Master mode is enabled, the user has six options. 1. 2. 3. 4. 5. 6. Assert a Start condition on SDA and SCL. Assert a Repeated Start condition on SDA and SCL. Write to the SSPBUF register initiating transmission of data/address. Configure the I2C port to receive data. Generate an Acknowledge condition at the end of a received byte of data. Generate a Stop condition on SDA and SCL. The MSSP module, when configured in I2C Master mode, does not allow queueing of events. For instance, the user is not allowed to initiate a Start condition and immediately write the SSPBUF register to initiate transmission before the Start condition is complete. In this case, the SSPBUF will not be written to and the WCOL bit will be set, indicating that a write to the SSPBUF did not occur.
The following events will cause the MSSP Interrupt Flag bit, SSPIF, to be set (MSSP interrupt, if enabled): * * * * * Start condition Stop condition Data transfer byte transmitted/received Acknowledge transmit Repeated Start
FIGURE 15-16:
MSSP BLOCK DIAGRAM (I2CTM MASTER MODE)
Internal Data Bus Read SSPBUF Write Baud Rate Generator Clock Arbitrate/WCOL Detect (hold off clock source) DS39629C-page 181 Shift Clock SSPSR Receive Enable MSb LSb SSPM3:SSPM0 SSPADD<6:0>
SDA
SDA In
SCL
SCL In Bus Collision
Start bit Detect Stop bit Detect Write Collision Detect Clock Arbitration State Counter for end of XMIT/RCV
Set/Reset, S, P, WCOL (SSPSTAT), Set SSPIF, BCLIF, Reset ACKSTAT, PEN (SSPCON2)
(c) 2007 Microchip Technology Inc.
Clock Cntl
Start bit, Stop bit, Acknowledge Generate
PIC18F6390/6490/8390/8490
15.4.6.1 I2C Master Mode Operation
A typical transmit sequence would go as follows: 1. The user generates a Start condition by setting the Start Enable bit, SEN (SSPCON2<0>). 2. SSPIF is set. The MSSP module will wait the required start time before any other operation takes place. 3. The user loads the SSPBUF with the slave address to transmit. 4. Address is shifted out the SDA pin until all 8 bits are transmitted. 5. The MSSP module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 6. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 7. The user loads the SSPBUF with 8 bits of data. 8. Data is shifted out the SDA pin until all 8 bits are transmitted. 9. The MSSP module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 10. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 11. The user generates a Stop condition by setting the Stop Enable bit, PEN (SSPCON2<2>). 12. Interrupt is generated once the Stop condition is complete. The master device generates all of the serial clock pulses and the Start and Stop conditions. A transfer is ended with a Stop condition or with a Repeated Start condition. Since the Repeated Start condition is also the beginning of the next serial transfer, the I2C bus will not be released. In Master Transmitter mode, serial data is output through SDA, while SCL outputs the serial clock. The first byte transmitted contains the slave address of the receiving device (7 bits) and the Read/Write (R/W) bit. In this case, the R/W bit will be logic `0'. Serial data is transmitted 8 bits at a time. After each byte is transmitted, an Acknowledge bit is received. Start and Stop conditions are output to indicate the beginning and the end of a serial transfer. In Master Receive mode, the first byte transmitted contains the slave address of the transmitting device (7 bits) and the R/W bit. In this case, the R/W bit will be logic `1'. Thus, the first byte transmitted is a 7-bit slave address, followed by a `1' to indicate the receive bit. Serial data is received via SDA, while SCL outputs the serial clock. Serial data is received 8 bits at a time. After each byte is received, an Acknowledge bit is transmitted. Start and Stop conditions indicate the beginning and end of transmission. The Baud Rate Generator used for the SPI mode operation is used to set the SCL clock frequency for either 100 kHz, 400 kHz or 1 MHz I2C operation. See Section 15.4.7 "Baud Rate" for more detail.
DS39629C-page 182
(c) 2007 Microchip Technology Inc.
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15.4.7
2
BAUD RATE
In I C Master mode, the Baud Rate Generator (BRG) reload value is placed in the lower 7 bits of the SSPADD register (Figure 15-17). When a write occurs to SSPBUF, the Baud Rate Generator will automatically begin counting. The BRG counts down to 0 and stops until another reload has taken place. The BRG count is decremented twice per instruction cycle (TCY) on the Q2 and Q4 clocks. In I2C Master mode, the BRG is reloaded automatically.
Once the given operation is complete (i.e., transmission of the last data bit is followed by ACK), the internal clock will automatically stop counting and the SCL pin will remain in its last state. Table 15-3 demonstrates clock rates based on instruction cycles and the BRG value loaded into SSPADD.
FIGURE 15-17:
BAUD RATE GENERATOR BLOCK DIAGRAM
SSPM3:SSPM0 SSPADD<6:0>
SSPM3:SSPM0 SCL
Reload Control CLKO
Reload
BRG Down Counter
FOSC/4
TABLE 15-3:
FCY
I2CTM CLOCK RATE w/BRG
FCY * 2 20 MHz 20 MHz 20 MHz 8 MHz 8 MHz 8 MHz 2 MHz 2 MHz 2 MHz BRG Value 19h 20h 3Fh 0Ah 0Dh 28h 03h 0Ah 00h FSCL (2 Rollovers of BRG) 400 kHz(1) 312.5 kHz 100 kHz 400 kHz(1) 308 kHz 100 kHz 333 kHz(1) 100 kHz 1 MHz(1)
10 MHz 10 MHz 10 MHz 4 MHz 4 MHz 4 MHz 1 MHz 1 MHz 1 MHz Note 1:
The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than 100 kHz) in all details, but may be used with care where higher rates are required by the application.
(c) 2007 Microchip Technology Inc.
DS39629C-page 183
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15.4.7.1 Clock Arbitration
Clock arbitration occurs when the master, during any receive, transmit or Repeated Start/Stop condition, deasserts the SCL pin (SCL allowed to float high). When the SCL pin is allowed to float high, the Baud Rate Generator (BRG) is suspended from counting until the SCL pin is actually sampled high. When the SCL pin is sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and begins counting. This ensures that the SCL high time will always be at least one BRG rollover count in the event that the clock is held low by an external device (Figure 15-18).
FIGURE 15-18:
SDA
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
DX DX - 1 SCL allowed to transition high
SCL deasserted but slave holds SCL low (clock arbitration) SCL BRG decrements on Q2 and Q4 cycles BRG Value 03h 02h 01h 00h (hold off)
03h
02h
SCL is sampled high, reload takes place and BRG starts its count BRG Reload
DS39629C-page 184
(c) 2007 Microchip Technology Inc.
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15.4.8 I2C MASTER MODE START CONDITION TIMING
Note: To initiate a Start condition, the user sets the Start Condition Enable bit, SEN (SSPCON2<0>). If the SDA and SCL pins are sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and starts its count. If SCL and SDA are both sampled high when the Baud Rate Generator times out (TBRG), the SDA pin is driven low. The action of the SDA being driven low while SCL is high is the Start condition and causes the S bit (SSPSTAT<3>) to be set. Following this, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and resumes its count. When the Baud Rate Generator times out (TBRG), the SEN bit (SSPCON2<0>) will be automatically cleared by hardware, the Baud Rate Generator is suspended, leaving the SDA line held low and the Start condition is complete. If at the beginning of the Start condition, the SDA and SCL pins are already sampled low, or if during the Start condition, the SCL line is sampled low before the SDA line is driven low, a bus collision occurs, the Bus Collision Interrupt Flag, BCLIF, is set, the Start condition is aborted and the I2C module is reset into its Idle state.
15.4.8.1
WCOL Status Flag
If the user writes the SSPBUF when a Start sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). Note: Because queueing of events is not allowed, writing to the lower 5 bits of SSPCON2 is disabled until the Start condition is complete.
FIGURE 15-19:
FIRST START BIT TIMING
Write to SEN bit occurs here Set S bit (SSPSTAT<3>) SDA = 1, SCL = 1 TBRG TBRG At completion of Start bit, hardware clears SEN bit and sets SSPIF bit Write to SSPBUF occurs here 1st bit TBRG TBRG S 2nd bit
SDA
SCL
(c) 2007 Microchip Technology Inc.
DS39629C-page 185
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15.4.9 I2C MASTER MODE REPEATED START CONDITION TIMING
Note 1: If RSEN is programmed while any other event is in progress, it will not take effect. 2: A bus collision during the Repeated Start condition occurs if: * SDA is sampled low when SCL goes from low-to-high. * SCL goes low before SDA is asserted low. This may indicate that another master is attempting to transmit a data `1'. Immediately following the SSPIF bit getting set, the user may write the SSPBUF with the 7-bit address in 7-bit mode, or the default first address in 10-bit mode. After the first 8 bits are transmitted and an ACK is received, the user may then transmit an additional eight bits of address (10-bit mode) or 8 bits of data (7-bit mode). A Repeated Start condition occurs when the RSEN bit (SSPCON2<1>) is programmed high and the I2C logic module is in the Idle state. When the RSEN bit is set, the SCL pin is asserted low. When the SCL pin is sampled low, the Baud Rate Generator is loaded with the contents of SSPADD<5:0> and begins counting. The SDA pin is released (brought high) for one Baud Rate Generator count (TBRG). When the Baud Rate Generator times out, if SDA is sampled high, the SCL pin will be deasserted (brought high). When SCL is sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and begins counting. SDA and SCL must be sampled high for one TBRG. This action is then followed by assertion of the SDA pin (SDA = 0) for one TBRG while SCL is high. Following this, the RSEN bit (SSPCON2<1>) will be automatically cleared and the Baud Rate Generator will not be reloaded, leaving the SDA pin held low. As soon as a Start condition is detected on the SDA and SCL pins, the S bit (SSPSTAT<3>) will be set. The SSPIF bit will not be set until the Baud Rate Generator has timed out.
15.4.9.1
WCOL Status Flag
If the user writes the SSPBUF when a Repeated Start sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). Note: Because queueing of events is not allowed, writing of the lower 5 bits of SSPCON2 is disabled until the Repeated Start condition is complete.
FIGURE 15-20:
REPEAT START CONDITION WAVEFORM
Write to SSPCON2 occurs here. SDA = 1, SCL (no change).
Set S (SSPSTAT<3>) SDA = 1, SCL = 1 At completion of Start bit, hardware clears RSEN bit and sets SSPIF TBRG 1st bit Write to SSPBUF occurs here TBRG TBRG Sr = Repeated Start
TBRG SDA Falling edge of ninth clock, end of Xmit SCL
TBRG
DS39629C-page 186
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
15.4.10 I2C MASTER MODE TRANSMISSION 15.4.10.3 ACKSTAT Status Flag
Transmission of a data byte, a 7-bit address or the other half of a 10-bit address is accomplished by simply writing a value to the SSPBUF register. This action will set the Buffer Full flag bit, BF, and allow the Baud Rate Generator to begin counting and start the next transmission. Each bit of address/data will be shifted out onto the SDA pin after the falling edge of SCL is asserted (see data hold time specification parameter #106). SCL is held low for one Baud Rate Generator rollover count (TBRG). Data should be valid before SCL is released high (see data setup time specification parameter #107). When the SCL pin is released high, it is held that way for TBRG. The data on the SDA pin must remain stable for that duration and some hold time after the next falling edge of SCL. After the eighth bit is shifted out (the falling edge of the eighth clock), the BF flag is cleared and the master releases SDA. This allows the slave device being addressed to respond with an ACK bit during the ninth bit time if an address match occurred, or if data was received properly. The status of ACK is written into the ACKDT bit on the falling edge of the ninth clock. If the master receives an Acknowledge, the Acknowledge Status bit, ACKSTAT, is cleared. If not, the bit is set. After the ninth clock, the SSPIF bit is set and the master clock (Baud Rate Generator) is suspended until the next data byte is loaded into the SSPBUF, leaving SCL low and SDA unchanged (Figure 15-21). After the write to the SSPBUF, each bit of address will be shifted out on the falling edge of SCL until all 7 address bits and the R/W bit are completed. On the falling edge of the eighth clock, the master will deassert the SDA pin, allowing the slave to respond with an Acknowledge. On the falling edge of the ninth clock, the master will sample the SDA pin to see if the address was recognized by a slave. The status of the ACK bit is loaded into the ACKSTAT status bit (SSPCON2<6>). Following the falling edge of the ninth clock transmission of the address, the SSPIF is set, the BF flag is cleared and the Baud Rate Generator is turned off until another write to the SSPBUF takes place, holding SCL low and allowing SDA to float. In Transmit mode, the ACKSTAT bit (SSPCON2<6>) is cleared when the slave has sent an Acknowledge (ACK = 0) and is set when the slave does not Acknowledge (ACK = 1). A slave sends an Acknowledge when it has recognized its address (including a general call), or when the slave has properly received its data.
15.4.11
I2C MASTER MODE RECEPTION
Master mode reception is enabled by programming the Receive Enable bit, RCEN (SSPCON2<3>). Note: The MSSP module must be in an Idle state before the RCEN bit is set or the RCEN bit will be disregarded.
The Baud Rate Generator begins counting and on each rollover, the state of the SCL pin changes (high-to-low/ low-to-high) and data is shifted into the SSPSR. After the falling edge of the eighth clock, the receive enable flag is automatically cleared, the contents of the SSPSR are loaded into the SSPBUF, the BF flag bit is set, the SSPIF flag bit is set and the Baud Rate Generator is suspended from counting, holding SCL low. The MSSP is now in Idle state awaiting the next command. When the buffer is read by the CPU, the BF flag bit is automatically cleared. The user can then send an Acknowledge bit at the end of reception by setting the Acknowledge Sequence Enable bit, ACKEN (SSPCON2<4>).
15.4.11.1
BF Status Flag
In receive operation, the BF bit is set when an address or data byte is loaded into SSPBUF from SSPSR. It is cleared when the SSPBUF register is read.
15.4.11.2
SSPOV Status Flag
In receive operation, the SSPOV bit is set when 8 bits are received into the SSPSR and the BF flag bit is already set from a previous reception.
15.4.11.3
WCOL Status Flag
15.4.10.1
BF Status Flag
If the user writes the SSPBUF when a receive is already in progress (i.e., SSPSR is still shifting in a data byte), the WCOL bit is set and the contents of the buffer are unchanged (the write doesn't occur).
In Transmit mode, the BF bit (SSPSTAT<0>) is set when the CPU writes to SSPBUF and is cleared when all 8 bits are shifted out.
15.4.10.2
WCOL Status Flag
If the user writes the SSPBUF when a transmit is already in progress (i.e., SSPSR is still shifting out a data byte), the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). WCOL must be cleared in software.
(c) 2007 Microchip Technology Inc.
DS39629C-page 187
FIGURE 15-21:
DS39629C-page 188
Write SSPCON2<0> SEN = 1 Start condition begins From slave, clear ACKSTAT bit SSPCON2<6> R/W = 0 A1 ACK = 0 D7 D6 D5 D4 D3 D2 D1 Transmitting Data or Second Half of 10-bit Address D0 ACK SEN = 0 Transmit Address to Slave SDA A7 SSPBUF written with 7-bit address and R/W start transmit SCL S 1 2 3 4 5 6 7 8 9 1 SCL held low while CPU responds to SSPIF 2 3 4 5 6 7 8 9 P A6 A5 A4 A3 A2 ACKSTAT in SSPCON2 = 1 SSPIF Cleared in software Cleared in software service routine from MSSP interrupt Cleared in software BF (SSPSTAT<0>) SSPBUF written SEN After Start condition, SEN cleared by hardware SSPBUF is written in software PEN
PIC18F6390/6490/8390/8490
I 2CTM MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)
(c) 2007 Microchip Technology Inc.
R/W
FIGURE 15-22:
(c) 2007 Microchip Technology Inc.
Write to SSPCON2<4> to start Acknowledge sequence SDA = ACKDT (SSPCON2<5>) = 0 Master configured as a receiver by programming SSPCON2<3> (RCEN = 1) ACK from Slave R/W = 1 Receiving Data from Slave ACK Receiving Data from Slave RCEN cleared automatically RCEN = 1, start next receive RCEN cleared automatically ACK ACK from Master SDA = ACKDT = 0 Set ACKEN, start Acknowledge sequence SDA = ACKDT = 1 PEN bit = 1 written here
Write to SSPCON2<0> (SEN = 1), begin Start Condition
SEN = 0 Write to SSPBUF occurs here, start XMIT
Transmit Address to Slave
SDA D0
A7 A1 D7 D6 D5 D4 D3 D2 D1 D7 D6 D5 D4 D3 D2 D1
A6 A5 A4 A3 A2
D0
ACK ACK is not sent Bus master terminates transfer
SCL
Set SSPIF interrupt at end of receive
S
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
Set SSPIF at end of receive
P
Set SSPIF interrupt at end of Acknowledge sequence
Data shifted in on falling edge of CLK
SSPIF
Cleared in software Cleared in software
Set SSPIF interrupt at end of Acknowledge sequence Cleared in software Cleared in software
SDA = 0, SCL = 1 while CPU responds to SSPIF
Cleared in software
Set P bit (SSPSTAT<4>) and SSPIF
BF (SSPSTAT<0>)
Last bit is shifted into SSPSR and contents are unloaded into SSPBUF
SSPOV
SSPOV is set because SSPBUF is still full
I 2CTM MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
PIC18F6390/6490/8390/8490
ACKEN
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15.4.12 ACKNOWLEDGE SEQUENCE TIMING 15.4.13 STOP CONDITION TIMING
An Acknowledge sequence is enabled by setting the Acknowledge Sequence Enable bit, ACKEN (SSPCON2<4>). When this bit is set, the SCL pin is pulled low and the contents of the Acknowledge data bit are presented on the SDA pin. If the user wishes to generate an Acknowledge, then the ACKDT bit should be cleared. If not, the user should set the ACKDT bit before starting an Acknowledge sequence. The Baud Rate Generator then counts for one rollover period (TBRG) and the SCL pin is deasserted (pulled high). When the SCL pin is sampled high (clock arbitration), the Baud Rate Generator counts for TBRG. The SCL pin is then pulled low. Following this, the ACKEN bit is automatically cleared, the Baud Rate Generator is turned off and the MSSP module then goes into Idle mode (Figure 15-23). A Stop bit is asserted on the SDA pin at the end of a receive/transmit by setting the Stop Sequence Enable bit, PEN (SSPCON2<2>). At the end of a receive/ transmit, the SCL line is held low after the falling edge of the ninth clock. When the PEN bit is set, the master will assert the SDA line low. When the SDA line is sampled low, the Baud Rate Generator is reloaded and counts down to `0'. When the Baud Rate Generator times out, the SCL pin will be brought high and one TBRG (Baud Rate Generator rollover count) later, the SDA pin will be deasserted. When the SDA pin is sampled high while SCL is high, the P bit (SSPSTAT<4>) is set. A TBRG later, the PEN bit is cleared and the SSPIF bit is set (Figure 15-24).
15.4.13.1
WCOL Status Flag
15.4.12.1
WCOL Status Flag
If the user writes the SSPBUF when an Acknowledge sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur).
If the user writes the SSPBUF when a Stop sequence is in progress, then the WCOL bit is set and the contents of the buffer are unchanged (the write doesn't occur).
FIGURE 15-23:
ACKNOWLEDGE SEQUENCE WAVEFORM
Acknowledge sequence starts here, write to SSPCON2 ACKEN = 1, ACKDT = 0 SDA SCL D0 8 ACKEN automatically cleared TBRG ACK TBRG
9
SSPIF Set SSPIF at the end of receive Note: TBRG = one Baud Rate Generator period. Cleared in software Set SSPIF at the end of Acknowledge sequence
Cleared in software
FIGURE 15-24:
STOP CONDITION RECEIVE OR TRANSMIT MODE
Write to SSPCON2, set PEN SCL = 1 for TBRG, followed by SDA = 1 for TBRG after SDA sampled high. P bit (SSPSTAT<4>) is set. PEN bit (SSPCON2<2>) is cleared by hardware and the SSPIF bit is set TBRG
Falling edge of 9th clock SCL
SDA
ACK P TBRG TBRG TBRG SCL brought high after TBRG SDA asserted low before rising edge of clock to setup Stop condition
Note: TBRG = one Baud Rate Generator period.
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15.4.14 SLEEP OPERATION
2
15.4.17
While in Sleep mode, the I C module can receive addresses or data and when an address match or complete byte transfer occurs, wake the processor from Sleep (if the MSSP interrupt is enabled).
MULTI-MASTER COMMUNICATION, BUS COLLISION AND BUS ARBITRATION
15.4.15
EFFECT OF A RESET
A Reset disables the MSSP module and terminates the current transfer.
15.4.16
MULTI-MASTER MODE
In Multi-Master mode, the interrupt generation on the detection of the Start and Stop conditions allows the determination of when the bus is free. The Stop (P) and Start (S) bits are cleared from a Reset or when the MSSP module is disabled. Control of the I 2C bus may be taken when the P bit (SSPSTAT<4>) is set, or the bus is Idle, with both the S and P bits clear. When the bus is busy, enabling the MSSP interrupt will generate the interrupt when the Stop condition occurs. In multi-master operation, the SDA line must be monitored for arbitration to see if the signal level is the expected output level. This check is performed in hardware with the result placed in the BCLIF bit. The states where arbitration can be lost are: * * * * * Address Transfer Data Transfer A Start Condition A Repeated Start Condition An Acknowledge Condition
Multi-Master mode support is achieved by bus arbitration. When the master outputs address/data bits onto the SDA pin, arbitration takes place when the master outputs a `1' on SDA, by letting SDA float high and another master asserts a `0'. When the SCL pin floats high, data should be stable. If the expected data on SDA is a `1' and the data sampled on the SDA pin = 0, then a bus collision has taken place. The master will set the Bus Collision Interrupt Flag, BCLIF and reset the I2C port to its Idle state (Figure 15-25). If a transmit was in progress when the bus collision occurred, the transmission is halted, the BF flag is cleared, the SDA and SCL lines are deasserted and the SSPBUF can be written to. When the user services the bus collision Interrupt Service Routine and if the I2C bus is free, the user can resume communication by asserting a Start condition. If a Start, Repeated Start, Stop or Acknowledge condition was in progress when the bus collision occurred, the condition is aborted, the SDA and SCL lines are deasserted and the respective control bits in the SSPCON2 register are cleared. When the user services the bus collision Interrupt Service Routine and if the I2C bus is free, the user can resume communication by asserting a Start condition. The master will continue to monitor the SDA and SCL pins. If a Stop condition occurs, the SSPIF bit will be set. A write to the SSPBUF will start the transmission of data at the first data bit, regardless of where the transmitter left off when the bus collision occurred. In Multi-Master mode, the interrupt generation on the detection of Start and Stop conditions allows the determination of when the bus is free. Control of the I2C bus can be taken when the P bit is set in the SSPSTAT register, or the bus is Idle and the S and P bits are cleared.
FIGURE 15-25:
BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE
Data changes while SCL = 0 SDA line pulled low by another source SDA released by master Sample SDA. While SCL is high, data doesn't match what is driven by the master. Bus collision has occurred.
SDA
SCL
Set bus collision interrupt (BCLIF)
BCLIF
(c) 2007 Microchip Technology Inc.
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15.4.17.1 Bus Collision During a Start Condition
During a Start condition, a bus collision occurs if: a) b) SDA or SCL are sampled low at the beginning of the Start condition (Figure 15-26). SCL is sampled low before SDA is asserted low (Figure 15-27). If the SDA pin is sampled low during this count, the BRG is reset and the SDA line is asserted early (Figure 15-28). If, however, a `1' is sampled on the SDA pin, the SDA pin is asserted low at the end of the BRG count. The Baud Rate Generator is then reloaded and counts down to 0 and during this time, if the SCL pins are sampled as `0', a bus collision does not occur. At the end of the BRG count, the SCL pin is asserted low. Note: The reason that bus collision is not a factor during a Start condition is that no two bus masters can assert a Start condition at the exact same time. Therefore, one master will always assert SDA before the other. This condition does not cause a bus collision because the two masters must be allowed to arbitrate the first address following the Start condition. If the address is the same, arbitration must be allowed to continue into the data portion, Repeated Start or Stop conditions.
During a Start condition, both the SDA and the SCL pins are monitored. If the SDA pin is already low, or the SCL pin is already low, then all of the following occur: * the Start condition is aborted, * the BCLIF flag is set and * the MSSP module is reset to its Idle state (Figure 15-26). The Start condition begins with the SDA and SCL pins deasserted. When the SDA pin is sampled high, the Baud Rate Generator is loaded from SSPADD<6:0> and counts down to `0'. If the SCL pin is sampled low while SDA is high, a bus collision occurs because it is assumed that another master is attempting to drive a data `1' during the Start condition.
FIGURE 15-26:
BUS COLLISION DURING START CONDITION (SDA ONLY)
SDA goes low before the SEN bit is set. Set BCLIF, S bit and SSPIF set because SDA = 0, SCL = 1.
SDA
SCL Set SEN, enable Start condition if SDA = 1, SCL = 1 SEN SDA sampled low before Start condition. Set BCLIF. S bit and SSPIF set because SDA = 0, SCL = 1. SSPIF and BCLIF are cleared in software S SEN cleared automatically because of bus collision. MSSP module reset into Idle state.
BCLIF
SSPIF SSPIF and BCLIF are cleared in software
DS39629C-page 192
(c) 2007 Microchip Technology Inc.
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FIGURE 15-27: BUS COLLISION DURING START CONDITION (SCL = 0)
SDA = 0, SCL = 1
TBRG TBRG
SDA Set SEN, enable Start sequence if SDA = 1, SCL = 1 SCL = 0 before SDA = 0, bus collision occurs. Set BCLIF. SCL = 0 before BRG time-out, bus collision occurs. Set BCLIF. BCLIF Interrupt cleared in software S SSPIF `0' `0' `0' `0'
SCL
SEN
FIGURE 15-28:
BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION
SDA = 0, SCL = 1 Set S Less than TBRG
TBRG
Set SSPIF
SDA
SDA pulled low by other master. Reset BRG and assert SDA.
SCL
S
SCL pulled low after BRG time-out Set SEN, enable START sequence if SDA = 1, SCL = 1
SEN
BCLIF
`0'
S
SSPIF SDA = 0, SCL = 1, set SSPIF Interrupts cleared in software
(c) 2007 Microchip Technology Inc.
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15.4.17.2 Bus Collision During a Repeated Start Condition
During a Repeated Start condition, a bus collision occurs if: a) b) A low level is sampled on SDA when SCL goes from low level to high level. SCL goes low before SDA is asserted low, indicating that another master is attempting to transmit a data `1'. If SDA is low, a bus collision has occurred (i.e., another master is attempting to transmit a data `0', Figure 15-29). If SDA is sampled high, the BRG is reloaded and begins counting. If SDA goes from high-to-low before the BRG times out, no bus collision occurs because no two masters can assert SDA at exactly the same time. If SCL goes from high-to-low before the BRG times out and SDA has not already been asserted, a bus collision occurs. In this case, another master is attempting to transmit a data `1' during the Repeated Start condition (see Figure 15-30). If, at the end of the BRG time-out, both SCL and SDA are still high, the SDA pin is driven low and the BRG is reloaded and begins counting. At the end of the count, regardless of the status of the SCL pin, the SCL pin is driven low and the Repeated Start condition is complete.
When the user deasserts SDA and the pin is allowed to float high, the BRG is loaded with SSPADD<6:0> and counts down to 0. The SCL pin is then deasserted and when sampled high, the SDA pin is sampled.
FIGURE 15-29:
SDA
BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
SCL Sample SDA when SCL goes high. If SDA = 0, set BCLIF and release SDA and SCL. RSEN
BCLIF Cleared in software `0' `0'
S SSPIF
FIGURE 15-30:
BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
TBRG TBRG
SDA SCL SCL goes low before SDA, set BCLIF. Release SDA and SCL. Interrupt cleared in software RSEN S SSPIF `0'
BCLIF
DS39629C-page 194
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
15.4.17.3 Bus Collision During a Stop Condition
Bus collision occurs during a Stop condition if: a) After the SDA pin has been deasserted and allowed to float high, SDA is sampled low after the BRG has timed out. After the SCL pin is deasserted, SCL is sampled low before SDA goes high. The Stop condition begins with SDA asserted low. When SDA is sampled low, the SCL pin is allowed to float. When the pin is sampled high (clock arbitration), the Baud Rate Generator is loaded with SSPADD<6:0> and counts down to 0. After the BRG times out, SDA is sampled. If SDA is sampled low, a bus collision has occurred. This is due to another master attempting to drive a data `0' (Figure 15-31). If the SCL pin is sampled low before SDA is allowed to float high, a bus collision occurs. This is another case of another master attempting to drive a data `0' (Figure 15-32).
b)
FIGURE 15-31:
BUS COLLISION DURING A STOP CONDITION (CASE 1)
TBRG TBRG TBRG SDA sampled low after TBRG, set BCLIF
SDA SDA asserted low SCL PEN BCLIF P SSPIF
`0' `0'
FIGURE 15-32:
BUS COLLISION DURING A STOP CONDITION (CASE 2)
TBRG TBRG TBRG
SDA Assert SDA SCL PEN BCLIF P SSPIF `0' `0' SCL goes low before SDA goes high, set BCLIF
(c) 2007 Microchip Technology Inc.
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PIC18F6390/6490/8390/8490
TABLE 15-4:
Name INTCON PIR1 PIE1 IPR1 TRISC SSPBUF SSPADD SSPCON1 SSPCON2 SSPSTAT Legend:
REGISTERS ASSOCIATED WITH I2CTM OPERATION
Bit 7 Bit 6 Bit 5 TMR0IE RC1IF RC1IE RC1IP Bit 4 INT0IE TX1IF TX1IE TX1IP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Reset Values on Page 59 61 61 61 62 60
2
GIE/GIEH PEIE/GIEL -- -- -- ADIF ADIE ADIP
PORTC Data Direction Register MSSP Receive Buffer/Transmit Register MSSP Address Register in I C Slave Mode. MSSP Baud Rate Reload Register in I C Slave Mode. WCOL GCEN SMP SSPOV ACKSTAT CKE SSPEN ACKDT D/A CKP ACKEN P SSPM3 RCEN S SSPM2 PEN R/W SSPM1 RSEN UA SSPM0 SEN BF
2
60 60 60 60
-- = unimplemented, read as `0'. Shaded cells are not used by the MSSP in SPI mode.
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16.0 ENHANCED UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (EUSART)
The pins of the EUSART are multiplexed with the functions of PORTC (RC6/TX1/CK1 and RC7/RX1/DT1). In order to configure these pins as an EUSART: * bit SPEN (RCSTA1<7>) must be set (= 1) * bit TRISC<7> must be set (= 1) * bit TRISC<6> must be set (= 1) Note: The USART control will automatically reconfigure the pin from input to output as needed.
PIC18F6390/6490/8390/8490 devices have three serial I/O modules: the MSSP module, discussed in the previous chapter and two Universal Synchronous Asynchronous Receiver Transmitter (USART) modules. (Generically, the USART is also known as a Serial Communications Interface or SCI.) The USART can be configured as a full-duplex asynchronous system that can communicate with peripheral devices, such as CRT terminals and personal computers. It can also be configured as a half-duplex synchronous system that can communicate with peripheral devices, such as A/D or D/A integrated circuits, serial EEPROMs, etc. There are two distinct implementations of the USART module in these devices: the Enhanced USART (EUSART) discussed here and the Addressable USART discussed in the next chapter. For this device family, USART1 always refers to the EUSART, while USART2 is always the AUSART. The EUSART and AUSART modules implement the same core features for serial communications; their basic operation is essentially the same. The EUSART module provides additional features, including Automatic Baud Rate Detection (ABD) and calibration, automatic wake-up on Sync Break reception and 12-bit Break character transmit. These features make it ideally suited for use in Local Interconnect Network bus (LIN bus) systems. The EUSART can be configured in the following modes: * Asynchronous (full-duplex) with: - Auto-wake-up on character reception - Auto-baud calibration - 12-bit Break character transmission * Synchronous - Master (half-duplex) with selectable clock polarity * Synchronous - Slave (half-duplex) with selectable clock polarity
The operation of the Enhanced USART module is controlled through three registers: * Transmit Status and Control Register 1 (TXSTA1) * Receive Status and Control Register 1 (RCSTA1) * Baud Rate Control Register 1 (BAUDCON1) The registers are described Register 16-2 and Register 16-3. in Register 16-1,
(c) 2007 Microchip Technology Inc.
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REGISTER 16-1:
R/W-0 CSRC bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
TXSTA1: EUSART TRANSMIT STATUS AND CONTROL REGISTER
R/W-0 TXEN(1) R/W-0 SYNC R/W-0 SENDB R/W-0 BRGH R-1 TRMT R/W-0 TX9D bit 0 TX9
R/W-0
CSRC: Clock Source Select bit Asynchronous mode: Don't care. Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) TX9: 9-Bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission TXEN: Transmit Enable bit(1) 1 = Transmit enabled 0 = Transmit disabled SYNC: EUSART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode SENDB: Send Break Character bit Asynchronous mode: 1 = Send Sync Break on next transmission (cleared by hardware upon completion) 0 = Sync Break transmission completed Synchronous mode: Don't care. BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode. TRMT: Transmit Shift Register Status bit 1 = TSR empty 0 = TSR full TX9D: 9th bit of Transmit Data Can be address/data bit or a parity bit. SREN/CREN overrides TXEN in Sync mode.
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note 1:
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(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 16-2:
R/W-0 SPEN bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
RCSTA1: EUSART RECEIVE STATUS AND CONTROL REGISTER
R/W-0 SREN R/W-0 CREN R/W-0 ADDEN R-0 FERR R-0 OERR R-x RX9D bit 0 RX9
R/W-0
SPEN: Serial Port Enable bit 1 = Serial port enabled (configures RX1/DT1 and TX1/CK1 pins as serial port pins) 0 = Serial port disabled (held in Reset) RX9: 9-Bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception SREN: Single Receive Enable bit Asynchronous mode: Don't care. Synchronous mode - Master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode - Slave: Don't care. CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables receiver 0 = Disables receiver Synchronous mode: 1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN) 0 = Disables continuous receive ADDEN: Address Detect Enable bit Asynchronous mode 9-Bit (RX9 = 1): 1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set 0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit Asynchronous mode 9-Bit (RX9 = 0): Don't care. FERR: Framing Error bit 1 = Framing error (can be updated by reading RCREG1 register and receiving next valid byte) 0 = No framing error OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit, CREN) 0 = No overrun error RX9D: 9th bit of Received Data This can be address/data bit or a parity bit and must be calculated by user firmware.
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
(c) 2007 Microchip Technology Inc.
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PIC18F6390/6490/8390/8490
REGISTER 16-3:
R/W-0 ABDOVF bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
BAUDCON1: BAUD RATE CONTROL REGISTER 1
R-1 U-0 -- R/W-0 SCKP R/W-0 BRG16 U-0 -- R/W-0 WUE R/W-0 ABDEN bit 0
RCIDL
ABDOVF: Auto-Baud Acquisition Rollover Status bit 1 = A BRG rollover has occurred during Auto-Baud Rate Detect mode (must be cleared in software) 0 = No BRG rollover has occurred RCIDL: Receive Operation Idle Status bit 1 = Receive operation is Idle 0 = Receive operation is active Unimplemented: Read as `0' SCKP: Synchronous Clock Polarity Select bit Asynchronous mode: Unused in this mode. Synchronous mode: 1 = Idle state for clock (CK1) is a high level 0 = Idle state for clock (CK1) is a low level BRG16: 16-Bit Baud Rate Register Enable bit 1 = 16-bit Baud Rate Generator - SPBRGH1 and SPBRG1 0 = 8-bit Baud Rate Generator - SPBRG1 only (Compatible mode), SPBRGH1 value ignored Unimplemented: Read as `0' WUE: Wake-up Enable bit Asynchronous mode: 1 = EUSART will continue to sample the RX1 pin - interrupt generated on falling edge; bit cleared in hardware on following rising edge 0 = RX1 pin not monitored or rising edge detected Synchronous mode: Unused in this mode. ABDEN: Auto-Baud Detect Enable bit Asynchronous mode: 1 = Enable baud rate measurement on the next character. Requires reception of a Sync field (55h); cleared in hardware upon completion. 0 = Baud rate measurement disabled or completed Synchronous mode: Unused in this mode.
bit 6
bit 5 bit 4
bit 3
bit 2 bit 1
bit 0
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16.1 EUSART Baud Rate Generator (BRG)
The BRG is a dedicated, 8-bit or 16-bit generator that supports both the Asynchronous and Synchronous modes of the EUSART. By default, the BRG operates in 8-bit mode; setting the BRG16 bit (BAUDCON1<3>) selects 16-bit mode. The SPBRGH1:SPBRG1 register pair controls the period of a free-running timer. In Asynchronous mode, the BRGH (TXSTA1<2>) and BRG16 (BAUDCON1<3>) bits also control the baud rate. In Synchronous mode, BRGH is ignored. Table 16-1 shows the formula for computation of the baud rate for different EUSART modes that only apply in Master mode (internally generated clock). Given the desired baud rate and FOSC, the nearest integer value for the SPBRGH1:SPBRG1 registers can be calculated using the formulas in Table 16-1. From this, the error in baud rate can be determined. An example calculation is shown in Example 16-1. Typical baud rates and error values for the various Asynchronous modes are shown in Table 16-3. It may be advantageous to use the high baud rate (BRGH = 1) or the 16-bit BRG to reduce the baud rate error, or achieve a slow baud rate for a fast oscillator frequency. Writing a new value to the SPBRGH1:SPBRG1 registers causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate.
16.1.1
OPERATION IN POWER-MANAGED MODES
The device clock is used to generate the desired baud rate. When one of the power-managed modes is entered, the new clock source may be operating at a different frequency. This may require an adjustment to the value in the SPBRG1 register pair.
16.1.2
SAMPLING
The data on the RX1 pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX1 pin.
TABLE 16-1:
BAUD RATE FORMULAS
BRG/EUSART Mode Baud Rate Formula FOSC/[64 (n + 1)] FOSC/[16 (n + 1)] FOSC/[4 (n + 1)]
Configuration Bits SYNC BRG16 BRGH
0 0 0 8-Bit/Asynchronous 0 0 1 8-Bit/Asynchronous 0 1 0 16-Bit/Asynchronous 0 1 1 16-Bit/Asynchronous 1 0 x 8-Bit/Synchronous 1 1 x 16-Bit/Synchronous Legend: x = Don't care, n = Value of SPBRGH1:SPBRG1 register pair
EXAMPLE 16-1:
CALCULATING BAUD RATE ERROR
For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, 8-bit BRG: Desired Baud Rate = FOSC/(64 ([SPBRGH1:SPBRG1] + 1)) Solving for SPBRGH1:SPBRG1: X = ((FOSC/Desired Baud Rate)/64) - 1 = ((16000000/9600)/64) - 1 = [25.042] = 25 Calculated Baud Rate = 16000000/(64 (25 + 1)) = 9615 Error = (Calculated Baud Rate - Desired Baud Rate)/Desired Baud Rate = (9615 - 9600)/9600 = 0.16%
TABLE 16-2:
Name TXSTA1 RCSTA1
REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR
Bit 7 CSRC SPEN Bit 6 TX9 RX9 Bit 5 TXEN SREN Bit 4 SYNC CREN Bit 3 SENDB ADDEN Bit 2 BRGH FERR -- Bit 1 TRMT OERR WUE Bit 0 TX9D RX9D ABDEN Reset Values on Page 61 61 62 62 61
-- SCKP BRG16 BAUDCON1 ABDOVF RCIDL SPBRGH1 EUSART1 Baud Rate Generator Register High Byte
SPBRG1 EUSART1 Baud Rate Generator Register Low Byte Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the BRG.
(c) 2007 Microchip Technology Inc.
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TABLE 16-3:
BAUD RATE (K)
BAUD RATES FOR ASYNCHRONOUS MODES
SYNC = 0, BRGH = 0, BRG16 = 0 FOSC = 20.000 MHz % Error -- 1.73 0.16 1.73 1.73 8.51 -9.58 FOSC = 10.000 MHz % Error -- 0.16 0.16 1.73 1.73 -9.58 -32.18 FOSC = 8.000 MHz % Error -- -0.16 -0.16 -0.16 -- -- -- SPBRG value (decimal) -- 103 51 12 -- -- --
FOSC = 40.000 MHz Actual Rate (K) -- -- 2.441 9.615 19.531 56.818 125.000 % Error -- -- 1.73 0.16 1.73 -1.36 8.51
SPBRG Actual value Rate (K) (decimal) -- -- 255 64 31 10 4 -- 1.221 2.404 9.766 19.531 62.500 104.167
SPBRG Actual value Rate (K) (decimal) -- 255 129 31 15 4 2 -- 1.202 2.404 9.766 19.531 52.083 78.125
SPBRG Actual value Rate (K) (decimal) -- 129 64 15 7 2 1 -- 1.201 2.403 9.615 -- -- --
0.3 1.2 2.4 9.6 19.2 57.6 115.2
SYNC = 0, BRGH = 0, BRG16 = 0 BAUD RATE (K) FOSC = 4.000 MHz Actual Rate (K) 0.300 1.202 2.404 8.929 20.833 62.500 62.500 % Error 0.16 0.16 0.16 -6.99 8.51 8.51 -45.75 FOSC = 2.000 MHz % Error -0.16 -0.16 -0.16 -- -- -- -- FOSC = 1.000 MHz % Error -0.16 -0.16 -- -- -- -- -- SPBRG value (decimal) 51 12 -- -- -- -- -- SPBRG Actual value Rate (K) (decimal) 207 51 25 6 2 0 0 0.300 1.201 2.403 -- -- -- -- SPBRG Actual value Rate (K) (decimal) 103 25 12 -- -- -- -- 0.300 1.201 -- -- -- -- --
0.3 1.2 2.4 9.6 19.2 57.6 115.2
SYNC = 0, BRGH = 1, BRG16 = 0 BAUD RATE (K) FOSC = 40.000 MHz Actual Rate (K) -- -- -- 9.766 19.231 58.140 113.636 % Error -- -- -- 1.73 0.16 0.94 -1.36 FOSC = 20.000 MHz % Error -- -- -- 0.16 0.16 -1.36 -1.36 FOSC = 10.000 MHz % Error -- -- 1.73 0.16 1.73 -1.36 8.51 FOSC = 8.000 MHz % Error -- -- -0.16 -0.16 -0.16 3.55 -- SPBRG value (decimal) -- -- 207 51 25 8 -- SPBRG Actual value Rate (K) (decimal) -- -- -- 255 129 42 21 -- -- -- 9.615 19.231 56.818 113.636 SPBRG Actual value Rate (K) (decimal) -- -- -- 129 64 21 10 -- -- 2.441 9.615 19.531 56.818 125.000 SPBRG Actual value Rate (K) (decimal) -- -- 255 64 31 10 4 -- -- 2.403 9.615 19.230 55.555 --
0.3 1.2 2.4 9.6 19.2 57.6 115.2
SYNC = 0, BRGH = 1, BRG16 = 0 BAUD RATE (K) FOSC = 4.000 MHz Actual Rate (K) -- 1.202 2.404 9.615 19.231 62.500 125.000 % Error -- 0.16 0.16 0.16 0.16 8.51 8.51 FOSC = 2.000 MHz % Error -- -0.16 -0.16 -0.16 -- -- -- FOSC = 1.000 MHz % Error -0.16 -0.16 -0.16 -- -- -- -- SPBRG value (decimal) 207 51 25 -- -- -- -- SPBRG Actual value Rate (K) (decimal) -- 207 103 25 12 3 1 -- 1.201 2.403 9615 -- -- -- SPBRG Actual value Rate (K) (decimal) -- 103 51 12 -- -- -- 0.300 1.201 2.403 -- -- -- --
0.3 1.2 2.4 9.6 19.2 57.6 115.2
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TABLE 16-3:
BAUD RATE (K)
BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
SYNC = 0, BRGH = 0, BRG16 = 1 FOSC = 20.000 MHz % Error 0.02 -0.03 -0.03 0.16 0.16 -1.36 -1.36 FOSC = 10.000 MHz % Error 0.02 -0.03 0.16 0.16 1.73 -1.36 8.51 FOSC = 8.000 MHz % Error -0.04 -0.16 -0.16 -0.16 -0.16 3.55 -- SPBRG value (decimal) 1665 415 207 51 25 8 --
FOSC = 40.000 MHz Actual Rate (K) 0.300 1.200 2.402 9.615 19.231 58.140 113.636 % Error 0.00 0.02 0.06 0.16 0.16 0.94 -1.36
SPBRG Actual value Rate (K) (decimal) 8332 2082 1040 259 129 42 21 0.300 1.200 2.399 9.615 19.231 56.818 113.636
SPBRG Actual value Rate (K) (decimal) 4165 1041 520 129 64 21 10 0.300 1.200 2.404 9.615 19.531 56.818 125.000
SPBRG Actual value Rate (K) (decimal) 2082 520 259 64 31 10 4 0.300 1.201 2.403 9.615 19.230 55.555 --
0.3 1.2 2.4 9.6 19.2 57.6 115.2
SYNC = 0, BRGH = 0, BRG16 = 1 BAUD RATE (K) FOSC = 4.000 MHz Actual Rate (K) 0.300 1.202 2.404 9.615 19.231 62.500 125.000 % Error 0.04 0.16 0.16 0.16 0.16 8.51 8.51 FOSC = 2.000 MHz % Error -0.16 -0.16 -0.16 -0.16 -- -- -- FOSC = 1.000 MHz % Error -0.16 -0.16 -0.16 -- -- -- -- SPBRG value (decimal) 207 51 25 -- -- -- -- SPBRG Actual value Rate (K) (decimal) 832 207 103 25 12 3 1 0.300 1.201 2.403 9.615 -- -- -- SPBRG Actual value Rate (K) (decimal) 415 103 51 12 -- -- -- 0.300 1.201 2.403 -- -- -- --
0.3 1.2 2.4 9.6 19.2 57.6 115.2
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 BAUD RATE (K) FOSC = 40.000 MHz Actual Rate (K) 0.300 1.200 2.400 9.606 19.193 57.803 114.943 % Error 0.00 0.00 0.02 0.06 -0.03 0.35 -0.22 FOSC = 20.000 MHz % Error 0.00 0.02 0.02 -0.03 0.16 -0.22 0.94 FOSC = 10.000 MHz % Error 0.00 0.02 0.06 0.16 0.16 0.94 -1.36 FOSC = 8.000 MHz % Error -0.01 -0.04 -0.04 -0.16 -0.16 0.79 -2.12 SPBRG value (decimal) 6665 1665 832 207 103 34 16 SPBRG Actual value Rate (K) (decimal) 33332 8332 4165 1040 520 172 86 0.300 1.200 2.400 9.596 19.231 57.471 116.279 SPBRG Actual value Rate (K) (decimal) 16665 4165 2082 520 259 86 42 0.300 1.200 2.402 9.615 19.231 58.140 113.636 SPBRG Actual value Rate (K) (decimal) 8332 2082 1040 259 129 42 21 0.300 1.200 2.400 9.615 19.230 57.142 117.647
0.3 1.2 2.4 9.6 19.2 57.6 115.2
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 BAUD RATE (K) FOSC = 4.000 MHz Actual Rate (K) 0.300 1.200 2.404 9.615 19.231 58.824 111.111 % Error 0.01 0.04 0.16 0.16 0.16 2.12 -3.55 FOSC = 2.000 MHz % Error -0.04 -0.16 -0.16 -0.16 -0.16 3.55 -- FOSC = 1.000 MHz % Error -0.04 -0.16 -0.16 -0.16 -0.16 -- -- SPBRG value (decimal) 832 207 103 25 12 -- -- SPBRG Actual value Rate (K) (decimal) 3332 832 415 103 51 16 8 0.300 1.201 2.403 9.615 19.230 55.555 -- SPBRG Actual value Rate (K) (decimal) 1665 415 207 51 25 8 -- 0.300 1.201 2403 9.615 19.230 -- --
0.3 1.2 2.4 9.6 19.2 57.6 115.2
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16.1.3 AUTO-BAUD RATE DETECT
The Enhanced USART module supports the automatic detection and calibration of baud rate. This feature is active only in Asynchronous mode and while the WUE bit is clear. The automatic baud rate measurement sequence (Figure 16-1) begins whenever a Start bit is received and the ABDEN bit is set. The calculation is self-averaging. In the Auto-Baud Rate Detect (ABD) mode, the clock to the BRG is reversed. Rather than the BRG clocking the incoming RX1 signal, the RX1 signal is timing the BRG. In ABD mode, the internal Baud Rate Generator is used as a counter to time the bit period of the incoming serial byte stream. Once the ABDEN bit is set, the state machine will clear the BRG and look for a Start bit. The Auto-Baud Rate Detect must receive a byte with the value, 55h (ASCII "U", which is also the LIN bus Sync character), in order to calculate the proper bit rate. The measurement is taken over both a low and a high bit time in order to minimize any effects caused by asymmetry of the incoming signal. After a Start bit, the SPBRG1 begins counting up, using the preselected clock source on the first rising edge of RX1. After eight bits on the RX1 pin or the fifth rising edge, an accumulated value totalling the proper BRG period is left in the SPBRGH1:SPBRG1 register pair. Once the 5th edge is seen (this should correspond to the Stop bit), the ABDEN bit is automatically cleared. If a rollover of the BRG occurs (an overflow from FFFFh to 0000h), the event is trapped by the ABDOVF status bit (BAUDCON1<7>). It is set in hardware by BRG rollovers and can be set or cleared by the user in software. ABD mode remains active after rollover events and the ABDEN bit remains set (Figure 16-2). While calibrating the baud rate period, the BRG registers are clocked at 1/8th the preconfigured clock rate. Note that the BRG clock will be configured by the BRG16 and BRGH bits. This allows the user to verify that no carry occurred for 8-bit modes by checking for 00h in the SPBRGH1 register. Refer to Table 16-4 for counter clock rates to the BRG. While the ABD sequence takes place, the EUSART state machine is held in Idle. The RC1IF interrupt is set once the fifth rising edge on RX1 is detected. The value in the RCREG1 needs to be read to clear the RC1IF interrupt. The contents of RCREG1 should be discarded. Note 1: If the WUE bit is set with the ABDEN bit, Auto-Baud Rate Detection will occur on the byte following the Break character. 2: It is up to the user to determine that the incoming character baud rate is within the range of the selected BRG clock source. Some combinations of oscillator frequency and EUSART baud rates are not possible due to bit error rates. Overall system timing and communication baud rates must be taken into consideration when using the Auto-Baud Rate Detection feature. 3: When the auto-baud feature is enabled, the BRG16 bit (BAUDCON<3>) must be set.
TABLE 16-4:
BRG16 0 0 1 1 BRGH 0 1 0 1
BRG COUNTER CLOCK RATES
BRG Counter Clock FOSC/512 FOSC/128 FOSC/128 FOSC/32
16.1.3.1
ABD and EUSART Transmission
Since the BRG clock is reversed during ABD acquisition, the EUSART transmitter cannot be used during ABD. This means that whenever the ABDEN bit is set, TXREG1 cannot be written to. Users should also ensure that ABDEN does not become set during a transmit sequence. Failing to do this may result in unpredictable EUSART operation.
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FIGURE 16-1:
BRG Value RX1 pin
AUTOMATIC BAUD RATE CALCULATION
XXXXh 0000h Start Edge #1 Bit 1 Bit 0 Edge #2 Bit 3 Bit 2 Edge #3 Bit 5 Bit 4 Edge #4 Bit 7 Bit 6 001Ch Edge #5 Stop Bit
BRG Clock Set by User ABDEN bit RC1IF bit (Interrupt) Read RCREG1 SPBRG1 SPBRGH1 XXXXh XXXXh 1Ch 00h Auto-Cleared
Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0.
FIGURE 16-2:
BRG Clock ABDEN bit RX1 pin ABDOVF bit
BRG OVERFLOW SEQUENCE
Start
Bit 0
FFFFh BRG Value XXXXh 0000h 0000h
(c) 2007 Microchip Technology Inc.
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16.2 EUSART Asynchronous Mode
The Asynchronous mode of operation is selected by clearing the SYNC bit (TXSTA1<4>). In this mode, the EUSART uses standard Non-Return-to-Zero (NRZ) format (one Start bit, eight or nine data bits and one Stop bit). The most common data format is 8 bits. An on-chip, dedicated 8-bit/16-bit Baud Rate Generator can be used to derive standard baud rate frequencies from the oscillator. The EUSART transmits and receives the LSb first. The EUSART's transmitter and receiver are functionally independent, but use the same data format and baud rate. The Baud Rate Generator produces a clock, either x16 or x64 of the bit shift rate, depending on the BRGH and BRG16 bits (TXSTA1<2> and BAUDCON1<3>). Parity is not supported by the hardware but can be implemented in software and stored as the 9th data bit. When operating in Asynchronous mode, the EUSART module consists of the following important elements: * * * * * * * Baud Rate Generator Sampling Circuit Asynchronous Transmitter Asynchronous Receiver Auto-Wake-up on Sync Break Character 12-Bit Break Character Transmit Auto-Baud Rate Detection Once the TXREG1 register transfers the data to the TSR register (occurs in one TCY), the TXREG1 register is empty and the TX1IF flag bit (PIR1<4>) is set. This interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX1IE (PIE1<4>). TX1IF will be set regardless of the state of TX1IE; it cannot be cleared in software. TX1IF is also not cleared immediately upon loading TXREG1, but becomes valid in the second instruction cycle following the load instruction. Polling TX1IF immediately following a load of TXREG1 will return invalid results. While TX1IF indicates the status of the TXREG1 register, another bit, TRMT (TXSTA1<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR register is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. Note 1: The TSR register is not mapped in data memory so it is not available to the user. 2: Flag bit, TX1IF, is set when enable bit TXEN is set. To set up an Asynchronous Transmission: 1. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. If interrupts are desired, set enable bit, TX1IE. If 9-bit transmission is desired, set transmit bit, TX9; can be used as address/data bit. Enable the transmission by setting bit, TXEN, which will also set bit, TX1IF. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Load data to the TXREG1 register (starts transmission). If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set.
2. 3. 4. 5. 6. 7. 8.
16.2.1
EUSART ASYNCHRONOUS TRANSMITTER
The EUSART transmitter block diagram is shown in Figure 16-3. The heart of the transmitter is the Transmit (Serial) Shift Register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG1. The TXREG1 register is loaded with data in software. The TSR register is not loaded until the Stop bit has been transmitted from the previous load. As soon as the Stop bit is transmitted, the TSR is loaded with new data from the TXREG1 register (if available).
FIGURE 16-3:
EUSART TRANSMIT BLOCK DIAGRAM
Data Bus TX1IF TXREG1 Register 8 MSb (8) Interrupt TXEN Baud Rate CLK TRMT SPEN *** TSR Register LSb 0 Pin Buffer and Control TX1 pin
TX1IE
BRG16
SPBRGH1
SPBRG1
TX9 TX9D
Baud Rate Generator
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FIGURE 16-4:
Write to TXREG1 BRG Output (Shift Clock) TX1 (pin) TX1IF bit (Transmit Buffer Reg. Empty Flag)
ASYNCHRONOUS TRANSMISSION
Word 1
Start bit 1 TCY
bit 0
bit 1 Word 1
bit 7/8
Stop bit
TRMT bit (Transmit Shift Reg. Empty Flag)
Word 1 Transmit Shift Reg
FIGURE 16-5:
Write to TXREG1
ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)
Word 1 Word 2
BRG Output (Shift Clock) TX1 (pin) TX1IF bit (Interrupt Reg. Flag) 1 TCY 1 TCY Word 1 Transmit Shift Reg. Word 2 Transmit Shift Reg. Start bit bit 0 bit 1 Word 1 bit 7/8 Stop bit Start bit Word 2 bit 0
TRMT bit (Transmit Shift Reg. Empty Flag) Note:
This timing diagram shows two consecutive transmissions.
TABLE 16-5:
Name INTCON PIR1 PIE1 IPR1 RCSTA1 TXREG1 TXSTA1 BAUDCON1 SPBRGH1 SPBRG1
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Bit 7 Bit 6 Bit 5 TMR0IE RC1IF RC1IE RC1IP SREN TXEN -- Bit 4 INT0IE TX1IF TX1IE TX1IP CREN SYNC SCKP Bit 3 RBIE SSPIF SSPIE SSPIP ADDEN SENDB BRG16 Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP FERR BRGH -- Bit 1 INT0IF TMR2IF TMR2IE TMR2IP OERR TRMT WUE Bit 0 RBIF TMR1IF TMR1IE TMR1IP RX9D TX9D ABDEN Reset Values on Page 59 61 61 61 61 61 61 62 62 61
GIE/GIEH PEIE/GIEL -- -- -- SPEN CSRC ABDOVF ADIF ADIE ADIP RX9 TX9 RCIDL
EUSART1 Transmit Register
EUSART1 Baud Rate Generator Register High Byte EUSART1 Baud Rate Generator Register Low Byte
Legend: -- = unimplemented locations read as `0'. Shaded cells are not used for asynchronous transmission.
(c) 2007 Microchip Technology Inc.
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16.2.2 EUSART ASYNCHRONOUS RECEIVER 16.2.3 SETTING UP 9-BIT MODE WITH ADDRESS DETECT
The receiver block diagram is shown in Figure 16-6. The data is received on the RX1 pin and drives the data recovery block. The data recovery block is actually a high-speed shifter operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC. This mode would typically be used in RS-232 systems. To set up an Asynchronous Reception: Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. 3. If interrupts are desired, set enable bit, RC1IE. 4. If 9-bit reception is desired, set bit, RX9. 5. Enable the reception by setting bit, CREN. 6. Flag bit, RC1IF, will be set when reception is complete and an interrupt will be generated if enable bit, RC1IE, was set. 7. Read the RCSTA1 register to get the 9th bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG1 register. 9. If any error occurred, clear the error by clearing enable bit, CREN. 10. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 1. This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: 1. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. 3. If interrupts are required, set the RCEN bit and select the desired priority level with the RC1IP bit. 4. Set the RX9 bit to enable 9-bit reception. 5. Set the ADDEN bit to enable address detect. 6. Enable reception by setting the CREN bit. 7. The RC1IF bit will be set when reception is complete. The interrupt will be Acknowledged if the RC1IE and GIE bits are set. 8. Read the RCSTA1 register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. Read RCREG1 to determine if the device is being addressed. 10. If any error occurred, clear the CREN bit. 11. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and interrupt the CPU.
FIGURE 16-6:
EUSART RECEIVE BLOCK DIAGRAM
CREN x64 Baud Rate CLK OERR FERR
BRG16
SPBRGH1
SPBRG1
Baud Rate Generator
/ 64 or / 16 or /4
MSb Stop (8) 7
RSR Register *** 1 0
LSb Start
RX9 Pin Buffer and Control RX1 Data Recovery RX9D RCREG1 Register FIFO
SPEN 8 Interrupt RC1IF RC1IE Data Bus
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FIGURE 16-7:
RX1 (pin) Rcv Shift Reg Rcv Buffer Reg RCREG1 Read Rcv Buffer Reg RC1IF (Interrupt Flag) OERR bit CREN bit Note: This timing diagram shows three words appearing on the RX1 input. The RCREG1 (Receive Buffer register) is read after the third word causing the OERR (Overrun) bit to be set.
ASYNCHRONOUS RECEPTION
Start bit bit 0 bit 1 bit 7/8 Stop bit Start bit bit 0 bit 7/8 Stop bit Start bit bit 7/8 Stop bit
Word 1 RCREG1
Word 2 RCREG1
TABLE 16-6:
Name INTCON PIR1 PIE1 IPR1 RCSTA1 RCREG1 TXSTA1 BAUDCON1 SPBRGH1 SPBRG1
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Bit 7 Bit 6 Bit 5 Bit 4 INT0IE TX1IF TX1IE TX1IP CREN SYNC SCKP Bit 3 RBIE SSPIF SSPIE SSPIP ADDEN SENDB BRG16 Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP FERR BRGH -- Bit 1 INT0IF TMR2IF TMR2IE TMR2IP OERR TRMT WUE Bit 0 RBIF TMR1IF TMR1IE TMR1IP RX9D TX9D ABDEN Reset Values on Page 59 61 61 61 61 61 61 62 62 61
GIE/GIEH PEIE/GIEL TMR0IE -- -- -- SPEN CSRC ABDOVF ADIF ADIE ADIP RX9 TX9 RCIDL RC1IF RC1IE RC1IP SREN TXEN --
EUSART1 Receive Register
EUSART1 Baud Rate Generator Register High Byte EUSART1 Baud Rate Generator Register Low Byte
Legend: -- = unimplemented locations read as `0'. Shaded cells are not used for asynchronous reception.
(c) 2007 Microchip Technology Inc.
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16.2.4 AUTO-WAKE-UP ON SYNC BREAK CHARACTER
During Sleep mode, all clocks to the EUSART are suspended. Because of this, the Baud Rate Generator is inactive and a proper byte reception cannot be performed. The auto-wake-up feature allows the controller to wake-up, due to activity on the RX1/DT1 line, while the EUSART is operating in Asynchronous mode. The auto-wake-up feature is enabled by setting the WUE bit (BAUDCON<1>). Once set, the typical receive sequence on RX1/DT1 is disabled and the EUSART remains in an Idle state, monitoring for a wake-up event independent of the CPU mode. A wake-up event consists of a high-to-low transition on the RX1/DT1 line. (This coincides with the start of a Sync Break or a Wake-up Signal character for the LIN protocol.) Following a wake-up event, the module generates an RC1IF interrupt. The interrupt is generated synchronously to the Q clocks in normal operating modes (Figure 16-8) and asynchronously, if the device is in Sleep mode (Figure 16-9). The interrupt condition is cleared by reading the RCREG1 register. The WUE bit is automatically cleared once a low-to-high transition is observed on the RX1 line following the wake-up event. At this point, the EUSART module is in Idle mode and returns to normal operation. This signals to the user that the Sync Break event is over. End-Of-Character (EOC) and cause data or framing errors. Therefore, to work properly, the initial character in the transmission must be all `0's. This can be 00h (8 bytes) for standard RS-232 devices, or 000h (12 bits) for LIN bus. Oscillator start-up time must also be considered, especially in applications using oscillators with longer start-up intervals (i.e., XT or HS mode). The Sync Break (or Wake-up Signal) character must be of sufficient length and be followed by a sufficient interval to allow enough time for the selected oscillator to start and provide proper initialization of the EUSART.
16.2.4.2
Special Considerations Using the WUE Bit
The timing of WUE and RC1IF events may cause some confusion when it comes to determining the validity of received data. As noted, setting the WUE bit places the EUSART in an Idle mode. The wake-up event causes a receive interrupt by setting the RC1IF bit. The WUE bit is cleared after this when a rising edge is seen on RX1/DT1. The interrupt condition is then cleared by reading the RCREG1 register. Ordinarily, the data in RCREG1 will be dummy data and should be discarded. The fact that the WUE bit has been cleared (or is still set), and the RC1IF flag is set, should not be used as an indicator of the integrity of the data in RCREG1. Users should consider implementing a parallel method in firmware to verify received data integrity. To assure that no actual data is lost, check the RCIDL bit to verify that a receive operation is not in process. If a receive operation is not occurring, the WUE bit may then be set just prior to entering the Sleep mode.
16.2.4.1
Special Considerations Using Auto-Wake-up
Since auto-wake-up functions by sensing rising edge transitions on RX1/DT1, information with any state changes before the Stop bit may signal a false
FIGURE 16-8:
OSC1 WUE bit RX1/DT1 Line RC1IF Note:
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION
Bit set by user
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Auto-Cleared
Cleared due to user read of RCREG1
The EUSART remains in Idle while the WUE bit is set.
FIGURE 16-9:
OSC1 WUE bit RX1/DT1 Line RC1IF
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Bit set by user
Auto-Cleared
Note 1 Sleep Ends Cleared due to user read of RCREG1
SLEEP Command Executed Note 1: 2:
If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur while the stposc signal is still active. This sequence should not depend on the presence of Q clocks. The EUSART remains in Idle while the WUE bit is set.
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16.2.5 BREAK CHARACTER SEQUENCE
3. 4. 5. The Enhanced USART module has the capability of sending the special Break character sequences that are required by the LIN bus standard. The Break character transmit consists of a Start bit, followed by twelve `0' bits and a Stop bit. The Frame Break character is sent whenever the SENDB and TXEN bits (TXSTA<3> and TXSTA<5>) are set while the Transmit Shift Register is loaded with data. Note that the value of data written to TXREG1 will be ignored and all `0's will be transmitted. The SENDB bit is automatically reset by hardware after the corresponding Stop bit is sent. This allows the user to preload the transmit FIFO with the next transmit byte following the Break character (typically, the Sync character in the LIN specification). Note that the data value written to the TXREG1 for the Break character is ignored. The write simply serves the purpose of initiating the proper sequence. The TRMT bit indicates when the transmit operation is active or Idle, just as it does during normal transmission. See Figure 16-10 for the timing of the Break character sequence. Load the TXREG1 with a dummy character to initiate transmission (the value is ignored). Write `55h' to TXREG1 to load the Sync character into the transmit FIFO buffer. After the Break has been sent, the SENDB bit is reset by hardware. The Sync character now transmits in the preconfigured mode.
When the TXREG1 becomes empty, as indicated by the TX1IF, the next data byte can be written to TXREG1.
16.2.6
RECEIVING A BREAK CHARACTER
The Enhanced USART module can receive a Break character in two ways. The first method forces configuration of the baud rate at a frequency of 9/13 the typical speed. This allows for the Stop bit transition to be at the correct sampling location (13 bits for Break versus Start bit and 8 data bits for typical data). The second method uses the auto-wake-up feature described in Section 16.2.4 "Auto-Wake-up on Sync Break Character". By enabling this feature, the EUSART will sample the next two transitions on RX1/DT1, cause an RC1IF interrupt and receive the next data byte followed by another interrupt. Note that following a Break character, the user will typically want to enable the Auto-Baud Rate Detect feature. For both methods, the user can set the ABD bit once the TX1IF interrupt is observed.
16.2.5.1
Break and Sync Transmit Sequence
The following sequence will send a message frame header made up of a Break, followed by an Auto-Baud Sync byte. This sequence is typical of a LIN bus master. 1. 2. Configure the EUSART for the desired mode. Set the TXEN and SENDB bits to set up the Break character.
FIGURE 16-10:
Write to TXREG1 BRG Output (Shift Clock) TX1 (pin)
SEND BREAK CHARACTER SEQUENCE
Dummy Write
Start bit
bit 0
bit 1 Break
bit 11
Stop bit
TX1IF bit (Transmit Buffer Reg. Empty Flag) TRMT bit (Transmit Shift Reg. Empty Flag) SENDB sampled here SENDB (Transmit Shift Reg. Empty Flag) Auto-Cleared
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16.3 EUSART Synchronous Master Mode
Once the TXREG1 register transfers the data to the TSR register (occurs in one TCYCLE), the TXREG1 is empty and the TX1IF flag bit (PIR1<4>) is set. The interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX1IE (PIE1<4>). TX1IF is set regardless of the state of enable bit, TX1IE; it cannot be cleared in software. It will reset only when new data is loaded into the TXREG1 register. While flag bit, TX1IF, indicates the status of the TXREG1 register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory so it is not available to the user. To set up a Synchronous Master Transmission: 1. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRG16 bit, as required, to achieve the desired baud rate. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. If interrupts are desired, set enable bit, TX1IE. If 9-bit transmission is desired, set bit, TX9. Enable the transmission by setting bit, TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Start transmission by loading data to the TXREG1 register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set.
The Synchronous Master mode is entered by setting the CSRC bit (TXSTA<7>). In this mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit, SYNC (TXSTA<4>). In addition, enable bit, SPEN (RCSTA1<7>), is set in order to configure the TX1 and RX1 pins to CK1 (clock) and DT1 (data) lines, respectively. The Master mode indicates that the processor transmits the master clock on the CK1 line. Clock polarity is selected with the SCKP bit (BAUDCON<4>); setting SCKP sets the Idle state on CK1 as high, while clearing the bit sets the Idle state as low. This option is provided to support Microwire devices with this module.
16.3.1
EUSART SYNCHRONOUS MASTER TRANSMISSION
2. 3. 4. 5. 6. 7. 8.
The EUSART transmitter block diagram is shown in Figure 16-3. The heart of the transmitter is the Transmit (Serial) Shift Register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG1. The TXREG1 register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG1 (if available).
FIGURE 16-11:
SYNCHRONOUS TRANSMISSION
Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 bit 7 bit 0 bit 1 bit 7
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RC7/RX1/DT1 pin RC6/TX1/CK1 pin (SCKP = 0) RC6/TX1/CK1 pin (SCKP = 1) Write to TXREG1 Reg TX1IF bit (Interrupt Flag) TRMT bit TXEN bit Note: `1'
bit 0
bit 1
bit 2
Word 1
Word 2
Write Word 1
Write Word 2
`1'
Sync Master mode, SPBRG1 = 0, continuous transmission of two 8-bit words.
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FIGURE 16-12: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
bit 0 bit 1 bit 2 bit 6 bit 7 RC7/RX1/DT1 pin
RC6/TX1/CK1 pin Write to TXREG1 Reg
TX1IF bit
TRMT bit
TXEN bit
TABLE 16-7:
Name INTCON PIR1 PIE1 IPR1 RCSTA1 TXREG1 TXSTA1 SPBRGH1 SPBRG1
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Bit 7 Bit 6 Bit 5 Bit 4 INT0IE TX1IF TX1IE TX1IP CREN SYNC SCKP Bit 3 RBIE SSPIF SSPIE SSPIP ADDEN SENDB BRG16 Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP FERR BRGH -- Bit 1 INT0IF TMR2IF TMR2IE TMR2IP OERR TRMT WUE Bit 0 RBIF TMR1IF TMR1IE TMR1IP RX9D TX9D ABDEN Reset Values on Page 59 61 61 61 61 61 61 62 62 61
GIE/GIEH PEIE/GIEL TMR0IE -- -- -- SPEN CSRC ADIF ADIE ADIP RX9 TX9 RCIDL RC1IF RC1IE RC1IP SREN TXEN --
EUSART1 Transmit Register
BAUDCON1 ABDOVF
EUSART1 Baud Rate Generator Register High Byte EUSART1 Baud Rate Generator Register Low Byte
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous master transmission.
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16.3.2 EUSART SYNCHRONOUS MASTER RECEPTION
Once Synchronous mode is selected, reception is enabled by setting either the Single Receive Enable bit, SREN (RCSTA1<5>), or the Continuous Receive Enable bit, CREN (RCSTA1<4>). Data is sampled on the RX1 pin on the falling edge of the clock. If enable bit, SREN, is set, only a single word is received. If enable bit, CREN, is set, the reception is continuous until CREN is cleared. If both bits are set, then CREN takes precedence. To set up a Synchronous Master Reception: 1. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRG16 bit, as required, to achieve the desired baud rate. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. 3. 4. 5. 6. Ensure bits, CREN and SREN, are clear. If interrupts are desired, set enable bit, RC1IE. If 9-bit reception is desired, set bit, RX9. If a single reception is required, set bit, SREN. For continuous reception, set bit, CREN. 7. Interrupt flag bit, RC1IF, will be set when reception is complete and an interrupt will be generated if the enable bit, RC1IE, was set. 8. Read the RCSTA1 register to get the 9th bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG1 register. 10. If any error occurred, clear the error by clearing bit, CREN. 11. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set.
2.
FIGURE 16-13:
SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RC7/RX1/DT1 pin RC6/TX1/CK1 pin (SCKP = 0) RC6/TX1/CK1 pin (SCKP = 1) Write to SREN bit SREN bit CREN bit `0' RC1IF bit (Interrupt) Read RCREG1 Note:
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
`0'
Timing diagram demonstrates Sync Master mode with SREN bit = 1 and BRGH bit = 0.
TABLE 16-8:
Name INTCON PIR1 PIE1 IPR1 RCSTA1 RCREG1 TXSTA1 SPBRGH1 SPBRG1
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Bit 7 Bit 6 Bit 5 TMR0IE RC1IF RC1IE RC1IP SREN TXEN -- Bit 4 INT0IE TX1IF TX1IE TX1IP CREN SYNC SCKP Bit 3 RBIE SSPIF SSPIE SSPIP ADDEN SENDB BRG16 Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP FERR BRGH -- Bit 1 INT0IF TMR2IF TMR2IE TMR2IP OERR TRMT WUE Bit 0 RBIF TMR1IF TMR1IE TMR1IP RX9D TX9D ABDEN Reset Values on Page 59 61 61 61 61 61 61 62 62 61
GIE/GIEH PEIE/GIEL -- -- -- SPEN CSRC ADIF ADIE ADIP RX9 TX9 RCIDL
EUSART1 Receive Register
BAUDCON1 ABDOVF
EUSART1 Baud Rate Generator Register High Byte EUSART1 Baud Rate Generator Register Low Byte
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous master reception.
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16.4 EUSART Synchronous Slave Mode
To set up a Synchronous Slave Transmission: 1. Enable the synchronous slave serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. Clear bits, CREN and SREN. If interrupts are desired, set enable bit, TX1IE. If 9-bit transmission is desired, set bit, TX9. Enable the transmission by setting enable bit, TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Start transmission by loading data to the TXREG1 register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. Synchronous Slave mode is entered by clearing bit, CSRC (TXSTA1<7>). This mode differs from the Synchronous Master mode in that the shift clock is supplied externally at the CK1 pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in any low-power mode.
2. 3. 4. 5. 6. 7. 8.
16.4.1
EUSART SYNCHRONOUS SLAVE TRANSMIT
The operation of the Synchronous Master and Slave modes are identical except in the case of the Sleep mode. If two words are written to the TXREG1, and then the SLEEP instruction is executed, the following will occur: a) b) c) d) The first word will immediately transfer to the TSR register and transmit. The second word will remain in the TXREG1 register. Flag bit, TX1IF, will not be set. When the first word has been shifted out of TSR, the TXREG1 register will transfer the second word to the TSR and flag bit, TX1IF, will now be set. If enable bit, TX1IE, is set, the interrupt will wake the chip from Sleep. If the global interrupt is enabled, the program will branch to the interrupt vector.
e)
TABLE 16-9:
Name INTCON PIR1 PIE1 IPR1 RCSTA1 TXREG1 TXSTA1 SPBRGH1 SPBRG1
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Bit 7 Bit 6 Bit 5 TMR0IE RC1IF RC1IE RC1IP SREN TXEN -- Bit 4 INT0IE TX1IF TX1IE TX1IP CREN SYNC SCKP Bit 3 RBIE SSPIF SSPIE SSPIP ADDEN SENDB BRG16 Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP FERR BRGH -- Bit 1 INT0IF TMR2IF TMR2IE TMR2IP OERR TRMT WUE Bit 0 RBIF TMR1IF TMR1IE TMR1IP RX9D TX9D ABDEN Reset Values on Page 59 61 61 61 61 61 61 62 62 61
GIE/GIEH PEIE/GIEL -- -- -- SPEN CSRC ADIF ADIE ADIP RX9 TX9 RCIDL
EUSART1 Transmit Register
BAUDCON1 ABDOVF
EUSART1 Baud Rate Generator Register High Byte EUSART1 Baud Rate Generator Register Low Byte
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous slave transmission.
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16.4.2 EUSART SYNCHRONOUS SLAVE RECEPTION
To set up a Synchronous Slave Reception: 1. Enable the synchronous master serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. If interrupts are desired, set enable bit, RC1IE. If 9-bit reception is desired, set bit, RX9. To enable reception, set enable bit, CREN. Flag bit, RC1IF, will be set when reception is complete. An interrupt will be generated if enable bit, RC1IE, was set. Read the RCSTA1 register to get the 9th bit (if enabled) and determine if any error occurred during reception. Read the 8-bit received data by reading the RCREG1 register. If any error occurred, clear the error by clearing bit, CREN. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. The operation of the Synchronous Master and Slave modes is identical except in the case of Sleep or any Idle mode and bit, SREN, which is a "don't care" in Slave mode. If receive is enabled by setting the CREN bit prior to entering Sleep or any Idle mode, then a word may be received while in this low-power mode. Once the word is received, the RSR register will transfer the data to the RCREG1 register. If the RC1IE enable bit is set, the interrupt generated will wake the chip from the low-power mode. If the global interrupt is enabled, the program will branch to the interrupt vector.
2. 3. 4. 5.
6.
7. 8. 9.
TABLE 16-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Name INTCON PIR1 PIE1 IPR1 RCSTA1 RCREG1 TXSTA1 SPBRGH1 SPBRG1 Bit 7 Bit 6 Bit 5 Bit 4 INT0IE TX1IF TX1IE TX1IP CREN SYNC SCKP Bit 3 RBIE SSPIF SSPIE SSPIP ADDEN SENDB BRG16 Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP FERR BRGH -- Bit 1 INT0IF TMR2IF TMR2IE TMR2IP OERR TRMT WUE Bit 0 RBIF TMR1IF TMR1IE TMR1IP RX9D TX9D ABDEN Reset Values on Page 59 61 61 61 61 61 61 62 62 61
GIE/GIEH PEIE/GIEL TMR0IE -- -- -- SPEN CSRC ADIF ADIE ADIP RX9 TX9 RCIDL RC1IF RC1IE RC1IP SREN TXEN --
EUSART1 Receive Register
BAUDCON1 ABDOVF
EUSART1 Baud Rate Generator Register High Byte EUSART1 Baud Rate Generator Register Low Byte
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous slave reception.
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17.0 ADDRESSABLE UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (AUSART)
The pins of the AUSART module are multiplexed with the functions of PORTG (RG1/TX2/CK2/SEG29 and RG2/RX2/DT2/SEG28, respectively). In order to configure these pins as an AUSART: * SPEN bit (RCSTA2<7>) must be set (= 1) * TRISG<2> bit must be set (= 1) * TRISG<1> bit must be cleared (= 0) for Asynchronous and Synchronous Master modes * TRISG<1> bit must be set (= 1) for Synchronous Slave mode Note: The AUSART control will automatically reconfigure the pin from input to output as needed.
The Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART) module is very similar in function to the Enhanced USART module, discussed in the previous chapter. It is provided as an additional channel for serial communication, with external devices, for those situations that do not require Auto-Baud Detection or LIN bus support. The AUSART can be configured in the following modes: * Asynchronous (full-duplex) * Synchronous - Master (half-duplex) * Synchronous - Slave (half-duplex)
The operation of the Addressable USART module is controlled through two registers, TXSTA2 and RXSTA2. These are detailed in Register 17-1 and Register 17-2 respectively.
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REGISTER 17-1:
R/W-0 CSRC bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
TXSTA2: AUSART TRANSMIT STATUS AND CONTROL REGISTER
R/W-0 TXEN(1) R/W-0 SYNC U-0 -- R/W-0 BRGH R-1 TRMT R/W-0 TX9D bit 0 TX9
R/W-0
CSRC: Clock Source Select bit Asynchronous mode: Don't care. Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) TX9: 9-Bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission TXEN: Transmit Enable bit(1) 1 = Transmit enabled 0 = Transmit disabled SYNC: AUSART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode Unimplemented: Read as `0' BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode. TRMT: Transmit Shift Register Status bit 1 = TSR empty 0 = TSR full TX9D: 9th bit of Transmit Data Can be address/data bit or a parity bit. SREN/CREN overrides TXEN in Sync mode.
bit 6
bit 5
bit 4
bit 3 bit 2
bit 1
bit 0
Note 1:
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REGISTER 17-2:
R/W-0 SPEN bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
RCSTA2: AUSART RECEIVE STATUS AND CONTROL REGISTER
R/W-0 SREN R/W-0 CREN R/W-0 ADDEN R-0 FERR R-0 OERR R-x RX9D bit 0 RX9
R/W-0
SPEN: Serial Port Enable bit 1 = Serial port enabled (configures RX2/DT2 and TX2/CK2 pins as serial port pins) 0 = Serial port disabled (held in Reset) RX9: 9-Bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception SREN: Single Receive Enable bit Asynchronous mode: Don't care. Synchronous mode - Master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode - Slave: Don't care. CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables receiver 0 = Disables receiver Synchronous mode: 1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN) 0 = Disables continuous receive ADDEN: Address Detect Enable bit Asynchronous mode 9-Bit (RX9 = 1): 1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set 0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit Asynchronous mode 9-Bit (RX9 = 0): Don't care. FERR: Framing Error bit 1 = Framing error (can be updated by reading RCREG2 register and receiving next valid byte) 0 = No framing error OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit, CREN) 0 = No overrun error RX9D: 9th bit of Received Data This can be address/data bit or a parity bit and must be calculated by user firmware.
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
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17.1 AUSART Baud Rate Generator (BRG)
geous to use the high baud rate (BRGH = 1) to reduce the baud rate error, or achieve a slow baud rate for a fast oscillator frequency. Writing a new value to the SPBRG2 register causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate.
The BRG is a dedicated 8-bit generator that supports both the Asynchronous and Synchronous modes of the AUSART. The SPBRG2 register controls the period of a free-running timer. In Asynchronous mode, bit BRGH (TXSTA<2>) also controls the baud rate. In Synchronous mode, BRGH is ignored. Table 17-1 shows the formula for computation of the baud rate for different AUSART modes, which only apply in Master mode (internally generated clock). Given the desired baud rate and FOSC, the nearest integer value for the SPBRG2 register can be calculated using the formulas in Table 17-1. From this, the error in baud rate can be determined. An example calculation is shown in Example 17-1. Typical baud rates and error values for the various Asynchronous modes are shown in Table 17-3. It may be advanta-
17.1.1
OPERATION IN POWER-MANAGED MODES
The device clock is used to generate the desired baud rate. When one of the power-managed modes is entered, the new clock source may be operating at a different frequency. This may require an adjustment to the value in the SPBRG2 register.
17.1.2
SAMPLING
The data on the RX2 pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX2 pin.
TABLE 17-1:
SYNC 0 0 1
BAUD RATE FORMULAS
BRGH 0 1 x BRG/AUSART Mode Asynchronous Asynchronous Synchronous Baud Rate Formula FOSC/[64 (n + 1)] FOSC/[16 (n + 1)] FOSC/[4 (n + 1)]
Configuration Bits
Legend: x = Don't care, n = Value of SPBRG2 register
EXAMPLE 17-1:
CALCULATING BAUD RATE ERROR
For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, BRGH = 0: Desired Baud Rate = FOSC/(64 ([SPBRG2] + 1)) Solving for SPBRG2: X = ((FOSC/Desired Baud Rate)/64) - 1 = ((16000000/9600)/64) - 1 = [25.042] = 25 Calculated Baud Rate = 16000000/(64 (25 + 1)) = 9615 Error = (Calculated Baud Rate - Desired Baud Rate)/Desired Baud Rate = (9615 - 9600)/9600 = 0.16%
TABLE 17-2:
Name TXSTA2 RCSTA2 SPBRG2
REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR
Bit 7 CSRC SPEN Bit 6 TX9 RX9 Bit 5 TXEN SREN Bit 4 SYNC CREN Bit 3 -- ADDEN Bit 2 BRGH FERR Bit 1 TRMT OERR Bit 0 TX9D RX9D Reset Values on Page 63 63 63
AUSART2 Baud Rate Generator Register
Legend: Shaded cells are not used by the BRG.
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TABLE 17-3: BAUD RATES FOR ASYNCHRONOUS MODES
BRGH = 0 FOSC = 40.000 MHz BAUD RATE (K) 0.3 1.2 2.4 9.6 19.2 57.6 115.2 Actual Rate (K) -- -- 2.441 9.615 19.531 56.818 125.000 % Error -- -- 1.73 0.16 1.73 -1.36 8.51 FOSC = 20.000 MHz % Error -- 1.73 0.16 1.73 1.73 8.51 -9.58 BRGH = 0 FOSC = 4.000 MHz BAUD RATE (K) 0.3 1.2 2.4 9.6 19.2 57.6 115.2 Actual Rate (K) 0.300 1.202 2.404 8.929 20.833 62.500 62.500 % Error 0.16 0.16 0.16 -6.99 8.51 8.51 -45.75 FOSC = 2.000 MHz % Error -0.16 -0.16 -0.16 -- -- -- -- FOSC = 1.000 MHz % Error -0.16 -0.16 -- -- -- -- -- SPBRG value (decimal) 51 12 -- -- -- -- -- SPBRG Actual value Rate (K) (decimal) 207 51 25 6 2 0 0 0.300 1.201 2.403 -- -- -- -- SPBRG Actual value Rate (K) (decimal) 103 25 12 -- -- -- -- 0.300 1.201 -- -- -- -- -- FOSC = 10.000 MHz % Error -- 0.16 0.16 1.73 1.73 -9.58 -32.18 FOSC = 8.000 MHz % Error -- -0.16 -0.16 -0.16 -- -- -- SPBRG value (decimal) -- 103 51 12 -- -- -- SPBRG Actual value Rate (K) (decimal) -- -- 255 64 31 10 4 -- 1.221 2.404 9.766 19.531 62.500 104.167 SPBRG Actual value Rate (K) (decimal) -- 255 129 31 15 4 2 -- 1.202 2.404 9.766 19.531 52.083 78.125 SPBRG Actual value Rate (K) (decimal) -- 129 64 15 7 2 1 -- 1.201 2.403 9.615 -- -- --
BRGH = 1 BAUD RATE (K) FOSC = 40.000 MHz Actual Rate (K) -- -- -- 9.766 19.231 58.140 113.636 % Error -- -- -- 1.73 0.16 0.94 -1.36 FOSC = 20.000 MHz % Error -- -- -- 0.16 0.16 -1.36 -1.36 BRGH = 1 BAUD RATE (K) FOSC = 4.000 MHz Actual Rate (K) -- 1.202 2.404 9.615 19.231 62.500 125.000 % Error -- 0.16 0.16 0.16 0.16 8.51 8.51 FOSC = 2.000 MHz % Error -- -0.16 -0.16 -0.16 -- -- -- FOSC = 1.000 MHz % Error -0.16 -0.16 -0.16 -- -- -- -- SPBRG value (decimal) 207 51 25 -- -- -- -- SPBRG Actual value Rate (K) (decimal) -- 207 103 25 12 3 1 -- 1.201 2.403 9.615 -- -- -- SPBRG Actual value Rate (K) (decimal) -- 103 51 12 -- -- -- 0.300 1.201 2.403 -- -- -- -- FOSC = 10.000 MHz % Error -- -- 1.73 0.16 1.73 -1.36 8.51 FOSC = 8.000 MHz % Error -- -- -0.16 -0.16 -0.16 3.55 -- SPBRG value (decimal) -- -- 207 51 25 8 -- SPBRG Actual value Rate (K) (decimal) -- -- -- 255 129 42 21 -- -- -- 9.615 19.231 56.818 113.636 SPBRG Actual value Rate (K) (decimal) -- -- -- 129 64 21 10 -- -- 2.441 9.615 19.531 56.818 125.000 SPBRG Actual value Rate (K) (decimal) -- -- 255 64 31 10 4 -- -- 2.403 9.615 19.230 55.555 --
0.3 1.2 2.4 9.6 19.2 57.6 115.2
0.3 1.2 2.4 9.6 19.2 57.6 115.2
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17.2 AUSART Asynchronous Mode
The Asynchronous mode of operation is selected by clearing the SYNC bit (TXSTA2<4>). In this mode, the AUSART uses standard Non-Return-to-Zero (NRZ) format (one Start bit, eight or nine data bits and one Stop bit). The most common data format is 8 bits. An on-chip, dedicated 8-bit Baud Rate Generator can be used to derive standard baud rate frequencies from the oscillator. The AUSART transmits and receives the LSb first. The AUSART's transmitter and receiver are functionally independent but use the same data format and baud rate. The Baud Rate Generator produces a clock, either x16 or x64 of the bit shift rate, depending on the BRGH bit (TXSTA2<2>). Parity is not supported by the hardware but can be implemented in software and stored as the 9th data bit. When operating in Asynchronous mode, the AUSART module consists of the following important elements: * * * * Baud Rate Generator Sampling Circuit Asynchronous Transmitter Asynchronous Receiver Once the TXREG2 register transfers the data to the TSR register (occurs in one TCY), the TXREG2 register is empty and the TX2IF flag bit (PIR3<4>) is set. This interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX2IE (PIE3<4>). TX2IF will be set regardless of the state of TX2IE; it cannot be cleared in software. TX2IF is also not cleared immediately upon loading TXREG2, but becomes valid in the second instruction cycle following the load instruction. Polling TX2IF immediately following a load of TXREG2 will return invalid results. While TX2IF indicates the status of the TXREG2 register, another bit, TRMT (TXSTA2<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR register is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. Note 1: The TSR register is not mapped in data memory, so it is not available to the user. 2: Flag bit, TX2IF, is set when enable bit, TXEN is set. To set up an Asynchronous Transmission: 1. Initialize the SPBRG2 register for the appropriate baud rate. Set or clear the BRGH bit, as required, to achieve the desired baud rate. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. If interrupts are desired, set enable bit, TX2IE. If 9-bit transmission is desired, set transmit bit, TX9. Can be used as address/data bit. Enable the transmission by setting bit, TXEN, which will also set bit, TX2IF. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Load data to the TXREG2 register (starts transmission). If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set.
17.2.1
AUSART ASYNCHRONOUS TRANSMITTER
2. 3. 4. 5. 6. 7. 8.
The AUSART transmitter block diagram is shown in Figure 17-1. The heart of the transmitter is the Transmit (Serial) Shift Register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG2. The TXREG2 register is loaded with data in software. The TSR register is not loaded until the Stop bit has been transmitted from the previous load. As soon as the Stop bit is transmitted, the TSR is loaded with new data from the TXREG2 register (if available).
FIGURE 17-1:
AUSART TRANSMIT BLOCK DIAGRAM
Data Bus TX2IF TXREG2 Register 8 MSb (8) Interrupt TXEN Baud Rate CLK TRMT TX9 TX9D SPEN *** TSR Register LSb 0 Pin Buffer and Control TX2 pin
TX2IE
SPBRG2 Baud Rate Generator
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FIGURE 17-2:
Write to TXREG2 BRG Output (Shift Clock) TX2 (pin) TX2IF bit (Transmit Buffer Reg. Empty Flag)
ASYNCHRONOUS TRANSMISSION
Word 1
Start bit 1 TCY
bit 0
bit 1 Word 1
bit 7/8
Stop bit
TRMT bit (Transmit Shift Reg. Empty Flag)
Word 1 Transmit Shift Reg
FIGURE 17-3:
Write to TXREG2
ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)
Word 1 Word 2
BRG Output (Shift Clock) TX2 (pin) TX2IF bit (Interrupt Reg. Flag) 1 TCY 1 TCY Word 1 Transmit Shift Reg. Word 2 Transmit Shift Reg. Start bit bit 0 bit 1 Word 1 bit 7/8 Stop bit Start bit Word 2 bit 0
TRMT bit (Transmit Shift Reg. Empty Flag) Note:
This timing diagram shows two consecutive transmissions.
TABLE 17-4:
Name INTCON PIR3 PIE3 IPR3 RCSTA2 TXREG2 TXSTA2 SPBRG2
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Bit 7 Bit 6 Bit 5 TMR0IE RC2IF RC2IE RC2IP SREN TXEN Bit 4 INT0IE TX2IF TX2IE TX2IP CREN SYNC Bit 3 RBIE -- -- -- ADDEN -- Bit 2 TMR0IF -- -- -- FERR BRGH Bit 1 INT0IF -- -- -- OERR TRMT Bit 0 RBIF -- -- -- RX9D TX9D Reset Values on Page 59 61 61 61 63 63 63 63
GIE/GIEH PEIE/GIEL -- -- -- SPEN CSRC LCDIF LCDIE LCDIP RX9 TX9
AUSART2 Transmit Register AUSART2 Baud Rate Generator Register
Legend: -- = unimplemented locations read as `0'. Shaded cells are not used for asynchronous transmission.
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17.2.2 AUSART ASYNCHRONOUS RECEIVER 17.2.3 SETTING UP 9-BIT MODE WITH ADDRESS DETECT
The receiver block diagram is shown in Figure 17-4. The data is received on the RX2 pin and drives the data recovery block. The data recovery block is actually a high-speed shifter, operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC. This mode would typically be used in RS-232 systems. To set up an Asynchronous Reception: Initialize the SPBRG2 register for the appropriate baud rate. Set or clear the BRGH bit, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. 3. If interrupts are desired, set enable bit, RC2IE. 4. If 9-bit reception is desired, set bit, RX9. 5. Enable the reception by setting bit, CREN. 6. Flag bit, RC2IF, will be set when reception is complete and an interrupt will be generated if enable bit, RC2IE, was set. 7. Read the RCSTA2 register to get the 9th bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG2 register. 9. If any error occurred, clear the error by clearing enable bit, CREN. 10. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 1. This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: Initialize the SPBRG2 register for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. 3. If interrupts are required, set the RCEN bit and select the desired priority level with the RC2IP bit. 4. Set the RX9 bit to enable 9-bit reception. 5. Set the ADDEN bit to enable address detect. 6. Enable reception by setting the CREN bit. 7. The RC2IF bit will be set when reception is complete. The interrupt will be Acknowledged if the RC2IE and GIE bits are set. 8. Read the RCSTA2 register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. Read RCREG2 to determine if the device is being addressed. 10. If any error occurred, clear the CREN bit. 11. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and interrupt the CPU. 1.
FIGURE 17-4:
AUSART RECEIVE BLOCK DIAGRAM
CREN x64 Baud Rate CLK SPBRG2 Baud Rate Generator / 64 or / 16 or /4 MSb Stop (8) 7 RSR Register *** 1 0 LSb Start OERR FERR
RX9 Pin Buffer and Control RX2 Data Recovery RX9D RCREG2 Register FIFO
SPEN 8 Interrupt RC2IF RC2IE Data Bus
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FIGURE 17-5:
RX2 (pin) Rcv Shift Reg Rcv Buffer Reg Read Rcv Buffer Reg RCREG2 RC2IF (Interrupt Flag) OERR bit CREN Note: This timing diagram shows three words appearing on the RX2 input. The RCREG2 (Receive Buffer register) is read after the third word causing the OERR (Overrun) bit to be set.
ASYNCHRONOUS RECEPTION
Start bit bit 0 bit 1 bit 7/8 Stop bit Start bit bit 0 bit 7/8 Stop bit Start bit bit 7/8 Stop bit
Word 1 RCREG2
Word 2 RCREG2
TABLE 17-5:
Name INTCON PIR3 PIE3 IPR3 RCSTA2 RCREG2 TXSTA2 SPBRG2
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Bit 7 Bit 6 Bit 5 Bit 4 INT0IE TX2IF TX2IE TX2IP CREN SYNC Bit 3 RBIE -- -- -- ADDEN -- Bit 2 TMR0IF -- -- -- FERR BRGH Bit 1 INT0IF -- -- -- OERR TRMT Bit 0 RBIF -- -- -- RX9D TX9D Reset Values on Page 59 61 61 61 63 63 63 63
GIE/GIEH PEIE/GIEL TMR0IE -- -- -- SPEN CSRC LCDIF LCDIE LCDIP RX9 TX9 RC2IF RC2IE RC2IP SREN TXEN
AUSART2 Receive Register AUSART2 Baud Rate Generator Register
Legend: -- = unimplemented locations read as `0'. Shaded cells are not used for asynchronous reception.
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17.3 AUSART Synchronous Master Mode
Once the TXREG2 register transfers the data to the TSR register (occurs in one TCYCLE), the TXREG2 is empty and the TX2IF flag bit (PIR3<4>) is set. The interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX2IE (PIE3<4>). TX2IF is set regardless of the state of enable bit, TX2IE; it cannot be cleared in software. It will reset only when new data is loaded into the TXREG2 register. While flag bit, TX2IF, indicates the status of the TXREG2 register, another bit, TRMT (TXSTA2<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory so it is not available to the user. To set up a Synchronous Master Transmission: 1. 2. 3. 4. 5. 6. 7. 8. Initialize the SPBRG2 register for the appropriate baud rate. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. If interrupts are desired, set enable bit, TX2IE. If 9-bit transmission is desired, set bit, TX9. Enable the transmission by setting bit, TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Start transmission by loading data to the TXREG2 register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set.
The Synchronous Master mode is entered by setting the CSRC bit (TXSTA2<7>). In this mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit, SYNC (TXSTA2<4>). In addition, enable bit, SPEN (RCSTA2<7>), is set in order to configure the TX2 and RX2 pins to CK2 (clock) and DT2 (data) lines, respectively. The Master mode indicates that the processor transmits the master clock on the CK2 line.
17.3.1
AUSART SYNCHRONOUS MASTER TRANSMISSION
The AUSART transmitter block diagram is shown in Figure 17-1. The heart of the transmitter is the Transmit (Serial) Shift Register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG2. The TXREG2 register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG2 (if available).
FIGURE 17-6:
SYNCHRONOUS TRANSMISSION
Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 bit 7 bit 0 bit 1 bit 7
Q1 Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4
RX2/DT2 pin
bit 0
bit 1
bit 2
Word 1 TX2/CK2 pin Write to TXREG2 Reg TX2IF bit (Interrupt Flag) TRMT bit TXEN bit Note: `1'
Word 2
Write Word 1
Write Word 2
`1'
Sync Master mode, SPBRG2 = 0, continuous transmission of two 8-bit words.
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FIGURE 17-7: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
bit 0 bit 1 bit 2 bit 6 bit 7 RX2/DT2 pin
TX2/CK2 pin Write to TXREG2 Reg
TX2IF bit
TRMT bit
TXEN bit
TABLE 17-6:
Name INTCON PIR3 PIE3 IPR3 RCSTA2 TXREG2 TXSTA2 SPBRG2
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Bit 7 Bit 6 Bit 5 Bit 4 INT0IE TX2IF TX2IE TX2IP CREN SYNC Bit 3 RBIE -- -- -- ADDEN -- Bit 2 TMR0IF -- -- -- FERR BRGH Bit 1 INT0IF -- -- -- OERR TRMT Bit 0 RBIF -- -- -- RX9D TX9D Reset Values on Page 59 61 61 61 63 63 63 63
GIE/GIEH PEIE/GIEL TMR0IE -- -- -- SPEN CSRC LCDIF LCDIE LCDIP RX9 TX9 RC2IF RC2IE RC2IP SREN TXEN
AUSART2 Transmit Register AUSART2 Baud Rate Generator Register
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous master transmission.
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17.3.2 AUSART SYNCHRONOUS MASTER RECEPTION
Once Synchronous mode is selected, reception is enabled by setting either the Single Receive Enable bit, SREN (RCSTA2<5>), or the Continuous Receive Enable bit, CREN (RCSTA2<4>). Data is sampled on the RX2 pin on the falling edge of the clock. If enable bit, SREN, is set, only a single word is received. If enable bit, CREN, is set, the reception is continuous until CREN is cleared. If both bits are set, then CREN takes precedence. To set up a Synchronous Master Reception: 1. 2. 3. Initialize the SPBRG2 register for the appropriate baud rate. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. Ensure bits, CREN and SREN, are clear. If interrupts are desired, set enable bit, RC2IE. If 9-bit reception is desired, set bit, RX9. If a single reception is required, set bit, SREN. For continuous reception, set bit, CREN. 7. Interrupt flag bit, RC2IF, will be set when reception is complete and an interrupt will be generated if the enable bit, RC2IE, was set. 8. Read the RCSTA2 register to get the 9th bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG2 register. 10. If any error occurred, clear the error by clearing bit, CREN. 11. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 4. 5. 6.
FIGURE 17-8:
SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RX2/DT2 pin TX2/CK2 pin Write to SREN bit SREN bit CREN bit `0' RC2IF bit (Interrupt) Read RCREG2 Note:
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
`0'
Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0.
TABLE 17-7:
Name INTCON PIR3 PIE3 IPR3 RCSTA2 RCREG2 TXSTA2 SPBRG2
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Bit 7 Bit 6 Bit 5 TMR0IE RC2IF RC2IE RC2IP SREN TXEN Bit 4 INT0IE TX2IF TX2IE TX2IP CREN SYNC Bit 3 RBIE -- -- -- ADDEN -- Bit 2 TMR0IF -- -- -- FERR BRGH Bit 1 INT0IF -- -- -- OERR TRMT Bit 0 RBIF -- -- -- RX9D TX9D Reset Values on Page 59 61 61 61 63 63 63 63
GIE/GIEH PEIE/GIEL -- -- -- SPEN CSRC LCDIF LCDIE LCDIP RX9 TX9
AUSART2 Receive Register AUSART2 Baud Rate Generator Register
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous master reception.
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17.4 AUSART Synchronous Slave Mode
To set up a Synchronous Slave Transmission: 1. Enable the synchronous slave serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. Clear bits, CREN and SREN. If interrupts are desired, set enable bit, TX2IE. If 9-bit transmission is desired, set bit, TX9. Enable the transmission by setting enable bit, TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Start transmission by loading data to the TXREG2 register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. Synchronous Slave mode is entered by clearing bit, CSRC (TXSTA2<7>). This mode differs from the Synchronous Master mode in that the shift clock is supplied externally at the CK2 pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in any low-power mode.
2. 3. 4. 5. 6. 7. 8.
17.4.1
AUSART SYNCHRONOUS SLAVE TRANSMIT
The operation of the Synchronous Master and Slave modes are identical except in the case of the Sleep mode. If two words are written to the TXREG2 and then the SLEEP instruction is executed, the following will occur: a) b) c) d) The first word will immediately transfer to the TSR register and transmit. The second word will remain in the TXREG2 register. Flag bit, TX2IF, will not be set. When the first word has been shifted out of TSR, the TXREG2 register will transfer the second word to the TSR and flag bit, TX2IF, will now be set. If enable bit, TX2IE, is set, the interrupt will wake the chip from Sleep. If the global interrupt is enabled, the program will branch to the interrupt vector.
e)
TABLE 17-8:
Name INTCON PIR3 PIE3 IPR3 RCSTA2 TXREG2 TXSTA2 SPBRG2
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Bit 7 Bit 6 Bit 5 TMR0IE RC2IF RC2IE RC2IP SREN TXEN Bit 4 INT0IE TX2IF TX2IE TX2IP CREN SYNC Bit 3 RBIE -- -- -- ADDEN -- Bit 2 TMR0IF -- -- -- FERR BRGH Bit 1 INT0IF -- -- -- OERR TRMT Bit 0 RBIF -- -- -- RX9D TX9D Reset Values on Page 59 61 61 61 63 63 63 63
GIE/GIEH PEIE/GIEL -- -- -- SPEN CSRC LCDIF LCDIE LCDIP RX9 TX9
AUSART2 Transmit Register AUSART2 Baud Rate Generator Register
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous slave transmission.
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17.4.2 AUSART SYNCHRONOUS SLAVE RECEPTION
To set up a Synchronous Slave Reception: 1. Enable the synchronous master serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. If interrupts are desired, set enable bit, RC2IE. If 9-bit reception is desired, set bit, RX9. To enable reception, set enable bit, CREN. Flag bit, RC2IF, will be set when reception is complete. An interrupt will be generated if enable bit, RC2IE, was set. Read the RCSTA2 register to get the 9th bit (if enabled) and determine if any error occurred during reception. Read the 8-bit received data by reading the RCREG2 register. If any error occurred, clear the error by clearing bit, CREN. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. The operation of the Synchronous Master and Slave modes is identical except in the case of Sleep, or any Idle mode and bit SREN, which is a "don't care" in Slave mode. If receive is enabled by setting the CREN bit prior to entering Sleep, or any Idle mode, then a word may be received while in this low-power mode. Once the word is received, the RSR register will transfer the data to the RCREG2 register; if the RC2IE enable bit is set, the interrupt generated will wake the chip from low-power mode. If the global interrupt is enabled, the program will branch to the interrupt vector.
2. 3. 4. 5.
6.
7. 8. 9.
TABLE 17-9:
Name INTCON PIR3 PIE3 IPR3 RCSTA2 RCREG2 TXSTA2 SPBRG2
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Bit 7 Bit 6 Bit 5 Bit 4 INT0IE TX2IF TX2IE TX2IP CREN SYNC Bit 3 RBIE -- -- -- ADDEN -- Bit 2 TMR0IF -- -- -- FERR BRGH Bit 1 INT0IF -- -- -- OERR TRMT Bit 0 RBIF -- -- -- RX9D TX9D Reset Values on Page 59 61 61 61 63 63 63 63
GIE/GIEH PEIE/GIEL TMR0IE -- -- -- SPEN CSRC LCDIF LCDIE LCDIP RX9 TX9 RC2IF RC2IE RC2IP SREN TXEN
AUSART2 Receive Register AUSART2 Baud Rate Generator Register
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous slave reception.
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18.0 10-BIT ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE
The module has five registers: * * * * * A/D Result High Register (ADRESH) A/D Result Low Register (ADRESL) A/D Control Register 0 (ADCON0) A/D Control Register 1 (ADCON1) A/D Control Register 2 (ADCON2)
The Analog-to-Digital (A/D) converter module has 12 inputs for the PIC18F6X90/8X90 devices. This module allows conversion of an analog input signal to a corresponding 10-bit digital number.
The ADCON0 register, shown in Register 18-1, controls the operation of the A/D module. The ADCON1 register, shown in Register 18-2, configures the functions of the port pins. The ADCON2 register, shown in Register 18-3, configures the A/D clock source, programmed acquisition time and justification.
REGISTER 18-1:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7-6 bit 5-2
ADCON0: A/D CONTROL REGISTER 0
U-0 -- R/W-0 CHS3 R/W-0 CHS2 R/W-0 CHS1 R/W-0 CHS0 R/W-0 GO/DONE R/W-0 ADON bit 0
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
Unimplemented: Read as `0' CHS3:CHS0: Analog Channel Select bits 0000 = Channel 0 (AN0) 0001 = Channel 1 (AN1) 0010 = Channel 2 (AN2) 0011 = Channel 3 (AN3) 0100 = Channel 4 (AN4) 0101 = Channel 5 (AN5) 0110 = Channel 6 (AN6) 0111 = Channel 7 (AN7) 1000 = Channel 8 (AN8) 1001 = Channel 9 (AN9) 1010 = Channel 10 (AN10) 1011 = Channel 11 (AN11) 1100 = Unimplemented(1) 1101 = Unimplemented(1) 1110 = Unimplemented(1) 1111 = Unimplemented(1) GO/DONE: A/D Conversion Status bit When ADON = 1: 1 = A/D conversion in progress 0 = A/D Idle ADON: A/D On bit 1 = A/D converter module is enabled 0 = A/D converter module is disabled Performing a conversion on unimplemented channels will return a floating input measurement.
bit 1
bit 0
Note 1:
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REGISTER 18-2:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7-6 bit 5 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
ADCON1: A/D CONTROL REGISTER 1
U-0 -- R/W-0 VCFG1 R/W-0 VCFG0 R/W-q PCFG3 R/W-q PCFG2 R/W-q PCFG1 R/W-q PCFG0 bit 0
Unimplemented: Read as `0' VCFG1: Voltage Reference Configuration bit (VREF- source) 1 = VREF- (AN2) 0 = AVSS VCFG0: Voltage Reference Configuration bit (VREF+ source) 1 = VREF+ (AN3) 0 = AVDD PCFG3:PCFG0: A/D Port Configuration Control bits: PCFG3: PCFG0 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 AN10 AN11 AN9 AN8 AN7 AN6 AN5 AN4 AN3 AN2 AN1 A A A A A A A A A A A A A A D D AN0 A A A A A A A A A A A A A A A D
bit 4
bit 3-0
A A A A D D D D D D D D D D D D
A A A A A D D D D D D D D D D D
A A A A A A D D D D D D D D D D
A A A A A A A D D D D D D D D D
A A A A A A A A D D D D D D D D
A A A A A A A A A D D D D D D D
A A A A A A A A A A D D D D D D
A A A A A A A A A A A D D D D D
A A A A A A A A A A A A D D D D
A A A A A A A A A A A A A D D D
A = Analog input
D = Digital I/O
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REGISTER 18-3:
R/W-0 ADFM bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
ADCON2: A/D CONTROL REGISTER 2
U-0 -- R/W-0 ACQT2 R/W-0 ACQT1 R/W-0 ACQT0 R/W-0 ADCS2 R/W-0 ADCS1 R/W-0 ADCS0 bit 0
ADFM: A/D Result Format Select bit 1 = Right justified 0 = Left justified Unimplemented: Read as `0' ACQT2:ACQT0: A/D Acquisition Time Select bits 111 = 20 TAD 110 = 16 TAD 101 = 12 TAD 100 = 8 TAD 011 = 6 TAD 010 = 4 TAD 001 = 2 TAD 000 = 0 TAD(1) ADCS2:ADCS0: A/D Conversion Clock Select bits 111 = FRC (clock derived from A/D RC oscillator)(1) 110 = FOSC/64 101 = FOSC/16 100 = FOSC/4 011 = FRC (clock derived from A/D RC oscillator)(1) 010 = FOSC/32 001 = FOSC/8 000 = FOSC/2 If the A/D FRC clock source is selected, a delay of one TCY (instruction cycle) is added before the A/D clock starts. This allows the SLEEP instruction to be executed before starting a conversion.
bit 6 bit 5-3
bit 2-0
Note 1:
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The analog reference voltage is software selectable to either the device's positive and negative supply voltage (AVDD and AVSS), or the voltage level on the RA3/AN3/VREF+/SEG17 and RA2/AN2/VREF-/SEG16 pins. The A/D converter has a unique feature of being able to operate while the device is in Sleep mode. To operate in Sleep, the A/D conversion clock must be derived from the A/D's internal RC oscillator. The output of the sample and hold is the input into the converter, which generates the result via successive approximation. A device Reset forces all registers to their Reset state. This forces the A/D module to be turned off and any conversion in progress is aborted. Each port pin associated with the A/D converter can be configured as an analog input or as a digital I/O. The ADRESH and ADRESL registers contain the result of the A/D conversion. When the A/D conversion is complete, the result is loaded into the ADRESH/ADRESL registers, the GO/DONE bit (ADCON0<1>) is cleared and the A/D Interrupt Flag bit, ADIF, is set. The block diagram of the A/D module is shown in Figure 18-1.
FIGURE 18-1:
A/D BLOCK DIAGRAM
CHS3:CHS0 1011 1010 1001 1000 0111 0110 0101 0100 VAIN AN11 AN10 AN9 AN8 AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0
10-Bit A/D Converter
(Input Voltage)
0011 0010
VCFG1:VCFG0 AVDD VREF+ VREFX0 X1 (1)
0001 0000
Reference Voltage
1X 0X AVSS(1)
Note 1:
I/O pins have diode protection to VDD and VSS.
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The value in the ADRESH:ADRESL registers is not modified for a Power-on Reset. The ADRESH:ADRESL registers will contain unknown data after a Power-on Reset. After the A/D module has been configured as desired, the selected channel must be acquired before the conversion is started. The analog input channels must have their corresponding TRIS bits selected as an input. To determine acquisition time, see Section 18.1 "A/D Acquisition Requirements". After this acquisition time has elapsed, the A/D conversion can be started. An acquisition time can be programmed to occur between setting the GO/DONE bit and the actual start of the conversion. The following steps should be followed to perform an A/D conversion:
Digital Code Output
5.
Wait for A/D conversion to complete, by either: * Polling for the GO/DONE bit to be cleared OR * Waiting for the A/D interrupt Read A/D Result registers (ADRESH:ADRESL); clear ADIF bit, if required. For next conversion, go to step 1 or step 2, as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 3 TAD is required before the next acquisition starts.
6. 7.
FIGURE 18-2:
3FFh 3FEh
A/D TRANSFER FUNCTION
1.
2.
3. 4.
Configure the A/D module: * Configure analog pins, voltage reference and digital I/O (ADCON1) * Select A/D input channel (ADCON0) * Select A/D acquisition time (ADCON2) * Select A/D conversion clock (ADCON2) * Turn on A/D module (ADCON0) Configure A/D interrupt (if desired): * Clear ADIF bit * Set ADIE bit * Set GIE bit Wait the required acquisition time (if required). Start conversion: * Set GO/DONE bit (ADCON0<1>)
003h 002h 001h 000h 1 LSB 0.5 LSB 1.5 LSB 2 LSB 2.5 LSB 3 LSB 1022 LSB 1023 LSB 1022.5 LSB 1023.5 LSB
Analog Input Voltage
FIGURE 18-3:
ANALOG INPUT MODEL
VDD VT = 0.6V RIC 1k Sampling Switch SS RSS
Rs
ANx
VAIN
CPIN 5 pF
VT = 0.6V
ILEAKAGE 100 nA
CHOLD = 25 pF
VSS
Legend: CPIN VT ILEAKAGE RIC SS CHOLD RSS
= Input Capacitance = Threshold Voltage = Leakage Current at the pin due to various junctions = Interconnect Resistance = Sampling Switch = Sample/Hold Capacitance (from DAC) = Sampling Switch Resistance
VDD
6V 5V 4V 3V 2V 1 2 3 4
Sampling Switch (k)
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18.1 A/D Acquisition Requirements
For the A/D converter to meet its specified accuracy, the charge holding capacitor (CHOLD) must be allowed to fully charge to the input channel voltage level. The analog input model is shown in Figure 18-3. The source impedance (RS) and the internal sampling switch (RSS) impedance directly affect the time required to charge the capacitor CHOLD. The sampling switch (RSS) impedance varies over the device voltage (VDD). The source impedance affects the offset voltage at the analog input (due to pin leakage current). The maximum recommended impedance for analog sources is 2.5 k. After the analog input channel is selected (changed), the channel must be sampled for at least the minimum acquisition time before starting a conversion. Note: When the conversion is started, the holding capacitor is disconnected from the input pin. To calculate the minimum acquisition time, Equation 18-1 may be used. This equation assumes that 1/2 LSb error is used (1024 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution. Example 18-3 shows the calculation of the minimum required acquisition time, TACQ. This calculation is based on the following application system assumptions: CHOLD Rs Conversion Error VDD Temperature = = = = 25 pF 2.5 k 1/2 LSb 5V Rss = 2 k 85C (system max.)
EQUATION 18-1:
TACQ = =
ACQUISITION TIME
Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient TAMP + TC + TCOFF
EQUATION 18-2:
VHOLD or TC = =
A/D MINIMUM CHARGING TIME
(VREF - (VREF/2048)) * (1 - e(-TC/CHOLD(RIC + RSS + RS))) -(CHOLD)(RIC + RSS + RS) ln(1/2048)
EQUATION 18-3:
TACQ TAMP TCOFF = = = 0.2 s
CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
TAMP + TC + TCOFF (Temp - 25C)(0.02 s/C) (50C - 25C)(0.02 s/C) 1.2 s -(CHOLD)(RIC + RSS + RS) ln(1/2047) s -(25 pF) (1 k + 2 k + 2.5 k) ln(0.0004883) s 5.03 s 0.2 s + 5 s + 1.2 s 6.4 s
Temperature coefficient is only required for temperatures > 25C. Below 25C, TCOFF = 0 ms. TC =
TACQ
=
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18.2 Selecting and Configuring Automatic Acquisition Time 18.3 Selecting the A/D Conversion Clock
The ADCON2 register allows the user to select an acquisition time that occurs each time the GO/DONE bit is set. When the GO/DONE bit is set, sampling is stopped and a conversion begins. The user is responsible for ensuring the required acquisition time has passed between selecting the desired input channel and setting the GO/DONE bit. This occurs when the ACQT2:ACQT0 bits (ADCON2<5:3>) remain in their Reset state (`000') and is compatible with devices that do not offer programmable acquisition times. If desired, the ACQT bits can be set to select a programmable acquisition time for the A/D module. When the GO/DONE bit is set, the A/D module continues to sample the input for the selected acquisition time, then automatically begins a conversion. Since the acquisition time is programmed, there may be no need to wait for an acquisition time between selecting a channel and setting the GO/DONE bit. In either case, when the conversion is completed, the GO/DONE bit is cleared, the ADIF flag is set and the A/D begins sampling the currently selected channel again. If an acquisition time is programmed, there is nothing to indicate if the acquisition time has ended or if the conversion has begun.
The A/D conversion time per bit is defined as TAD. The A/D conversion requires 11 TAD per 10-bit conversion. The source of the A/D conversion clock is software selectable. There are seven possible options for TAD: * * * * * * * 2 TOSC 4 TOSC 8 TOSC 16 TOSC 32 TOSC 64 TOSC Internal RC Oscillator
For correct A/D conversions, the A/D conversion clock (TAD) must be as short as possible, but greater than the minimum TAD (approximately 2 s, see parameter 130 for more information). Table 18-1 shows the resultant TAD times derived from the device operating frequencies and the A/D clock source selected.
TABLE 18-1:
TAD vs. DEVICE OPERATING FREQUENCIES
AD Clock Source (TAD) Maximum Device Frequency PIC18F6X90/8X90 1.25 MHz 2.50 MHz 5.00 MHz 10.0 MHz 20.0 MHz 40.0 MHz 1.00 MHz(1) PIC18LF6X90/8X90(4) 666 kHz 1.33 MHz 2.66 MHz 5.33 MHz 10.65 MHz 21.33 MHz 1.00 MHz(2) ADCS2:ADCS0 000 100 001 101 010 110 x11
Operation 2 TOSC 4 TOSC 8 TOSC 16 TOSC 32 TOSC 64 TOSC RC(3) Note 1: 2: 3: 4:
The RC source has a typical TAD time of 4 s. The RC source has a typical TAD time of 6 s. For device frequencies above 1 MHz, the device must be in Sleep for the entire conversion or the A/D accuracy may be out of specification. Low-power (PIC18LFXXXX) devices only.
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18.4 Operation in Power-Managed Modes 18.5 Configuring Analog Port Pins
The ADCON1, TRISA and TRISF registers all configure the A/D port pins. The port pins needed as analog inputs must have their corresponding TRIS bits set (input). If the TRIS bit is cleared (output), the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the CHS3:CHS0 bits and the TRIS bits. Note 1: When reading the PORT register, all pins configured as analog input channels will read as cleared (a low level). Pins configured as digital inputs will convert an analog input. Analog levels on a digitally configured input will be accurately converted. 2: Analog levels on any pin defined as a digital input may cause the digital input buffer to consume current out of the device's specification limits.
The selection of the automatic acquisition time and A/D conversion clock is determined in part by the clock source and frequency while in a power-managed mode. If the A/D is expected to operate while the device is in a power-managed mode, the ACQT2:ACQT0 and ADCS2:ADCS0 bits in ADCON2 should be updated in accordance with the power-managed mode clock that will be used. After the power-managed mode is entered, an A/D acquisition or conversion may be started. Once an acquisition or conversion is started, the device should continue to be clocked by the same power-managed mode clock source until the conversion has been completed. If desired, the device may be placed into the corresponding power-managed Idle mode during the conversion. If the power-managed mode clock frequency is less than 1 MHz, the A/D RC clock source should be selected. Operation in the Sleep mode requires the A/D FRC clock to be selected. If bits, ACQT2:ACQT0, are set to `000' and a conversion is started, the conversion will be delayed one instruction cycle to allow execution of the SLEEP instruction and entry to Sleep mode. The IDLEN and SCS bits in the OSCCON register must have already been cleared prior to starting the conversion.
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18.6 A/D Conversions
Figure 18-4 shows the operation of the A/D converter after the GO/DONE bit has been set and the ACQT2:ACQT0 bits are cleared. A conversion is started after the following instruction to allow entry into Sleep mode before the conversion begins. Figure 18-5 shows the operation of the A/D converter after the GO/DONE bit has been set, the ACQT2:ACQT0 bits are set to `010' and a 4 TAD acquisition time has been selected before the conversion starts. Clearing the GO/DONE bit during a conversion will abort the current conversion. The A/D Result register pair will NOT be updated with the partially completed A/D conversion sample. This means the ADRESH:ADRESL registers will continue to contain the value of the last completed conversion (or the last value written to the ADRESH:ADRESL registers). After the A/D conversion is completed or aborted, a 2 TAD wait is required before the next acquisition can be started. After this wait, acquisition on the selected channel is automatically started. Note: The GO/DONE bit should NOT be set in the same instruction that turns on the A/D.
18.7
Discharge
The discharge phase is used to initialize the value of the capacitor array. The array is discharged before every sample. This feature helps to optimize the unity-gain amplifier as the circuit always needs to charge the capacitor array, rather than charge/discharge based on previous measure values.
FIGURE 18-4:
A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0)
TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 TAD1 b4 b1 b0 b6 b7 b2 b9 b8 b3 b5 Conversion starts Holding capacitor is disconnected from analog input (typically 100 ns) Set GO/DONE bit On the following cycle: ADRESH:ADRESL is loaded, GO/DONE bit is cleared, ADIF bit is set, holding capacitor is connected to analog input. Discharge
FIGURE 18-5:
A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD)
TAD Cycles 4 1 2 b9 3 b8 4 b7 5 b6 6 b5 7 b4 8 b3 9 b2 10 b1 11 b0 Discharge TAD1
TACQT Cycles 1 2 3
Automatic Acquisition Time
Conversion starts (Holding capacitor is disconnected)
Set GO/DONE bit (Holding capacitor continues acquiring input)
On the following cycle: ADRESH:ADRESL is loaded, GO/DONE bit is cleared, ADIF bit is set, holding capacitor is connected to analog input.
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18.8 Use of the CCP2 Trigger
An A/D conversion can be started by the "Special Event Trigger" of the CCP2 module. This requires that the CCP2M3:CCP2M0 bits (CCP2CON<3:0>) be programmed as `1011' and that the A/D module is enabled (ADON bit is set). When the trigger occurs, the GO/DONE bit will be set, starting the A/D acquisition and conversion and the Timer1 (or Timer3) counter will be reset to zero. Timer1 (or Timer3) is reset to automatically repeat the A/D acquisition period with minimal software overhead (moving ADRESH/ADRESL to the desired location). The appropriate analog input channel must be selected and the minimum acquisition period is either timed by the user, or an appropriate TACQ time selected before the "Special Event Trigger" sets the GO/DONE bit (starts a conversion). If the A/D module is not enabled (ADON is cleared), the "Special Event Trigger" will be ignored by the A/D module, but will still reset the Timer1 (or Timer3) counter.
TABLE 18-2:
Name INTCON PIR1 PIE1 IPR1 PIR2 PIE2 IPR2 ADRESH ADRESL ADCON0 ADCON1 ADCON2 PORTA TRISA PORTF TRISF LATF
REGISTERS ASSOCIATED WITH A/D OPERATION
Bit 7 Bit 6 Bit 5 TMR0IE RC1IF RC1IE RC1IP -- -- -- Bit 4 INT0IE TX1IF TX1IE TX1IP -- -- -- Bit 3 RBIE SSPIF SSPIE SSPIP BCLIF BCLIE BCLIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP HLVDIF HLVDIE HLVDIP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP TMR3IF TMR3IE TMR3IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP CCP2IF CCP2IE CCP2IP Reset Values on Page 59 61 61 61 61 61 61 61 61 CHS2 VCFG0 ACQT1 RA4 CHS1 PCFG3 ACQT0 RA3 CHS0 PCFG2 ADCS2 RA2 GO/DONE PCFG1 ADCS1 RA1 ADON PCFG0 ADCS0 RA0 61 61 61 62 62 62 62 62
GIE/GIEH PEIE/GIEL -- -- -- OSCFIF OSCFIE OSCFIP ADIF ADIE ADIP CMIF CMIE CMIP
A/D Result Register High Byte A/D Result Register Low Byte -- -- ADFM RA7(1) -- -- -- RA6(1) CHS3 VCFG1 ACQT2 RA5
TRISA7(1) TRISA6(1) PORTA Data Direction Register Read PORTF pins, Write LATF Latch PORTF Data Direction Register LATF Data Output Register
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for A/D conversion. Note 1: These pins may be configured as port pins depending on the oscillator mode selected.
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19.0 COMPARATOR MODULE
The analog comparator module contains two comparators that can be configured in a variety of ways. The inputs can be selected from the analog inputs multiplexed with pins RF3 through RF6, as well as the on-chip voltage reference (see Section 20.0 "Comparator Voltage Reference Module"). The digital outputs (normal or inverted) are available at the pin level and can also be read through the control register. The CMCON register (Register 19-1) selects the comparator input and output configuration. Block diagrams of the various comparator configurations are shown in Figure 19-1.
REGISTER 19-1:
R-0 C2OUT bit 7 Legend: R = Readable bit -n = Value at POR bit 7
CMCON: COMPARATOR CONTROL REGISTER
R/W-0 C2INV R/W-0 C1INV R/W-0 CIS R/W-1 CM2 R/W-1 CM1 R/W-1 CM0 bit 0
R-0 C1OUT
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
C2OUT: Comparator 2 Output bit When C2INV = 0: 1 = C2 VIN+ > C2 VIN0 = C2 VIN+ < C2 VINWhen C2INV = 1: 1 = C2 VIN+ < C2 VIN0 = C2 VIN+ > C2 VINC1OUT: Comparator 1 Output bit When C1INV = 0: 1 = C1 VIN+ > C1 VIN0 = C1 VIN+ < C1 VINWhen C1INV = 1: 1 = C1 VIN+ < C1 VIN0 = C1 VIN+ > C1 VINC2INV: Comparator 2 Output Inversion bit 1 = C2 output inverted 0 = C2 output not inverted C1INV: Comparator 1 Output Inversion bit 1 = C1 Output inverted 0 = C1 Output not inverted CIS: Comparator Input Switch bit When CM2:CM0 = 110: 1 = C1 VIN- connects to RF5/AN10 C2 VIN- connects to RF3/AN8 0 = C1 VIN- connects to RF6/AN11 C2 VIN- connects to RF4/AN9 CM2:CM0: Comparator Mode bits Figure 19-1 shows the Comparator modes and the CM2:CM0 bit settings.
bit 4
bit 3
bit 2-0
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19.1 Comparator Configuration
There are eight modes of operation for the comparators, shown in Figure 19-1. Bits, CM2:CM0 of the CMCON register, are used to select these modes. The TRISF register controls the data direction of the comparator pins for each mode. If the Comparator mode is changed, the comparator output level may not be valid for the specified mode change delay shown in Section 26.0 "Electrical Characteristics". Note: Comparator interrupts should be disabled during a Comparator mode change; otherwise, a false interrupt may occur.
FIGURE 19-1:
COMPARATOR I/O OPERATING MODES
Comparators Off CM2:CM0 = 111 RF6/AN11/ D SEG24 RF5/AN10/ D CVREF/SEG23 RF4/AN9/ SEG22 RF3/AN8/ SEG21
D D VINVIN+
Comparators Reset (POR Default Value) CM2:CM0 = 000 RF6/AN11/ A SEG24 RF5/AN10/ A CVREF/SEG23 RF4/AN9/ SEG22 RF3/AN8/ SEG21
A A VINVIN+
C1
Off (Read as `0')
C1
Off (Read as `0')
VINVIN+
VINVIN+
C2
Off (Read as `0')
C2
Off (Read as `0')
Two Independent Comparators CM2:CM0 = 010 RF6/AN11/ A VINSEG24 C1 VIN+ RF5/AN10/ A CVREF/SEG23 RF4/AN9/ SEG22 RF3/AN8/ SEG21
A A VINVIN+
C1OUT
Two Independent Comparators with Outputs CM2:CM0 = 011 RF6/AN11/ A VINSEG24 C1OUT C1 VIN+ RF5/AN10/ A CVREF/SEG23 RF2/AN7/C1OUT*/SEG20
C2
C2OUT
RF4/AN9/ SEG22 RF3/AN8/ SEG21
A A
VINVIN+
C2
C2OUT
RF1/AN6/C2OUT*/SEG19 Two Common Reference Comparators CM2:CM0 = 100 RF6/AN11/ A VINSEG24 C1OUT C1 VIN+ RF5/AN10/ A CVREF/SEG23 RF4/AN9/ SEG22 RF3/AN8/ SEG21
A D VINVIN+
Two Common Reference Comparators with Outputs CM2:CM0 = 101 RF6/AN11/ SEG24 RF5/AN10/ CVREF/SEG23
A A VINVIN+
C1
C1OUT
RF2/AN7/C1OUT*/SEG20 C2 C2OUT RF4/AN9/ SEG22 RF3/AN8/ SEG21
A D VINVIN+
C2
C2OUT
RF1/AN6/C2OUT*/SEG19 One Independent Comparator with Output CM2:CM0 = 001 RF6/AN11/ A SEG24 RF5/AN10/ A CVREF/SEG23
VINVIN+
Four Inputs Multiplexed to Two Comparators CM2:CM0 = 110 RF6/AN11/ A SEG24 RF5/AN10/ A CVREF/SEG23 RF4/AN9/ SEG22 RF3/AN8/ SEG21
A A CIS = 0 CIS = 1 VINVIN+ CIS = 0 CIS = 1 VINVIN+
C1
C1OUT
C1
C1OUT
RF2/AN7/C1OUT*/SEG20 RF4/AN9/ SEG22 RF3/AN8/ SEG21
D D VINVIN+
C2
C2OUT
C2
Off (Read as `0')
CVREF
From VREF Module
A = Analog Input, port reads zeros always D = Digital Input CIS (CMCON<3>) is the Comparator Input Switch * Setting the TRISF<2:1> bits will disable the comparator outputs by configuring the pins as inputs.
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19.2 Comparator Operation
19.3.2 INTERNAL REFERENCE SIGNAL
A single comparator is shown in Figure 19-2, along with the relationship between the analog input levels and the digital output. When the analog input at VIN+ is less than the analog input VIN-, the output of the comparator is a digital low level. When the analog input at VIN+ is greater than the analog input VIN-, the output of the comparator is a digital high level. The shaded areas of the output of the comparator in Figure 19-2 represent the uncertainty, due to input offsets and response time. The comparator module also allows the selection of an internally generated voltage reference from the comparator voltage reference module. This module is described in more detail in Section 20.0 "Comparator Voltage Reference Module". The internal reference is only available in the mode where four inputs are multiplexed to two comparators (CM2:CM0 = 110). In this mode, the internal voltage reference is applied to the VIN+ pin of both comparators.
19.3
Comparator Reference
19.4
Comparator Response Time
Depending on the comparator operating mode, either an external or internal voltage reference may be used. The analog signal present at VIN- is compared to the signal at VIN+ and the digital output of the comparator is adjusted accordingly (Figure 19-2).
FIGURE 19-2:
SINGLE COMPARATOR
Response time is the minimum time, after selecting a new reference voltage or input source, before the comparator output has a valid level. If the internal reference is changed, the maximum delay of the internal voltage reference must be considered when using the comparator outputs. Otherwise, the maximum delay of the comparators should be used (see Section 26.0 "Electrical Characteristics").
VIN+ VIN-
+ -
19.5
Output
Comparator Outputs
VINVIN+
The comparator outputs are read through the CMCON register. These bits are read-only. The comparator outputs may also be directly output to the RF2 and RF1 I/O pins. When enabled, multiplexers in the output path of the RF2 and RF1 pins will switch and the output of each pin will be the unsynchronized output of the comparator. The uncertainty of each of the comparators is related to the input offset voltage and the response time given in the specifications. Figure 19-3 shows the comparator output block diagram. The TRISF bits will still function as an output enable/ disable for the RF2 and RF1 pins while in this mode. The polarity of the comparator outputs can be changed using the C2INV and C1INV bits (CMCON<5:4>).
Output
19.3.1
EXTERNAL REFERENCE SIGNAL
When external voltage references are used, the comparator module can be configured to have the comparators operate from the same, or different reference sources. However, threshold detector applications may require the same reference. The reference signal must be between VSS and VDD and can be applied to either pin of the comparator(s).
Note 1: When reading the PORT register, all pins configured as analog inputs will read as a `0'. Pins configured as digital inputs will convert an analog input according to the Schmitt Trigger input specification. 2: Analog levels on any pin defined as a digital input may cause the input buffer to consume more current than is specified.
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FIGURE 19-3: COMPARATOR OUTPUT BLOCK DIAGRAM
MULTIPLEX
Port pins
+
To RF2 or RF1 pin D CxINV EN Q Bus Data
Read CMCON
-
D EN Reset
Q CL From Other Comparator
Set CMIF bit
19.6
Comparator Interrupts
19.7
The comparator interrupt flag is set whenever there is a change in the output value of either comparator. Software will need to maintain information about the status of the output bits, as read from CMCON<7:6>, to determine the actual change that occurred. The CMIF bit (PIR2<6>) is the Comparator Interrupt Flag. The CMIF bit must be reset by clearing it. Since it is also possible to write a `1' to this register, a simulated interrupt may be initiated. Both the CMIE bit (PIE2<6>) and the PEIE bit (INTCON<6>) must be set to enable the interrupt. In addition, the GIE bit (INTCON<7>) must also be set. If any of these bits are clear, the interrupt is not enabled, though the CMIF bit will still be set if an interrupt condition occurs. Note: If a change in the CMCON register (C1OUT or C2OUT) should occur when a read operation is being executed (start of the Q2 cycle), then the CMIF (PIR2<6>) interrupt flag may not get set.
Comparator Operation During Sleep
When a comparator is active and the device is placed in Sleep mode, the comparator remains active and the interrupt is functional, if enabled. This interrupt will wake-up the device from Sleep mode, when enabled. While the comparator is powered up, higher Sleep currents than shown in the power-down current specification will occur. Each operational comparator will consume additional current, as shown in the comparator specifications. To minimize power consumption while in Sleep mode, turn off the comparators (CM2:CM0 = 111) before entering Sleep. If the device wakes up from Sleep, the contents of the CMCON register are not affected.
19.8
Effects of a Reset
The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) b) Any read or write of CMCON will end the mismatch condition. Clear flag bit, CMIF.
A device Reset forces the CMCON register to its Reset state, causing the comparator module to be in the Comparator Reset mode (CM2:CM0 = 000). This ensures that all potential inputs are analog inputs. Device current is minimized when analog inputs are present at Reset time. The comparators are powered down during the Reset interval.
A mismatch condition will continue to set flag bit, CMIF. Reading CMCON will end the mismatch condition and allow flag bit, CMIF, to be cleared.
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19.9 Analog Input Connection Considerations
range by more than 0.6V in either direction, one of the diodes is forward biased and a latch-up condition may occur. A maximum source impedance of 10 k is recommended for the analog sources. Any external component connected to an analog input pin, such as a capacitor or a Zener diode, should have very little leakage current.
A simplified circuit for an analog input is shown in Figure 19-4. Since the analog pins are connected to a digital output, they have reverse biased diodes to VDD and VSS. The analog input, therefore, must be between VSS and VDD. If the input voltage deviates from this
FIGURE 19-4:
COMPARATOR ANALOG INPUT MODEL
VDD RS < 10k AIN VT = 0.6V RIC Comparator Input CPIN 5 pF VT = 0.6V ILEAKAGE 500 nA
VA
VSS Legend: CPIN VT ILEAKAGE RIC RS VA = = = = = = Input Capacitance Threshold Voltage Leakage Current at the pin due to various junctions Interconnect Resistance Source Impedance Analog Voltage
TABLE 19-1:
Name CMCON CVRCON INTCON PIR2 PIE2 IPR2 PORTF LATF TRISF
REGISTERS ASSOCIATED WITH COMPARATOR MODULE
Bit 7 C2OUT CVREN OSCFIF OSCFIE OSCFIP Bit 6 C1OUT CVROE CMIF CMIE CMIP Bit 5 C2INV CVRR TMR0IE -- -- -- Bit 4 C1INV CVRSS INT0IE -- -- -- Bit 3 CIS CVR3 RBIE BCLIF BCLIE BCLIP Bit 2 CM2 CVR2 TMR0IF HLVDIF HLVDIE HLVDIP Bit 1 CM1 CVR1 INT0IF TMR3IF TMR3IE TMR3IP Bit 0 CM0 CVR0 RBIF CCP2IF CCP2IE CCP2IP Reset Values on Page 61 61 59 61 61 61 62 62 62
GIE/GIEH PEIE/GIEL
Read PORTF pins, Write LATF Latch LATF Data Output Register PORTF Data Direction Register
Legend: -- = unimplemented, read as `0'. Shaded cells are unused by the comparator module.
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20.0 COMPARATOR VOLTAGE REFERENCE MODULE
used is selected by the CVRR bit (CVRCON<5>). The primary difference between the ranges is the size of the steps selected by the CVREF selection bits (CVR3:CVR0), with one range offering finer resolution. The equations used to calculate the output of the comparator voltage reference are as follows: If CVRR = 1: CVREF = ((CVR3:CVR0)/24) x CVRSRC If CVRR = 0: CVREF = (CVDD x 1/4) + (((CVR3:CVR0)/32) x CVRSRC) The comparator reference supply voltage can come from either VDD and VSS, or the external VREF+ and VREF- that are multiplexed with RA2 and RA3. The voltage source is selected by the CVRSS bit (CVRCON<4>). The settling time of the comparator voltage reference must be considered when changing the CVREF output (see Table 26-3 in Section 26.0 "Electrical Characteristics").
The comparator voltage reference is a 16-tap resistor ladder network that provides a selectable reference voltage. Although its primary purpose is to provide a reference for the analog comparators, it may also be used independently of them. A block diagram of the module is shown in Figure 20-1. The resistor ladder is segmented to provide two ranges of CVREF values and has a power-down function to conserve power when the reference is not being used. The module's supply reference can be provided from either device VDD/VSS, or an external voltage reference.
20.1
Configuring the Comparator Voltage Reference
The voltage reference module is controlled through the CVRCON register (Register 20-1). The comparator voltage reference provides two ranges of output voltage, each with 16 distinct levels. The range to be
REGISTER 20-1:
R/W-0 CVREN bit 7 Legend: R = Readable bit -n = Value at POR bit 7
CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER
R/W-0 CVRR R/W-0 CVRSS R/W-0 CVR3 R/W-0 CVR2 R/W-0 CVR1 R/W-0 CVR0 bit 0
R/W-0 CVROE(1)
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
CVREN: Comparator Voltage Reference Enable bit 1 = CVREF circuit powered on 0 = CVREF circuit powered down CVROE: Comparator VREF Output Enable bit(1) 1 = CVREF voltage level is also output on the RF5/AN10/CVREF/SEG23 pin 0 = CVREF voltage is disconnected from the RF5/AN10/CVREF/SEG23 pin CVRR: Comparator VREF Range Selection bit 1 = 0.00 CVRSRC to 0.75 CVRSRC, with CVRSRC/24 step size 0 = 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size CVRSS: Comparator VREF Source Selection bit 1 = Comparator reference source, CVRSRC = (VREF+) - (VREF-) 0 = Comparator reference source, CVRSRC = VDD - VSS CVR3:CVR0: Comparator VREF Value Selection bits (0 (CVR3:CVR0) 15) When CVRR = 1: CVREF = ((CVR3:CVR0)/24) * (CVRSRC) When CVRR = 0: CVREF = (CVRSRC/4) + ((CVR3:CVR0)/32) * (CVRSRC) CVROE overrides the TRISF<5> bit setting if enabled for output; RF5 must also be configured as an input by setting TRISF<5> to `1'.
bit 6
bit 5
bit 4
bit 3-0
Note 1:
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FIGURE 20-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
VREF+ VDD CVRSS = 1
CVRSS = 0
8R R R R
CVR3:CVR0
CVREN
16 Steps
16-to-1 MUX
R
CVREF
R R R CVRR VREFCVRSS = 1
8R
CVRSS = 0
20.2
Voltage Reference Accuracy/Error
20.4
Effects of a Reset
The full range of voltage reference cannot be realized due to the construction of the module. The transistors on the top and bottom of the resistor ladder network (Figure 20-1) keep CVREF from approaching the reference source rails. The voltage reference is derived from the reference source; therefore, the CVREF output changes with fluctuations in that source. The tested absolute accuracy of the voltage reference can be found in Section 26.0 "Electrical Characteristics".
A device Reset disables the voltage reference by clearing bit, CVREN (CVRCON<7>). This Reset also disconnects the reference from the RA2 pin by clearing bit, CVROE (CVRCON<6>), and selects the high-voltage range by clearing bit, CVRR (CVRCON<5>). The CVR value select bits are also cleared.
20.5
Connection Considerations
20.3
Operation During Sleep
When the device wakes up from Sleep through an interrupt or a Watchdog Timer time-out, the contents of the CVRCON register are not affected. To minimize current consumption in Sleep mode, the voltage reference should be disabled.
The voltage reference module operates independently of the comparator module. The output of the reference generator may be connected to the RF5 pin if the TRISF<5> bit and the CVROE bit are both set. Enabling the voltage reference output onto the RF5 pin, with an input signal present, will increase current consumption. Connecting RF5 as a digital output with CVRSS enabled will also increase current consumption. The RF5 pin can be used as a simple D/A output with limited drive capability. Due to the limited current drive capability, a buffer must be used on the voltage reference output for external connections to VREF. Figure 20-2 shows an example buffering technique.
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FIGURE 20-2: VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
PIC18FXXXX
CVREF Module R(1) Voltage Reference Output Impedance RF5
+ -
CVREF Output
Note 1:
R is dependent upon the voltage reference configuration bits, CVRCON<3:0> and CVRCON<5>.
TABLE 20-1:
Name CVRCON CMCON TRISF
REGISTERS ASSOCIATED WITH THE COMPARATOR VOLTAGE REFERENCE
Bit 7 CVREN C2OUT Bit 6 CVROE C1OUT Bit 5 CVRR C2INV Bit 4 CVRSS C1INV Bit 3 CVR3 CIS Bit 2 CVR2 CM2 Bit 1 CVR1 CM1 Bit 0 CVR0 CM0 Reset Values on Page 61 61 62
PORTF Data Direction Register
Legend: Shaded cells are not used with the comparator voltage reference.
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21.0 HIGH/LOW-VOLTAGE DETECT (HLVD)
The High/Low-Voltage Detect Control register (Register 21-1) completely controls the operation of the HLVD module. This allows the circuitry to be "turned off" by the user under software control, which minimizes the current consumption for the device. The block diagram for the HLVD module is shown in Figure 21-1.
PIC18F6390/6490/8390/8490 devices have a High/Low-Voltage Detect module (HLVD). This is a programmable circuit that allows the user to specify both a device voltage trip point and the direction of change from that point. If the device experiences an excursion past the trip point in that direction, an interrupt flag is set. If the interrupt is enabled, the program execution will branch to the interrupt vector address and the software can then respond to the interrupt.
REGISTER 21-1:
R/W-0 VDIRMAG bit 7 Legend: R = Readable bit -n = Value at POR bit 7
HLVDCON: HIGH/LOW-VOLTAGE DETECT CONTROL REGISTER
U-0 -- R-0 IRVST R/W-0 HLVDEN R/W-0 HLVDL3(1) R/W-1 HLVDL2(1) R/W-0 HLVDL1(1) R/W-1 HLVDL0(1) bit 0
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
VDIRMAG: Voltage Direction Magnitude Select bit 1 = Event occurs when voltage equals or exceeds trip point (HLVDL3:HLVDL0) 0 = Event occurs when voltage equals or falls below trip point (HLVDL3:HLVDL0) Unimplemented: Read as `0' IRVST: Internal Reference Voltage Stable Flag bit 1 = Indicates that the voltage detect logic will generate the interrupt flag at the specified voltage range 0 = Indicates that the voltage detect logic will not generate the interrupt flag at the specified voltage range and the HLVD interrupt should not be enabled HLVDEN: High/Low-Voltage Detect Power Enable bit 1 = HLVD enabled 0 = HLVD disabled HLVDL3:HLVDL0: Voltage Detection Limit bits(1) 1111 = External analog input is used (input comes from the HLVDIN pin) 1110 = 4.41V-4.87V 1101 = 4.11V-4.55V 1100 = 3.92V-4.34V 1011 = 3.72V-4.12V 1010 = 3.53V-3.91V 1001 = 3.43V-3.79V 1000 = 3.24V-3.58V 0111 = 2.95V-3.26V 0110 = 2.75V-3.03V 0101 = 2.64V-2.92V 0100 = 2.43V-2.69V 0011 = 2.35V-2.59V 0010 = 2.16V-2.38V 0001 = 1.96V-2.16V 0000 = Reserved HLVDL3:HLVDL0 modes that result in a trip point below the valid operating voltage of the device are not tested.
bit 6 bit 5
bit 4
bit 3-0
Note 1:
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The module is enabled by setting the HLVDEN bit. Each time that the HLVD module is enabled, the circuitry requires some time to stabilize. The IRVST bit is a read-only bit and is used to indicate when the circuit is stable. The module can only generate an interrupt after the circuit is stable and IRVST is set. The VDIRMAG bit determines the overall operation of the module. When VDIRMAG is cleared, the module monitors for drops in VDD below a predetermined set point. When the bit is set, the module monitors for rises in VDD above the set point. event, depending on the configuration of the module. When the supply voltage is equal to the trip point, the voltage tapped off of the resistor array is equal to the internal reference voltage generated by the voltage reference module. The comparator then generates an interrupt signal by setting the HLVDIF bit. The trip point voltage is software programmable to any one of 16 values. The trip point is selected by programming the HLVDL3:HLVDL0 bits (HLVDCON<3:0>). The HLVD module has an additional feature that allows the user to supply the trip voltage to the module from an external source. This mode is enabled when bits, HLVDL3:HLVDL0, are set to `1111'. In this state, the comparator input is multiplexed from the external input pin, HLVDIN. This gives users flexibility because it allows them to configure the High/Low-Voltage Detect interrupt to occur at any voltage in the valid operating range.
21.1
Operation
When the HLVD module is enabled, a comparator uses an internally generated reference voltage as the set point. The set point is compared with the trip point where each node in the resistor divider represents a trip point voltage. The "trip point" voltage is the voltage level at which the device detects a high or low-voltage
FIGURE 21-1:
HLVD MODULE BLOCK DIAGRAM (WITH EXTERNAL INPUT)
Externally Generated Trip Point VDD VDD HLVDL3:HLVDL0 HLVDCON Register VDIRMAG
HLVDIN
HLVDIN
HLVDEN
16-to-1 MUX
Set HLVDIF
HLVDEN
BOREN
Internal Voltage Reference
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21.2 HLVD Setup
The following steps are needed to set up the HLVD module: 1. 2. 3. 4. 5. 6. Disable the module by clearing the HLVDEN bit (HLVDCON<4>). Write the value to the HLVDL3:HLVDL0 bits that selects the desired HLVD trip point. Set the VDIRMAG bit to detect high voltage (VDIRMAG = 1) or low voltage (VDIRMAG = 0). Enable the HLVD module by setting the HLVDEN bit. Clear the HLVD interrupt flag (PIR2<2>), which may have been set from a previous interrupt. Enable the HLVD interrupt, if interrupts are desired, by setting the HLVDIE and GIE bits (PIE<2> and INTCON<7>). An interrupt will not be generated until the IRVST bit is set. Depending on the application, the HLVD module does not need to be operating constantly. To decrease the current requirements, the HLVD circuitry may only need to be enabled for short periods where the voltage is checked. After doing the check, the HLVD module may be disabled.
21.4
HLVD Start-up Time
The internal reference voltage of the HLVD module, specified in electrical specification parameter #D423, may be used by other internal circuitry, such as the programmable Brown-out Reset. If the HLVD or other circuits using the voltage reference are disabled to lower the device's current consumption, the reference voltage circuit will require time to become stable before a low or high-voltage condition can be reliably detected. This start-up time, TIRVST, is an interval that is independent of device clock speed. It is specified in electrical specification parameter 36 (Table 26-10). The HLVD interrupt flag is not enabled until TIRVST has expired and a stable reference voltage is reached. For this reason, brief excursions beyond the set point may not be detected during this interval. Refer to Figure 21-2 or Figure 21-3.
21.3
Current Consumption
When the module is enabled, the HLVD comparator and voltage divider are enabled and will consume static current. The total current consumption, when enabled, is specified in electrical specification parameter #D022B.
FIGURE 21-2:
CASE 1: VDD
LOW-VOLTAGE DETECT OPERATION (VDIRMAG = 0)
HLVDIF may not be set
VLVD HLVDIF Enable HLVD IRVST TIRVST Internal Reference is stable CASE 2: VDD VLVD HLVDIF Enable HLVD IRVST Internal Reference is stable HLVDIF cleared in software HLVDIF cleared in software, HLVDIF remains set since HLVD condition still exists TIRVST HLVDIF cleared in software
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FIGURE 21-3:
CASE 1:
HIGH-VOLTAGE DETECT OPERATION (VDIRMAG = 1)
HLVDIF may not be set VLVD VDD
HLVDIF Enable HLVD IRVST TIRVST HLVDIF cleared in software Internal Reference is stable CASE 2: VLVD VDD HLVDIF Enable HLVD IRVST Internal Reference is stable HLVDIF cleared in software HLVDIF cleared in software, HLVDIF remains set since HLVD condition still exists TIRVST
21.5
Applications
FIGURE 21-4:
For general battery applications, Figure 21-4 shows a possible voltage curve. Over time, the device voltage decreases. When the device voltage reaches voltage, VA, the HLVD logic generates an interrupt at time, TA. The interrupt could cause the execution of an ISR, which would allow the application to perform "housekeeping tasks" and perform a controlled shutdown before the device voltage exits the valid operating range at TB. The HLVD, thus, would give the application a time window, represented by the difference between TA and TB, to safely exit.
Voltage
In many applications, the ability to detect a drop below, or rise above a particular threshold, is desirable. For example, the HLVD module could be periodically enabled to detect USB attach or detach. This assumes the device is powered by a lower voltage source than the Universal Serial Bus when detached. An attach would indicate a high-voltage detect from, for example, 3.3V to 5V (the voltage on USB) and vice versa for a detach. This feature could save a design a few extra components and an attach signal (input pin).
TYPICAL LOW-VOLTAGE DETECT APPLICATION
VA VB
Time
TA
TB
Legend: VA = HLVD trip point VB = Minimum valid device operating voltage
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21.6 Operation During Sleep 21.7 Effects of a Reset
When enabled, the HLVD circuitry continues to operate during Sleep. If the device voltage crosses the trip point, the HLVDIF bit will be set and the device will wake-up from Sleep. Device execution will continue from the interrupt vector address if interrupts have been globally enabled. A device Reset forces all registers to their Reset state. This forces the HLVD module to be turned off.
TABLE 21-1:
Name HLVDCON INTCON PIR2 PIE2 IPR2
REGISTERS ASSOCIATED WITH HIGH/LOW-VOLTAGE DETECT MODULE
Bit 7 Bit 6 -- CMIF CMIE CMIP Bit 5 IRVST TMR0IE -- -- -- Bit 4 HLVDEN INT0IE -- -- -- Bit 3 HLVDL3 RBIE BCLIF BCLIE BCLIP Bit 2 HLVDL2 TMR0IF HLVDIF HLVDIE HLVDIP Bit 1 HLVDL1 INT0IF TMR3IF TMR3IE TMR3IP Bit 0 HLVDL0 RBIF CCP2IF CCP2IE CCP2IP Reset Values on Page 60 59 61 61 61
VDIRMAG OSCFIF OSCFIE OSCFIP
GIE/GIEH PEIE/GIEL
Legend: -- = unimplemented, read as `0'. Shaded cells are unused by the HLVD module.
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22.0 LIQUID CRYSTAL DISPLAY (LCD) DRIVER MODULE
The LCD driver module supports: * Direct driving of LCD panel * Three LCD clock sources with selectable prescaler * Up to four commons: - Static - 1/2 multiplex - 1/3 multiplex - 1/4 multiplex * Up to 48 (in 80-pin devices)/32 (in 64-pin devices) segments * Static, 1/2 or 1/3 LCD bias A simplified block diagram of the module is shown in Figure 22-1.
The Liquid Crystal Display (LCD) driver module generates the timing control to drive a static or multiplexed LCD panel. In the 80-pin devices (PIC18F8390/8490), the module drives the panels of up to four commons and up to 48 segments and in the 64-pin devices (PIC18F6390/6490), the module drives the panels of up to four commons and up to 32 segments. It also provides control of the LCD pixel data.
FIGURE 22-1:
LCD DRIVER MODULE BLOCK DIAGRAM
Data Bus
LCDDATAx Registers 24 x 8 (= 4 x 48)
192-to-48 MUX
SE<47:0> To I/O Pads
Timing Control LCDCON LCDPS LCDSEx COM3:COM0 To I/O Pads
FOSC/4 T13CKI INTRC Oscillator Clock Source Select and Prescaler
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22.1 LCD Registers
The LCD driver module has 32 registers: * LCD Control Register (LCDCON) * LCD Phase Register (LCDPS) * Six LCD Segment Enable Registers (LCDSE5:LCDSE0) * 24 LCD Data Registers (LCDDATA23:LCDDATA0) The LCDCON register, shown in Register 22-1, controls the overall operation of the module. Once the module is configured, the LCDEN (LCDCON<7>) bit is used to enable or disable the LCD module. The LCD panel can also operate during Sleep by clearing the SLPEN (LCDCON<6>) bit. The LCDPS register, shown in Register 22-2, configures the LCD clock source prescaler and the type of waveform, Type-A or Type-B. Details on these features are provided in Section 22.2 "LCD Clock Source Selection", Section 22.3 "LCD Bias Types" and Section 22.8 "LCD Waveform Generation".
REGISTER 22-1:
R/W-0 LCDEN bit 7 Legend: R = Readable bit -n = Value at POR bit 7
LCDCON: LCD CONTROL REGISTER
R/C-0 WERR U-0 -- R/W-0 CS1 R/W-0 CS0 R/W-0 LMUX1 R/W-0 LMUX0 bit 0 C = Clearable Only bit W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
R/W-0 SLPEN
LCDEN: LCD Driver Enable bit 1 = LCD driver module is enabled 0 = LCD driver module is disabled SLPEN: LCD Driver Enable in Sleep mode bit 1 = LCD driver module is disabled in Sleep mode 0 = LCD driver module is enabled in Sleep mode WERR: LCD Write Failed Error bit 1 = LCDDATAx register written while LCDPS = 0 (must be cleared in software) 0 = No LCD write error Unimplemented: Read as `0' CS1:CS0: Clock Source Select bits 00 = (FOSC/4)/8192 01 = T13CKI (Timer1)/32 1x = INTRC (31.25 kHz)/32 LMUX1:LMUX0: Commons Select bits Maximum Maximum Number of Number of Pixels Pixels (PIC18F6X90) (PIC18F8X90) 32 64 96 128 48 96 144 192
bit 6
bit 5
bit 4 bit 3-2
bit 1-0
LMUX1:LMUX0
Multiplex Static (COM0) 1/2 (COM1:COM0) 1/3 (COM2:COM0) 1/4 (COM3:COM0)
Bias Static 1/2 or 1/3 1/2 or 1/3 1/3
00 01 10 11
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REGISTER 22-2:
R/W-0 WFT bit 7 Legend: R = Readable bit -n = Value at POR bit 7 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
LCDPS: LCD PHASE REGISTER
R-0 LCDA R-0 WA R/W-0 LP3 R/W-0 LP2 R/W-0 LP1 R/W-0 LP0 bit 0
R/W-0 BIASMD
WFT: Waveform Type Select bit 1 = Type-B waveform (phase changes on each frame boundary) 0 = Type-A waveform (phase changes within each common type) BIASMD: Bias Mode Select bit When LMUX1:LMUX0 = 00: 0 = Static Bias mode (do not set this bit to `1') When LMUX1:LMUX0 = 01: 1 = 1/2 Bias mode 0 = 1/3 Bias mode When LMUX1:LMUX0 = 10: 1 = 1/2 Bias mode 0 = 1/3 Bias mode When LMUX1:LMUX0 = 11: 0 = 1/3 Bias mode (do not set this bit to `1') LCDA: LCD Active Status bit 1 = LCD driver module is active 0 = LCD driver module is inactive WA: LCD Write Allow Status bit 1 = Write into the LCDDATAx registers is allowed 0 = Write into the LCDDATAx registers is not allowed LP3:LP0: LCD Prescaler Select bits 1111 = 1:16 1110 = 1:15 1101 = 1:14 1100 = 1:13 1011 = 1:12 1010 = 1:11 1001 = 1:10 1000 = 1:9 0111 = 1:8 0110 = 1:7 0101 = 1:6 0100 = 1:5 0011 = 1:4 0010 = 1:3 0001 = 1:2 0000 = 1:1
bit 6
bit 5
bit 4
bit 3-0
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The LCDSE5:LCDSE0 registers configure the functions of the port pins. Setting the segment enable bit for a particular segment configures that pin as an LCD driver. There are six LCD Segment Enable registers listed in Table 22-1. The prototype LCDSEx register is shown in Register 22-3. Once the module is initialized for the LCD panel, the individual bits of the LCDDATA23:LCDDATA0 registers are cleared or set to represent a clear or dark pixel, respectively. Specific sets of LCDDATA registers are used with specific segments and common signals. Each bit represents a unique combination of a specific segment connected to a specific common. Individual LCDDATA bits are named by the convention "SxxCy", with "xx" as the segment number and "y" as the common number. The relationship is summarized in Table 22-2. The prototype LCDDATAx register is shown in Register 22-4. Note: Writing into the registers, LCDDATA4, LCDDATA5, LCDDATA10, LCDDATA11, LCDDATA16, LCDDATA17, LCDDATA22 and LCDDATA23, in PIC18F6X90 devices will not affect the status of any pixel and these registers can be used as General Purpose Registers.
TABLE 22-1:
LCDSE REGISTERS AND ASSOCIATED SEGMENTS
Segments 7:0 15:8 23:16 31:24 39:32 47:40
Register LCDSE0 LCDSE1 LCDSE2 LCDSE3 LCDSE4 LCDSE5 . Note:
The LCDSE5:LCDSE4 registers are not implemented in PIC18F6X90 devices.
REGISTER 22-3:
R/W-0 SE(n + 7) bit 7 Legend: R = Readable bit -n = Value at POR bit 7-0
LCDSEx: LCD SEGMENTx ENABLE REGISTER
R/W-0 SE(n + 5) R/W-0 SE(n + 4) R/W-0 SE(n + 3) R/W-0 SE(n + 2) R/W-0 SE(n + 1) R/W-0 SE(n) bit 0
R/W-0 SE(n + 6)
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
SE(n + 7):SE(n): Segment Enable bits For LCDSE0: n = 0 For LCDSE1: n = 8 For LCDSE2: n = 16 For LCDSE3: n = 24 For LCDSE4: n = 32 For LCDSE5: n = 40 1 = Segment function of the pin is enabled, digital I/O is disabled 0 = I/O function of the pin is enabled
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TABLE 22-2:
Segments
LCDDATA REGISTERS AND BITS FOR SEGMENT AND COM COMBINATIONS
COM Lines 0 LCDDATA0 S00C0:S07C0 LCDDATA1 S08C0:S15C0 LCDDATA2 S16C0:S23C0 LCDDATA3 S24C0:S31C0 LCDDATA4(1) S32C0:S39C0 LCDDATA5(1) S40C0:S47C0 1 LCDDATA6 S00C1:S07C1 LCDDATA7 S08C1:S15C1 LCDDATA8 S16C1:S23C1 LCDDATA9 S24C1:S31C1 LCDDATA10(1) S32C1:S39C1 LCDDATA11(1) S40C1:S47C1 2 LCDDATA12 S00C2:S07C2 LCDDATA13 S08C2:S15C2 LCDDATA14 S16C2:S23C2 LCDDATA15 S24C2:S31C2 LCDDATA16(1) S32C2:S39C2 LCDDATA17(1) S40C2:S47C2 3 LCDDATA18 S00C3:S07C3 LCDDATA19 S08C0:S15C3 LCDDATA20 S16C3:S23C3 LCDDATA21 S24C3:S31C3 LCDDATA22(1) S32C3:S39C3 LCDDATA23(1) S40C3:S47C3
0 through 7 8 through 15 16 through 23 24 through 31 32 through 39 40 through 47 Note 1:
These registers are implemented but not used as LCD data registers in 64-pin devices. They may be used as general purpose data memory.
REGISTER 22-4:
R/W-0 S(n + 7)Cy bit 7 Legend: R = Readable bit -n = Value at POR bit 7-0
LCDDATAx: LCD DATAx REGISTER
R/W-0 S(n + 5)Cy R/W-0 S(n + 4)Cy R/W-0 S(n + 3)Cy R/W-0 S(n + 2)Cy R/W-0 S(n + 1)Cy R/W-0 S(n)Cy bit 0
R/W-0 S(n + 6)Cy
W = Writable bit `1' = Bit is set
U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
S(n + 7)Cy:S(n)Cy: Pixel On bits For LCDDATA0 through LCDDATA5: n = (8x), y = 0 For LCDDATA6 through LCDDATA11: n = (8(x - 6)), y = 1 For LCDDATA12 through LCDDATA17: n = (8(x - 12)), y = 2 For LCDDATA18 through LCDDATA23: n = (8(x - 18)), y = 3 1 = Pixel on (dark) 0 = Pixel off (clear)
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22.2 LCD Clock Source Selection
The LCD driver module has 3 possible clock sources: * (FOSC/4)/8192 * T13CKI Clock/32 * INTRC/32 The first clock source is the system clock divided by 8192 ((FOSC/4)/8192). This divider ratio is chosen to provide about 1 kHz output when the system clock is 8 MHz. The divider is not programmable. Instead, the LCD prescaler bits, LCDPS<3:0>, are used to set the LCD frame clock rate. The second clock source is the Timer1 oscillator/32. This also gives about 1 kHz when a 32.768 kHz crystal is used with the Timer1 oscillator. To use the Timer1 oscillator as a clock source, the T1OSCEN (T1CON<3>) bit should be set. The third clock source is a 31.25 kHz internal RC oscillator/32, which provides approximately 1 kHz output. The second and third clock sources may be used to continue running the LCD while the processor is in Sleep. Using the bits, CS1:CS0 (LCDCON<3:2>), any of these clock sources can be selected.
22.2.1
LCD PRESCALER
A 16-bit counter is available as a prescaler for the LCD clock. The prescaler is not directly readable or writable; its value is set by the LP3:LP0 bits (LCDPS<3:0>), which determine the prescaler assignment and prescale ratio. The prescale values from 1:1 through 1:32768 in power-of-2 increments are selectable.
FIGURE 22-2:
LCD CLOCK GENERATION
COM0 COM1 COM2 COM3
System Clock (FOSC/4) TMR1 32 kHz Crystal Oscillator Internal RC Oscillator Nom FRC = 31.25 kHz
/8192 /4 /32 /2 STAT DUP TRIP QUAD LP3:LP0 (LCDPS<3:0>) LMUX1:LMUX0 (LCDCON<1:0>) LMUX1:LMUX0 (LCDCON<1:0>) 4-Bit Prog Prescaler /1, 2, 3, 4 Ring Counter
/32
CS1:CS0 (LCDCON<3:2>)
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22.3 LCD Bias Types
The LCD driver module can be configured into three bias types: * Static Bias (2 voltage levels: AVSS and AVDD) * 1/2 Bias (3 voltage levels: AVSS, 1/2 AVDD and AVDD) * 1/3 Bias (4 voltage levels: AVSS, 1/3 AVDD, 2/3 AVDD and AVDD) This module uses an external resistor ladder to generate the LCD bias voltages. The external resistor ladder should be connected to the Bias 1 pin, Bias 2 pin, Bias 3 pin and VSS. The Bias 3 pin should also be connected to AVDD. Figure 22-3 shows the proper way to connect the resistor ladder to the Bias pins. If the pin is a digital I/O, the corresponding TRIS bit controls the data direction. If the pin is a COM drive, then the TRIS setting of that pin is overridden. Note: On a Power-on Reset, the LMUX1:LMUX0 bits are `00'.
TABLE 22-3:
LMUX1: LMUX0 00 01 10 11
PORTE<6:4> FUNCTION
PORTE<5> Digital I/O Digital I/O PORTE<4> Digital I/O COM1 Driver
PORTE<6> Digital I/O Digital I/O Digital I/O
COM2 Driver COM1 Driver
COM3 Driver COM2 Driver COM1 Driver
22.5
Segment Enables
22.4
LCD Multiplex Types
The LCD driver module can be configured into four multiplex types: * * * * Static (only COM0 used) 1/2 multiplex (COM0 and COM1 are used) 1/3 multiplex (COM0, COM1 and COM2 are used) 1/4 multiplex (all COM0, COM1, COM2 and COM3 are used)
The LCDSEx registers are used to select the pin function for each segment pin. The selection allows each pin to operate as either an LCD segment driver or a digital only pin. To configure the pin as a segment pin, the corresponding bits in the LCDSEx registers must be set to `1'. If the pin is a digital I/O, the corresponding TRIS bit controls the data direction. Any bit set in the LCDSEx registers overrides any bit settings in the corresponding TRIS register. Note: On a Power-on Reset, these pins are configured as digital I/O.
The LMUX1:LMUX0 setting decides the function of the PORTE<6:4> bits (see Table 22-3 for details).
FIGURE 22-3:
LCD BIAS RESISTOR LADDER CONNECTION DIAGRAM
Static Bias VLCD 0 VLCD 3 To VLCD 2 LCD VLCD 1 Driver VLCD 0 VLCD 1 VLCD 2 VLCD 3 AVSS -- -- AVDD 1/2 Bias 1/3 Bias AVSS AVSS
1/2 AVDD 1/3 AVDD 1/2 AVDD 2/3 AVDD AVDD AVDD
LCD Bias 3 AVDD* AVDD* 10 k*
LCD Bias 2
LCD Bias 1
Connections for External R-ladder Static Bias 1/2 Bias AVSS
10 k*
AVDD*
10 k*
10 k*
10 k* AVSS
1/3 Bias
* These values are provided for design guidance only and should be optimized for the application by the designer.
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22.6 Pixel Control 22.8 LCD Waveform Generation
The LCDDATAx registers contain bits which define the state of each pixel. Each bit defines one unique pixel. Table 22-2 shows the correlation of each bit in the LCDDATAx registers to the respective common and segment signals. Any LCD pixel location not being used for display can be used as general purpose RAM. LCD waveform generation is based on the philosophy that the net AC voltage across the dark pixel should be maximized and the net AC voltage across the clear pixel should be minimized. The net DC voltage across any pixel should be zero. The COM signal represents the time slice for each common, while the SEG contains the pixel data. The pixel signal (COM-SEG) will have no DC component and it can take only one of the two rms values. The higher rms value will create a dark pixel and a lower rms value will create a clear pixel. As the number of commons increases, the delta between the two rms values decreases. The delta represents the maximum contrast that the display can have. The LCDs can be driven by two types of waveform: Type-A and Type-B. In Type-A waveform, the phase changes within each common type, whereas in Type-B waveform, the phase changes on each frame boundary. Thus, Type-A waveform maintains 0 VDC over a single frame, whereas Type-B waveform takes two frames. Note 1: If Sleep has to be executed with LCD Sleep enabled (LCDCON is `1'), then care must be taken to execute Sleep only when VDC on all the pixels is `0'. 2: When the LCD clock source is (FOSC/4)/8192, if Sleep is executed irrespective of the LCDCON setting, the LCD goes into Sleep. Thus, take care to see that VDC on all pixels is `0' when Sleep is executed. Figure 22-4 through Figure 22-14 provide waveforms for static, half-multiplex, one-third-multiplex and quarter-multiplex drives for Type-A and Type-B waveforms.
22.7
LCD Frame Frequency
The rate at which the COM and SEG outputs changes is called the LCD frame frequency
TABLE 22-4:
Multiplex Static 1/2 1/3 1/4 Note:
FRAME FREQUENCY FORMULAS
Frame Frequency = Clock Source/(4 x 1 x (LP3:LP0 + 1)) Clock Source/(2 x 2 x (LP3:LP0 + 1)) Clock Source/(1 x 3 x (LP3:LP0 + 1)) Clock Source/(1 x 4 x (LP3:LP0 + 1))
Clock source is (FOSC/4)/8192, Timer1 Osc/32 or INTRC/32.
TABLE 22-5:
APPROXIMATE FRAME FREQUENCY (IN Hz) USING FOSC @ 32 MHz, TIMER1 @ 32.768 kHz OR INTRC OSCILLATOR
Static 125 83 62 50 42 36 31 1/2 125 83 62 50 42 36 31 1/3 167 111 83 67 56 48 42 1/4 125 83 62 50 42 36 31
LP3:LP0 1 2 3 4 5 6 7
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FIGURE 22-4: TYPE-A/TYPE-B WAVEFORMS IN STATIC DRIVE
COM0 COM0
V1 V0
V1 SEG0 V0
SEG1
V1 V0
SEG7 SEG6 SEG5 SEG4 SEG3
SEG2
SEG1 SEG0
V1 COM0-SEG0 V0 -V1
COM0-SEG1
V0
1 Frame
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FIGURE 22-5: TYPE-A WAVEFORMS IN 1/2 MUX, 1/2 BIAS DRIVE
V2 COM0 COM1 V1 V0
COM0
V2 COM1 V1 V0
V2 SEG0 V1 V0
V2 SEG3 SEG2 SEG1 SEG0 SEG1 V1 V0
V2 V1 COM0-SEG0 V0 -V1 -V2
V2 V1 COM0-SEG1 V0 -V1 -V2 1 Frame
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FIGURE 22-6: TYPE-B WAVEFORMS IN 1/2 MUX, 1/2 BIAS DRIVE
V2 COM1 COM0 V1 V0 COM0 V2 COM1 V1 V0
SEG0
V2 V1 V0
SEG3
SEG2
SEG1
SEG0
SEG1
V2 V1 V0
V2 V1 COM0-SEG0 V0 -V1 -V2
V2 V1 COM0-SEG1 V0 -V1 -V2 2 Frames
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FIGURE 22-7: TYPE-A WAVEFORMS IN 1/2 MUX, 1/3 BIAS DRIVE
V3 COM0 COM1 V2 V1 V0 COM0 COM1 V3 V2 V1 V0 V3 SEG0 V2 V1 V0 V3 SEG3 SEG2 SEG1 SEG0 SEG1 V2 V1 V0
V3 V2 V1 COM0-SEG0 V0 -V1 -V2 -V3
V3 V2 V1 COM0-SEG1 V0 -V1 -V2 1 Frame -V3
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FIGURE 22-8: TYPE-B WAVEFORMS IN 1/2 MUX, 1/3 BIAS DRIVE
V3 COM0 COM1 V2 V1 V0 COM0 COM1 V3 V2 V1 V0 V3 SEG0 V2 V1 V0 V3 SEG3 SEG2 SEG1 SEG0 SEG1 V2 V1 V0
V3 V2 V1 COM0-SEG0 V0 -V1 -V2 -V3
V3 V2 V1 COM0-SEG1 V0 -V1 -V2 2 Frames -V3
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FIGURE 22-9: TYPE-A WAVEFORMS IN 1/3 MUX, 1/2 BIAS DRIVE
V2 COM0 V1 V0
COM2 COM1 COM1 COM0 COM2
V2 V1 V0 V2 V1 V0
V2 SEG0 SEG2 V1 V0 SEG2 SEG1 SEG0
V2 SEG1 V1 V0
V2 V1 COM0-SEG0 V0 -V1 -V2
V2 V1 COM0-SEG1 V0 -V1 -V2
1 Frame
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FIGURE 22-10: TYPE-B WAVEFORMS IN 1/3 MUX, 1/2 BIAS DRIVE
COM0
V2 V1 V0
COM2 COM1 COM1 COM0 V2 V1 V0
COM2
V2 V1 V0
SEG0 SEG2 SEG1 SEG0
V2 V1 V0
SEG1
V2 V1 V0
V2 V1 COM0-SEG0 V0 -V1 -V2
V2 V1 COM0-SEG1 V0 -V1 -V2
2 Frames
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FIGURE 22-11: TYPE-A WAVEFORMS IN 1/3 MUX, 1/3 BIAS DRIVE
V3 COM0 V2 V1 V0 COM2 COM1 COM1 COM0 V3 V2 V1 V0 V3 COM2 V2 V1 V0 V3 V2 SEG0 SEG2 SEG2 SEG1 SEG0 V1 V0 V3 SEG1 V2 V1 V0 V3 V2 V1 COM0-SEG0 V0 -V1 -V2 -V3 V3 V2 V1 COM0-SEG1 V0 -V1 -V2 -V3 1 Frame
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FIGURE 22-12: TYPE-B WAVEFORMS IN 1/3 MUX, 1/3 BIAS DRIVE
V3 COM0 V2 V1 V0 COM2 COM1 COM1 COM0 V3 V2 V1 V0 V3 COM2 V2 V1 V0 V3 SEG0 V2 V1 V0 V3 SEG1 V2 V1 V0 V3 V2 V1 COM0-SEG0 V0 -V1 -V2 -V3 V3 V2 V1 COM0-SEG1 V0 -V1 -V2 -V3 2 Frames
SEG2
SEG1
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SEG0
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FIGURE 22-13:
COM3 COM2 COM0
TYPE-A WAVEFORMS IN 1/4 MUX, 1/3 BIAS DRIVE
V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 -V1 -V2 -V3 V3 V2 V1 V0 -V1 -V2 -V3
COM1 COM0
COM1
COM2
COM3
SEG0 SEG1 SEG0
SEG1
COM0-SEG0
COM0-SEG1
1 Frame
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FIGURE 22-14:
COM3 COM2 COM0
TYPE-B WAVEFORMS IN 1/4 MUX, 1/3 BIAS DRIVE
V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 -V1 -V2 -V3 V3 V2 V1 V0 -V1 -V2 -V3
COM1 COM0
COM1
COM2
COM3
SEG0 SEG1 SEG0
SEG1
COM0-SEG0
COM0-SEG1
2 Frames
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22.9 LCD Interrupts
The LCD timing generation provides an interrupt that defines the LCD frame timing. This interrupt can be used to coordinate the writing of the pixel data with the start of a new frame. Writing pixel data at the frame boundary allows a visually crisp transition of the image. This interrupt can also be used to synchronize external events to the LCD. For example, the interface to an external segment driver can be synchronized for segment data update to the LCD frame. A new frame is defined to begin at the leading edge of the COM0 common signal. The interrupt will be set immediately after the LCD controller completes accessing all pixel data required for a frame. This will occur at a fixed interval before the frame boundary (TFINT), as shown in Figure 22-15. The LCD controller will begin to access data for the next frame within the interval from the interrupt to when the controller begins to access data after the interrupt (TFWR). New data must be written within TFWR, as this is when the LCD controller will begin to access the data for the next frame. When the LCD driver is running with Type-B waveforms and the LMUX1:LMUX0 bits are not equal to `00', there are some additional issues that must be addressed. Since the DC voltage on the pixel takes two frames to maintain zero volts, the pixel data must not change between subsequent frames. If the pixel data were allowed to change, the waveform for the odd frames would not necessarily be the complement of the waveform generated in the even frames and a DC component would be introduced into the panel. Therefore, when using Type-B waveforms, the user must synchronize the LCD pixel updates to occur within a subframe after the frame interrupt. To correctly sequence writing while in Type-B, the interrupt will only occur on complete phase intervals. If the user attempts to write when the write is disabled, the WERR (LCDCON<5>) bit is set. Note: The interrupt is not generated when the Type-A waveform is selected and when the Type-B with no multiplex (static) is selected.
FIGURE 22-15:
EXAMPLE WAVEFORMS AND INTERRUPT TIMING IN QUARTER-DUTY CYCLE DRIVE
LCD Interrupt Occurs Controller Accesses Next Frame Data V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0 V3 V2 V1 V0
COM0
COM1
COM2
COM3
2 Frames TFINT Frame Boundary TFWR = TFRAME/2*(LMUX1:LMUX0 + 1) + TCY/2 TFINT = (TFWR/2 - (2 TCY + 40 ns)) minimum = 1.5(TFRAME/4) - (2 TCY + 40 ns) (TFWR/2 - (1 TCY + 40 ns)) maximum = 1.5(TFRAME/4) - (1 TCY + 40 ns) Frame Boundary TFWR Frame Boundary
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22.10 Operation During Sleep
The LCD module can operate during Sleep. The selection is controlled by bit, SLPEN (LCDCON<6>). Setting the SLPEN bit allows the LCD module to go to Sleep. Clearing the SLPEN bit allows the module to continue to operate during Sleep. If a SLEEP instruction is executed and SLPEN = 1, the LCD module will cease all functions and go into a very low-current consumption mode. The module will stop operation immediately and drive the minimum LCD voltage on both segment and common lines. Figure 22-16 shows this operation. To ensure that no DC component is introduced on the panel, the SLEEP instruction should be executed immediately after a LCD frame boundary. The LCD interrupt can be used to determine the frame boundary. See Section 22.9 "LCD Interrupts" for the formulas to calculate the delay. If a SLEEP instruction is executed and SLPEN = 0, the module will continue to display the current contents of the LCDDATA registers. To allow the module to continue operation while in Sleep, the clock source must be either the internal RC oscillator or Timer1 external oscillator. While in Sleep, the LCD data cannot be changed. The LCD module current consumption will not decrease in this mode, however, the overall consumption of the device will be lower due to shut down of the core and other peripheral functions. If the system clock is selected and the module is programmed to not Sleep, the module will ignore the SLPEN bit and stop operation immediately. The minimum LCD voltage will then be driven onto the segments and commons. Note: The internal RC oscillator or external Timer1 oscillator must be used to operate the LCD module during Sleep.
FIGURE 22-16:
SLEEP ENTRY/EXIT WHEN SLPEN = 1 OR CS1:CS0 = 00
V3 V2 V1
COM0
V0 V3 V2 V1
COM1
V0 V3 V2 V1
COM2
V0 V3 V2 V1
SEG0
V0 2 Frames
SLEEP Instruction Execution
Wake-up
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22.11 Configuring the LCD Module
The following is the sequence of steps to configure the LCD module. 1. 2. 3. Select the frame clock prescale using bits, LP3:LP0 (LCDPS<3:0>). Configure the appropriate pins to function as segment drivers using the LCDSEx registers. Configure the LCD module for the following using the LCDCON register: - Multiplex and Bias mode, LMUX1:LMUX0 bits - Timing source, CS1:CS0 bits - Sleep mode, SLPEN bit 4. 5. Write initial values to Pixel Data registers, LCDDATA0 through LCDDATA23. Clear LCD Interrupt Flag, LCDIF (PIR3<6>), and if desired, enable the interrupt by setting bit, LCDIE (PIE3<6>). Enable the LCD module by setting bit, LCDEN (LCDCON<7>).
6.
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TABLE 22-6:
Name INTCON PIR3 PIE3 IPR3 RCON LCDDATA23(1) LCDDATA22(1) LCDDATA21 LCDDATA20 LCDDATA19 LCDDATA18 LCDDATA17
(1)
REGISTERS ASSOCIATED WITH LCD OPERATION
Bit 7 Bit 6 Bit 5 Bit 4 INT0IE TX2IF TX2IE TX2IP RI S44C3 S36C3 S28C3 S20C3 S12C3 S04C3 S44C2 S36C2 S28C2 S20C2 S12C2 S04C2 S44C1 S36C1 S28C1 S20C1 S12C1 S04C1 S44C0 S36C0 S28C0 S20C0 S12C0 S04C0 SE44 SE36 SE28 SE20 SE12 SE4 -- WA Bit 3 RBIE -- -- -- TO S43C3 S35C3 S27C3 S19C3 S11C3 S03C3 S43C2 S35C2 S27C2 S19C2 S11C2 S03C2 S43C1 S35C1 S27C1 S19C1 S11C1 S03C1 S43C0 S35C0 S27C0 S19C0 S11C0 S03C0 SE43 SE35 SE27 SE19 SE11 SE3 CS1 LP3 Bit 2 TMR0IF -- -- -- PD S42C3 S34C3 S26C3 S18C3 S10C3 S02C3 S42C2 S34C2 S26C2 S18C2 S10C2 S02C2 S42C1 S34C1 S26C1 S18C1 S10C1 S02C1 S42C0 S34C0 S26C0 S18C0 S10C0 S02C0 SE42 SE34 SE26 SE18 SE10 SE2 CS0 LP2 Bit 1 INT0IF -- -- -- POR S41C3 S33C3 S25C3 S17C3 S09C3 S01C3 S41C2 S33C2 S25C2 S17C2 S09C2 S01C2 S41C1 S33C1 S25C1 S17C1 S09C1 S01C1 S41C0 S33C0 S25C0 S17C0 S09C0 S01C0 SE41 SE33 SE25 SE17 SE9 SE1 LMUX1 LP1 Bit 0 RBIF -- -- -- BOR S40C3 S32C3 S24C3 S16C3 S08C3 S00C3 S40C2 S32C2 S24C2 S16C2 S08C2 S00C2 S40C1 S32C1 S24C1 S16C1 S08C1 S00C1 S40C0 S32C0 S24C0 S16C0 S08C0 S00C0 SE40 SE32 SE24 SE16 SE8 SE0 LMUX0 LP0 Reset Values on Page 59 61 61 61 60 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 64 64 64 64 64 64 64 64
GIE/GIEH PEIE/GIEL TMR0IE -- -- -- IPEN S47C3 S39C3 S31C3 S23C3 S15C3 S07C3 S47C2 S39C2 S31C2 S23C2 S15C2 S07C2 S47C1 S39C1 S31C1 S23C1 S15C1 S07C1 S47C0 S39C0 S31C0 S23C0 S15C0 S07C0 SE47 SE39 SE31 SE23 SE15 SE7 LCDEN WFT LCDIF LCDIE LCDIP SBOREN S46C3 S38C3 S30C3 S22C3 S14C3 S06C3 S46C2 S38C2 S30C2 S22C2 S14C2 S06C2 S46C1 S38C1 S30C1 S22C1 S14C1 S06C1 S46C0 S38C0 S30C0 S22C0 S14C0 S06C0 SE46 SE38 SE30 SE22 SE14 SE6 SLPEN BIASMD RC2IF RC2IE RC2IP -- S45C3 S37C3 S29C3 S21C3 S13C3 S05C3 S45C2 S37C2 S29C2 S21C2 S13C2 S05C2 S45C1 S37C1 S29C1 S21C1 S13C1 S05C1 S45C0 S37C0 S29C0 S21C0 S13C0 S05C0 SE45 SE37 SE29 SE21 SE13 SE5 WERR LCDA
LCDDATA16(1) LCDDATA15 LCDDATA14 LCDDATA13 LCDDATA12 LCDDATA11 LCDDATA9 LCDDATA8 LCDDATA7 LCDDATA6 LCDDATA5
(1) (1)
LCDDATA10(1)
LCDDATA4(1) LCDDATA3 LCDDATA2 LCDDATA1 LCDDATA0 LCDSE5
(2)
LCDSE4(2) LCDSE3 LCDSE2 LCDSE1 LCDSE0 LCDCON LCDPS
Legend: -- = unimplemented, read as `0'. Shaded cells are not used for A/D conversion. Note 1: These registers are implemented but unused on 64-pin devices and may be used as general purpose data RAM. 2: These registers are unimplemented on 64-pin devices.
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NOTES:
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23.0 SPECIAL FEATURES OF THE CPU
A complete discussion of device Resets and interrupts is available in previous sections of this data sheet. In addition to their Power-up and Oscillator Start-up Timers provided for Resets, PIC18F6390/6490/8390/ 8490 devices have a Watchdog Timer, which is either permanently enabled via the Configuration bits, or software controlled (if configured as disabled). The inclusion of an internal RC oscillator also provides the additional benefits of a Fail-Safe Clock Monitor (FSCM) and Two-Speed Start-up. FSCM provides for background monitoring of the peripheral clock and automatic switchover in the event of its failure. TwoSpeed Start-up enables code to be executed almost immediately on start-up, while the primary clock source completes its start-up delays. All of these features are enabled and configured by setting the appropriate Configuration register bits.
PIC18F6390/6490/8390/8490 devices include several features intended to maximize reliability and minimize cost through elimination of external components. These are: * Oscillator Selection * Resets: - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) * Interrupts * Watchdog Timer (WDT) * Fail-Safe Clock Monitor * Two-Speed Start-up * Code Protection * ID Locations * In-Circuit Serial ProgrammingTM (ICSPTM) The oscillator can be configured for the application depending on frequency, power, accuracy and cost. All of the options are discussed in detail in Section 2.0 "Oscillator Configurations".
23.1
Configuration Bits
The Configuration bits can be programmed (read as `0'), or left unprogrammed (read as `1'), to select various device configurations. These bits are mapped starting at program memory location 300000h. The user will note that address 300000h is beyond the user program memory space. In fact, it belongs to the configuration memory space (300000h-3FFFFFh), which can only be accessed using table reads.
TABLE 23-1:
File Name 300001h 300002h 300003h 300005h 300006h 300008h 3FFFFFh Legend: Note 1:
CONFIGURATION BITS AND DEVICE IDs
Bit 7 IESO -- -- MCLRE DEBUG -- DEV2 DEV10 Bit 6 FCMEN -- -- -- XINST -- DEV1 DEV9 Bit 5 -- -- -- -- -- -- DEV0 DEV8 Bit 4 -- BORV1 -- -- -- REV4 DEV7 Bit 3 FOSC3 BORV0 -- -- -- REV3 DEV6 Bit 2 FOSC2 BOREN1 LPT1OSC -- -- REV2 DEV5 Bit 1 FOSC1 Bit 0 FOSC0 WDTEN CCP2MX STVREN CP REV0 DEV3 Default/ Unprogrammed Value 00-- 0111 ---1 1111 ---1 1111 1--- -0-1 10-- ---1 ---- ---1 xxxx xxxx(1) 0000 xxxx(1)
CONFIG1H CONFIG2L CONFIG2H CONFIG3H CONFIG4L CONFIG5L DEVID2
BOREN0 PWRTEN -- -- -- REV1 DEV4
WDTPS3 WDTPS2 WDTPS1 WDTPS0
3FFFFEh DEVID1
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. Shaded cells are unimplemented, read as `0'. See Register 23-7 for DEVID values. DEVID registers are read-only and cannot be programmed by the user.
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REGISTER 23-1:
R/P-0 IESO bit 7 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state -n = Value when device is unprogrammed bit 7
CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)
U-0 -- U-0 -- R/P-0 FOSC3 R/P-1 FOSC2 R/P-1 FOSC1 R/P-1 FOSC0 bit 0
R/P-0 FCMEN
IESO: Internal/External Oscillator Switchover bit 1 = Oscillator Switchover mode enabled 0 = Oscillator Switchover mode disabled FCMEN: Fail-Safe Clock Monitor Enable bit 1 = Fail-Safe Clock Monitor enabled 0 = Fail-Safe Clock Monitor disabled Unimplemented: Read as `0' FOSC3:FOSC0: Oscillator Selection bits 11xx = External RC oscillator, CLKO function on RA6 101x = External RC oscillator, CLKO function on RA6 1001 = Internal oscillator block, CLKO function on RA6, port function on RA7 1000 = Internal oscillator block, port function on RA6 and RA7 0111 = External RC oscillator, port function on RA6 0110 = HS oscillator, PLL enabled (clock frequency = 4 x FOSC1) 0101 = EC oscillator, port function on RA6 0100 = EC oscillator, CLKO function on RA6 0011 = External RC oscillator, CLKO function on RA6 0010 = HS oscillator 0001 = XT oscillator 0000 = LP oscillator
bit 6
bit 5-4 bit 3-0
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REGISTER 23-2:
U-0 -- bit 7 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state -n = Value when device is unprogrammed bit 7-5 bit 4-3 Unimplemented: Read as `0' BORV1:BORV0: Brown-out Reset Voltage bits 11 = VBOR set to 2.1V 10 = VBOR set to 2.8V 01 = VBOR set to 4.3V 00 = VBOR set to 4.6V BOREN1:BOREN0 Brown-out Reset Enable bits(1) 11 = Brown-out Reset enabled in hardware only (SBOREN is disabled) 10 = Brown-out Reset enabled in hardware only and disabled in Sleep mode (SBOREN is disabled) 10 = Brown-out Reset enabled and controlled by software (SBOREN is enabled) 10 = Brown-out Reset disabled in hardware and software PWRTEN: Power-up Timer Enable bit(1) 1 = PWRT disabled 0 = PWRT enabled The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently controlled.
CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h)
U-0 -- U-0 -- R/P-1 BORV1 R/P-1 BORV0 R/P-1 BOREN1(1) R/P-1 BOREN0(1) R/P-1 PWRTEN(1) bit 0
bit 2-1
bit 0
Note 1:
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REGISTER 23-3:
U-0 -- bit 7 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state -n = Value when device is unprogrammed bit 7-5 bit 4-1 Unimplemented: Read as `0' WDTPS3:WDTPS0: Watchdog Timer Postscale Select bits 1111 = 1:32,768 1110 = 1:16,384 1101 = 1:8,192 1100 = 1:4,096 1011 = 1:2,048 1010 = 1:1,024 1001 = 1:512 1000 = 1:256 0111 = 1:128 0110 = 1:64 0101 = 1:32 0100 = 1:16 0011 = 1:8 0010 = 1:4 0001 = 1:2 0000 = 1:1 WDTEN: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled (control is placed on the SWDTEN bit)
CONFIG2H: CONFIGURATION REGISTER 2 HIGH (BYTE ADDRESS 300003h)
U-0 -- U-0 -- R/P-1 WDTPS3 R/P-1 WDTPS2 R/P-1 WDTPS1 R/P-1 WDTPS0 R/P-1 WDTEN bit 0
bit 0
REGISTER 23-4:
R/P-1 MCLRE bit 7 Legend: R = Readable bit
CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h)
U-0 -- U-0 -- U-0 -- U-0 -- R/P-0 LPT1OSC U-0 -- R/P-1 CCP2MX bit 0
P = Programmable bit
U = Unimplemented bit, read as `0' u = Unchanged from programmed state
-n = Value when device is unprogrammed bit 7
MCLRE: MCLR Pin Enable bit 1 = MCLR pin enabled; RG5 input pin disabled 0 = RG5 input pin enabled; MCLR disabled Unimplemented: Read as `0' LPT1OSC: Low-Power Timer 1 Oscillator Enable bit 1 = Timer1 configured for low-power operation 0 = Timer1 configured for higher power operation Unimplemented: Read as `0' CCP2MX: CCP2 MUX bit 1 = CCP2 input/output is multiplexed with RC1 0 = CCP2 input/output is multiplexed with RE7
bit 6-3 bit 2
bit 1 bit 0
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REGISTER 23-5:
R/P-1 DEBUG bit 7 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state -n = Value when device is unprogrammed bit 7
CONFIG4L: CONFIGURATION REGISTER 4 LOW (BYTE ADDRESS 300006h)
U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- R/P-1 STVREN bit 0
R/P-0 XINST
DEBUG: Background Debugger Enable bit 1 = Background debugger disabled, RB6 and RB7 configured as general purpose I/O pins 0 = Background debugger enabled, RB6 and RB7 are dedicated to In-Circuit Debug XINST: Extended Instruction Set Enable bit 1 = Instruction set extension and Indexed Addressing mode enabled 0 = Instruction set extension and Indexed Addressing mode disabled (Legacy mode) Unimplemented: Read as `0' STVREN: Stack Full/Underflow Reset Enable bit 1 = Stack full/underflow will cause Reset 0 = Stack full/underflow will not cause Reset
bit 6
bit 5-1 bit 0
REGISTER 23-6:
U-0 -- bit 7 Legend: R = Readable bit
CONFIG5L: CONFIGURATION REGISTER 5 LOW (BYTE ADDRESS 300008h)
U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- R/C-1 CP bit 0
C = Clearable bit
U = Unimplemented bit, read as `0' u = Unchanged from programmed state
-n = Value when device is unprogrammed bit 7-1 bit 0 Unimplemented: Read as `0'
CP: Code Protection bit 1 = Program memory block (000000-003FFFh) not code-protected 0 = Program memory block (000000-003FFFh) code-protected
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REGISTER 23-7:
R DEV2 bit 7 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state -n = Value when device is unprogrammed bit 7-5 DEV2:DEV0: Device ID bits 100 = PIC18F8390/8490 101 = PIC18F6390/6490 REV4:REV0: Revision ID bits These bits are used to indicate the device revision.
DEVID1: DEVICE ID REGISTER 1 FOR PIC18F6390/6490/8390/8490 DEVICES
R R DEV0 R REV4 R REV3 R REV2 R REV1 R REV0 bit 0
DEV1
bit 4-0
REGISTER 23-8:
R DEV10(1) bit 7 Legend: R = Readable bit
DEVID2: DEVICE ID REGISTER 2 FOR PIC18F6390/6490/8390/8490 DEVICES
R R DEV8(1) R DEV7(1) R DEV6(1) R DEV5(1) R DEV4(1) R DEV3(1) bit 0
DEV9(1)
P = Programmable bit
U = Unimplemented bit, read as `0' u = Unchanged from programmed state
-n = Value when device is unprogrammed bit 7-0
DEV10:DEV3: Device ID bits(1) These bits are used with the DEV2:DEV0 bits in the Device ID Register 1 to identify the part number. 0000 0110 = PIC18F6490/8490 devices 0000 1011 = PIC18F6390/8390 devices These values for DEV10:DEV3 may be shared with other devices. The specific device is always identified by using the entire DEV10:DEV0 bit sequence.
Note 1:
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23.2 Watchdog Timer (WDT)
For PIC18F6390/6490/8390/8490 devices, the WDT is driven by the INTRC source. When the WDT is enabled, the clock source is also enabled. The nominal WDT period is 4 ms and has the same stability as the INTRC oscillator. The 4 ms period of the WDT is multiplied by a 16-bit postscaler. Any output of the WDT postscaler is selected by a multiplexer, controlled by bits in Configuration Register 2H. Available periods range from 4 ms to 134.2 seconds (2.24 minutes). The WDT and postscaler are cleared when any of the following events occur: a SLEEP or CLRWDT instruction is executed, the IRCF bits (OSCCON<6:4>) are changed, or a clock failure has occurred. Note 1: The CLRWDT and SLEEP instructions clear the WDT and postscaler counts when executed. 2: Changing the setting of the IRCF bits (OSCCON<6:4>) clears the WDT and postscaler counts. 3: When a CLRWDT instruction is executed, the postscaler count will be cleared.
23.2.1
CONTROL REGISTER
Register 23-9 shows the WDTCON register. This is a readable and writable register, which contains a control bit that allows software to override the WDT enable Configuration bit, but only if the Configuration bit has disabled the WDT.
FIGURE 23-1:
SWDTEN WDTEN INTRC Source Change on IRCF bits CLRWDT All Device Resets WDTPS<3:0> Sleep
WDT BLOCK DIAGRAM
Enable WDT
INTRC Control /128 Wake-up from Power-Managed Modes Programmable Postscaler 1:1 to 1:32,768 4 Reset WDT Reset
WDT Counter
WDT
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REGISTER 23-9:
U-0 -- bit 7 Legend: R = Readable bit -n = Value at POR bit 7-1 bit 0 W = Writable bit `1' = Bit is set U = Unimplemented bit, read as `0' `0' = Bit is cleared x = Bit is unknown
WDTCON: WATCHDOG TIMER CONTROL REGISTER
U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- R/W-0 SWDTEN(1) bit 0
Unimplemented: Read as `0' SWDTEN: Software Controlled Watchdog Timer Enable bit(1) 1 = Watchdog Timer is on 0 = Watchdog Timer is off This bit has no effect if the Configuration bit, WDTEN, is enabled.
Note 1:
TABLE 23-2:
Name RCON WDTCON
SUMMARY OF WATCHDOG TIMER REGISTERS
Bit 7 IPEN -- Bit 6 SBOREN -- Bit 5 -- -- Bit 4 RI -- Bit 3 TO -- Bit 2 PD -- Bit 1 POR -- Bit 0 BOR SWDTEN Reset Values on Page 60 60
Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the Watchdog Timer.
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23.3 Two-Speed Start-up
The Two-Speed Start-up feature helps to minimize the latency period from oscillator start-up to code execution by allowing the microcontroller to use the INTRC oscillator as a clock source until the primary clock source is available. It is enabled by setting the IESO Configuration bit. Two-Speed Start-up should be enabled only if the primary oscillator mode is LP, XT, HS or HSPLL (Crystal-Based modes). Other sources do not require a OST start-up delay; for these, Two-Speed Start-up should be disabled. When enabled, Resets and wake-ups from Sleep mode cause the device to configure itself to run from the internal oscillator block as the clock source, following the time-out of the Power-up Timer after a Power-on Reset is enabled. This allows almost immediate code execution while the primary oscillator starts and the OST is running. Once the OST times out, the device automatically switches to PRI_RUN mode. Because the OSCCON register is cleared on Reset events, the INTOSC (or postscaler) clock source is not initially available after a Reset event; the INTRC clock is used directly at its base frequency. To use a higher clock speed on wake-up, the INTOSC or postscaler clock sources can be selected to provide a higher clock speed by setting bits, IRCF2:IRCF0, immediately after Reset. For wake-ups from Sleep, the INTOSC or postscaler clock sources can be selected by setting the IRCF2:IRCF0 bits prior to entering Sleep mode. In all other power-managed modes, Two-Speed Start-up is not used. The device will be clocked by the currently selected clock source until the primary clock source becomes available. The setting of the IESO bit is ignored.
23.3.1
SPECIAL CONSIDERATIONS FOR USING TWO-SPEED START-UP
While using the INTRC oscillator in Two-Speed Start-up, the device still obeys the normal command sequences for entering power-managed modes, including serial SLEEP instructions (refer to Section 3.1.2 "Entering Power-Managed Modes"). In practice, this means that user code can change the SCS1:SCS0 bit settings or issue SLEEP instructions before the OST times out. This would allow an application to briefly wake-up, perform routine "housekeeping" tasks and return to Sleep before the device starts to operate from the primary oscillator. User code can also check if the primary clock source is currently providing the device clocking by checking the status of the OSTS bit (OSCCON<3>). If the bit is set, the primary oscillator is providing the clock. Otherwise, the internal oscillator block is providing the clock during wake-up from Reset or Sleep mode.
FIGURE 23-2:
INTOSC Multiplexer OSC1
TIMING TRANSITION FOR TWO-SPEED START-UP (INTOSC TO HSPLL)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3
TOST(1) PLL Clock Output CPU Clock Peripheral Clock Program Counter PC
TPLL(1) 1 2 n-1 n
Clock Transition
PC + 2 OSTS bit Set
PC + 4
PC + 6
Wake from Interrupt Event
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
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23.4 Fail-Safe Clock Monitor
The Fail-Safe Clock Monitor (FSCM) allows the microcontroller to continue operation in the event of an external oscillator failure by automatically switching the device clock to the internal oscillator block. The FSCM function is enabled by setting the FCMEN Configuration bit. When FSCM is enabled, the INTRC oscillator runs at all times to monitor clocks to peripherals and provide a backup clock in the event of a clock failure. Clock monitoring (shown in Figure 23-3) is accomplished by creating a sample clock signal, which is the INTRC output divided by 64. This allows ample time between FSCM sample clocks for a peripheral clock edge to occur. The peripheral device clock and the sample clock are presented as inputs to the Clock Monitor latch (CM). The CM is set on the falling edge of the device clock source, but cleared on the rising edge of the sample clock. To use a higher clock speed on wake-up, the INTOSC or postscaler clock sources can be selected to provide a higher clock speed by setting bits, IRCF2:IRCF0, immediately after Reset. For wake-ups from Sleep, the INTOSC or postscaler clock sources can be selected by setting the IRCF2:IRCF0 bits prior to entering Sleep mode. The FSCM will detect failures of the primary or secondary clock sources only. If the internal oscillator block fails, no failure would be detected, nor would any action be possible.
23.4.1
FSCM AND THE WATCHDOG TIMER
Both the FSCM and the WDT are clocked by the INTRC oscillator. Since the WDT operates with a separate divider and counter, disabling the WDT has no effect on the operation of the INTRC oscillator when the FSCM is enabled. As already noted, the clock source is switched to the INTOSC clock when a clock failure is detected. Depending on the frequency selected by the IRCF2:IRCF0 bits, this may mean a substantial change in the speed of code execution. If the WDT is enabled with a small prescale value, a decrease in clock speed allows a WDT time-out to occur and a subsequent device Reset. For this reason, Fail-Safe Clock Monitor events also reset the WDT and postscaler, allowing them to start timing from when execution speed was changed and decreasing the likelihood of an erroneous time-out.
FIGURE 23-3:
FSCM BLOCK DIAGRAM
Clock Monitor Latch (CM) (edge-triggered)
Peripheral Clock
S
Q
INTRC Source (32 s)
/ 64 488 Hz (2.048 ms)
C
Q
23.4.2
Clock Failure Detected
EXITING FAIL-SAFE OPERATION
Clock failure is tested for on the falling edge of the sample clock. If a sample clock falling edge occurs while CM is still set, a clock failure has been detected (Figure 23-4). This causes the following: * the FSCM generates an oscillator fail interrupt by setting bit OSCFIF (PIR2<7>); * the device clock source is switched to the internal oscillator block (OSCCON is not updated to show the current clock source - this is the Fail-Safe condition); and * the WDT is reset. During switchover, the postscaler frequency from the internal oscillator block may not be sufficiently stable for timing sensitive applications. In these cases, it may be desirable to select another clock configuration and enter an alternate power-managed mode. This can be done to attempt a partial recovery or execute a controlled shutdown. See Section 3.1.2 "Entering Power-Managed Modes" and Section 23.3.1 "Special Considerations for Using Two-Speed Start-up" for more details.
The Fail-Safe condition is terminated by either a device Reset or by entering a power-managed mode. On Reset, the controller starts the primary clock source specified in Configuration Register 1H (with any required start-up delays that are required for the oscillator mode, such as the OST or PLL timer). The INTOSC multiplexer provides the device clock until the primary clock source becomes ready (similar to a TwoSpeed Start-up). The clock source is then switched to the primary clock (indicated by the OSTS bit in the OSCCON register becoming set). The Fail-Safe Clock Monitor then resumes monitoring the peripheral clock. The primary clock source may never become ready during start-up. In this case, operation is clocked by the INTOSC multiplexer. The OSCCON register will remain in its Reset state until a power-managed mode is entered.
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FIGURE 23-4:
Sample Clock Device Clock Output CM Output (Q) OSCFIF Oscillator Failure
FSCM TIMING DIAGRAM
Failure Detected
CM Test Note:
CM Test
CM Test
The device clock is normally at a much higher frequency than the sample clock. The relative frequencies in this example have been chosen for clarity.
23.4.3
FSCM INTERRUPTS IN POWER-MANAGED MODES
23.4.4
POR OR WAKE FROM SLEEP
By entering a power-managed mode, the clock multiplexer selects the clock source selected by the OSCCON register. Fail-Safe Clock Monitoring of the power-managed clock source resumes in the power-managed mode. If an oscillator failure occurs during power-managed operation, the subsequent events depend on whether or not the Oscillator Failure Interrupt Flag is enabled. If enabled (OSCFIF = 1), code execution will be clocked by the INTOSC multiplexer. An automatic transition back to the failed clock source will not occur. If the interrupt is disabled, the device will not exit the power-managed mode on oscillator failure. Instead, the device will continue to operate as before, but clocked by the INTOSC multiplexer. While in Idle mode, subsequent interrupts will cause the CPU to begin executing instructions while being clocked by the INTOSC multiplexer.
The FSCM is designed to detect oscillator failure at any point after the device has exited Power-on Reset (POR) or low-power Sleep mode. When the primary device clock is EC, RC or INTRC modes, monitoring can begin immediately following these events. For oscillator modes involving a crystal or resonator (HS, HSPLL, LP or XT), the situation is somewhat different. Since the oscillator may require a start-up time considerably longer than the FCSM sample clock time, a false clock failure may be detected. To prevent this, the internal oscillator block is automatically configured as the device clock and functions until the primary clock is stable (the OST and PLL timers have timed out). This is identical to Two-Speed Start-up mode. Once the primary clock is stable, the INTRC returns to its role as the FSCM source. Note: The same logic that prevents false oscillator failure interrupts on POR, or wake from Sleep, will also prevent the detection of the oscillator's failure to start at all following these events. This can be avoided by monitoring the OSTS bit and using a timing routine to determine if the oscillator is taking too long to start. Even so, no oscillator failure interrupt will be flagged.
As noted in Section 23.3.1 "Special Considerations for Using Two-Speed Start-up", it is also possible to select another clock configuration and enter an alternate power-managed mode while waiting for the primary clock to become stable. When the new powermanaged mode is selected, the primary clock is disabled.
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23.5 Program Verification and Code Protection
23.5.1 READING PROGRAM MEMORY AND OTHER LOCATIONS
The program memory may be read to any location using the table read instructions. The Device ID and the Configuration registers may be read with the table read instructions.
The overall structure of the code protection on the PIC18F6390/6490/8390/8490 Flash devices differs from previous PIC18 devices. For all devices in the PIC18F6X90/8X90 family, the user program memory is made of a single block. Figure 23-5 shows the program memory organization for individual devices. Code protection for this block is controlled by a single bit, CP (CONFIG5L<0>). The CP bit inhibits external reads from and writes to the entire program memory space. It has no direct effect in normal execution mode.
23.5.2
CONFIGURATION REGISTER PROTECTION
The Configuration registers can only be written via ICSP using an external programmer. No separate protection bit is associated with them.
FIGURE 23-5:
CODE-PROTECTED PROGRAM MEMORY FOR PIC18F6390/6490/8390/8490
MEMORY SIZE/DEVICE Block Code Protection Controlled By:
8 Kbytes Address (PIC18F6390/8390) Range Program Memory Block 000000h 001FFFh 002000h
16 Kbytes (PIC18F6490/8490) Program Memory Block
Address Range 000000h 003FFFh 004000h
CP, EBTR
Unimplemented Read `0's
Unimplemented Read `0's
(Unimplemented Memory Space)
1FFFFFh
1FFFFFh
TABLE 23-3:
300008h Legend:
SUMMARY OF CODE PROTECTION REGISTERS
Bit 7 -- Bit 6 -- Bit 5 -- Bit 4 -- Bit 3 -- Bit 2 -- Bit 1 -- Bit 0 CP
File Name CONFIG5L
Shaded cells are unimplemented.
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23.6 ID Locations 23.8 In-Circuit Debugger
Eight memory locations (200000h-200007h) are designated as ID locations, where the user can store checksum or other code identification numbers. These locations are readable during normal execution through the TBLRD instruction. During program/verify, these locations are readable and writable. The ID locations can be read when the device is code-protected. When the DEBUG Configuration bit is programmed to a `0', the In-Circuit Debugger functionality is enabled. This function allows simple debugging functions when used with MPLAB(R) IDE. When the microcontroller has this feature enabled, some resources are not available for general use. Table 23-4 shows which resources are required by the background debugger.
23.7
In-Circuit Serial Programming
TABLE 23-4:
I/O pins: Stack:
DEBUGGER RESOURCES
RB6, RB7 2 levels 512 bytes 10 bytes
PIC18F6390/6490/8390/8490 microcontrollers can be serially programmed while in the end application circuit. This is simply done with two lines for clock and data and three other lines for power, ground and the programming voltage. This allows customers to manufacture boards with unprogrammed devices and then program the microcontroller just before shipping the product. This also allows the most recent firmware or a custom firmware to be programmed.
Program Memory: Data Memory:
To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial Programming connections to MCLR/VPP, VDD, VSS, RB7 and RB6. This will interface to the In-Circuit Debugger module available from Microchip or one of the third party development tool companies.
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NOTES:
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24.0 INSTRUCTION SET SUMMARY
PIC18FXX90 devices incorporate the standard set of seventy-five PIC18 core instructions, as well as an extended set of 8 new instructions for the optimization of code that is recursive or that utilizes a software stack. The extended set is discussed later in this section. The literal instructions may use some of the following operands: * A literal value to be loaded into a file register (specified by `k') * The desired FSR register to load the literal value into (specified by `f') * No operand required (specified by `--') The control instructions may use some of the following operands: * A program memory address (specified by `n') * The mode of the CALL or RETURN instructions (specified by `s') * The mode of the table read and table write instructions (specified by `m') * No operand required (specified by `--') All instructions are a single word, except for four double-word instructions. These instructions were made double-word to contain the required information in 32 bits. In the second word, the 4 MSbs are `1's. If this second word is executed as an instruction (by itself), it will execute as a NOP. All single-word instructions are executed in a single instruction cycle, unless a conditional test is true or the program counter is changed as a result of the instruction. In these cases, the execution takes two instruction cycles with the additional instruction cycle(s) executed as a NOP. The double-word instructions execute in two instruction cycles. One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 s. If a conditional test is true, or the program counter is changed as a result of an instruction, the instruction execution time is 2 s. Two-word branch instructions (if true) would take 3 s. Figure 24-1 shows the general formats that the instructions can have. All examples use the convention `nnh' to represent a hexadecimal number. The Instruction Set Summary, shown in Table 24-2, lists the standard instructions recognized by the Microchip MPASMTM Assembler. Section 24.1.1 "Standard Instruction Set" provides a description of each instruction.
24.1
Standard Instruction Set
The standard PIC18 instruction set adds many enhancements to the previous PIC(R) MCU instruction sets, while maintaining an easy migration from these PIC MCU instruction sets. Most instructions are a single program memory word (16 bits), but there are four instructions that require two program memory locations. Each single-word instruction is a 16-bit word divided into an opcode, which specifies the instruction type and one or more operands, which further specify the operation of the instruction. The instruction set is highly orthogonal and is grouped into four basic categories: * * * * Byte-oriented operations Bit-oriented operations Literal operations Control operations
The PIC18 instruction set summary in Table 24-2 lists byte-oriented, bit-oriented, literal and control operations. Table 24-1 shows the opcode field descriptions. Most byte-oriented instructions have three operands: 1. 2. 3. The file register (specified by `f') The destination of the result (specified by `d') The accessed memory (specified by `a')
The file register designator, `f', specifies which file register is to be used by the instruction. The destination designator, `d', specifies where the result of the operation is to be placed. If `d' is zero, the result is placed in the WREG register. If `d' is one, the result is placed in the file register specified in the instruction. All bit-oriented instructions have three operands: 1. 2. 3. The file register (specified by `f') The bit in the file register (specified by `b') The accessed memory (specified by `a')
The bit field designator, `b', selects the number of the bit affected by the operation, while the file register designator, `f', represents the number of the file in which the bit is located.
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TABLE 24-1:
Field a
OPCODE FIELD DESCRIPTIONS
Description RAM access bit a = 0: RAM location in Access RAM (BSR register is ignored) a = 1: RAM bank is specified by BSR register Bit address within an 8-bit file register (0 to 7). Bank Select Register. Used to select the current RAM bank. ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative. Destination select bit d = 0: store result in WREG d = 1: store result in file register f Destination: either the WREG register or the specified register file location. 8-bit register file address (00h to FFh), or 2-bit FSR designator (0h to 3h). 12-bit register file address (000h to FFFh). This is the source address. 12-bit register file address (000h to FFFh). This is the destination address. Global Interrupt Enable bit. Literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value). Label name. The mode of the TBLPTR register for the table read and table write instructions. Only used with table read and table write instructions: No change to register (such as TBLPTR with table reads and writes) Post-Increment register (such as TBLPTR with table reads and writes) Post-Decrement register (such as TBLPTR with table reads and writes) Pre-Increment register (such as TBLPTR with table reads and writes) The relative address (2's complement number) for relative branch instructions or the direct address for Call/Branch and Return instructions. Program Counter. Program Counter Low Byte. Program Counter High Byte. Program Counter High Byte Latch. Program Counter Upper Byte Latch. Power-Down bit. Product of Multiply High Byte. Product of Multiply Low Byte. Fast Call/Return mode select bit s = 0: do not update into/from shadow registers s = 1: certain registers loaded into/from shadow registers (Fast mode) 21-bit Table Pointer (points to a Program Memory location). 8-bit Table Latch. Time-out bit. Top-of-Stack. Unused or unchanged. Watchdog Timer. Working register (accumulator). Don't care (`0' or `1'). The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all Microchip software tools. 7-bit offset value for Indirect Addressing of register files (source). 7-bit offset value for Indirect Addressing of register files (destination).
bbb BSR C, DC, Z, OV, N d
dest f fs fd GIE k label mm * *+ *+* n PC PCL PCH PCLATH PCLATU PD PRODH PRODL s
TBLPTR TABLAT TO TOS u WDT WREG x zs zd { } [text] (text) [expr] <> italics
Optional argument. Indicates an indexed address. The contents of text. Specifies bit n of the register indicated by the pointer expr. Assigned to. Register bit field. In the set of. User-defined term (font is Courier New).
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FIGURE 24-1: GENERAL FORMAT FOR INSTRUCTIONS
Byte-oriented file register operations 15 10 OPCODE d 9 87 a f (FILE #) 0 ADDWF MYREG, W, B Example Instruction
d = 0 for result destination to be WREG register d = 1 for result destination to be file register (f) a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address Byte to Byte move operations (2-word) 15 15 1111 12 11 f (Source FILE #) 0 f (Destination FILE #) 12 11 0 MOVFF MYREG1, MYREG2 OPCODE
f = 12-bit file register address Bit-oriented file register operations 15 12 11 98 7 f (FILE #) 0 BSF MYREG, bit, B OPCODE b (BIT #) a
b = 3-bit position of bit in file register (f) a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address Literal operations 15 OPCODE k = 8-bit immediate value Control operations CALL, GOTO and Branch operations 15 OPCODE 15 1111 12 11 n<19:8> (literal) 87 n<7:0> (literal) 0 0 GOTO Label 8 7 k (literal) 0 MOVLW 7Fh
n = 20-bit immediate value 15 OPCODE 15 1111 S = Fast bit 15 OPCODE 15 OPCODE 87 n<7:0> (literal) 11 10 n<10:0> (literal) 0 BC MYFUNC 0 BRA MYFUNC 12 11 n<19:8> (literal) 87 S n<7:0> (literal) 0 0 CALL MYFUNC
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TABLE 24-2:
Mnemonic, Operands
PIC18FXXXX INSTRUCTION SET
Description Cycles 16-Bit Instruction Word MSb 0010 0010 0001 0110 0001 0110 0110 0110 0000 0010 0100 0010 0011 0100 0001 0101 1100 1111 0110 0000 0110 0011 0100 0011 0100 0110 0101 01da 00da 01da 101a 11da 001a 010a 000a 01da 11da 11da 10da 11da 10da 00da 00da ffff ffff 111a 001a 110a 01da 01da 00da 00da 100a 01da ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff LSb ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff Status Affected Notes
BYTE-ORIENTED OPERATIONS ADDWF ADDWFC ANDWF CLRF COMF CPFSEQ CPFSGT CPFSLT DECF DECFSZ DCFSNZ INCF INCFSZ INFSNZ IORWF MOVF MOVFF MOVWF MULWF NEGF RLCF RLNCF RRCF RRNCF SETF SUBFWB SUBWF SUBWFB SWAPF TSTFSZ XORWF Note 1: f, d, a f, d, a f, d, a f, a f, d, a f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a fs, fd f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a Add WREG and f Add WREG and Carry bit to f AND WREG with f Clear f Complement f Compare f with WREG, Skip = Compare f with WREG, Skip > Compare f with WREG, Skip < Decrement f Decrement f, Skip if 0 Decrement f, Skip if Not 0 Increment f Increment f, Skip if 0 Increment f, Skip if Not 0 Inclusive OR WREG with f Move f Move fs (source) to 1st word fd (destination) 2nd word Move WREG to f Multiply WREG with f Negate f Rotate Left f through Carry Rotate Left f (No Carry) Rotate Right f through Carry Rotate Right f (No Carry) Set f Subtract f from WREG with Borrow Subtract WREG from f Subtract WREG from f with Borrow Swap Nibbles in f Test f, Skip if 0 Exclusive OR WREG with f 1 1 1 1 1 1 (2 or 3) 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 2 1 1 1 1 1 1 1 1 1 1 1 C, DC, Z, OV, N C, DC, Z, OV, N Z, N Z Z, N None None None C, DC, Z, OV, N None None C, DC, Z, OV, N None None Z, N Z, N None 1, 2 1, 2 1,2 2 1, 2 4 4 1, 2 1, 2, 3, 4 1, 2, 3, 4 1, 2 1, 2, 3, 4 4 1, 2 1, 2 1
None None 1, 2 C, DC, Z, OV, N C, Z, N 1, 2 Z, N C, Z, N Z, N None 1, 2 C, DC, Z, OV, N
0101 11da 0101 10da
ffff C, DC, Z, OV, N 1, 2 ffff C, DC, Z, OV, N ffff None ffff None ffff Z, N 4 1, 2
1 0011 10da 1 (2 or 3) 0110 011a 1 0001 10da
2: 3: 4:
5:
When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is `1' for a pin configured as an input and is driven low by an external device, the data will be written back with a `0'. If this instruction is executed on the TMR0 register (and where applicable, `d' = 1), the prescaler will be cleared if assigned. If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction. If the table write starts the write cycle to internal memory, the write will continue until terminated.
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TABLE 24-2:
Mnemonic, Operands
PIC18FXXXX INSTRUCTION SET (CONTINUED)
Description Cycles 16-Bit Instruction Word MSb 1001 1000 1011 1010 0111 1110 1110 1110 1110 1110 1110 1110 1101 1110 1110 1111 0000 0000 1110 1111 0000 1111 0000 0000 1101 0000 0000 bbba bbba bbba bbba bbba 0010 0110 0011 0111 0101 0001 0100 0nnn 0000 110s kkkk 0000 0000 1111 kkkk 0000 xxxx 0000 0000 1nnn 0000 0000 ffff ffff ffff ffff ffff nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0000 0000 kkkk kkkk 0000 xxxx 0000 0000 nnnn 1111 0001 kkkk 0001 0000 LSb ffff ffff ffff ffff ffff nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0100 0111 kkkk kkkk 0000 xxxx 0110 0101 nnnn 1111 000s Status Affected Notes
BIT-ORIENTED OPERATIONS BCF BSF BTFSC BTFSS BTG BC BN BNC BNN BNOV BNZ BOV BRA BZ CALL CLRWDT DAW GOTO NOP NOP POP PUSH RCALL RESET RETFIE RETLW RETURN SLEEP Note 1: f, b, a f, b, a f, b, a f, b, a f, d, a n n n n n n n n n n, s -- -- n -- -- -- -- n s k s -- Bit Clear f Bit Set f Bit Test f, Skip if Clear Bit Test f, Skip if Set Bit Toggle f Branch if Carry Branch if Negative Branch if Not Carry Branch if Not Negative Branch if Not Overflow Branch if Not Zero Branch if Overflow Branch Unconditionally Branch if Zero Call Subroutine 1st word 2nd word Clear Watchdog Timer Decimal Adjust WREG Go to Address 1st word 2nd word No Operation No Operation Pop Top of Return Stack (TOS) Push Top of Return Stack (TOS) Relative Call Software Device Reset Return from Interrupt Enable Return with Literal in WREG Return from Subroutine Go into Standby mode 1 1 1 (2 or 3) 1 (2 or 3) 1 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 2 1 (2) 2 1 1 2 1 1 1 1 2 1 2 2 2 1 None None None None None None None None None None None None None None None TO, PD C None 1, 2 1, 2 3, 4 3, 4 1, 2
CONTROL OPERATIONS
0000 1100 0000 0000 0000 0000
None None None None None All GIE/GIEH, PEIE/GIEL kkkk None 001s None 0011 TO, PD
4
2: 3: 4:
5:
When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is `1' for a pin configured as an input and is driven low by an external device, the data will be written back with a `0'. If this instruction is executed on the TMR0 register (and where applicable, `d' = 1), the prescaler will be cleared if assigned. If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction. If the table write starts the write cycle to internal memory, the write will continue until terminated.
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TABLE 24-2:
Mnemonic, Operands LITERAL OPERATIONS ADDLW ANDLW IORLW LFSR MOVLB MOVLW MULLW RETLW SUBLW XORLW TBLRD* TBLRD*+ TBLRD*TBLRD+* TBLWT* TBLWT*+ TBLWT*TBLWT+* Note 1: k k k f, k k k k k k k Add Literal and WREG AND Literal with WREG Inclusive OR Literal with WREG Move Literal (12-bit) 2nd word to FSR(f) 1st word Move Literal to BSR<3:0> Move Literal to WREG Multiply Literal with WREG Return with Literal in WREG Subtract WREG from Literal Exclusive OR Literal with WREG 1 1 1 2 1 1 1 2 1 1 0000 0000 0000 1110 1111 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1111 1011 1001 1110 0000 0001 1110 1101 1100 1000 1010 0000 0000 0000 0000 0000 0000 0000 0000 kkkk kkkk kkkk 00ff kkkk 0000 kkkk kkkk kkkk kkkk kkkk 0000 0000 0000 0000 0000 0000 0000 0000 kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk 1000 1001 1010 1011 1100 1101 1110 1111 C, DC, Z, OV, N Z, N Z, N None None None None None C, DC, Z, OV, N Z, N None None None None None None None None
PIC18FXXXX INSTRUCTION SET (CONTINUED)
Description Cycles 16-Bit Instruction Word MSb LSb Status Affected Notes
DATA MEMORY PROGRAM MEMORY OPERATIONS Table Read 2 Table Read with Post-Increment Table Read with Post-Decrement Table Read with Pre-Increment Table Write 2 Table Write with Post-Increment Table Write with Post-Decrement Table Write with Pre-Increment
5 5 5 5
2: 3: 4:
5:
When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is `1' for a pin configured as an input and is driven low by an external device, the data will be written back with a `0'. If this instruction is executed on the TMR0 register (and where applicable, `d' = 1), the prescaler will be cleared if assigned. If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory locations have a valid instruction. If the table write starts the write cycle to internal memory, the write will continue until terminated.
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24.1.1
ADDLW
Syntax: Operands: Operation: Status Affected: Encoding: Description:
STANDARD INSTRUCTION SET
ADD Literal to W
ADDLW 0 k 255 (W) + k W N, OV, C, DC, Z 0000 1111 kkkk kkkk The contents of W are added to the 8-bit literal `k' and the result is placed in W. 1 1 Q1 Q2 Read literal `k' Q3 Process Data Q4 Write to W Operation: Status Affected: Encoding: Description: k
ADDWF
Syntax: Operands:
ADD W to f
ADDWF 0 f 255 d [0,1] a [0,1] (W) + (f) dest N, OV, C, DC, Z 0010 01da ffff ffff Add W to register `f'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
Words: Cycles: Q Cycle Activity: Decode
Example:
ADDLW
15h
Before Instruction W = 10h After Instruction W= 25h
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' Q3 Process Data Q4 Write to destination
Example:
ADDWF 17h 0C2h 0D9h 0C2h
REG, 0, 0
Before Instruction W = REG = After Instruction W = REG =
Note:
All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).
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ADDWFC
Syntax: Operands:
ADD W and Carry bit to f
ADDWFC 0 f 255 d [0,1] a [0,1] (W) + (f) + (C) dest N,OV, C, DC, Z 0010 00da ffff ffff Add W, the Carry flag and data memory location `f'. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed in data memory location `f'. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
ANDLW
Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1 Decode
AND Literal with W
ANDLW 0 k 255 (W) .AND. k W N, Z 0000 1011 kkkk kkkk The contents of W are ANDed with the 8-bit literal `k'. The result is placed in W. 1 1 Q2 Read literal `k' ANDLW A3h 03h Q3 Process Data 05Fh Q4 Write to W k
Operation: Status Affected: Encoding: Description:
Example:
Before Instruction W = After Instruction W =
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' ADDWFC 1 02h 4Dh 0 02h 50h Q3 Process Data REG, 0, 1 Q4 Write to destination
Example:
Before Instruction Carry bit = REG = W = After Instruction Carry bit = REG = W =
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ANDWF
Syntax: Operands:
AND W with f
ANDWF 0 f 255 d [0,1] a [0,1] (W) .AND. (f) dest N, Z 0001 01da ffff ffff The contents of W are ANDed with register `f'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
BC
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Carry
BC n -128 n 127 if Carry bit is `1', (PC) + 2 + 2n PC None 1110 0010 nnnn nnnn If the Carry bit is `1', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction.
Operation: Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: If Jump: Q1 Decode No operation
1 1(2)
Q2 Read literal `n' No operation Q2 Read literal `n' HERE = = = = =
Q3 Process Data No operation Q3 Process Data BC 5
Q4 Write to PC No operation Q4 No operation
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' ANDWF 17h C2h 02h C2h Q3 Process Data REG, 0, 0 Q4 Write to destination
If No Jump: Q1 Decode
Example:
Before Instruction W = REG = After Instruction W = REG =
Example:
Before Instruction PC After Instruction If Carry PC If Carry PC
address (HERE) 1; address (HERE + 12) 0; address (HERE + 2)
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BCF
Syntax: Operands:
Bit Clear f
BCF f, b {,a} 0 f 255 0b7 a [0,1] 0 f None 1001 bbba ffff ffff Bit `b' in register `f' is cleared. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
BN
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Negative
BN n -128 n 127 if Negative bit is `1', (PC) + 2 + 2n PC None 1110 0110 nnnn nnnn If the Negative bit is `1', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction.
Operation: Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: If Jump: Q1 Decode
1 1(2)
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' BCF Q3 Process Data FLAG_REG, Q4 Write register `f' 7, 0
Q2 Read literal `n' No operation Q2 Read literal `n' HERE = = = = =
Q3 Process Data No operation Q3 Process Data BN Jump
Q4 Write to PC No operation Q4 No operation
No operation If No Jump: Q1 Decode
Example:
Before Instruction FLAG_REG = C7h After Instruction FLAG_REG = 47h
Example:
Before Instruction PC After Instruction If Negative PC If Negative PC
address (HERE) 1; address (Jump) 0; address (HERE + 2)
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BNC
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Not Carry
BNC n -128 n 127 if Carry bit is `0', (PC) + 2 + 2n PC None 1110 0011 nnnn nnnn If the Carry bit is `0', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction.
BNN
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Not Negative
BNN n -128 n 127 if Negative bit is `0', (PC) + 2 + 2n PC None 1110 0111 nnnn nnnn If the Negative bit is `0', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction.
Words: Cycles: Q Cycle Activity: If Jump: Q1 Decode No operation If No Jump: Q1 Decode
1 1(2)
Words: Cycles: Q Cycle Activity: If Jump: Q2 Q3 Process Data No operation Q3 Process Data BNC Jump Q4 Write to PC No operation Q4 No operation Q1 Decode No operation If No Jump: Q2 Q1 Decode
1 1(2)
Q2 Read literal `n' No operation Q2 Read literal `n' HERE = = = = =
Q3 Process Data No operation Q3 Process Data BNN Jump
Q4 Write to PC No operation Q4 No operation
Read literal `n' No operation
Read literal `n' HERE = = = = =
Example:
Example:
Before Instruction PC After Instruction If Carry PC If Carry PC
address (HERE) 0; address (Jump) 1; address (HERE + 2)
Before Instruction PC After Instruction If Negative PC If Negative PC
address (HERE) 0; address (Jump) 1; address (HERE + 2)
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BNOV
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Not Overflow
BNOV n -128 n 127 if Overflow bit is `0', (PC) + 2 + 2n PC None 1110 0101 nnnn nnnn If the Overflow bit is `0', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction.
BNZ
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Not Zero
BNZ n -128 n 127 if Zero bit is `0', (PC) + 2 + 2n PC None 1110 0001 nnnn nnnn If the Zero bit is `0', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction.
Words: Cycles: Q Cycle Activity: If Jump: Q1 Decode No operation If No Jump: Q1 Decode
1 1(2)
Words: Cycles: Q Cycle Activity: If Jump: Q2 Q3 Process Data No operation Q3 Process Data BNOV Jump address (HERE) 0; address (Jump) 1; address (HERE + 2) Q4 Write to PC No operation Q4 No operation Q1 Decode No operation If No Jump: Q2 Q1 Decode
1 1(2)
Q2 Read literal `n' No operation Q2 Read literal `n' HERE = = = = =
Q3 Process Data No operation Q3 Process Data BNZ Jump
Q4 Write to PC No operation Q4 No operation
Read literal `n' No operation
Read literal `n' HERE = = = = =
Example:
Example:
Before Instruction PC After Instruction If Overflow PC If Overflow PC
Before Instruction PC After Instruction If Zero PC If Zero PC
address (HERE) 0; address (Jump) 1; address (HERE + 2)
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BRA
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Unconditional Branch
BRA n -1024 n 1023 (PC) + 2 + 2n PC None 1101 0nnn nnnn nnnn Add the 2's complement number `2n' to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is a two-cycle instruction. 1 2 Q1 Decode No operation Q2 Read literal `n' No operation Q3 Process Data No operation Q4 Write to PC No operation
BSF
Syntax: Operands:
Bit Set f
BSF f, b {,a} 0 f 255 0b7 a [0,1] 1 f None 1000 bbba ffff ffff Bit `b' in register `f' is set. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
Operation: Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity:
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' BSF = = Q3 Process Data Q4 Write register `f'
Example:
HERE = =
BRA
Jump
Before Instruction PC After Instruction PC
address (HERE) address (Jump) Example:
FLAG_REG, 7, 1 0Ah 8Ah
Before Instruction FLAG_REG After Instruction FLAG_REG
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BTFSC
Syntax: Operands:
Bit Test File, Skip if Clear
BTFSC f, b {,a} 0 f 255 0b7 a [0,1] skip if (f) = 0 None 1011 bbba ffff ffff If bit `b' in register `f' is `0', then the next instruction is skipped. If bit `b' is `0', then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
BTFSS
Syntax: Operands:
Bit Test File, Skip if Set
BTFSS f, b {,a} 0 f 255 0b<7 a [0,1] skip if (f) = 1 None 1010 bbba ffff ffff If bit `b' in register `f' is `1', then the next instruction is skipped. If bit `b' is `1', then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
Operation: Status Affected: Encoding: Description:
Operation: Status Affected: Encoding: Description:
Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction.
Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction.
Q Cycle Activity: Q1 Decode If skip: Q1 No operation Q1 No operation No operation Example: Q2 No operation Q2 No operation No operation HERE FALSE TRUE = = = = = Q3 No operation Q3 No operation No operation BTFSC : : Q4 No operation Q4 No operation No operation Q2 Read register `f' Q3 Process Data Q4 No operation
Q Cycle Activity: Q1 Decode If skip: Q1 No operation Q1 No operation No operation Example: Q2 No operation Q2 No operation No operation HERE FALSE TRUE = = = = = Q3 No operation Q3 No operation No operation BTFSS : : Q4 No operation Q4 No operation No operation Q2 Read register `f' Q3 Process Data Q4 No operation
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
FLAG, 1, 0
FLAG, 1, 0
Before Instruction PC After Instruction If FLAG<1> PC If FLAG<1> PC
address (HERE) 0; address (TRUE) 1; address (FALSE)
Before Instruction PC After Instruction If FLAG<1> PC If FLAG<1> PC
address (HERE) 0; address (FALSE) 1; address (TRUE)
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BTG
Syntax: Operands:
Bit Toggle f
BTG f, b {,a} 0 f 255 0b<7 a [0,1] (f) f None 0111 bbba ffff ffff Bit `b' in data memory location `f' is inverted. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
BOV
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Overflow
BOV n -128 n 127 if Overflow bit is `1', (PC) + 2 + 2n PC None 1110 0100 nnnn nnnn If the Overflow bit is `1', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction.
Operation: Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: If Jump: Q1 Decode
1 1(2)
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' BTG Q3 Process Data PORTC, 4, 0 Q4 Write register `f'
Q2 Read literal `n' No operation Q2 Read literal `n' HERE = = = = =
Q3 Process Data No operation Q3 Process Data BOV Jump
Q4 Write to PC No operation Q4 No operation
No operation If No Jump: Q1 Decode
Example:
Before Instruction: PORTC = 0111 0101 [75h] After Instruction: PORTC = 0110 0101 [65h]
Example:
Before Instruction PC After Instruction If Overflow PC If Overflow PC
address (HERE) 1; address (Jump) 0; address (HERE + 2)
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BZ
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Zero
BZ n -128 n 127 if Zero bit is `1', (PC) + 2 + 2n PC None 1110 0000 nnnn nnnn If the Zero bit is `1', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction.
CALL
Syntax: Operands: Operation:
Subroutine Call
CALL k {,s} 0 k 1048575 s [0,1] (PC) + 4 TOS, k PC<20:1>; if s = 1, (W) WS, (STATUS) STATUSS, (BSR) BSRS None 1110 1111 110s k19kkk k7kkk kkkk kkkk0 kkkk8
Status Affected: Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) Description:
Words: Cycles: Q Cycle Activity: If Jump: Q1 Decode No operation If No Jump: Q1 Decode
1 1(2)
Q2 Read literal `n' No operation Q2 Read literal `n' HERE = = = = =
Q3 Process Data No operation Q3 Process Data BZ Jump
Q4 Write to PC No operation Q4 No operation Words: Cycles: Q Cycle Activity: Q1 Decode
Subroutine call of entire 2-Mbyte memory range. First, return address (PC + 4) is pushed onto the return stack. If `s' = 1, the W, STATUS and BSR registers are also pushed into their respective shadow registers, WS, STATUSS and BSRS. If `s' = 0, no update occurs (default). Then, the 20-bit value `k' is loaded into PC<20:1>. CALL is a two-cycle instruction. 2 2 Q2 Read literal `k'<7:0>, No operation HERE Q3 Push PC to stack No operation CALL Q4 Read literal `k'<19:8>, Write to PC No operation
Example:
Before Instruction PC After Instruction If Zero PC If Zero PC
address (HERE) 1; address (Jump) 0; address (HERE + 2)
No operation Example:
THERE,1
Before Instruction PC = After Instruction PC = TOS = WS = BSRS = STATUSS=
address (HERE) address (THERE) address (HERE + 4) W BSR STATUS
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CLRF
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Clear f
CLRF f {,a} 0 f 255 a [0,1] 000h f, 1Z Z 0110 101a ffff ffff
CLRWDT
Syntax: Operands: Operation:
Clear Watchdog Timer
CLRWDT None 000h WDT, 000h WDT postscaler, 1 TO, 1 PD TO, PD 0000 0000 0000 0100
Status Affected: Encoding: Description:
Clears the contents of the specified register. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
CLRWDT instruction resets the
Watchdog Timer. It also resets the postscaler of the WDT. Status bits, TO and PD, are set.
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 No operation CLRWDT = = = = = ? 00h 0 1 1 Q3 Process Data Q4 No operation
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' CLRF = = 5Ah 00h Q3 Process Data FLAG_REG,1 Q4 Write register `f' Example: Before Instruction WDT Counter After Instruction WDT Counter WDT Postscaler TO PD
Example:
Before Instruction FLAG_REG After Instruction FLAG_REG
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COMF
Syntax: Operands:
Complement f
COMF f {,d {,a}} 0 f 255 d [0,1] a [0,1] (f) dest N, Z 0001 11da ffff ffff The contents of register `f' are complemented. If `d' is `1', the result is stored in W. If `d' is `0', the result is stored back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
CPFSEQ
Syntax: Operands: Operation:
Compare f with W, Skip if f = W
CPFSEQ 0 f 255 a [0,1] (f) - (W), skip if (f) = (W) (unsigned comparison) None 0110 001a ffff ffff Compares the contents of data memory location `f' to the contents of W by performing an unsigned subtraction. If `f' = W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `0', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,a}
Operation: Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' COMF 13h 13h ECh If skip: Q3 Process Data REG, 0, 0 Q4 Write to destination Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction.
Example:
Q Cycle Activity: Q1 Decode Q2 Read register `f' Q3 Process Data Q4 No operation Q4 No operation Q4 No operation No operation
Before Instruction REG = After Instruction REG = W =
Q1 Q2 Q3 No No No operation operation operation If skip and followed by 2-word instruction: Q1 Q2 Q3 No No No operation operation operation No No No operation operation operation Example: HERE NEQUAL EQUAL = = = = = =
CPFSEQ REG, 0 : : HERE ? ? W; Address (EQUAL) W; Address (NEQUAL)
Before Instruction PC Address W REG After Instruction If REG PC If REG PC
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CPFSGT
Syntax: Operands: Operation:
Compare f with W, Skip if f > W
CPFSGT 0 f 255 a [0,1] (f) - (W), skip if (f) > (W) (unsigned comparison) None 0110 010a ffff ffff Compares the contents of data memory location `f' to the contents of the W by performing an unsigned subtraction. If the contents of `f' are greater than the contents of WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,a}
CPFSLT
Syntax: Operands: Operation:
Compare f with W, Skip if f < W
CPFSLT 0 f 255 a [0,1] (f) - (W), skip if (f) < (W) (unsigned comparison) None 0110 000a ffff ffff Compares the contents of data memory location `f' to the contents of W by performing an unsigned subtraction. If the contents of `f' are less than the contents of W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. f {,a}
Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q3 Process Data Q3 No operation Q3 No operation No operation Q4 No operation Q4 No operation Q4 No operation No operation
Q Cycle Activity: Q1 Decode Q2 Read register `f' Q2 No operation Q2 No operation No operation HERE NLESS LESS = = < = =
Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q3 Process Data Q4 No operation Q4 No operation Q4 No operation No operation If skip:
Q Cycle Activity: Q1 Decode If skip:
Q1 Q2 Read register `f' No operation Q1 No operation No operation Example:
If skip and followed by 2-word instruction:
Q1 Q2 Q3 No No No operation operation operation If skip and followed by 2-word instruction: Q1 Q2 Q3 No No No operation operation operation No No No operation operation operation Example: HERE NGREATER GREATER = = > = =
CPFSLT REG, 1 : : Address (HERE) ? W; Address (LESS) W; Address (NLESS)
CPFSGT REG, 0 : :
Before Instruction PC W After Instruction If REG PC If REG PC
Address (HERE) ? W; Address (GREATER) W; Address (NGREATER)
Before Instruction PC W After Instruction If REG PC If REG PC
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DAW
Syntax: Operands: Operation:
Decimal Adjust W Register
DAW None If [W<3:0> >9] or [DC = 1] then, (W<3:0>) + 6 W<3:0>; else, (W<3:0>) W<3:0>; If [W<7:4> >9] or [C = 1] then, (W<7:4>) + 6 W<7:4>, C = 1; else, (W<7:4>) W<7:4>
DECF
Syntax: Operands:
Decrement f
DECF f {,d {,a}} 0 f 255 d [0,1] a [0,1] (f) - 1 dest C, DC, N, OV, Z 0000 01da ffff ffff Decrement register `f'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
Operation: Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
C 0000 0000 0000 0111 DAW adjusts the eight-bit value in W, resulting from the earlier addition of two variables (each in packed BCD format) and produces a correct packed BCD result. 1 1 Words: Q2 Read register W DAW Q3 Process Data Q4 Write W Cycles: Q Cycle Activity: Q1 Decode
Words: Cycles: Q Cycle Activity: Q1 Decode Example 1:
1 1 Q2 Read register `f' DECF 01h 0 00h 1 Q3 Process Data CNT, 1, 0 Q4 Write to destination
Before Instruction W = C = DC = After Instruction W = C = DC = Example 2: Before Instruction W = C = DC = After Instruction W = C = DC =
A5h 0 0 05h 1 0
Example:
Before Instruction CNT = Z = After Instruction CNT = Z =
CEh 0 0 34h 1 0
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DECFSZ
Syntax: Operands:
Decrement f, Skip if 0
DECFSZ f {,d {,a}} 0 f 255 d [0,1] a [0,1] (f) - 1 dest, skip if result = 0 None 0010 11da ffff ffff The contents of register `f' are decremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). If the result is `0', the next instruction which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
DCFSNZ
Syntax: Operands:
Decrement f, Skip if not 0
DCFSNZ 0 f 255 d [0,1] a [0,1] (f) - 1 dest, skip if result 0 None 0100 11da ffff ffff The contents of register `f' are decremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). If the result is not `0', the next instruction which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
Operation: Status Affected: Encoding: Description:
Operation: Status Affected: Encoding: Description:
Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q3 Process Data Q3 No operation Q3 No operation No operation DECFSZ GOTO Q4 Write to destination Q4 No operation Q4 No operation No operation CNT, 1, 1 LOOP If skip: Q1 No operation Q1 No operation No operation Example: Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q3 Process Data Q3 No operation Q3 No operation No operation DCFSNZ : : = = = = = ? TEMP - 1, 0; Address (ZERO) 0; Address (NZERO) Q4 Write to destination Q4 No operation Q4 No operation No operation
Q Cycle Activity: Q1 Decode If skip: Q1 No operation Q1 No operation No operation Example: Q2 No operation Q2 No operation No operation HERE CONTINUE Before Instruction PC = After Instruction CNT = If CNT = PC = If CNT PC = Address (HERE) CNT - 1 0; Address (CONTINUE) 0; Address (HERE + 2) Q2 Read register `f' Q Cycle Activity: Q1 Decode Q2
Read register `f' Q2 No operation Q2 No operation No operation HERE ZERO NZERO
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
TEMP, 1, 0
Before Instruction TEMP After Instruction TEMP If TEMP PC If TEMP PC
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GOTO
Syntax: Operands: Operation: Status Affected: Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) Description: 1110 1111 1111 k19kkk k7kkk kkkk kkkk0 kkkk8
Unconditional Branch
GOTO k 0 k 1048575 k PC<20:1> None
INCF
Syntax: Operands:
Increment f
INCF f {,d {,a}} 0 f 255 d [0,1] a [0,1] (f) + 1 dest C, DC, N, OV, Z 0010 10da ffff ffff The contents of register `f' are incremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
Operation: Status Affected: Encoding: Description:
GOTO allows an unconditional branch
anywhere within entire 2-Mbyte memory range. The 20-bit value `k' is loaded into PC<20:1>. GOTO is always a two-cycle instruction.
Words: Cycles: Q Cycle Activity: Q1 Decode
2 2 Q2 Read literal `k'<7:0>, No operation Q3 No operation No operation Q4 Read literal `k'<19:8>, Write to PC No operation
No operation Example:
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' INCF FFh 0 ? ? 00h 1 1 1 Q3 Process Data CNT, 1, 0 Q4 Write to destination
GOTO THERE
After Instruction PC = Address (THERE)
Example:
Before Instruction CNT = Z = C = DC = After Instruction CNT = Z = C = DC =
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INCFSZ
Syntax: Operands:
Increment f, Skip if 0
INCFSZ 0 f 255 d [0,1] a [0,1] (f) + 1 dest, skip if result = 0 None 0011 11da ffff ffff The contents of register `f' are incremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). If the result is `0', the next instruction which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
INFSNZ
Syntax: Operands:
Increment f, Skip if not 0
INFSNZ 0 f 255 d [0,1] a [0,1] (f) + 1 dest, skip if result 0 None 0100 10da ffff ffff The contents of register `f' are incremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). If the result is not `0', the next instruction which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
Operation: Status Affected: Encoding: Description:
Operation: Status Affected: Encoding: Description:
Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction.
Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q3 Process Data Q3 No operation Q3 No operation No operation INFSNZ Q4 Write to destination Q4 No operation Q4 No operation No operation
Q Cycle Activity: Q1 Decode If skip: Q1 No operation Q1 No operation No operation Example: Q2 No operation Q2 No operation No operation HERE NZERO ZERO Q3 No operation Q3 No operation No operation INCFSZ : : Q4 No operation Q4 No operation No operation CNT, 1, 0 Q2 Read register `f' Q3 Process Data Q4 Write to destination
Q Cycle Activity: Q1 Decode If skip: Q1 No operation Q1 No operation No operation Example: Q2 No operation Q2 No operation No operation HERE ZERO NZERO Q2 Read register `f'
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
REG, 1, 0
Before Instruction PC = After Instruction CNT = If CNT = PC = If CNT PC =
Address (HERE) CNT + 1 0; Address (ZERO) 0; Address (NZERO)
Before Instruction PC = After Instruction REG = If REG PC = If REG = PC =
Address (HERE) REG + 1 0; Address (NZERO) 0; Address (ZERO)
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IORLW
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Inclusive OR Literal with W
IORLW k 0 k 255 (W) .OR. k W N, Z 0000 1001 kkkk kkkk The contents of W are ORed with the eight-bit literal `k'. The result is placed in W. 1 1 Q1 Q2 Read literal `k' IORLW 9Ah BFh Q3 Process Data 35h Q4 Write to W
IORWF
Syntax: Operands:
Inclusive OR W with f
IORWF f {,d {,a}} 0 f 255 d [0,1] a [0,1] (W) .OR. (f) dest N, Z 0001 00da ffff ffff Inclusive OR W with register `f'. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
Operation: Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Decode
Example:
Before Instruction W = After Instruction W =
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' IORWF 13h 91h 13h 93h Q3 Process Data RESULT, 0, 1 Q4 Write to destination
Example:
Before Instruction RESULT = W = After Instruction RESULT = W =
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LFSR
Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1 Decode Q2 Read literal `k' MSB Q3 Process Data Q4 Write literal `k' MSB to FSRfH Write literal `k' to FSRfL
Load FSR
LFSR f, k 0f2 0 k 4095 k FSRf None 1110 1111 1110 0000 00ff k7kkk k11kkk kkkk
MOVF
Syntax: Operands:
Move f
MOVF f {,d {,a}} 0 f 255 d [0,1] a [0,1] f dest N, Z 0101 00da ffff ffff The contents of register `f' are moved to a destination dependent upon the status of `d'. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). Location `f' can be anywhere in the 256-byte bank. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
Operation: Status Affected: Encoding: Description:
The 12-bit literal `k' is loaded into the file select register pointed to by `f'. 2 2
Decode
Read literal `k' LSB
Process Data
Example: After Instruction FSR2H FSR2L
LFSR 2, 3ABh = = 03h ABh Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' MOVF = = = = Q3 Process Data REG, 0, 0 22h FFh 22h 22h Q4 Write W
Example:
Before Instruction REG W After Instruction REG W
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MOVFF
Syntax: Operands: Operation: Status Affected: Encoding: 1st word (source) 2nd word (destin.) Description: 1100 1111 ffff ffff ffff ffff ffffs ffffd
Move f to f
MOVFF fs,fd 0 fs 4095 0 fd 4095 (fs) fd None
MOVLB
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Move Literal to Low Nibble in BSR
MOVLW k 0 k 255 k BSR None 0000 0001 kkkk kkkk The eight-bit literal `k' is loaded into the Bank Select Register (BSR). The value of BSR<7:4> always remains `0', regardless of the value of k7:k4. 1 1 Q1 Q2 Read literal `k' MOVLB 02h 05h Q3 Process Data 5 Q4 Write literal `k' to BSR
The contents of source register `fs' are moved to destination register `fd'. Location of source `fs' can be anywhere in the 4096-byte data space (000h to FFFh) and location of destination `fd' can also be anywhere from 000h to FFFh. Either source or destination can be W (a useful special situation).
Words: Cycles: Q Cycle Activity: Decode
MOVFF is particularly useful for
transferring a data memory location to a peripheral register (such as the transmit buffer or an I/O port). The MOVFF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register Words: Cycles: Q Cycle Activity: Q1 Decode Q2 Read register `f' (src) No operation No dummy read Example: MOVFF = = = = REG1, REG2 33h 11h 33h 33h Q3 Process Data No operation Q4 No operation Write register `f' (dest) 2 2 (3)
Example:
Before Instruction BSR Register = After Instruction BSR Register =
Decode
Before Instruction REG1 REG2 After Instruction REG1 REG2
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MOVLW
Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1 Decode Q2 Read literal `k' MOVLW 5Ah Words: Cycles: Q Cycle Activity: Q1 Decode Q2 Read register `f' MOVWF 4Fh FFh 4Fh 4Fh Q3 Process Data REG, 0 Q4 Write register `f' Q3 Process Data 5Ah Q4 Write to W 1 1
Move Literal to W
MOVLW k 0 k 255 kW None 0000 1110 kkkk kkkk The eight-bit literal `k' is loaded into W.
MOVWF
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Move W to f
MOVWF 0 f 255 a [0,1] (W) f None 0110 111a ffff ffff Move data from W to register `f'. Location `f' can be anywhere in the 256-byte bank. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 1 1 f {,a}
Example: After Instruction W =
Example:
Before Instruction W = REG = After Instruction W = REG =
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MULLW
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Multiply Literal with W
MULLW k 0 k 255 (W) x k PRODH:PRODL None 0000 1101 kkkk kkkk An unsigned multiplication is carried out between the contents of W and the 8-bit literal `k'. The 16-bit result is placed in the PRODH:PRODL register pair. PRODH contains the high byte. W is unchanged. None of the Status flags are affected. Note that neither Overflow nor Carry is possible in this operation. A Zero result is possible but not detected.
MULWF
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Multiply W with f
MULWF 0 f 255 a [0,1] (W) x (f) PRODH:PRODL None 0000 001a ffff ffff An unsigned multiplication is carried out between the contents of W and the register file location `f'. The 16-bit result is stored in the PRODH:PRODL register pair. PRODH contains the high byte. Both W and `f' are unchanged. None of the Status flags are affected. Note that neither Overflow nor Carry is possible in this operation. A Zero result is possible but not detected. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,a}
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read literal `k' Q3 Process Data Q4 Write registers PRODH: PRODL
Example: Before Instruction W PRODH PRODL After Instruction W PRODH PRODL
MULLW = = = = = =
0C4h E2h ? ? E2h ADh 08h Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' Q3 Process Data Q4 Write registers PRODH: PRODL
Example: Before Instruction W REG PRODH PRODL After Instruction W REG PRODH PRODL
MULWF = = = = = = = =
REG, 1 C4h B5h ? ? C4h B5h 8Ah 94h
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NEGF
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Negate f
NEGF f {,a} 0 f 255 a [0,1] (f) + 1 f N, OV, C, DC, Z 0110 110a ffff ffff Location `f' is negated using two's complement. The result is placed in the data memory location `f'. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
NOP
Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1 Decode
No Operation
NOP None No operation None 0000 1111 1 1 Q2 No operation Q3 No operation Q4 No operation 0000 xxxx 0000 xxxx 0000 xxxx
No operation.
Example: None.
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' NEGF Q3 Process Data REG, 1 Q4 Write register `f'
Example:
Before Instruction REG = After Instruction REG =
0011 1010 [3Ah] 1100 0110 [C6h]
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POP
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Pop Top of Return Stack
POP None (TOS) bit bucket None 0000 0000 0000 0110 The TOS value is pulled off the return stack and is discarded. The TOS value then becomes the previous value that was pushed onto the return stack. This instruction is provided to enable the user to properly manage the return stack to incorporate a software stack.
PUSH
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Push Top of Return Stack
PUSH None (PC + 2) TOS None 0000 0000 0000 0101 The PC + 2 is pushed onto the top of the return stack. The previous TOS value is pushed down on the stack. This instruction allows implementing a software stack by modifying TOS and then pushing it onto the return stack.
Words: Cycles: Q Cycle Activity: Q1
1 1 Q2 PUSH PC + 2 onto return stack PUSH = = = = = 345Ah 0124h 0126h 0126h 345Ah Q3 No operation Q4 No operation
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 No operation POP GOTO Q3 POP TOS value Q4 No operation
Decode
Example:
Example: NEW = = = = 0031A2h 014332h 014332h NEW
Before Instruction TOS Stack (1 level down) After Instruction TOS PC
Before Instruction TOS PC After Instruction PC TOS Stack (1 level down)
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RCALL
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Relative Call
RCALL n -1024 n 1023 (PC) + 2 TOS, (PC) + 2 + 2n PC None 1101 1nnn nnnn nnnn Subroutine call with a jump up to 1K from the current location. First, return address (PC + 2) is pushed onto the stack. Then, add the 2's complement number `2n' to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is a two-cycle instruction. 1 2 Q1 Q2 Read literal `n' PUSH PC to stack Q3 Process Data Q4 Write to PC
RESET
Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1 Decode
Reset
RESET None Reset all registers and flags that are affected by a MCLR Reset. All 0000 0000 1111 1111 This instruction provides a way to execute a MCLR Reset in software. 1 1 Q2 Start Reset RESET Reset Value Reset Value Q3 No operation Q4 No operation
Words: Cycles: Q Cycle Activity: Decode
Example: After Instruction Registers = Flags* =
No operation Example:
No operation HERE
No operation RCALL Jump
No operation
Before Instruction PC = Address (HERE) After Instruction PC = Address (Jump) TOS = Address (HERE + 2)
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RETFIE
Syntax: Operands: Operation:
Return from Interrupt
RETFIE {s} s [0,1] (TOS) PC, 1 GIE/GIEH or PEIE/GIEL; if s = 1, (WS) W, (STATUSS) STATUS, (BSRS) BSR, PCLATU, PCLATH are unchanged GIE/GIEH, PEIE/GIEL. 0000 0000 0001 000s Return from Interrupt. Stack is popped and Top-of-Stack (TOS) is loaded into the PC. Interrupts are enabled by setting either the high or low-priority global interrupt enable bit. If `s' = 1, the contents of the shadow registers, WS, STATUSS and BSRS, are loaded into their corresponding registers, W, STATUS and BSR. If `s' = 0, no update of these registers occurs (default). 1 2
RETLW
Syntax: Operands: Operation:
Return Literal to W
RETLW k 0 k 255 k W, (TOS) PC, PCLATU, PCLATH are unchanged None 0000 1100 kkkk kkkk W is loaded with the eight-bit literal `k'. The program counter is loaded from the top of the stack (the return address). The high address latch (PCLATH) remains unchanged. 1 2 Q1 Q2 Read literal `k' No operation Q3 Process Data No operation Q4 POP PC from stack, Write to W No operation
Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Decode
Words: Cycles: Q Cycle Activity: Q1 Decode
No operation Example: Q2 Q3 No operation Q4 POP PC from stack Set GIEH or GIEL : TABLE ADDWF RETLW RETLW : : RETLW CALL
No operation
TABLE ; ; ; ;
W contains table offset value W now has table value
No operation Example:
No operation RETFIE 1
No operation
No operation
PCL k0 k1
; W = offset ; Begin table ;
After Interrupt PC W BSR STATUS GIE/GIEH, PEIE/GIEL
= = = = =
TOS WS BSRS STATUSS 1
kn
; End of table 07h value of kn
Before Instruction W = After Instruction W =
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RETURN
Syntax: Operands: Operation:
Return from Subroutine
RETURN {s} s [0,1] (TOS) PC; if s = 1, (WS) W, (STATUSS) STATUS, (BSRS) BSR, PCLATU, PCLATH are unchanged None 0000 0000 0001 001s Return from subroutine. The stack is popped and the top of the stack (TOS) is loaded into the program counter. If `s'= 1, the contents of the shadow registers, WS, STATUSS and BSRS, are loaded into their corresponding registers, W, STATUS and BSR. If `s' = 0, no update of these registers occurs (default). 1 2 Q1 Q2 No operation No operation Q3 Process Data No operation Q4 POP PC from stack No operation
RLCF
Syntax: Operands:
Rotate Left f through Carry
RLCF f {,d {,a}} 0 f 255 d [0,1] a [0,1] (f) dest, (f<7>) C, (C) dest<0> C, N, Z 0011 01da ffff ffff The contents of register `f' are rotated one bit to the left through the Carry flag. If `d' is `0', the result is placed in W. If `d' is `1', the result is stored back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. C register f
Operation:
Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Decode No operation
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' RLCF Q3 Process Data Q4 Write to destination
Example:
RETURN
After Interrupt PC = TOS
Example: Before Instruction REG = C = After Instruction REG = W = C =
REG, 0, 0
1110 0110 0 1110 0110 1100 1100 1
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RLNCF
Syntax: Operands:
Rotate Left f (No Carry)
RLNCF 0 f 255 d [0,1] a [0,1] (f) dest, (f<7>) dest<0> N, Z 0100 01da ffff ffff f {,d {,a}}
RRCF
Syntax: Operands:
Rotate Right f through Carry
RRCF f {,d {,a}} 0 f 255 d [0,1] a [0,1] (f) dest, (f<0>) C, (C) dest<7> C, N, Z 0011 00da ffff ffff The contents of register `f' are rotated one bit to the right through the Carry flag. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. C register f
Operation: Status Affected: Encoding: Description:
Operation:
Status Affected: Encoding: Description:
The contents of register `f' are rotated one bit to the left. If `d' is `0', the result is placed in W. If `d' is `1', the result is stored back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. register f
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' RLNCF Q3 Process Data Q4 Write to destination Words: Cycles: Q Cycle Activity: Q1 Decode Q2 1 1
Q3 Process Data REG, 0, 0
Q4 Write to destination
Example: Before Instruction REG = After Instruction REG =
REG, 1, 0 Example:
Read register `f' RRCF
1010 1011 0101 0111
Before Instruction REG = C = After Instruction REG = W = C =
1110 0110 0 1110 0110 0111 0011 0
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RRNCF
Syntax: Operands:
Rotate Right f (No Carry)
RRNCF f {,d {,a}} 0 f 255 d [0,1] a [0,1] (f) dest, (f<0>) dest<7> N, Z 0100 00da ffff ffff The contents of register `f' are rotated one bit to the right. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f' (default). If `a' is `0', the Access Bank will be selected, overriding the BSR value. If `a' is `1', then the bank will be selected as per the BSR value. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. register f
SETF
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Set f
SETF f {,a} 0 f 255 a [0,1] FFh f None 0110 100a ffff ffff The contents of the specified register are set to FFh. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
Operation: Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' SETF = = 5Ah FFh Q3 Process Data REG,1 Q4 Write register `f'
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' RRNCF Q3 Process Data REG, 1, 0 Q4 Write to destination Example:
Before Instruction REG After Instruction REG
Example 1:
Before Instruction REG = After Instruction REG = Example 2:
1101 0111 1110 1011 REG, 0, 0
RRNCF
Before Instruction W = REG = After Instruction W = REG =
? 1101 0111 1110 1011 1101 0111
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SLEEP
Syntax: Operands: Operation:
Enter Sleep mode
SLEEP None 00h WDT, 0 WDT postscaler, 1 TO, 0 PD TO, PD 0000 0000 0000 0011 The Power-Down status bit (PD) is cleared. The Time-out status bit (TO) is set. Watchdog Timer and its postscaler are cleared. The processor is put into Sleep mode with the oscillator stopped.
SUBFWB
Syntax: Operands:
Subtract f from W with Borrow
SUBFWB 0 f 255 d [0,1] a [0,1] (W) - (f) - (C) dest N, OV, C, DC, Z 0101 01da ffff ffff Subtract register `f' and Carry flag (borrow) from W (2's complement method). If `d' is `0', the result is stored in W. If `d' is `1', the result is stored in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
Operation: Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 No operation SLEEP Q3 Process Data Q4 Go to Sleep Words: Cycles: Q Cycle Activity: Q1 Decode
Example: Before Instruction TO = ? ? PD =
1 1 Q2 Read register `f' Q3 Process Data Q4 Write to destination
After Instruction 1 TO = PD = 0 If WDT causes wake-up, this bit is cleared.
SUBFWB REG, 1, 0 Example 1: Before Instruction REG = 3 W = 2 C = 1 After Instruction REG = FF W = 2 C = 0 Z = 0 N = 1 ; result is negative Example 2: SUBFWB REG, 0, 0 Before Instruction REG = 2 W = 5 C = 1 After Instruction REG = 2 W = 3 C = 1 Z = 0 N = 0 ; result is positive SUBFWB REG, 1, 0 Example 3: Before Instruction REG = 1 W = 2 C = 0 After Instruction REG = 0 W = 2 C = 1 Z = 1 ; result is zero N = 0
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SUBLW
Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1 Decode Example 1: Before Instruction W = C = After Instruction W = C = Z = N = Example 2: Before Instruction W = C = After Instruction W = C = Z = N = Example 3: Before Instruction W = C = After Instruction W = C = Z = N = Q2 Read literal `k' SUBLW 01h ? 01h 1 ; result is positive 0 0 SUBLW 02h ? 00h 1 ; result is zero 1 0 SUBLW 03h ? FFh; (2's complement) 0 ; result is negative 0 1 02h 02h Q3 Process Data 02h Q4 Write to W
Subtract W from Literal
SUBLW k 0 k 255 k - (W) W N, OV, C, DC, Z 0000 1000 kkkk kkkk W is subtracted from the eight-bit literal `k'. The result is placed in W. 1 1
SUBWF
Syntax: Operands:
Subtract W from f
SUBWF 0 f 255 d [0,1] a [0,1] (f) - (W) dest N, OV, C, DC, Z 0101 11da ffff ffff Subtract W from register `f' (2's complement method). If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
Operation: Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Q1 Decode Example 1: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 2: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 3: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N =
1 1 Q2 Read register `f' SUBWF 3 2 ? 1 2 1 0 0 SUBWF 2 2 ? 2 0 1 1 0 SUBWF 1 2 ? FFh ;(2's complement) 2 0 ; result is negative 0 1 Q3 Process Data REG, 1, 0 Q4 Write to destination
; result is positive REG, 0, 0
; result is zero REG, 1, 0
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SUBWFB
Syntax: Operands:
Subtract W from f with Borrow
SUBWFB
0 f 255 d [0,1] a [0,1] (f) - (W) - (C) dest N, OV, C, DC, Z 0101 10da ffff ffff
SWAPF
Syntax: Operands:
Swap f
SWAPF f {,d {,a}} 0 f 255 d [0,1] a [0,1] (f<3:0>) dest<7:4>, (f<7:4>) dest<3:0> None 0011 10da ffff ffff The upper and lower nibbles of register `f' are exchanged. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
f {,d {,a}}
Operation: Status Affected: Encoding: Description:
Operation: Status Affected: Encoding: Description:
Subtract W and the Carry flag (borrow) from register `f' (2's complement method). If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
Words: Cycles: Q Cycle Activity: Q1 Decode Example 1:
1 1 Q2 Read register `f' SUBWFB 19h 0Dh 1 0Ch 0Dh 1 0 0 Q3 Process Data REG, 1, 0 (0001 1001) (0000 1101) (0000 1011) (0000 1101) ; result is positive Example: Q4 Write to destination Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' SWAPF 53h 35h Q3 Process Data REG, 1, 0 Q4 Write to destination
Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 2: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 3: Before Instruction REG = W = C = After Instruction REG = W C Z N = = = =
Before Instruction REG = After Instruction REG =
SUBWFB REG, 0, 0 1Bh 1Ah 0 1Bh 00h 1 1 0 SUBWFB 03h 0Eh 1 F5h 0Eh 0 0 1 (0001 1011) (0001 1010) (0001 1011) ; result is zero REG, 1, 0 (0000 0011) (0000 1101) (1111 0100) ; [2's comp] (0000 1101) ; result is negative
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TBLRD
Syntax: Operands: Operation:
Table Read
TBLRD ( *; *+; *-; +*) None if TBLRD *, (Prog Mem (TBLPTR)) TABLAT, TBLPTR - No Change; if TBLRD *+, (Prog Mem (TBLPTR)) TABLAT, (TBLPTR) + 1 TBLPTR; if TBLRD *-, (Prog Mem (TBLPTR)) TABLAT, (TBLPTR) - 1 TBLPTR; if TBLRD +*, (TBLPTR) + 1 TBLPTR, (Prog Mem (TBLPTR)) TABLAT 0000 0000 0000 10nn nn=0 * =1 *+ =2 *=3 +*
TBLRD
Example 1:
Table Read (Continued)
TBLRD *+ ; = = = = = +* ; = = = = = = 0AAh 01A357h 12h 34h 34h 01A358h 55h 00A356h 34h 34h 00A357h
Before Instruction TABLAT TBLPTR MEMORY(00A356h) After Instruction TABLAT TBLPTR Example 2: TBLRD Before Instruction TABLAT TBLPTR MEMORY(01A357h) MEMORY(01A358h) After Instruction TABLAT TBLPTR
Status Affected: None Encoding:
Description:
This instruction is used to read the contents of Program Memory (P.M.). To address the program memory, a pointer, called Table Pointer (TBLPTR), is used. The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-Mbyte address range. TBLPTR<0> = 0: Least Significant Byte of Program Memory Word TBLPTR<0> = 1: Most Significant Byte of Program Memory Word The TBLRD instruction can modify the value of TBLPTR as follows: * * * * no change post-increment post-decrement pre-increment
Words: Cycles: Q Cycle Activity: Q1 Decode
1 2 Q2 No operation Q3 No operation No operation Q4 No operation No operation (Write TABLAT)
No No operation operation (Read Program Memory)
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TBLWT
Syntax: Operands: Operation:
Table Write
TBLWT ( *; *+; *-; +*) None if TBLWT*, (TABLAT) Holding Register, TBLPTR - No Change; if TBLWT*+, (TABLAT) Holding Register, (TBLPTR) + 1 TBLPTR; if TBLWT*-, (TABLAT) Holding Register, (TBLPTR) - 1 TBLPTR; if TBLWT+*, (TBLPTR) + 1 TBLPTR, (TABLAT) Holding Register
TBLWT
Example 1:
Table Write (Continued) TBLWT *+;
Before Instruction TABLAT = 55h TBLPTR = 00A356h HOLDING REGISTER (00A356h) = FFh After Instructions (table write completion) TABLAT = 55h TBLPTR = 00A357h HOLDING REGISTER (00A356h) = 55h Example 2:
TBLWT +*;
Status Affected: None Encoding: 0000 0000 0000 11nn nn=0 * =1 *+ =2 *=3 +*
Description:
This instruction uses the 3 LSBs of the TBLPTR to determine which of the 8 holding registers the TABLAT is written to. The holding registers are used to program the contents of Program Memory (P.M.). (Refer to Section 6.0 "Flash Program Memory" for additional details on programming Flash memory.) The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-MBtye address range. The LSb of the TBLPTR selects which byte of the program memory location to access. TBLPTR<0> = 0: Least Significant Byte of Program Memory Word TBLPTR<0> = 1: Most Significant Byte of Program Memory Word The TBLWT instruction can modify the value of TBLPTR as follows: * * * * no change post-increment post-decrement pre-increment
Before Instruction TABLAT = 34h TBLPTR = 01389Ah HOLDING REGISTER (01389Ah) = FFh HOLDING REGISTER (01389Bh) = FFh After Instruction (table write completion) TABLAT = 34h TBLPTR = 01389Bh HOLDING REGISTER (01389Ah) = FFh HOLDING REGISTER (01389Bh) = 34h
Note:
The table write (TBLWT) instructions are not available in user mode in PIC18F6X90/8X90 devices, as these devices are standard Flash parts without an external bus interface.
Words: Cycles: Q Cycle Activity:
1 2 Q1 Decode Q2 Q3 Q4
No No No operation operation operation
No No No No operation operation operation operation (Read (Write to TABLAT) Holding Register )
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TSTFSZ
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Test f, Skip if 0
TSTFSZ f {,a} 0 f 255 a [0,1] skip if f = 0 None 0110 011a ffff ffff If `f' = 0, the next instruction fetched during the current instruction execution is discarded and a NOP is executed, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details.
XORLW
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Exclusive OR Literal with W
XORLW k 0 k 255 (W) .XOR. k W N, Z 0000 1010 kkkk kkkk The contents of W are XORed with the 8-bit literal `k'. The result is placed in W. 1 1 Q1 Q2 Read literal `k' Q3 Process Data Q4 Write to W
Words: Cycles: Q Cycle Activity: Decode
Example: Before Instruction W = After Instruction W =
XORLW
B5h 1Ah
0AFh
Words: Cycles:
1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction.
Q Cycle Activity: Q1 Decode If skip: Q1 No operation Q1 No operation No operation Example: Q2 No operation Q2 No operation No operation HERE NZERO ZERO = = = = Q3 No operation Q3 No operation No operation TSTFSZ : : Q4 No operation Q4 No operation No operation Q2 Read register `f' Q3 Process Data Q4 No operation
If skip and followed by 2-word instruction:
CNT, 1
Before Instruction PC After Instruction If CNT PC If CNT PC
Address (HERE) 00h, Address (ZERO) 00h, Address (NZERO)
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XORWF
Syntax: Operands:
Exclusive OR W with f
XORWF 0 f 255 d [0,1] a [0,1] (W) .XOR. (f) dest N, Z 0001 10da ffff ffff Exclusive OR the contents of W with register `f'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in the register `f' (default). If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,d {,a}}
Operation: Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Q1 Decode
1 1 Q2 Read register `f' XORWF AFh B5h 1Ah B5h Q3 Process Data REG, 1, 0 Q4 Write to destination
Example:
Before Instruction REG = W = After Instruction REG = W =
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24.2 Extended Instruction Set
In addition to the standard 75 instructions of the PIC18 instruction set, PIC18FXX90 devices also provide an optional extension to the core CPU functionality. The added features include eight additional instructions that augment Indirect and Indexed Addressing operations and the implementation of Indexed Literal Offset Addressing mode for many of the standard PIC18 instructions. The additional features are disabled by default. To enable them, users must set the XINST Configuration bit. The instructions in the extended set can all be classified as literal operations, which either manipulate the File Select Registers or use them for Indexed Addressing. Two of the instructions, ADDFSR and SUBFSR, each have an additional special instantiation for using FSR2. These versions (ADDULNK and SUBULNK) allow for automatic return after execution. The extended instructions are specifically implemented to optimize re-entrant program code (that is, code that is recursive or that uses a software stack) written in high-level languages, particularly C. Among other things, they allow users working in high-level languages to perform certain operations on data structures more efficiently. These include: * dynamic allocation and deallocation of software stack space when entering and leaving subroutines * Function Pointer invocation * Software Stack Pointer manipulation * manipulation of variables located in a software stack A summary of the instructions in the extended instruction set is provided in Table 24-3. Detailed descriptions are provided in Section 24.2.2 "Extended Instruction Set". The opcode field descriptions in Table 24-1 apply to both the standard and extended PIC18 instruction sets. Note: The instruction set extension and the Indexed Literal Offset Addressing mode were designed for optimizing applications written in C; the user may likely never use these instructions directly in assembler. The syntax for these commands is provided as a reference for users who may be reviewing code that has been generated by a compiler.
24.2.1
EXTENDED INSTRUCTION SYNTAX
Most of the extended instructions use indexed arguments, using one of the File Select Registers and some offset to specify a source or destination register. When an argument for an instruction serves as part of Indexed Addressing, it is enclosed in square brackets ("[ ]"). This is done to indicate that the argument is used as an index or offset. MPASMTM Assembler will flag an error if it determines that an index or offset value is not bracketed. When the extended instruction set is enabled, brackets are also used to indicate index arguments in byteoriented and bit-oriented instructions. This is in addition to other changes in their syntax. For more details, see Section 24.2.3.1 "Extended Instruction Syntax with Standard PIC18 Commands". Note: In the past, square brackets have been used to denote optional arguments in the PIC18 and earlier instruction sets. In this text and going forward, optional arguments are denoted by braces ("{ }").
TABLE 24-3:
Mnemonic, Operands ADDFSR ADDULNK CALLW MOVSF MOVSS PUSHL SUBFSR SUBULNK f, k k
EXTENSIONS TO THE PIC18 INSTRUCTION SET
Description Add Literal to FSR Add Literal to FSR2 and Return Call Subroutine using WREG Move zs (source) to 1st word fd (destination) 2nd word Move zs (source) to 1st word zd (destination) 2nd word Store Literal at FSR2, Decrement FSR2 Subtract Literal from FSR Subtract Literal from FSR2 and Return Cycles 1 2 2 2 2 1 1 2 16-Bit Instruction Word MSb 1110 1110 0000 1110 1111 1110 1111 1110 1110 1110 1000 1000 0000 1011 ffff 1011 xxxx 1010 1001 1001 ffkk 11kk 0001 0zzz ffff 1zzz xzzz kkkk ffkk 11kk LSb kkkk kkkk 0100 zzzz ffff zzzz zzzz kkkk kkkk kkkk Status Affected None None None None None None None None
zs, fd zs, zd k f, k k
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24.2.2
ADDFSR
Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1 Decode Q2 Read literal `k' Q3 Process Data Q4 Write to FSR Words: Cycles: Q Cycle Activity: Q1 Decode No Operation Q2 Read literal `k' No Operation Q3 Process Data No Operation Q4 Write to FSR No Operation
EXTENDED INSTRUCTION SET
Add Literal to FSR
ADDFSR f, k 0 k 63 f [ 0, 1, 2 ] FSR(f) + k FSR(f) None 1110 1000 ffkk kkkk The 6-bit literal `k' is added to the contents of the FSR specified by `f'. 1 1
ADDULNK
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Add Literal to FSR2 and Return
ADDULNK k 0 k 63 FSR2 + k FSR2, PC = (TOS) None 1110 1000 11kk kkkk The 6-bit literal `k' is added to the contents of FSR2. A RETURN is then executed by loading the PC with the TOS. The instruction takes two cycles to execute; a NOP is performed during the second cycle. This may be thought of as a special case of the ADDFSR instruction, where f = 3 (binary `11'); it operates only on FSR2. 1 2
Example:
ADDFSR 2, 23h 03FFh 0422h
Before Instruction FSR2 = After Instruction FSR2 =
Example:
ADDULNK 23h 03FFh 0100h 0422h (TOS)
Before Instruction FSR2 = PC = After Instruction FSR2 = PC =
Note:
All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in symbolic addressing. If a label is used, the instruction syntax then becomes: {label} instruction argument(s).
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CALLW
Syntax: Operands: Operation:
Subroutine Call Using WREG
CALLW None (PC + 2) TOS, (W) PCL, (PCLATH) PCH, (PCLATU) PCU None 0000 0000 0001 0100 First, the return address (PC + 2) is pushed onto the return stack. Next, the contents of W are written to PCL; the existing value is discarded. Then, the contents of PCLATH and PCLATU are latched into PCH and PCU, respectively. The second cycle is executed as a NOP instruction while the new next instruction is fetched. Unlike CALL, there is no option to update W, STATUS or BSR.
MOVSF
Syntax: Operands: Operation: Status Affected: Encoding: 1st word (source) 2nd word (destin.) Description:
Move Indexed to f
MOVSF [zs], fd 0 zs 127 0 fd 4095 ((FSR2) + zs) fd None 1110 1111 1011 ffff 0zzz ffff zzzzs ffffd
Status Affected: Encoding: Description
The contents of the source register are moved to destination register `fd'. The actual address of the source register is determined by adding the 7-bit literal offset `zs' in the first word to the value of FSR2. The address of the destination register is specified by the 12-bit literal `fd' in the second word. Both addresses can be anywhere in the 4096-byte data space (000h to FFFh). The MOVSF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. If the resultant source address points to an Indirect Addressing register, the value returned will be 00h.
Words: Cycles: Q Cycle Activity: Q1 Decode No operation
1 2 Q2 Read WREG No operation Q3 Push PC to stack No operation Q4 No operation No operation Words: Cycles: Q Cycle Activity: Q1
2 2 Q2 Q3 Q4 Read source reg Write register `f' (dest)
Example:
HERE
CALLW
Decode Decode
Determine Determine source addr source addr No operation No dummy read No operation
Before Instruction PC = PCLATH = PCLATU = W = After Instruction PC = TOS = PCLATH = PCLATU = W =
address (HERE) 10h 00h 06h 001006h address (HERE + 2) 10h 00h 06h
Example:
MOVSF = = = = = =
[05h], REG2 80h 33h 11h 80h 33h 33h
Before Instruction FSR2 Contents of 85h REG2 After Instruction FSR2 Contents of 85h REG2
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MOVSS
Syntax: Operands: Operation: Status Affected: Encoding: 1st word (source) 2nd word (dest.) Description 1110 1111 1011 xxxx 1zzz xzzz zzzzs zzzzd
Move Indexed to Indexed
MOVSS [zs], [zd] 0 zs 127 0 zd 127 ((FSR2) + zs) ((FSR2) + zd) None
PUSHL
Syntax: Operands: Operation:
Store Literal at FSR2, Decrement FSR2
PUSHL k 0 k 255 k (FSR2), FSR2 - 1 FSR2 1111 1010 kkkk kkkk
Status Affected: None Encoding: Description: The 8-bit literal `k' is written to the data memory address specified by FSR2. FSR2 is decremented by 1 after the operation. This instruction allows users to push values onto a software stack. Words: Cycles: Q1 Decode 1 1 Q2 Read `k' Q3 Process data Q4 Write to destination
The contents of the source register are moved to the destination register. The addresses of the source and destination registers are determined by adding the 7-bit literal offsets `zs' or `zd', respectively, to the value of FSR2. Both registers can be located anywhere in the 4096-byte data memory space (000h to FFFh). The MOVSS instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. If the resultant source address points to an Indirect Addressing register, the value returned will be 00h. If the resultant destination address points to an Indirect Addressing register, the instruction will execute as a NOP.
Q Cycle Activity:
Example:
PUSHL 08h = = = = 01ECh 00h 01EBh 08h
Before Instruction FSR2H:FSR2L Memory (01ECh) After Instruction FSR2H:FSR2L Memory (01ECh)
Words: Cycles: Q Cycle Activity: Q1 Decode Decode
2 2 Q2 Q3 Q4 Read source reg Write to dest reg
Determine Determine source addr source addr Determine dest addr Determine dest addr
Example:
MOVSS [05h], [06h] = = = = = = 80h 33h 11h 80h 33h 33h
Before Instruction FSR2 Contents of 85h Contents of 86h After Instruction FSR2 Contents of 85h Contents of 86h
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SUBFSR
Syntax: Operands: Operation: Status Affected: Encoding: Description:
Subtract Literal from FSR
SUBFSR f, k 0 k 63 f [ 0, 1, 2 ] FSRf - k FSRf None 1110 1001 ffkk kkkk The 6-bit literal `k' is subtracted from the contents of the FSR specified by `f'. 1 1 Q1 Q2 Read register `f' Q3 Process Data Q4 Write to destination
SUBULNK
Syntax: Operands: Operation:
Subtract Literal from FSR2 and Return
SUBULNK k 0 k 63 FSR2 - k FSR2, (TOS) PC 1110 1001 11kk kkkk
Status Affected: None Encoding: Description: The 6-bit literal `k' is subtracted from the contents of the FSR2. A RETURN is then executed by loading the PC with the TOS. The instruction takes two cycles to execute; a NOP is performed during the second cycle. This may be thought of as a special case of the SUBFSR instruction, where f = 3 (binary `11'); it operates only on FSR2. Words: Cycles: Q1 Decode No Operation 1 2 Q2 Read register `f' No Operation Q3 Process Data No Operation Q4 Write to destination No Operation
Words: Cycles: Q Cycle Activity: Decode
Q Cycle Activity: Example: Before Instruction FSR2 = After Instruction FSR2 = SUBFSR 2, 23h 03FFh 03DCh
Example: Before Instruction FSR2 = PC = After Instruction FSR2 = PC =
SUBULNK 23h 03FFh 0100h 03DCh (TOS)
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24.2.3 BYTE-ORIENTED AND BIT-ORIENTED INSTRUCTIONS IN INDEXED LITERAL OFFSET MODE
Enabling the PIC18 instruction set extension may cause legacy applications to behave erratically or fail entirely.
24.2.3.1
Extended Instruction Syntax with Standard PIC18 Commands
Note:
In addition to eight new commands in the extended set, enabling the extended instruction set also enables Indexed Literal Offset Addressing mode (Section 5.6.1 "Indexed Addressing With Literal Offset"). This has a significant impact on the way that many commands of the standard PIC18 instruction set are interpreted. When the extended set is disabled, addresses embedded in opcodes are treated as literal memory locations: either as a location in the Access Bank (a = 0), or in a GPR bank designated by the BSR (a = 1). When the extended instruction set is enabled and a = 0, however, a file register argument of 5Fh or less is interpreted as an offset from the pointer value in FSR2 and not as a literal address. For practical purposes, this means that all instructions that use the Access RAM bit as an argument - that is, all byte-oriented and bit-oriented instructions, or almost half of the core PIC18 instructions - may behave differently when the extended instruction set is enabled. When the content of FSR2 is 00h, the boundaries of the Access RAM are essentially remapped to their original values. This may be useful in creating backward compatible code. If this technique is used, it may be necessary to save the value of FSR2 and restore it when moving back and forth between `C' and assembly routines in order to preserve the Stack Pointer. Users must also keep in mind the syntax requirements of the extended instruction set (see Section 24.2.3.1 "Extended Instruction Syntax with Standard PIC18 Commands"). Although the Indexed Literal Offset Addressing mode can be very useful for dynamic stack and pointer manipulation, it can also be very annoying if a simple arithmetic operation is carried out on the wrong register. Users who are accustomed to the PIC18 programming must keep in mind that, when the extended instruction set is enabled, register addresses of 5Fh or less are used for Indexed Literal Offset Addressing. Representative examples of typical byte-oriented and bit-oriented instructions in the Indexed Literal Offset Addressing mode are provided on the following page to show how execution is affected. The operand conditions shown in the examples are applicable to all instructions of these types.
When the extended instruction set is enabled, the file register argument, `f', in the standard byte-oriented and bit-oriented commands is replaced with the literal offset value, `k'. As already noted, this occurs only when `f' is less than or equal to 5Fh. When an offset value is used, it must be indicated by square brackets ("[ ]"). As with the extended instructions, the use of brackets indicates to the compiler that the value is to be interpreted as an index or an offset. Omitting the brackets, or using a value greater than 5Fh within brackets, will generate an error in the MPASMTM Assembler. If the index argument is properly bracketed for Indexed Literal Offset Addressing, the Access RAM argument is never specified; it will automatically be assumed to be `0'. This is in contrast to standard operation (extended instruction set disabled) when `a' is set on the basis of the target address. Declaring the Access RAM bit in this mode will also generate an error in the MPASM Assembler. The destination argument, `d', functions as before. In the latest versions of the MPASM Assembler, language support for the extended instruction set must be explicitly invoked. This is done with either the command line option, /y, or the PE directive in the source listing.
24.2.4
CONSIDERATIONS WHEN ENABLING THE EXTENDED INSTRUCTION SET
It is important to note that the extensions to the instruction set may not be beneficial to all users. In particular, users who are not writing code that uses a software stack may not benefit from using the extensions to the instruction set. Additionally, the Indexed Literal Offset Addressing mode may create issues with legacy applications written to the PIC18 assembler. This is because instructions in the legacy code may attempt to address registers in the Access Bank below 5Fh. Since these addresses are interpreted as literal offsets to FSR2 when the instruction set extension is enabled, the application may read or write to the wrong data addresses. When porting an application to the PIC18FXX90, it is very important to consider the type of code. A large, reentrant application that is written in `C' and would benefit from efficient compilation will do well when using the instruction set extensions. Legacy applications that heavily use the Access Bank will most likely not benefit from using the extended instruction set.
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ADDWF
Syntax: Operands:
ADD W to Indexed (Indexed Literal Offset mode)
ADDWF 0 k 95 d [0,1] a=0 (W) + ((FSR2) + k) dest 0010 01d0 kkkk kkkk [k] {,d}
BSF
Syntax: Operands:
Bit Set Indexed (Indexed Literal Offset mode)
BSF [k], b 0 f 95 0b7 a=0 1 ((FSR2 + k)) None 1000 bbb0 kkkk kkkk Bit `b' of the register indicated by FSR2, offset by the value `k', is set. 1 1 Q1 Decode Q2 Read register `f' BSF = = = = Q3 Process Data Q4 Write to destination
Operation: Encoding: Description:
Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity:
Status Affected: N, OV, C, DC, Z The contents of W are added to the contents of the register indicated by FSR2, offset by the value `k'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f' (default). Words: Cycles: Q1 Decode 1 1 Q2 Read `k' Q3 Process Data [OFST] ,0 = = = = = = 17h 2Ch 0A00h 20h 37h 20h Q4 Write to destination
Q Cycle Activity:
Example:
[FLAG_OFST], 7 0Ah 0A00h 55h D5h
Example:
ADDWF
Before Instruction W OFST FSR2 Contents of 0A2Ch After Instruction W Contents of 0A2Ch
Before Instruction FLAG_OFST FSR2 Contents of 0A0Ah After Instruction Contents of 0A0Ah
SETF
Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1 Decode
Set Indexed (Indexed Literal Offset mode)
SETF [k] 0 k 95 FFh ((FSR2) + k) None 0110 1000 kkkk kkkk The contents of the register indicated by FSR2, offset by `k', are set to FFh. 1 1 Q2 Read `k' Q3 Process Data [OFST] 2Ch 0A00h 00h FFh Q4 Write register
Example:
SETF = = = =
Before Instruction OFST FSR2 Contents of 0A2Ch After Instruction Contents of 0A2Ch
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24.2.5 SPECIAL CONSIDERATIONS WITH MICROCHIP MPLAB(R) IDE TOOLS
The latest versions of Microchip's software tools have been designed to fully support the extended instruction set of the PIC18FXX90 family of devices. This includes the MPLAB C18 C compiler, MPASM assembly language and MPLAB Integrated Development Environment (IDE). When selecting a target device for software development, MPLAB IDE will automatically set default Configuration bits for that device. The default setting for the XINST Configuration bit is `0', disabling the extended instruction set and Indexed Literal Offset Addressing mode. For proper execution of applications developed to take advantage of the extended instruction set, XINST must be set during programming. To develop software for the extended instruction set, the user must enable support for the instructions and the Indexed Addressing mode in their language tool(s). Depending on the environment being used, this may be done in several ways: * A menu option, or dialog box within the environment, that allows the user to configure the language tool and its settings for the project * A command line option * A directive in the source code These options vary between different compilers, assemblers and development environments. Users are encouraged to review the documentation accompanying their development systems for the appropriate information.
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25.0 DEVELOPMENT SUPPORT
25.1
The PIC(R) microcontrollers are supported with a full range of hardware and software development tools: * Integrated Development Environment - MPLAB(R) IDE Software * Assemblers/Compilers/Linkers - MPASMTM Assembler - MPLAB C18 and MPLAB C30 C Compilers - MPLINKTM Object Linker/ MPLIBTM Object Librarian - MPLAB ASM30 Assembler/Linker/Library * Simulators - MPLAB SIM Software Simulator * Emulators - MPLAB ICE 2000 In-Circuit Emulator - MPLAB REAL ICETM In-Circuit Emulator * In-Circuit Debugger - MPLAB ICD 2 * Device Programmers - PICSTART(R) Plus Development Programmer - MPLAB PM3 Device Programmer - PICkitTM 2 Development Programmer * Low-Cost Demonstration and Development Boards and Evaluation Kits
MPLAB Integrated Development Environment Software
The MPLAB IDE software brings an ease of software development previously unseen in the 8/16-bit microcontroller market. The MPLAB IDE is a Windows(R) operating system-based application that contains: * A single graphical interface to all debugging tools - Simulator - Programmer (sold separately) - Emulator (sold separately) - In-Circuit Debugger (sold separately) * A full-featured editor with color-coded context * A multiple project manager * Customizable data windows with direct edit of contents * High-level source code debugging * Visual device initializer for easy register initialization * Mouse over variable inspection * Drag and drop variables from source to watch windows * Extensive on-line help * Integration of select third party tools, such as HI-TECH Software C Compilers and IAR C Compilers The MPLAB IDE allows you to: * Edit your source files (either assembly or C) * One touch assemble (or compile) and download to PIC MCU emulator and simulator tools (automatically updates all project information) * Debug using: - Source files (assembly or C) - Mixed assembly and C - Machine code MPLAB IDE supports multiple debugging tools in a single development paradigm, from the cost-effective simulators, through low-cost in-circuit debuggers, to full-featured emulators. This eliminates the learning curve when upgrading to tools with increased flexibility and power.
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25.2 MPASM Assembler 25.5
The MPASM Assembler is a full-featured, universal macro assembler for all PIC MCUs. The MPASM Assembler generates relocatable object files for the MPLINK Object Linker, Intel(R) standard HEX files, MAP files to detail memory usage and symbol reference, absolute LST files that contain source lines and generated machine code and COFF files for debugging. The MPASM Assembler features include: * Integration into MPLAB IDE projects * User-defined macros to streamline assembly code * Conditional assembly for multi-purpose source files * Directives that allow complete control over the assembly process
MPLAB ASM30 Assembler, Linker and Librarian
MPLAB ASM30 Assembler produces relocatable machine code from symbolic assembly language for dsPIC30F devices. MPLAB C30 C Compiler uses the assembler to produce its object file. The assembler generates relocatable object files that can then be archived or linked with other relocatable object files and archives to create an executable file. Notable features of the assembler include: * * * * * * Support for the entire dsPIC30F instruction set Support for fixed-point and floating-point data Command line interface Rich directive set Flexible macro language MPLAB IDE compatibility
25.6
MPLAB SIM Software Simulator
25.3
MPLAB C18 and MPLAB C30 C Compilers
The MPLAB C18 and MPLAB C30 Code Development Systems are complete ANSI C compilers for Microchip's PIC18 and PIC24 families of microcontrollers and the dsPIC30 and dsPIC33 family of digital signal controllers. These compilers provide powerful integration capabilities, superior code optimization and ease of use not found with other compilers. For easy source level debugging, the compilers provide symbol information that is optimized to the MPLAB IDE debugger.
The MPLAB SIM Software Simulator allows code development in a PC-hosted environment by simulating the PIC MCUs and dsPIC(R) DSCs on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a comprehensive stimulus controller. Registers can be logged to files for further run-time analysis. The trace buffer and logic analyzer display extend the power of the simulator to record and track program execution, actions on I/O, most peripherals and internal registers. The MPLAB SIM Software Simulator fully supports symbolic debugging using the MPLAB C18 and MPLAB C30 C Compilers, and the MPASM and MPLAB ASM30 Assemblers. The software simulator offers the flexibility to develop and debug code outside of the hardware laboratory environment, making it an excellent, economical software development tool.
25.4
MPLINK Object Linker/ MPLIB Object Librarian
The MPLINK Object Linker combines relocatable objects created by the MPASM Assembler and the MPLAB C18 C Compiler. It can link relocatable objects from precompiled libraries, using directives from a linker script. The MPLIB Object Librarian manages the creation and modification of library files of precompiled code. When a routine from a library is called from a source file, only the modules that contain that routine will be linked in with the application. This allows large libraries to be used efficiently in many different applications. The object linker/library features include: * Efficient linking of single libraries instead of many smaller files * Enhanced code maintainability by grouping related modules together * Flexible creation of libraries with easy module listing, replacement, deletion and extraction
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25.7 MPLAB ICE 2000 High-Performance In-Circuit Emulator 25.9 MPLAB ICD 2 In-Circuit Debugger
Microchip's In-Circuit Debugger, MPLAB ICD 2, is a powerful, low-cost, run-time development tool, connecting to the host PC via an RS-232 or high-speed USB interface. This tool is based on the Flash PIC MCUs and can be used to develop for these and other PIC MCUs and dsPIC DSCs. The MPLAB ICD 2 utilizes the in-circuit debugging capability built into the Flash devices. This feature, along with Microchip's In-Circuit Serial ProgrammingTM (ICSPTM) protocol, offers costeffective, in-circuit Flash debugging from the graphical user interface of the MPLAB Integrated Development Environment. This enables a designer to develop and debug source code by setting breakpoints, single stepping and watching variables, and CPU status and peripheral registers. Running at full speed enables testing hardware and applications in real time. MPLAB ICD 2 also serves as a development programmer for selected PIC devices.
The MPLAB ICE 2000 In-Circuit Emulator is intended to provide the product development engineer with a complete microcontroller design tool set for PIC microcontrollers. Software control of the MPLAB ICE 2000 In-Circuit Emulator is advanced by the MPLAB Integrated Development Environment, which allows editing, building, downloading and source debugging from a single environment. The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring features. Interchangeable processor modules allow the system to be easily reconfigured for emulation of different processors. The architecture of the MPLAB ICE 2000 In-Circuit Emulator allows expansion to support new PIC microcontrollers. The MPLAB ICE 2000 In-Circuit Emulator system has been designed as a real-time emulation system with advanced features that are typically found on more expensive development tools. The PC platform and Microsoft(R) Windows(R) 32-bit operating system were chosen to best make these features available in a simple, unified application.
25.10 MPLAB PM3 Device Programmer
The MPLAB PM3 Device Programmer is a universal, CE compliant device programmer with programmable voltage verification at VDDMIN and VDDMAX for maximum reliability. It features a large LCD display (128 x 64) for menus and error messages and a modular, detachable socket assembly to support various package types. The ICSPTM cable assembly is included as a standard item. In Stand-Alone mode, the MPLAB PM3 Device Programmer can read, verify and program PIC devices without a PC connection. It can also set code protection in this mode. The MPLAB PM3 connects to the host PC via an RS-232 or USB cable. The MPLAB PM3 has high-speed communications and optimized algorithms for quick programming of large memory devices and incorporates an SD/MMC card for file storage and secure data applications.
25.8
MPLAB REAL ICE In-Circuit Emulator System
MPLAB REAL ICE In-Circuit Emulator System is Microchip's next generation high-speed emulator for Microchip Flash DSC and MCU devices. It debugs and programs PIC(R) Flash MCUs and dsPIC(R) Flash DSCs with the easy-to-use, powerful graphical user interface of the MPLAB Integrated Development Environment (IDE), included with each kit. The MPLAB REAL ICE probe is connected to the design engineer's PC using a high-speed USB 2.0 interface and is connected to the target with either a connector compatible with the popular MPLAB ICD 2 system (RJ11) or with the new high-speed, noise tolerant, LowVoltage Differential Signal (LVDS) interconnection (CAT5). MPLAB REAL ICE is field upgradeable through future firmware downloads in MPLAB IDE. In upcoming releases of MPLAB IDE, new devices will be supported, and new features will be added, such as software breakpoints and assembly code trace. MPLAB REAL ICE offers significant advantages over competitive emulators including low-cost, full-speed emulation, real-time variable watches, trace analysis, complex breakpoints, a ruggedized probe interface and long (up to three meters) interconnection cables.
(c) 2007 Microchip Technology Inc.
DS39629C-page 347
PIC18FXX90
25.11 PICSTART Plus Development Programmer
The PICSTART Plus Development Programmer is an easy-to-use, low-cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB Integrated Development Environment software makes using the programmer simple and efficient. The PICSTART Plus Development Programmer supports most PIC devices in DIP packages up to 40 pins. Larger pin count devices, such as the PIC16C92X and PIC17C76X, may be supported with an adapter socket. The PICSTART Plus Development Programmer is CE compliant.
25.13 Demonstration, Development and Evaluation Boards
A wide variety of demonstration, development and evaluation boards for various PIC MCUs and dsPIC DSCs allows quick application development on fully functional systems. Most boards include prototyping areas for adding custom circuitry and provide application firmware and source code for examination and modification. The boards support a variety of features, including LEDs, temperature sensors, switches, speakers, RS-232 interfaces, LCD displays, potentiometers and additional EEPROM memory. The demonstration and development boards can be used in teaching environments, for prototyping custom circuits and for learning about various microcontroller applications. In addition to the PICDEMTM and dsPICDEMTM demonstration/development board series of circuits, Microchip has a line of evaluation kits and demonstration software for analog filter design, KEELOQ(R) security ICs, CAN, IrDA(R), PowerSmart battery management, SEEVAL(R) evaluation system, Sigma-Delta ADC, flow rate sensing, plus many more. Check the Microchip web page (www.microchip.com) for the complete list of demonstration, development and evaluation kits.
25.12 PICkit 2 Development Programmer
The PICkitTM 2 Development Programmer is a low-cost programmer and selected Flash device debugger with an easy-to-use interface for programming many of Microchip's baseline, mid-range and PIC18F families of Flash memory microcontrollers. The PICkit 2 Starter Kit includes a prototyping development board, twelve sequential lessons, software and HI-TECH's PICCTM Lite C compiler, and is designed to help get up to speed quickly using PIC(R) microcontrollers. The kit provides everything needed to program, evaluate and develop applications using Microchip's powerful, mid-range Flash memory family of microcontrollers.
DS39629C-page 348
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.0 ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings()
Ambient temperature under bias.............................................................................................................-40C to +125C Storage temperature .............................................................................................................................. -65C to +150C Voltage on any pin with respect to VSS (except VDD and MCLR) ................................................... -0.3V to (VDD + 0.3V) Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +7.5V Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V Total power dissipation (Note 1) ...............................................................................................................................1.0W Maximum current out of VSS pin ...........................................................................................................................300 mA Maximum current into VDD pin ..............................................................................................................................250 mA Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... 20 mA Output clamp current, IOK (VO < 0 or VO > VDD) .............................................................................................................. 20 mA Maximum output current sunk by any I/O pin..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................25 mA Maximum current sunk by all ports .......................................................................................................................200 mA Maximum current sourced by all ports ..................................................................................................................200 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - IOH} + {(VDD - VOH) x IOH} + (VOL x IOL) 2: Voltage spikes below VSS at the MCLR/VPP/RG5 pin, inducing currents greater than 80 mA, may cause latch-up. Thus, a series resistor of 50-100 should be used when applying a "low" level to the MCLR/VPP/ RG5 pin, rather than pulling this pin directly to VSS.
NOTICE: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.
(c) 2007 Microchip Technology Inc.
DS39629C-page 349
PIC18F6390/6490/8390/8490
FIGURE 26-1: PIC18F6390/6490/8390/8490 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V 5.5V 5.0V PIC18FX390/X490 4.2V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V
Voltage
40 MHz
Frequency
FIGURE 26-2:
PIC18LF6390/6490/8390/8490 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V PIC18LFX390/X490 4.2V
Voltage
4 MHz
40 MHz
Frequency
FMAX = (16.36 MHz/V) (VDDAPPMIN - 2.0V) + 4 MHz Note: VDDAPPMIN is the minimum voltage of the PIC(R) device in the application.
DS39629C-page 350
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.1 DC Characteristics: Supply Voltage PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Min Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. D001 Symbol VDD Characteristic Supply Voltage PIC18LF6390/6490/8390/8490 PIC18F6390/6490/8390/8490 D002 D003 VDR VPOR RAM Data Retention Voltage(1) VDD Start Voltage to Ensure Internal Power-on Reset Signal VDD Rise Rate to Ensure Internal Power-on Reset Signal Brown-out Reset Voltage PIC18LF6390/6490/8390/8490 BORV1:BORV0 = 11 BORV1:BORV0 = 10 D005 All devices BORV1:BORV0 = 01 BORV1:BORV0 = 00 Legend: Note 1:
2.0 4.2 1.5 --
-- -- -- --
5.5 5.5 -- 0.7
V V V V
HS, XT, RC and LP Oscillator modes
See section on Power-on Reset for details
D004
SVDD
0.05
--
--
V/ms See section on Power-on Reset for details
VBOR D005
2.00 2.65 4.11 4.36
2.05 2.79 4.33 4.59
2.16 2.93 4.55 4.82
V V V V
Shading of rows is to assist in readability of the table. This is the limit to which VDD can be lowered in Sleep mode, or during a device Reset, without losing RAM data.
(c) 2007 Microchip Technology Inc.
DS39629C-page 351
PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device Power-Down Current (IPD)(1) PIC18LF6390/6490/8390/8490
0.1 0.1 0.2
1 1 5 2 2 8 2.0 2.0 15
A A A A A A A A A
-40C +25C +85C -40C +25C +85C -40C +25C +85C
VDD = 2.0V (Sleep mode) VDD = 3.0V (Sleep mode) VDD = 5.0V (Sleep mode)
PIC18LF6390/6490/8390/8490
0.1 0.1 0.3
All devices
0.1 0.1 0.4
Legend: Note 1:
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
DS39629C-page 352
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device Supply Current (IDD)(2) PIC18LF6390/6490/8390/8490
12 12 12
26 24 23 50 48 46 134 128 128 .8 .8 .8 1.04 .96 .88 1.84 1.76 1.68
A A A A A A A A A mA mA mA mA mA mA mA mA mA
-40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C VDD = 5.0V VDD = 3.0V FOSC = 1 MHz (RC_RUN mode, INTOSC source) VDD = 2.0V VDD = 5.0V VDD = 3.0V FOSC = 31 kHz (RC_RUN mode, INTRC source) VDD = 2.0V
PIC18LF6390/6490/8390/8490
32 27 22
All devices
84 82 72
PIC18LF6390/6490/8390/8490
.26 .26 .26
PIC18LF6390/6490/8390/8490
.48 .44 .48
All devices
.88 .88 .8
Legend: Note 1:
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
(c) 2007 Microchip Technology Inc.
DS39629C-page 353
PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device Supply Current (IDD)(2) PIC18LF6390/6490/8390/8490
0.6 0.6 0.6
1.7 1.6 1.5 2.4 2.4 2.4 4.2 4 3.8 6.4 6.4 8.8 8.8 8.8 12 16 16 29
mA mA mA mA mA mA mA mA mA A A A A A A A A A
-40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C VDD = 5.0V VDD = 3.0V FOSC = 31 kHz (RC_IDLE mode, INTRC source) VDD = 2.0V VDD = 5.0V VDD = 3.0V FOSC = 4 MHz (RC_RUN mode, INTOSC source) VDD = 2.0V
PIC18LF6390/6490/8390/8490
1.0 1.0 1.0
All devices
2.0 2.0 2.0
PIC18LF6390/6490/8390/8490
2.3 2.5 2.9
PIC18LF6390/6490/8390/8490
3.6 3.8 4.6
All devices
7.4 7.8 9.1
Legend: Note 1:
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
DS39629C-page 354
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device Supply Current (IDD)(2) PIC18LF6390/6490/8390/8490
132 140 152
400 400 400 600 600 600 1 1 1 700 700 700 1 1 1 1.6 1.6 1.6
A A A A A A mA mA mA A A A mA mA mA mA mA mA
-40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C VDD = 5.0V VDD = 3.0V FOSC = 4 MHz (RC_IDLE mode, INTOSC source) VDD = 2.0V VDD = 5.0V VDD = 3.0V FOSC = 1 MHz (RC_IDLE mode, INTOSC source) VDD = 2.0V
PIC18LF6390/6490/8390/8490
200 216 252
All devices 0.40 0.42 0.44 PIC18LF6390/6490/8390/8490 272 280 288 PIC18LF6390/6490/8390/8490 0.416 0.432 0.464 All devices .8 .9 .9 Legend: Note 1:
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
(c) 2007 Microchip Technology Inc.
DS39629C-page 355
PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device Supply Current (IDD)(2) PIC18LF6390/6490/8390/8490
250 260 250
500 500 500 650 650 650 1.6 1.5 1.4 2.0 2.0 2.0 3.0 3.0 3.0 6.0 6.0 6.0 35 35 35 40 40 40
A A A A A A mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA
-40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C VDD = 5.0V VDD = 4.2V FOSC = 40 MHZ (PRI_RUN, EC oscillator) VDD = 5.0V VDD = 3.0V FOSC = 4 MHz (PRI_RUN, EC oscillator) VDD = 2.0V VDD = 5.0V VDD = 3.0V FOSC = 1 MHZ (PRI_RUN, EC oscillator) VDD = 2.0V
PIC18LF6390/6490/8390/8490
550 480 460
All devices
1.2 1.1 1.0
PIC18LF6390/6490/8390/8490 0.72 0.74 0.74 PIC18LF6390/6490/8390/8490 1.3 1.3 1.3 All devices 2.7 2.6 2.5 All devices 15 16 16 All devices 21 21 21 Legend: Note 1:
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
DS39629C-page 356
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device Supply Current (IDD)(2) All devices
7.5 7.4 7.3
16 15 14 21 20 19 35 35 35 40 40 40
mA mA mA mA mA mA mA mA mA mA mA mA
-40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C VDD = 5.0V VDD = 4.2V VDD = 5.0V VDD = 4.2V
FOSC = 4 MHZ. 16 MHz internal (PRI_RUN HS+PLL) FOSC = 4 MHZ, 16 MHz internal (PRI_RUN HS+PLL) FOSC = 10 MHZ, 40 MHz internal (PRI_RUN HS+PLL) FOSC = 10 MHZ, 40 MHz internal (PRI_RUN HS+PLL)
All devices
10 10 9.7
All devices
17 17 17
All devices
23 23 23
Legend: Note 1:
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
(c) 2007 Microchip Technology Inc.
DS39629C-page 357
PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device Supply Current (IDD)(2) PIC18LF6390/6490/8390/8490
59 59 63
117 108 104 243 225 216 432 405 387 428 405 387 810 765 729 1.35 1.26 1.17 14.4 14.4 14.4 16.2 16.2 16.2
A A A A A A A A A A A A A A A mA mA mA mA mA mA mA mA mA
-40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C VDD = 5.0V VDD = 4.2V FOSC = 40 MHz (PRI_IDLE mode, EC oscillator) VDD = 5.0V VDD = 3.0V FOSC = 4 MHz (PRI_IDLE mode, EC oscillator) VDD = 2.0V VDD = 5.0V VDD = 3.0V FOSC = 1 MHz (PRI_IDLE mode, EC oscillator) VDD = 2.0V
PIC18LF6390/6490/8390/8490
108 108 117
All devices
270 216 270
PIC18LF6390/6490/8390/8490
234 230 243
PIC18LF6390/6490/8390/8490
378 387 405
All devices
.8 .8 .8
All devices
5.4 5.6 5.9
All devices
7.3 8.2 7.5
Legend: Note 1:
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
DS39629C-page 358
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device Supply Current (IDD)(2) PIC18LF6390/6490/8390/8490
13 14 16
40 40 40 70 70 70 150 150 150 15 15 18 30 30 35 80 80 85
A A A A A A A A A A A A A A A A A A
-40C +25C +80C -40C +25C +80C -40C +25C +80C -40C +25C +80C -40C +25C +80C -40C +25C +80C VDD = 5.0V VDD = 3.0V FOSC = 32 kHz (SEC_IDLE mode, Timer1 as clock)(4) VDD = 2.0V VDD = 5.0V VDD = 3.0V FOSC = 32 kHz (SEC_RUN mode, Timer1 as clock)(4) VDD = 2.0V
PIC18LF6390/6490/8390/8490
34 31 28
All devices
72 65 59
PIC18LF6390/6490/8390/8490
5.5 5.8 6.1
PIC18LF6390/6490/8390/8490
8.2 8.6 8.8
All devices
13 13 13
Legend: Note 1:
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
(c) 2007 Microchip Technology Inc.
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PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device
Module Differential Currents (IWDT, IBOR, ILVD, ILCD, IOSCB, IAD) D022 (IWDT) Watchdog Timer 1.7 2.1 2.6 2.2 2.4 2.8 2.9 3.1 3.3 D022A (IBOR) Brown-out Reset 17 42 D022B (ILVD) High/Low-Voltage Detect 14 18 21 D024 (ILCD) LCD Module 1.5 1.5 1.7 2.2 2.5 2.7 6.1 6.5 7.2 Legend: Note 1: 4 4 5 6 6 7 10 10 13 50 60 38 40 45 3 3 4 5 5 6 10 10 10 A A A A A A A A A A A A A A A A A A A A A A A -40C +25C +85C -40C +25C +85C -40C +25C +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C +25C +85C -40C +25C +85C -40C +25C +85C VDD = 5.0V VDD = 3.0V VDD = 2.0V VDD = 3.0V VDD = 5.0V VDD = 2.0V VDD = 3.0V VDD = 5.0V VDD = 5.0V VDD = 3.0V VDD = 2.0V
LCD on INTRC clock, LCD segments enabled. LCD on INTRC clock, LCD segments enabled. LCD on INTRC clock, LCD segments enabled.
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
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PIC18F6390/6490/8390/8490
26.2 DC Characteristics: Power-Down and Supply Current PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device
Module Differential Currents (IWDT, IBOR, ILVD, ILCD, IOSCB, IAD) D025 (IOSCB) Timer1 Oscillator 1.0 1.1 1.1 1.2 1.3 1.2 1.8 1.9 1.9 D026 (IAD) Legend: Note 1: A/D Converter 1.0 1.0 1.0 3.5 3.5 4.5 4.5 4.5 5.5 6.0 6.0 7.0 3.0 4.0 8.0 A A A A A A A A A A A A -10C +25C +70C -10C +25C +70C -10C +25C +70C -- -- -- VDD = 2.0V VDD = 3.0V VDD = 5.0V A/D on, not converting VDD = 5.0V 32 kHz on Timer1(4) VDD = 3.0V 32 kHz on Timer1(4) VDD = 2.0V 32 kHz on Timer1(4)
2:
3: 4:
Shading of rows is to assist in readability of the table. The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS; MCLR = VDD; WDT enabled/disabled as specified. Low-power Timer1 oscillator selected. BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than the sum of both specifications.
(c) 2007 Microchip Technology Inc.
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PIC18F6390/6490/8390/8490
26.3 DC Characteristics: PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Characteristic Input Low Voltage I/O Ports: D030 D030A D031 D032 D032A D033 VIH D040 D040A D041 D042 D042A D043 IIL D060 D061 D063 IPU D070 Note 1: 2: IPURB with Schmitt Trigger Buffer RC3 and RC4 MCLR OSC1 and T1OSI OSC1 Input Leakage Current(2,3) I/O Ports MCLR OSC1 Weak Pull-up Current PORTB Weak Pull-up Current 50 400 A VDD = 5V, VPIN = VSS -- -- -- 1 5 5 A A A VSS VPIN VDD, Pin at hi-impedance VSS VPIN VDD VSS VPIN VDD with Schmitt Trigger Buffer RC3 and RC4 MCLR OSC1 and T1OSI OSC1 Input High Voltage I/O Ports: with TTL Buffer 0.25 VDD + 0.8V 2.0 0.8 VDD 0.7 VDD 0.8 VDD 0.7 VDD 0.8 VDD VDD VDD VDD VDD VDD VDD VDD V V V V V V V LP, XT, HS, HSPLL modes(1) EC mode(1) VDD < 4.5V 4.5V VDD 5.5V with TTL Buffer VSS -- VSS VSS VSS VSS VSS 0.15 VDD 0.8 0.2 VDD 0.3 VDD 0.2 VDD 0.3 VDD 0.2 VDD V V V V V V V LP, XT, HS, HSPLL modes(1) EC mode(1) VDD < 4.5V 4.5V VDD 5.5V Min Max Units Conditions
DC CHARACTERISTICS Param Symbol No. VIL
3: 4:
In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC(R) device be driven with an external clock while in RC mode. The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. Negative current is defined as current sourced by the pin. Parameter is characterized but not tested.
DS39629C-page 362
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PIC18F6390/6490/8390/8490
26.3 DC Characteristics: PIC18F6390/6490/8390/8490 (Industrial) PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Characteristic Output Low Voltage I/O Ports OSC2/CLKO (RC, RCIO, EC, ECIO modes) VOH D090 D092 D150 VOD Output High Voltage(3) I/O Ports OSC2/CLKO (RC, RCIO, EC, ECIO modes) Open-Drain High Voltage Capacitive Loading Specs on Output Pins D100(4) COSC2 OSC2 pin -- 15 pF In XT, HS and LP modes when external clock is used to drive OSC1 To meet the AC Timing Specifications I2CTM Specification VDD - 0.7 VDD - 0.7 -- -- -- 8.5 V V V IOH = -3.0 mA, VDD = 4.5V, -40C to +85C IOH = -1.3 mA, VDD = 4.5V, -40C to +85C RA4 pin -- -- 0.6 0.6 V V IOL = 8.5 mA, VDD = 4.5V, -40C to +85C IOL = 1.6 mA, VDD = 4.5V, -40C to +85C Min Max Units Conditions
DC CHARACTERISTICS Param Symbol No. VOL D080 D083
D101 D102 Note 1: 2:
CIO CB
All I/O pins and OSC2 (in RC mode) SCL, SDA
-- --
50 400
pF pF
3: 4:
In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC(R) device be driven with an external clock while in RC mode. The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. Negative current is defined as current sourced by the pin. Parameter is characterized but not tested.
(c) 2007 Microchip Technology Inc.
DS39629C-page 363
PIC18F6390/6490/8390/8490
TABLE 26-1: MEMORY PROGRAMMING REQUIREMENTS
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Characteristic Program Flash Memory D110 D113 D130 D131 D132 VPP IDDP EP VPR VIE Voltage on MCLR/VPP pin Supply Current during Programming Cell Endurance VDD for Read VDD for Block Erase VDD for Externally Timed Erase or Write VDD for Self-Timed Write ICSP Block Erase Cycle Time ICSP Erase or Write Cycle Time (externally timed) Self-Timed Write Cycle Time 10.0 -- -- VMIN 2.75 2.75 VMIN -- 2 -- 40 -- -- 1K -- -- -- -- 4 -- 2 100 12.0 1 -- 5.5 5.5 5.5 5.5 -- -- -- -- V mA E/W -40C to +85C V V V V ms ms ms Year Provided no other specifications are violated VMIN = Minimum operating voltage Using ICSPTM port Using ICSP port VMIN = Minimum operating voltage VDD > 4.5V VDD > 4.5V Min Typ Max Units Conditions DC Characteristics Param No. Sym
D132A VIW D132B VPEW D133 TIE
D133A TIW D133A TIW D134
TRETD Characteristic Retention
Data in "Typ" column is at 5.0V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested.
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(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 26-2:
Param No. D300 D301 D302 300 300A 301 * Note 1: TMC2OV Comparator Mode Change to Output Valid*
COMPARATOR SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 5.5V, -40C < TA < +85C, unless otherwise stated. Sym VIOFF VICM CMRR TRESP Characteristics Input Offset Voltage Input Common Mode Voltage* Common Mode Rejection Ratio* Response Time*(1) Min -- 0 55 -- -- -- Typ 5.0 -- -- 150 150 -- Max 10 VDD - 1.5 -- 400 600 10 Units mV V dB ns ns s PIC18FXXXX PIC18LFXXXX, VDD = 2.0V Comments
These parameters are characterized but not tested. Response time measured with one comparator input at (VDD - 1.5)/2, while the other input transitions from VSS to VDD.
TABLE 26-3:
Param No. D310 D311 D312 310 Note 1:
VOLTAGE REFERENCE SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 5.5V, -40C < TA < +85C, unless otherwise stated. Sym VRES VRAA VRUR TSET Characteristics Resolution Absolute Accuracy Unit Resistor Value (R) Settling Time(1) Min VDD/24 -- -- -- Typ -- -- 2k -- Max VDD/32 1/2 -- 10 Units LSb LSb s Comments
Settling time measured while CVRR = 1 and CVR3:CVR0 transitions from `0000' to `1111'.
(c) 2007 Microchip Technology Inc.
DS39629C-page 365
PIC18F6390/6490/8390/8490
FIGURE 26-3: HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS
VDD VHLVD For VDIRMAG = 1:
(HLVDIF set by hardware)
(HLVDIF can be cleared in software)
VHLVD For VDIRMAG = 0: VDD
HLVDIF
TABLE 26-4:
HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial
Param Sym No. D420
Characteristic HLVD Voltage on VDD Transition High-to-Low HLVDL<3:0> = 0000 HLVDL<3:0> = 0001 HLVDL<3:0> = 0010 HLVDL<3:0> = 0011 HLVDL<3:0> = 0100 HLVDL<3:0> = 0101 HLVDL<3:0> = 0110 HLVDL<3:0> = 0111 HLVDL<3:0> = 1000 HLVDL<3:0> = 1001 HLVDL<3:0> = 1010 HLVDL<3:0> = 1011 HLVDL<3:0> = 1100 HLVDL<3:0> = 1101 HLVDL<3:0> = 1110
Min 2.06 2.12 2.24 2.32 2.47 2.65 2.74 2.96 3.22 3.37 3.52 3.70 3.90 4.11 4.36 --
Typ 2.17 2.23 2.36 2.44 2.60 2.79 2.89 3.12 3.39 3.55 3.71 3.90 4.11 4.33 4.59 1.2
Max 2.28 2.34 2.48 2.56 2.73 2.93 3.04 3.28 3.56 3.73 3.90 4.10 4.32 4.55 4.82 --
Units V V V V V V V V V V V V V V V V
Conditions
D423
VBG
Band Gap Reference Voltage Value
HLVDL<3:0> = 1111
HLVD input external.
Production tested at TAMB = 25C. Specifications over temperature limits ensured by characterization.
DS39629C-page 366
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PIC18F6390/6490/8390/8490
26.4
26.4.1
AC (Timing) Characteristics
TIMING PARAMETER SYMBOLOGY
The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 2. TppS T F Frequency Lowercase letters (pp) and their meanings: pp cc CCP1 ck CLKO cs CS di SDI do SDO dt Data in io I/O port mc MCLR Uppercase letters and their meanings: S F Fall H High I Invalid (High-impedance) L Low I2C only AA output access BUF Bus free TCC:ST (I2C specifications only) CC HD Hold ST DAT DATA input hold STA Start condition 3. TCC:ST 4. Ts T (I2C specifications only) (I2C specifications only) Time
osc rd rw sc ss t0 t1 wr
OSC1 RD RD or WR SCK SS T0CKI T13CKI WR
P R V Z High Low
Period Rise Valid High-impedance High Low
SU STO
Setup Stop condition
(c) 2007 Microchip Technology Inc.
DS39629C-page 367
PIC18F6390/6490/8390/8490
26.4.2 TIMING CONDITIONS
Note: The temperature and voltages specified in Table 26-5 apply to all timing specifications unless otherwise noted. Figure 26-4 specifies the load conditions for the timing specifications. Because of space limitations, the generic terms "PIC18FXXXX" and "PIC18LFXXXX" are used throughout this section to refer to the PIC18F6390/6490/8390/8490 and PIC18LF6390/6490/8390/8490 families of devices specifically and only those devices.
TABLE 26-5:
TEMPERATURE AND VOLTAGE SPECIFICATIONS - AC
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Operating voltage VDD range as described in DC spec Section 26.1 and Section 26.3. LF parts operate for industrial temperatures only.
AC CHARACTERISTICS
FIGURE 26-4:
LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS
Load Condition 1 VDD/2 RL Pin VSS Pin VSS CL RL = 464 CL = 50 pF for all pins except OSC2/CLKO and including D and E outputs as ports CL Load Condition 2
DS39629C-page 368
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.4.3 TIMING DIAGRAMS AND SPECIFICATIONS EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)
Q4 Q1 Q2 Q3 Q4 Q1
FIGURE 26-5:
OSC1
1 2 3 3 4 4
CLKO
TABLE 26-6:
Param. No. 1A
EXTERNAL CLOCK TIMING REQUIREMENTS
Characteristic External CLKI Frequency(1) Min DC DC DC Oscillator Frequency
(1)
Symbol FOSC
Max 1 20 31.25 4 4 20 200 -- -- -- -- 1 250 250 -- -- -- -- -- 20 50 7.5
Units MHz MHz kHz MHz MHz MHz kHz ns ns s ns s ns ns s ns ns s ns ns ns ns
Conditions XT, RC Oscillator mode HS Oscillator mode LP Oscillator mode RC Oscillator mode XT Oscillator mode HS Oscillator mode LP Oscillator mode XT, RC Oscillator mode HS Oscillator mode LP Oscillator mode RC Oscillator mode XT Oscillator mode HS Oscillator mode HS Oscillator mode LP Oscillator mode TCY = 4/FOSC XT Oscillator mode LP Oscillator mode HS Oscillator mode XT Oscillator mode LP Oscillator mode HS Oscillator mode
DC 0.1 4 5
1
TOSC
External CLKI Period(1)
1000 50 32
Oscillator Period
(1)
250 250 100 50 5
2 3
TCY TOSL, TOSH TOSR, TOSF
Instruction Cycle Time(1) External Clock in (OSC1) High or Low Time External Clock in (OSC1) Rise or Fall Time
100 30 2.5 10 -- -- --
4
Note 1:
Instruction cycle period (TCY) equals four times the input oscillator time base period for all configurations except PLL. All specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at "min." values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the "max." cycle time limit is "DC" (no clock) for all devices.
(c) 2007 Microchip Technology Inc.
DS39629C-page 369
PIC18F6390/6490/8390/8490
TABLE 26-7:
Param No. F10 F11 F12 F13 Sym
PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2V TO 5.5V)
Characteristic Min 4 16 -- -2 Typ -- -- -- -- Max 10 40 2 +2 Units Conditions
FOSC Oscillator Frequency Range FSYS On-Chip VCO System Frequency trc CLK PLL Start-up Time (Lock Time) CLKO Stability (Jitter)
MHz HS mode only MHz HS mode only ms %
Data in "Typ" column is at 5V, 25C, unless otherwise stated. These parameters are for design guidance only and are not tested.
TABLE 26-8:
AC CHARACTERISTICS: INTERNAL RC ACCURACY PIC18LF6390/6490/8390/8490 (INDUSTRIAL) PIC18F6390/6490/8390/8490 (INDUSTRIAL)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Min Typ Max Units Conditions
PIC18LF6390/6490/8390/8490 (Industrial) PIC18F6390/6490/8390/8490 (Industrial) Param No. Device
INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz(1) PIC18LF6390/6490/8390/8490 -2 -5 -10 PIC18F6390/6490/8390/8490 -2 -5 -10 INTRC Accuracy @ Freq = 31 kHz(2) PIC18LF6390/6490/8390/8490 26.562 PIC18F6390/6490/8390/8490 26.562 Legend: Note 1: 2: -- -- 35.938 35.938 kHz kHz -40C to +85C -40C to +85C VDD = 2.7-3.3V VDD = 4.5-5.5V +/-1 -- +/-1 +/-1 -- +/-1 2 5 10 2 5 10 % % % % % % +25C -10C to +85C -40C to +85C +25C -10C to +85C -40C to +85C VDD = 2.7-3.3V VDD = 2.7-3.3V VDD = 2.7-3.3V VDD = 4.5-5.5V VDD = 4.5-5.5V VDD = 4.5-5.5V
Shading of rows is to assist in readability of the table. Frequency calibrated at 25C. OSCTUNE register can be used to compensate for temperature drift. INTRC frequency after calibration.
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FIGURE 26-6: CLKO AND I/O TIMING
Q4 OSC1 10 CLKO 13 14 I/O pin (Input) 17 I/O pin (Output) Old Value 20, 21 Refer to Figure 26-4 for load conditions. 15 New Value 19 18 12 16 11 Q1 Q2 Q3
Note:
TABLE 26-9:
Param No. 10 11 12 13 14 15 16 17 18 18A 19 20 20A 21 21A 22 23 TINP TRBP TIOF
CLKO AND I/O TIMING REQUIREMENTS
Characteristic Min -- -- -- -- -- 0.25 TCY + 25 0 -- 100 200 0 -- -- -- -- TCY TCY PIC18FXXXX PIC18LFXXXX Typ 75 75 35 35 -- -- -- 50 -- -- -- 10 -- 10 -- -- -- Max 200 200 100 100 0.5 TCY + 20 -- -- 150 -- -- -- 25 60 25 60 -- -- Units Conditions ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns VDD = 2.0V VDD = 2.0V VDD = 2.0V (Note 1) (Note 1) (Note 1) (Note 1) (Note 1) (Note 1) (Note 1)
Symbol
TOSH2CKL OSC1 to CLKO TOSH2CKH OSC1 to CLKO TCKR TCKF CLKO Rise Time CLKO Fall Time
TCKL2IOV CLKO to Port Out Valid TIOV2CKH Port In Valid before CLKO TCKH2IOI TOSH2IOI Port In Hold after CLKO OSC1 (Q2 cycle) to Port Input Invalid (I/O in hold time) Port Output Rise Time Port Output Fall Time TOSH2IOV OSC1 (Q1 cycle) to Port Out Valid
TIOV2OSH Port Input Valid to OSC1 (I/O in setup time) TIOR PIC18FXXXX PIC18LFXXXX PIC18FXXXX PIC18LFXXXX INTx pin High or Low Time RB7:RB4 Change INTx High or Low Time
These parameters are asynchronous events not related to any internal clock edges. Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC.
(c) 2007 Microchip Technology Inc.
DS39629C-page 371
PIC18F6390/6490/8390/8490
FIGURE 26-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING
VDD MCLR Internal POR PWRT Time-out Oscillator Time-out Internal Reset Watchdog Timer Reset 34 I/O pins Note: Refer to Figure 26-4 for load conditions. 33 32 30
31
34
FIGURE 26-8:
VDD VIRVST Enable Internal Reference Voltage Internal Reference Voltage Stable
BROWN-OUT RESET TIMING
BVDD 35 VBGAP = 1.2V
36
TABLE 26-10: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER AND BROWN-OUT RESET REQUIREMENTS
Param. Symbol No. 30 31 32 33 34 35 36 37 38 39 TMCL TWDT TOST TPWRT TIOZ TBOR TIRVST TLVD TCSD TIOBST Characteristic MCLR Pulse Width (low) Watchdog Timer Time-out Period (No postscaler) Oscillator Start-up Timer Period Power-up Timer Period I/O High-Impedance from MCLR Low or Watchdog Timer Reset Brown-out Reset Pulse Width Time for Internal Reference Voltage to become Stable Low-Voltage Detect Pulse Width CPU Start-up Time Time for INTRC Block to Stabilize Min 2 3.4 1024 TOSC 55.5 -- 200 -- 200 -- -- Typ -- 4.0 -- 65.5 2 -- 20 -- 10 1 Max -- 4.6 1024 TOSC 75 -- -- 50 -- -- -- Units s ms -- ms s s s s s ms VDD VLVD VDD BVDD (see D005) TOSC = OSC1 period Conditions
DS39629C-page 372
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PIC18F6390/6490/8390/8490
FIGURE 26-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
40 42 T1OSO/T13CKI
41
45 47 TMR0 or TMR1 Note: Refer to Figure 26-4 for load conditions.
46
48
TABLE 26-11: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param No. 40 41 42 Symbol TT0H TT0L TT0P Characteristic T0CKI High Pulse Width T0CKI Low Pulse Width T0CKI Period No Prescaler With Prescaler No Prescaler With Prescaler No Prescaler With Prescaler Min 0.5 TCY + 20 10 0.5 TCY + 20 10 TCY + 10 Greater of: 20 ns or (TCY + 40)/N 0.5 TCY + 20 10 25 30 50 0.5 TCY + 5 10 25 30 50 Greater of: 20 ns or (TCY + 40)/N 60 DC 2 TOSC Max -- -- -- -- -- -- Units ns ns ns ns ns ns N = prescale value (1, 2, 4,..., 256) Conditions
45
TT1H
T13CKI Synchronous, No Prescaler High Time Synchronous, PIC18FXXXX with Prescaler PIC18LFXXXX Asynchronous PIC18FXXXX PIC18LFXXXX
-- -- -- -- -- -- -- -- -- -- --
ns ns ns ns ns ns ns ns ns ns ns VDD = 2.0V N = prescale value (1, 2, 4, 8) VDD = 2.0V VDD = 2.0V VDD = 2.0V
46
TT1L
T13CKI Low Time
Synchronous, No Prescaler Synchronous, with Prescaler Asynchronous PIC18FXXXX PIC18LFXXXX PIC18FXXXX PIC18LFXXXX
47
TT1P
T13CKI Input Period
Synchronous
Asynchronous FT1 48 T13CKI Oscillator Input Frequency Range TCKE2TMRI Delay from External T13CKI Clock Edge to Timer Increment
-- 50 7 TOSC
ns kHz --
(c) 2007 Microchip Technology Inc.
DS39629C-page 373
PIC18F6390/6490/8390/8490
FIGURE 26-10: CAPTURE/COMPARE/PWM TIMINGS (ALL CCP MODULES)
CCPx (Capture Mode)
50 52
51
CCPx (Compare or PWM Mode) 53 Note: Refer to Figure 26-4 for load conditions. 54
TABLE 26-12: CAPTURE/COMPARE/PWM REQUIREMENTS (ALL CCP MODULES)
Param Symbol No. 50 TCCL Characteristic CCPx Input Low No Prescaler Time With PIC18FXXXX Prescaler PIC18LFXXXX CCPx Input High Time No Prescaler With Prescaler PIC18FXXXX PIC18LFXXXX Min 0.5 TCY + 20 10 20 0.5 TCY + 20 10 20 3 TCY + 40 N PIC18FXXXX PIC18LFXXXX 54 TCCF CCPx Output Fall Time PIC18FXXXX PIC18LFXXXX -- -- -- -- Max -- -- -- -- -- -- -- 25 45 25 45 Units ns ns ns ns ns ns ns ns ns ns ns VDD = 2.0V VDD = 2.0V VDD = 2.0V N = prescale value (1, 4 or 16) VDD = 2.0V Conditions
51
TCCH
52 53
TCCP TCCR
CCPx Input Period CCPx Output Fall Time
DS39629C-page 374
(c) 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-11:
SS 70 SCK (CKP = 0) 71 72 78 79
EXAMPLE SPI MASTER MODE TIMING (CKE = 0)
SCK (CKP = 1) 79 MSb 75, 76 SDI MSb In 74 73 Note: Refer to Figure 26-4 for load conditions. bit 6 - - - - 1 LSb In bit 6 - - - - - - 1 78 LSb
80 SDO
TABLE 26-13: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)
Param No. 70 71 71A 72 72A 73 73A 74 75 76 78 79 80 Note 1: 2: TDIV2SCH, TDIV2SCL TB2B TSCH2DIL, TSCL2DIL TDOR TDOF TSCR TSCF TSCL Symbol TSSL2SCH, TSSL2SCL TSCH Characteristic SS to SCK or SCK Input SCK Input High Time (Slave mode) SCK Input Low Time (Slave mode) Continuous Single Byte Continuous Single Byte Min TCY 1.25 TCY + 30 40 1.25 TCY + 30 40 100 1.5 TCY + 40 100 -- -- -- PIC18FXXXX PIC18LFXXXX PIC18FXXXX PIC18LFXXXX -- -- -- -- -- Max Units -- -- -- -- -- -- -- -- 25 45 25 25 45 25 50 100 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns VDD = 2.0V VDD = 2.0V VDD = 2.0V (Note 2) (Note 1) (Note 1) Conditions
Setup Time of SDI Data Input to SCK Edge Last Clock Edge of Byte 1 to the 1st Clock Edge of Byte 2 Hold Time of SDI Data Input to SCK Edge SDO Data Output Rise Time SDO Data Output Fall Time SCK Output Rise Time (Master mode) PIC18FXXXX PIC18LFXXXX
SCK Output Fall Time (Master mode)
TSCH2DOV, SDO Data Output Valid after TSCL2DOV SCK Edge
Requires the use of Parameter #73A. Only if Parameter #71A and #72A are used.
(c) 2007 Microchip Technology Inc.
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FIGURE 26-12:
SS 81 SCK (CKP = 0) 71 73 SCK (CKP = 1) 72 79
EXAMPLE SPI MASTER MODE TIMING (CKE = 1)
80 78 MSb 75, 76 bit 6 - - - - - - 1 LSb
SDO
SDI
MSb In 74
bit 6 - - - - 1
LSb In
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-14: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)
Param. No. 71 71A 72 72A 73 73A 74 75 76 78 79 80 81 Note 1: 2: TDIV2SCH, TDIV2SCL TB2B TSCH2DIL, TSCL2DIL TDOR TDOF TSCR TSCF TSCL Symbol TSCH Characteristic SCK Input High Time (Slave mode) SCK Input Low Time (Slave mode) Continuous Single Byte Continuous Single Byte Min 1.25 TCY + 30 40 1.25 TCY + 30 40 100 1.5 TCY + 40 100 -- -- -- PIC18FXXXX PIC18LFXXXX PIC18FXXXX PIC18LFXXXX -- -- -- -- -- TCY Max Units -- -- -- -- -- -- -- 25 45 25 25 45 25 50 100 -- ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns VDD = 2.0V VDD = 2.0V VDD = 2.0V (Note 2) (Note 1) (Note 1) Conditions
Setup Time of SDI Data Input to SCK Edge Last Clock Edge of Byte 1 to the 1st Clock Edge of Byte 2 Hold Time of SDI Data Input to SCK Edge SDO Data Output Rise Time SDO Data Output Fall Time SCK Output Rise Time (Master mode) PIC18FXXXX PIC18LFXXXX
SCK Output Fall Time (Master mode)
TSCH2DOV, SDO Data Output Valid after TSCL2DOV SCK Edge
TDOV2SCH, SDO Data Output Setup to SCK Edge TDOV2SCL Requires the use of Parameter #73A. Only if Parameter #71A and #72A are used.
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FIGURE 26-13:
SS 70 SCK (CKP = 0) 71 72 78 79 83
EXAMPLE SPI SLAVE MODE TIMING (CKE = 0)
SCK (CKP = 1) 80 SDO MSb 75, 76 SDI MSb In 74 73 Note: Refer to Figure 26-4 for load conditions. bit 6 - - - - 1 LSb In 79 bit 6 - - - - - - 1 78 LSb 77
TABLE 26-15: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING, CKE = 0)
Param No. 70 71 71A 72 72A 73 73A 74 75 76 77 78 79 80 83 Note 1: 2: TSCL Symbol Characteristic Min TCY Continuous Single Byte Continuous Single Byte 1.25 TCY + 30 40 1.25 TCY + 30 40 100 Max Units Conditions -- -- -- -- -- -- -- -- 25 45 25 50 25 45 25 50 100 -- ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns VDD = 2.0V VDD = 2.0V VDD = 2.0V (Note 2) (Note 1) (Note 1)
TSSL2SCH, SS to SCK or SCK Input TSSL2SCL TSCH SCK Input High Time (Slave mode) SCK Input Low Time (Slave mode)
TDIV2SCH, Setup Time of SDI Data Input to SCK Edge TDIV2SCL TB2B TSCH2DIL, Hold Time of SDI Data Input to SCK Edge TSCL2DIL TDOR TDOF TSCR TSCF SDO Data Output Rise Time SDO Data Output Fall Time SCK Output Rise Time (Master mode) SCK Output Fall Time (Master mode) PIC18FXXXX PIC18LFXXXX TSCH2DOV, SDO Data Output Valid after SCK Edge PIC18FXXXX TSCL2DOV PIC18LFXXXX TSCH2SSH, SS after SCK Edge TSCL2SSH Requires the use of Parameter #73A. Only if Parameter #71A and #72A are used. PIC18FXXXX PIC18LFXXXX TSSH2DOZ SS to SDO Output High-Impedance
Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40 100 -- -- -- 10 -- -- -- -- -- 1.5 TCY + 40
(c) 2007 Microchip Technology Inc.
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FIGURE 26-14:
SS 70 83 71 72
EXAMPLE SPI SLAVE MODE TIMING (CKE = 1)
82
SCK (CKP = 0)
SCK (CKP = 1) 80
SDO
MSb 75, 76
bit 6 - - - - - - 1
LSb 77
SDI
MSb In
bit 6 - - - - 1
LSb In
Note:
74 Refer to Figure 26-4 for load conditions.
TABLE 26-16: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)
Param No. 70 71 71A 72 72A 73A 74 75 76 77 78 79 80 82 83 TB2B TSCL Symbol Characteristic Min TCY Continuous Single Byte Continuous Single Byte 1.25 TCY + 30 40 1.25 TCY + 30 40 100 -- -- -- 10 -- -- -- -- -- -- -- 1.5 TCY + 40 PIC18FXXXX PIC18LFXXXX PIC18FXXXX PIC18LFXXXX PIC18FXXXX PIC18LFXXXX Max Units Conditions -- -- -- -- -- -- -- 25 45 25 50 25 45 25 50 100 50 100 -- ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns VDD = 2.0V VDD = 2.0V VDD = 2.0V VDD = 2.0V (Note 1) (Note 2) (Note 1)
TSSL2SCH, SS to SCK or SCK Input TSSL2SCL TSCH SCK Input High Time (Slave mode) SCK Input Low Time (Slave mode)
Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40
TSCH2DIL, Hold Time of SDI Data Input to SCK Edge TSCL2DIL TDOR TDOF TSCR TSCF SDO Data Output Rise Time SDO Data Output Fall Time SCK Output Rise Time (Master mode) PIC18FXXXX PIC18LFXXXX TSSH2DOZ SS to SDO Output High-Impedance
SCK Output Fall Time (Master mode)
TSCH2DOV, SDO Data Output Valid after SCK TSCL2DOV Edge TSSL2DOV SDO Data Output Valid after SS Edge TSCH2SSH, SS after SCK Edge TSCL2SSH Requires the use of Parameter #73A. Only if Parameter #71A and #72A are used.
Note 1: 2:
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FIGURE 26-15: I2CTM BUS START/STOP BITS TIMING
SCL 90 SDA
91 92
93
Start Condition
Stop Condition
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-17: I2CTM BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)
Param. Symbol No. 90 91 92 93 TSU:STA THD:STA TSU:STO Setup Time Start Condition Hold Time Stop Condition Setup Time THD:STO Stop Condition Hold Time Characteristic Start Condition 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode Min 4700 600 4000 600 4700 600 4000 600 Max -- -- -- -- -- -- -- -- ns ns ns Units ns Conditions Only relevant for Repeated Start condition After this period, the first clock pulse is generated
FIGURE 26-16:
I2CTM BUS DATA TIMING
103 100 101 102
SCL
90 91
106
107 92
SDA In
110 109 109
SDA Out Note: Refer to Figure 26-4 for load conditions.
(c) 2007 Microchip Technology Inc.
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TABLE 26-18: I2CTM BUS DATA REQUIREMENTS (SLAVE MODE)
Param. No. 100 Symbol THIGH Characteristic Clock High Time 100 kHz mode 400 kHz mode MSSP module 101 TLOW Clock Low Time 100 kHz mode 400 kHz mode MSSP module 102 TR SDA and SCL Rise Time 100 kHz mode 400 kHz mode 103 TF SDA and SCL Fall Time 100 kHz mode 400 kHz mode 90 91 106 107 92 109 110 TSU:STA THD:STA THD:DAT TSU:DAT TSU:STO TAA TBUF Start Condition Setup Time 100 kHz mode 400 kHz mode Start Condition Hold Time Data Input Hold Time Data Input Setup Time 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode Stop Condition Setup Time 100 kHz mode 400 kHz mode Output Valid from Clock Bus Free Time 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode D102 Note 1: 2: CB Bus Capacitive Loading Min 4.0 0.6 1.5 TCY 4.7 1.3 1.5 TCY -- 20 + 0.1 CB -- 20 + 0.1 CB 4.7 0.6 4.0 0.6 0 0 250 100 4.7 0.6 -- -- 4.7 1.3 -- Max -- -- -- -- -- -- 1000 300 300 300 -- -- -- -- -- 0.9 -- -- -- -- 3500 -- -- -- 400 ns ns ns ns s s s s ns s ns ns s s ns ns s s pF Time the bus must be free before a new transmission can start (Note 1) (Note 2) CB is specified to be from 10 to 400 pF Only relevant for Repeated Start condition After this period, the first clock pulse is generated CB is specified to be from 10 to 400 pF s s PIC18FXXXX must operate at a minimum of 1.5 MHz PIC18FXXXX must operate at a minimum of 10 MHz Units s s Conditions PIC18FXXXX must operate at a minimum of 1.5 MHz PIC18FXXXX must operate at a minimum of 10 MHz
As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions. A Fast mode I2C bus device can be used in a Standard mode I2CTM bus system, but the requirement, TSU:DAT 250 ns, must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification), before the SCL line is released.
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FIGURE 26-17: MASTER SSP I2CTM BUS START/STOP BITS TIMING WAVEFORMS
SCL 90 SDA
91 92
93
Start Condition Note: Refer to Figure 26-4 for load conditions.
Stop Condition
TABLE 26-19: MASTER SSP I2CTM BUS START/STOP BITS REQUIREMENTS
Param. Symbol No. 90 TSU:STA Characteristic Start Condition Setup Time 91 THD:STA Start Condition Hold Time 92 TSU:STO Stop Condition Setup Time 93 THD:STO Stop Condition Hold Time Note 1: 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) Min 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) Max -- -- -- -- -- -- -- -- -- -- -- -- ns ns ns Units ns Conditions Only relevant for Repeated Start condition After this period, the first clock pulse is generated
Maximum pin capacitance = 10 pF for all I2CTM pins.
FIGURE 26-18:
MASTER SSP I2CTM BUS DATA TIMING
103 100 101 102
SCL SDA In
90
91
106
107
92
109
109
110
SDA Out Note: Refer to Figure 26-4 for load conditions.
(c) 2007 Microchip Technology Inc.
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TABLE 26-20: MASTER SSP I2CTM BUS DATA REQUIREMENTS
Param. Symbol No. 100 THIGH Characteristic Clock High Time 100 kHz mode 400 kHz mode 1 MHz 101 TLOW mode(1) Clock Low Time 100 kHz mode 400 kHz mode 1 MHz 102 TR SDA and SCL Rise Time SDA and SCL Fall Time Start Condition Setup Time mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) 103 TF 100 kHz mode 400 kHz mode 1 MHz mode(1) 90 TSU:STA 100 kHz mode 400 kHz mode 1 MHz mode(1) 91 THD:STA Start Condition Hold Time THD:DAT Data Input Hold Time TSU:DAT Data Input Setup Time 100 kHz mode 400 kHz mode 1 MHz mode(1) 106 100 kHz mode 400 kHz mode 1 MHz mode(1) 107 100 kHz mode 400 kHz mode 1 MHz mode(1) 92 TSU:STO Stop Condition Setup Time TAA Output Valid from Clock Bus Free Time 100 kHz mode 400 kHz mode 1 MHz 109 mode(1) 100 kHz mode 400 kHz mode 1 MHz mode 110 TBUF
(1)
Min 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) -- 20 + 0.1 CB -- -- 20 + 0.1 CB -- 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 0 0 -- 250 100 -- 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) -- -- -- 4.7 1.3 -- --
Max -- -- -- -- -- -- 1000 300 300 300 300 100 -- -- -- -- -- -- -- 0.9 -- -- -- -- -- -- -- 3500 1000 -- -- -- -- 400
Units ms ms ms ms ms ms ns ns ns ns ns ns ms ms ms ms ms ms ns ms ns ns ns ns ms ms ms ns ns ns ms ms ms pF
Conditions
CB is specified to be from 10 to 400 pF CB is specified to be from 10 to 400 pF Only relevant for Repeated Start condition After this period, the first clock pulse is generated
(Note 2)
100 kHz mode 400 kHz mode 1 MHz mode(1)
Time the bus must be free before a new transmission can start
D102 Note 1: 2:
CB
Bus Capacitive Loading
Maximum pin capacitance = 10 pF for all I2CTM pins. A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but parameter #107 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode,) before the SCL line is released.
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FIGURE 26-19:
RC6/TX1/CK1 pin RC7/RX1/DT1 pin 120 Note: Refer to Figure 26-4 for load conditions. 122
USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
121
121
TABLE 26-21: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS
Param No. 120 Symbol Characteristic Min -- -- -- -- -- -- Max 40 100 20 50 20 50 Units ns ns ns ns ns ns VDD = 2.0V VDD = 2.0V VDD = 2.0V Conditions
TCKH2DTV SYNC XMIT (MASTER and SLAVE) Clock High to Data Out Valid PIC18FXXXX PIC18LFXXXX TCKRF TDTRF Clock Out Rise Time and Fall Time (Master mode) Data Out Rise Time and Fall Time PIC18FXXXX PIC18LFXXXX PIC18FXXXX PIC18LFXXXX
121 122
FIGURE 26-20:
RC6/TX1/CK1 pin RC7/RX1/DT1 pin
USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
125
126 Note: Refer to Figure 26-4 for load conditions.
TABLE 26-22: USART SYNCHRONOUS RECEIVE REQUIREMENTS
Param. No. 125 126 Symbol Characteristic Min 10 15 Max -- -- Units ns ns Conditions
TDTV2CKL SYNC RCV (MASTER and SLAVE) Data Hold before CKx (DTx hold time) TCKL2DTL Data Hold after CKx (DTx hold time)
(c) 2007 Microchip Technology Inc.
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TABLE 26-23: A/D CONVERTER CHARACTERISTICS: PIC18F6390/6490/8390/8490 (INDUSTRIAL) PIC18LF6390/6490/8390/8490 (INDUSTRIAL)
Param Symbol No. A01 A03 A04 A06 A07 A10 A20 A21 A22 A25 A30 A50 NR EIL EDL EOFF EGN -- VREF VREFH VREFL VAIN ZAIN IREF Characteristic Resolution Integral Linearity Error Differential Linearity Error Offset Error Gain Error Monotonicity Reference Voltage Range (VREFH - VREFL) Reference Voltage High Reference Voltage Low Analog Input Voltage Recommended Impedance of Analog Voltage Source VREF Input Current (Note 2) 3 AVSS + 3.0V AVSS - 0.3V VREFL -- -- -- Min -- -- -- -- -- Typ -- -- -- -- -- Guaranteed(1) -- -- -- -- -- -- -- AVDD - AVSS AVDD + 0.3V AVDD - 3.0V VREFH 2.5 5 150 Max 10 <1 <1 <1 <1 Units bit Conditions VREF 3.0V
LSb VREF 3.0V LSb VREF 3.0V LSb VREF 3.0V LSb VREF 3.0V -- V V V V k A A During VAIN acquisition. During A/D conversion cycle. For 10-bit resolution For 10-bit resolution For 10-bit resolution
Note 1: 2:
The A/D conversion result never decreases with an increase in the input voltage and has no missing codes. VREFH current is from RA3/AN3/VREF+/SEG17 pin or AVDD, whichever is selected as the VREFH source. VREFL current is from RA2/AN2/VREF-/SEG16 pin or AVSS, whichever is selected as the VREFL source.
DS39629C-page 384
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PIC18F6390/6490/8390/8490
FIGURE 26-21: A/D CONVERSION TIMING
BSF ADCON0, GO (Note 2) Q4 A/D CLK 132 131 130
A/D DATA
9
8
7
...
...
2
1
0
ADRES ADIF GO
OLD_DATA
NEW_DATA TCY DONE
SAMPLE Note 1: 2:
SAMPLING STOPPED
If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input.
TABLE 26-24: A/D CONVERSION REQUIREMENTS
Param Symbol No. 130 TAD Characteristic A/D Clock Period PIC18FXXXX PIC18LFXXXX PIC18FXXXX PIC18LFXXXX 131 132 135 TBD TCNV TACQ TSWC TDIS Conversion Time (not including acquisition time) (Note 2) Acquisition Time (Note 3) Switching Time from Convert Sample Discharge Time Min 0.7 1.4 TBD TBD 11 1.4 TBD -- 0.2 Max 25.0(1) 25.0(1) 1 3 12 -- -- (Note 4) -- s Units s s s s TAD s s -40C to +85C 0C to +85C Conditions TOSC based, VREF 3.0V VDD = 2.0V; TOSC based, VREF full range A/D RC mode VDD = 2.0V; A/D RC mode
Legend: Note 1: 2: 3: 4:
TBD = To Be Determined The time of the A/D clock period is dependent on the device frequency and the TAD clock divider. ADRES register may be read on the following TCY cycle. The time for the holding capacitor to acquire the "New" input voltage when the voltage changes full scale after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50. On the following cycle of the device clock.
(c) 2007 Microchip Technology Inc.
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NOTES:
DS39629C-page 386
(c) 2007 Microchip Technology Inc.
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27.0 DC AND AC CHARACTERISTICS GRAPHS AND TABLES
Graphs and tables are not available at this time.
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NOTES:
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28.0
28.1
PACKAGING INFORMATION
Package Marking Information
64-Lead TQFP
Example
XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN
PIC18F6490 -I/PT e3 0710017
80-Lead TQFP
Example
XXXXXXXXXXXX XXXXXXXXXXXX YYWWNNN
PIC18F8490-E /PT e3 0710017
Legend: XX...X Y YY WW NNN
e3
* Note:
Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week `01') Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free. The Pb-free JEDEC designator ( e3 ) can be found on the outer packaging for this package.
In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information.
(c) 2007 Microchip Technology Inc.
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28.2 Package Details
The following sections give the technical details of the packages.
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NOTES:
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APPENDIX A: REVISION HISTORY APPENDIX B:
Revision A (July 2004)
Original data sheet for PIC18F6390/6490/8390/8490 devices.
DEVICE DIFFERENCES
The differences between the devices listed in this data sheet are shown in Table B-1.
Revision B (August 2004)
Updated preliminary "electrical characteristics" data.
Revision C (November 2007)
Revised I2CTM Slave Mode Timing figure. Updated DC Power-Down and Supply Current table and package drawings.
TABLE B-1:
DEVICE DIFFERENCES
PIC18F6390 128 (4 x 32) PIC18F6490 128 (4 x 32) PIC18F8390 192 (4 x 48) PIC18F8490 192 (4 x 48)
Features Number of Pixels the LCD Driver can Drive I/O Ports Flash Program Memory Packages
Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E, F, G F, G F, G, H, J F, G, H, J 8 Kbytes 64-Pin TQFP 16 Kbytes 64-Pin TQFP 8 Kbytes 80-Pin TQFP 16 Kbytes 80-Pin TQFP
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APPENDIX C: CONVERSION CONSIDERATIONS APPENDIX D: MIGRATION FROM BASELINE TO ENHANCED DEVICES
This appendix discusses the considerations for converting from previous versions of a device to the ones listed in this data sheet. Typically, these changes are due to the differences in the process technology used. An example of this type of conversion is from a PIC16C74A to a PIC16C74B. Not Applicable
This section discusses how to migrate from a Baseline device (i.e., PIC16C5X) to an Enhanced MCU device (i.e., PIC18FXXX). The following are the list of modifications over the PIC16C5X microcontroller family: Not Currently Available
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APPENDIX E: MIGRATION FROM MID-RANGE TO ENHANCED DEVICES APPENDIX F: MIGRATION FROM HIGH-END TO ENHANCED DEVICES
A detailed discussion of the differences between the mid-range MCU devices (i.e., PIC16CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN716, "Migrating Designs from PIC16C74A/74B to PIC18C442." The changes discussed, while device specific, are generally applicable to all mid-range to enhanced device migrations. This Application Note is available as Literature Number DS00716.
A detailed discussion of the migration pathway and differences between the high-end MCU devices (i.e., PIC17CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN726, "PIC17CXXX to PIC18CXXX Migration." This Application Note is available as Literature Number DS00726.
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NOTES:
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INDEX
A
A/D ................................................................................... 231 A/D Converter Interrupt, Configuring ....................... 235 Acquisition Requirements ........................................ 236 ADCON0 Register .................................................... 231 ADCON1 Register .................................................... 231 ADCON2 Register .................................................... 231 ADRESH Register ............................................ 231, 234 ADRESL Register .................................................... 231 Analog Port Pins, Configuring .................................. 238 Associated Registers ............................................... 240 Automatic Acquisition Time ...................................... 237 Configuring the Module ............................................ 235 Conversion Clock (TAD) ........................................... 237 Conversion Status (GO/DONE Bit) .......................... 234 Conversions ............................................................. 239 Converter Characteristics ........................................ 384 Discharge ................................................................. 239 Operation in Power-Managed Modes ...................... 238 Special Event Trigger (CCP) .................................... 240 Use of the CCP2 Trigger .......................................... 240 Absolute Maximum Ratings ............................................. 349 AC (Timing) Characteristics ............................................. 367 Load Conditions for Device Timing Specifications ................................................... 368 Parameter Symbology ............................................. 367 Temperature and Voltage Specifications ................. 368 Timing Conditions .................................................... 368 Access Bank ...................................................................... 73 Mapping with Indexed Literal Offset Mode ................. 86 ACKSTAT ........................................................................ 187 ACKSTAT Status Flag ..................................................... 187 ADCON0 Register ............................................................ 231 GO/DONE Bit ........................................................... 234 ADCON1 Register ............................................................ 231 ADCON2 Register ............................................................ 231 ADDFSR .......................................................................... 338 ADDLW ............................................................................ 301 Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART). See AUSART. ADDULNK ........................................................................ 338 ADDWF ............................................................................ 301 ADDWFC ......................................................................... 302 ADRESH Register ............................................................ 231 ADRESL Register .................................................... 231, 234 Analog-to-Digital Converter. See A/D. ANDLW ............................................................................ 302 ANDWF ............................................................................ 303 Assembler MPASM Assembler .................................................. 346 AUSART Asynchronous Mode ................................................ 222 Associated Registers, Receive ........................ 225 Associated Registers, Transmit ....................... 223 Receiver ........................................................... 224 Setting up 9-Bit Mode with Address Detect ........................................ 224 Transmitter ....................................................... 222 Baud Rate Generator (BRG) ................................... 220 Associated Registers ....................................... 220 Baud Rate Error, Calculating ........................... 220 Baud Rates, Asynchronous Modes ................. 221 High Baud Rate Select (BRGH Bit) ................. 220 Operation in Power-Managed Modes .............. 220 Sampling ......................................................... 220 Synchronous Master Mode ...................................... 226 Associated Registers, Receive ........................ 228 Associated Registers, Transmit ....................... 227 Reception ........................................................ 228 Transmission ................................................... 226 Synchronous Slave Mode ........................................ 229 Associated Registers, Receive ........................ 230 Associated Registers, Transmit ....................... 229 Reception ........................................................ 230 Transmission ................................................... 229 Auto-Wake-up on Sync Break Character ......................... 210
B
Bank Select Register (BSR) .............................................. 71 Baud Rate Generator ...................................................... 183 BC .................................................................................... 303 BCF ................................................................................. 304 BF .................................................................................... 187 BF Status Flag ................................................................. 187 Block Diagrams A/D ........................................................................... 234 Analog Input Model .................................................. 235 AUSART Receive .................................................... 224 AUSART Transmit ................................................... 222 Baud Rate Generator .............................................. 183 Capture Mode Operation ......................................... 150 Comparator Analog Input Model .............................. 245 Comparator I/O Operating Modes ........................... 242 Comparator Output .................................................. 244 Comparator Voltage Reference ............................... 248 Compare Mode Operation ....................................... 151 Device Clock .............................................................. 36 EUSART Receive .................................................... 208 EUSART Transmit ................................................... 206 External Power-on Reset Circuit (Slow VDD Power-up) ........................................ 53 Fail-Safe Clock Monitor ........................................... 290 Generic I/O Port Operation ...................................... 109 HLVD Module (with External Input) ......................... 252 Interrupt Logic ............................................................ 94 LCD Clock Generation ............................................. 262 LCD Driver Module .................................................. 257 LCD Resistor Ladder Connection ............................ 263 MSSP (I2C Master Mode) ........................................ 181 MSSP (I2C Mode) .................................................... 166 MSSP (SPI Mode) ................................................... 157 On-Chip Reset Circuit ................................................ 51 PLL (HS Mode) .......................................................... 33 PWM Operation (Simplified) .................................... 153 Reads from Flash Program Memory ......................... 88 Single Comparator ................................................... 243 Table Read Operation ............................................... 87 Timer0 in 16-Bit Mode ............................................. 132
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Timer0 in 8-Bit Mode ................................................ 132 Timer1 ...................................................................... 136 Timer1 (16-Bit Read/Write Mode) ............................ 136 Timer2 ...................................................................... 142 Timer3 ...................................................................... 144 Timer3 (16-Bit Read/Write Mode) ............................ 144 Voltage Reference Output Buffer Example .............. 249 Watchdog Timer ....................................................... 287 BN .................................................................................... 304 BNC .................................................................................. 305 BNN .................................................................................. 305 BNOV ............................................................................... 306 BNZ .................................................................................. 306 BOR. See Brown-out Reset. BOV .................................................................................. 309 BRA .................................................................................. 307 Break Character (12-Bit) Transmit and Receive .............. 211 BRG. See Baud Rate Generator. Brown-out Reset (BOR) ............................................. 54, 281 Disabling in Sleep Mode ............................................ 54 BSF .................................................................................. 307 BSR .................................................................................... 86 BTFSC ............................................................................. 308 BTFSS .............................................................................. 308 BTG .................................................................................. 309 BZ ..................................................................................... 310 Initializing PORTA .................................................... 109 Initializing PORTB .................................................... 112 Initializing PORTC ................................................... 115 Initializing PORTD ................................................... 118 Initializing PORTE .................................................... 120 Initializing PORTF .................................................... 122 Initializing PORTG ................................................... 125 Initializing PORTH ................................................... 127 Initializing PORTJ .................................................... 129 Loading the SSPBUF (SSPSR) Register ................. 160 Reading a Flash Program Memory Word .................. 89 Saving STATUS, WREG and BSR Registers in RAM ............................................. 108 Code Protection ............................................................... 281 COMF .............................................................................. 312 Comparator ...................................................................... 241 Analog Input Connection Considerations ................ 245 Associated Registers ............................................... 245 Configuration ........................................................... 242 Effects of a Reset .................................................... 244 Interrupts ................................................................. 244 Operation ................................................................. 243 Operation During Sleep ........................................... 244 Outputs .................................................................... 243 Reference ................................................................ 243 External Signal ................................................ 243 Internal Signal .................................................. 243 Response Time ........................................................ 243 Comparator Specifications ............................................... 365 Comparator Voltage Reference ....................................... 247 Accuracy and Error .................................................. 248 Associated Registers ............................................... 249 Configuring .............................................................. 247 Connection Considerations ...................................... 248 Effects of a Reset .................................................... 248 Operation During Sleep ........................................... 248 Compare (CCP Module) .................................................. 151 Associated Registers ............................................... 152 CCP Pin Configuration ............................................. 151 CCPR2 Register ...................................................... 151 Software Interrupt .................................................... 151 Special Event Trigger .............................. 145, 151, 240 Timer1/Timer3 Mode Selection ................................ 151 Computed GOTO ............................................................... 68 Configuration Bits ............................................................ 281 Configuration Register Protection .................................... 292 Context Saving During Interrupts ..................................... 108 Conversion Considerations .............................................. 396 CPFSEQ .......................................................................... 312 CPFSGT .......................................................................... 313 CPFSLT ........................................................................... 313 Crystal Oscillator/Ceramic Resonator ................................ 31 Customer Change Notification Service ............................ 409 Customer Notification Service ......................................... 409 Customer Support ............................................................ 409
C
C Compilers MPLAB C18 ............................................................. 346 MPLAB C30 ............................................................. 346 CALL ................................................................................ 310 CALLW ............................................................................. 339 Capture (CCP Module) ..................................................... 150 Associated Registers ............................................... 152 CCP Pin Configuration ............................................. 150 CCPR2H:CCPR2L Registers ................................... 150 Software Interrupt .................................................... 150 Timer1/Timer3 Mode Selection ................................ 150 Capture/Compare/PWM (CCP) ........................................ 147 Capture Mode. See Capture. CCP Mode and Timer Resources ............................ 148 CCPRxH Register .................................................... 148 CCPRxL Register ..................................................... 148 Compare Mode. See Compare. Interaction of CCP1 and CCP2 for Timer Resources .............................................. 149 Interconnect Configurations ..................................... 148 Module Configuration ............................................... 148 Clock Sources .................................................................... 36 Selecting the 31 kHz Source ...................................... 37 Selection Using OSCCON Register ........................... 37 CLRF ................................................................................ 311 CLRWDT .......................................................................... 311 Code Examples 16 x 16 Signed Multiply Routine ................................ 92 16 x 16 Unsigned Multiply Routine ............................ 92 8 x 8 Signed Multiply Routine .................................... 91 8 x 8 Unsigned Multiply Routine ................................ 91 Changing Between Capture Prescalers ................... 150 Computed GOTO Using an Offset Value ................... 68 Fast Register Stack .................................................... 68 How to Clear RAM (Bank 1) Using Indirect Addressing ............................................ 81 Implementing a Real-Time Clock Using a Timer1 Interrupt Service ............................... 139
D
Data Addressing Modes .................................................... 81 Comparing Addressing Modes with the Extended Instruction Set Enabled ..................... 85 Direct ......................................................................... 81 Indexed Literal Offset ................................................ 84 Indirect ....................................................................... 81 Inherent and Literal .................................................... 81
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Data Memory ..................................................................... 71 Access Bank .............................................................. 73 and the Extended Instruction Set ............................... 84 Bank Select Register (BSR) ....................................... 71 General Purpose Registers ........................................ 73 Map for PIC18F6X90/8X90 Devices .......................... 72 Special Function Registers ........................................ 74 DAW ................................................................................. 314 DC and AC Characteristics Graphs and Tables .................................................. 387 DC Characteristics ........................................................... 362 Power-Down and Supply Current ............................ 352 Supply Voltage ......................................................... 351 DCFSNZ .......................................................................... 315 DECF ............................................................................... 314 DECFSZ ........................................................................... 315 Development Support ...................................................... 345 Device Differences ........................................................... 395 Device Overview .................................................................. 7 Features (table) ............................................................ 9 New Core Features ...................................................... 7 Special Features .......................................................... 8 Direct Addressing ............................................................... 82 Extended Instruction Set ADDFSR .................................................................. 338 ADDULNK ............................................................... 338 CALLW .................................................................... 339 MOVSF .................................................................... 339 MOVSS .................................................................... 340 PUSHL ..................................................................... 340 SUBFSR .................................................................. 341 SUBULNK ................................................................ 341 External Clock Input ........................................................... 32
F
Fail-Safe Clock Monitor ........................................... 281, 290 Interrupts in Power-Managed Modes ...................... 291 POR or Wake from Sleep ........................................ 291 WDT During Oscillator Failure ................................. 290 Fast Register Stack ........................................................... 68 Firmware Instructions ...................................................... 295 Flash Program Memory ..................................................... 87 Associated Registers ................................................. 89 Control Registers ....................................................... 88 TABLAT (Table Latch) Register ........................ 88 TBLPTR (Table Pointer) Register ...................... 88 Reading ..................................................................... 88 Table Reads .............................................................. 87 FSCM. See Fail-Safe Clock Monitor.
E
Effect on Standard Instructions .......................................... 84 Effect on Standard PIC MCU Instructions ........................ 342 Electrical Characteristics .................................................. 349 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART). See EUSART. Equations A/D Acquisition Time ................................................ 236 A/D Minimum Charging Time ................................... 236 Calculating the Minimum Required Acquisition Time .............................................. 236 Errata ................................................................................... 5 EUSART Asynchronous Mode ................................................ 206 12-Bit Break Transmit and Receive ................. 211 Associated Registers, Receive ........................ 209 Associated Registers, Transmit ....................... 207 Auto-Wake-up on Sync Break ......................... 210 Receiver ........................................................... 208 Setting up 9-Bit Mode with Address Detect ........................................ 208 Transmitter ....................................................... 206 Baud Rate Generator (BRG) .................................... 201 Associated Registers ....................................... 201 Auto-Baud Rate Detect .................................... 204 Baud Rate Error, Calculating ........................... 201 Baud Rates, Asynchronous Modes ................. 202 High Baud Rate Select (BRGH Bit) ................. 201 Operation in Power-Managed Modes .............. 201 Sampling .......................................................... 201 Synchronous Master Mode ...................................... 212 Associated Registers, Receive ........................ 214 Associated Registers, Transmit ....................... 213 Reception ......................................................... 214 Transmission ................................................... 212 Synchronous Slave Mode ........................................ 215 Associated Registers, Receive ........................ 216 Associated Registers, Transmit ....................... 215 Reception ......................................................... 216 Transmission ................................................... 215
G
GOTO .............................................................................. 316
H
Hardware Multiplier ............................................................ 91 Introduction ................................................................ 91 Operation ................................................................... 91 Performance Comparison .......................................... 91 High/Low-Voltage Detect ................................................. 251 Applications ............................................................. 254 Typical Low-Voltage Detect (diagram) ............ 254 Associated Registers ............................................... 255 Characteristics ......................................................... 366 Current Consumption .............................................. 253 Effects of a Reset .................................................... 255 Operation ................................................................. 252 During Sleep .................................................... 255 Setup ....................................................................... 253 Start-up Time ........................................................... 253 HLVD. See High/Low-Voltage Detect. ............................. 251
I
I/O Ports .......................................................................... 109 I2C Mode (MSSP) Acknowledge Sequence Timing .............................. 190 Associated Registers ............................................... 196 Baud Rate Generator .............................................. 183 Bus Collision During a Repeated Start Condition .................. 194 During a Start Condition .................................. 192 During a Stop Condition .................................. 195 Clock Arbitration ...................................................... 184 Clock Stretching ...................................................... 176 10-Bit Slave Receive Mode (SEN = 1) ............ 176 10-Bit Slave Transmit Mode ............................ 176 7-Bit Slave Receive Mode (SEN = 1) .............. 176 7-Bit Slave Transmit Mode .............................. 176
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Effect of a Reset ...................................................... 191 General Call Address Support ................................. 180 I2C Clock Rate w/BRG ............................................. 183 Master Mode ............................................................ 181 Operation ......................................................... 182 Reception ......................................................... 187 Repeated Start Condition Timing ..................... 186 Start Condition ................................................. 185 Transmission .................................................... 187 Transmit Sequence .......................................... 182 Multi-Master Communication, Bus Collision and Arbitration .................................................. 191 Multi-Master Mode ................................................... 191 Operation ................................................................. 170 Read/Write Bit Information (R/W Bit) ............... 170, 171 Registers .................................................................. 166 Serial Clock (RC3/SCK/SCL) ................................... 171 Slave Mode .............................................................. 170 Addressing ....................................................... 170 Reception ......................................................... 171 Sleep Operation ....................................................... 191 Stop Condition Timing .............................................. 190 Transmission ............................................................ 171 ID Locations ............................................................. 281, 293 INCF ................................................................................. 316 INCFSZ ............................................................................ 317 In-Circuit Debugger .......................................................... 293 In-Circuit Serial Programming (ICSP) ...................... 281, 293 Indexed Literal Offset Addressing Mode .......................... 342 and Standard PIC18 Instructions ............................. 342 Indexed Literal Offset Mode ......................................... 84, 86 Indirect Addressing ............................................................ 82 INFSNZ ............................................................................ 317 Initialization Conditions for all Registers ...................... 59-64 Instruction Cycle ................................................................. 69 Clocking Scheme ....................................................... 69 Instruction Flow/Pipelining ................................................. 69 Instruction Set .................................................................. 295 ADDLW .................................................................... 301 ADDWF .................................................................... 301 ADDWF (Indexed Literal Offset mode) .................... 343 ADDWFC ................................................................. 302 ANDLW .................................................................... 302 ANDWF .................................................................... 303 BC ............................................................................ 303 BCF .......................................................................... 304 BN ............................................................................ 304 BNC ......................................................................... 305 BNN ......................................................................... 305 BNOV ....................................................................... 306 BNZ .......................................................................... 306 BOV ......................................................................... 309 BRA .......................................................................... 307 BSF .......................................................................... 307 BSF (Indexed Literal Offset mode) .......................... 343 BTFSC ..................................................................... 308 BTFSS ..................................................................... 308 BTG .......................................................................... 309 BZ ............................................................................ 310 CALL ........................................................................ 310 CLRF ........................................................................ 311 CLRWDT .................................................................. 311 COMF ...................................................................... 312 CPFSEQ .................................................................. 312 CPFSGT .................................................................. 313 CPFSLT ................................................................... 313 DAW ........................................................................ 314 DCFSNZ .................................................................. 315 DECF ....................................................................... 314 DECFSZ .................................................................. 315 Extended Instructions .............................................. 337 and Using MPLAB IDE Tools .......................... 344 Considerations when Enabling ........................ 342 Syntax .............................................................. 337 General Format ........................................................ 297 GOTO ...................................................................... 316 INCF ........................................................................ 316 INCFSZ .................................................................... 317 INFSNZ .................................................................... 317 IORLW ..................................................................... 318 IORWF ..................................................................... 318 LFSR ....................................................................... 319 MOVF ...................................................................... 319 MOVFF .................................................................... 320 MOVLB .................................................................... 320 MOVLW ................................................................... 321 MOVWF ................................................................... 321 MULLW .................................................................... 322 MULWF .................................................................... 322 NEGF ....................................................................... 323 NOP ......................................................................... 323 POP ......................................................................... 324 PUSH ....................................................................... 324 RCALL ..................................................................... 325 RESET ..................................................................... 325 RETFIE .................................................................... 326 RETLW .................................................................... 326 RETURN .................................................................. 327 RLCF ....................................................................... 327 RLNCF ..................................................................... 328 RRCF ....................................................................... 328 RRNCF .................................................................... 329 SETF ....................................................................... 329 SETF (Indexed Literal Offset mode) ........................ 343 SLEEP ..................................................................... 330 Standard Instructions ............................................... 295 SUBFWB ................................................................. 330 SUBLW .................................................................... 331 SUBWF .................................................................... 331 SUBWFB ................................................................. 332 SWAPF .................................................................... 332 TBLRD ..................................................................... 333 TBLWT .................................................................... 334 TSTFSZ ................................................................... 335 XORLW ................................................................... 335 XORWF ................................................................... 336 Summary Table ....................................................... 298 INTCON Register RBIF Bit ................................................................... 112 INTCON Registers ............................................................. 95 Inter-Integrated Circuit. See I2C. Internal Oscillator Block ..................................................... 34 Adjustment ................................................................. 34 INTIO Modes ............................................................. 34 INTOSC Output Frequency ....................................... 34 OSCTUNE Register ................................................... 34 Internal RC Oscillator Use with WDT .......................................................... 287 Internet Address .............................................................. 409
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Interrupt Sources ............................................................. 281 A/D Conversion Complete ....................................... 235 Capture Complete (CCP) ......................................... 150 Compare Complete (CCP) ....................................... 151 Interrupt-on-Change (RB7:RB4) .............................. 112 INTx Pin ................................................................... 108 PORTB, Interrupt-on-Change .................................. 108 TMR0 ....................................................................... 108 TMR0 Overflow ........................................................ 133 TMR1 Overflow ........................................................ 135 TMR2 to PR2 Match (PWM) .................................... 153 TMR3 Overflow ................................................ 143, 145 Interrupts ............................................................................ 93 Interrupts, Flag Bits Interrupt-on-Change (RB7:RB4) Flag (RBIF Bit) ......................................................... 112 INTOSC Frequency Drift .................................................... 34 INTOSC, INTRC. See Internal Oscillator Block. IORLW ............................................................................. 318 IORWF ............................................................................. 318 IPR Registers ................................................................... 104 MOVWF ........................................................................... 321 MPLAB ASM30 Assembler, Linker, Librarian .................. 346 MPLAB ICD 2 In-Circuit Debugger .................................. 347 MPLAB ICE 2000 High-Performance Universal In-Circuit Emulator ................................... 347 MPLAB Integrated Development Environment Software ............................................. 345 MPLAB PM3 Device Programmer ................................... 347 MPLAB REAL ICE In-Circuit Emulator System ............... 347 MPLINK Object Linker/MPLIB Object Librarian ............... 346 MSSP ACK Pulse ....................................................... 170, 171 Control Registers (general) ..................................... 157 I2C Mode. See I2C Mode. Module Overview ..................................................... 157 SPI Master/Slave Connection .................................. 161 SPI Mode. See SPI Mode. SSPBUF .................................................................. 162 SSPSR .................................................................... 162 MULLW ............................................................................ 322 MULWF ............................................................................ 322
L
LCD Associated Registers ............................................... 279 Bias Types ............................................................... 263 Clock Source Selection ............................................ 262 Configuring the Module ............................................ 278 Frame Frequency ..................................................... 264 Interrupts .................................................................. 276 LCDCON Register ................................................... 258 LCDDATA Register .................................................. 258 LCDPS Register ....................................................... 258 LCDSE Register ....................................................... 258 Multiplex Types ........................................................ 263 Operation During Sleep ........................................... 277 Pixel Control ............................................................. 264 Prescaler .................................................................. 262 Segment Enables ..................................................... 263 Waveform Generation .............................................. 264 LCDCON Register ........................................................... 258 LCDDATA Register .......................................................... 258 LCDPS Register ............................................................... 258 LP3:LP0 Bits ............................................................ 262 LCDSE Register ............................................................... 258 LFSR ................................................................................ 319 Liquid Crystal Display (LCD) Driver ................................. 257 Look-up Tables .................................................................. 68
N
NEGF ............................................................................... 323 NOP ................................................................................. 323
O
Opcode Field Descriptions ............................................... 296 Oscillator Configuration ..................................................... 31 EC .............................................................................. 31 ECIO .......................................................................... 31 HS .............................................................................. 31 HSPLL ....................................................................... 31 Internal Oscillator Block ............................................. 34 INTIO1 ....................................................................... 31 INTIO2 ....................................................................... 31 LP .............................................................................. 31 RC ............................................................................. 31 RCIO .......................................................................... 31 XT .............................................................................. 31 Oscillator Selection .......................................................... 281 Oscillator Start-up Timer (OST) ........................... 39, 55, 281 Oscillator Switching ........................................................... 36 Oscillator Transitions ......................................................... 37 Oscillator, Timer1 ..................................................... 135, 145 Oscillator, Timer3 ............................................................. 143
P
Packaging ........................................................................ 389 Details ...................................................................... 390 Marking .................................................................... 389 PICSTART Plus Development Programmer .................... 348 PIE Registers ................................................................... 101 Pin Functions AVDD .......................................................................... 29 AVDD .......................................................................... 19 AVSS .......................................................................... 29 AVSS .......................................................................... 19 COM0 .................................................................. 17, 25 LCDBIAS1 ........................................................... 17, 25 LCDBIAS2 ........................................................... 17, 25 LCDBIAS3 ........................................................... 17, 25 MCLR/VPP/RG5 ................................................... 12, 20 OSC1/CLKI/RA7 .................................................. 12, 20 OSC2/CLKO/RA6 ................................................ 12, 20 RA0/AN0 .............................................................. 13, 21
M
Master Clear (MCLR) ......................................................... 53 Master Synchronous Serial Port (MSSP). See MSSP. Memory Organization ......................................................... 65 Data Memory ............................................................. 71 Program Memory ....................................................... 65 Memory Programming Requirements .............................. 364 Microchip Internet Web Site ............................................. 409 Migration from Baseline to Enhanced Devices ................ 396 Migration from High-End to Enhanced Devices ............... 397 Migration from Mid-Range to Enhanced Devices ............ 397 MOVF ............................................................................... 319 MOVFF ............................................................................ 320 MOVLB ............................................................................ 320 MOVLW ........................................................................... 321 MOVSF ............................................................................ 339 MOVSS ............................................................................ 340
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RA1/AN1 .............................................................. 13, 21 RA2/AN2/VREF-/SEG16 ....................................... 13, 21 RA3/AN3/VREF+/SEG17 ...................................... 13, 21 RA4/T0CKI/SEG14 .............................................. 13, 21 RA5/AN4/HLVDIN/SEG15 ................................... 13, 21 RB0/INT0 ............................................................. 14, 22 RB1/INT1/SEG8 ................................................... 14, 22 RB2/INT2/SEG9 ................................................... 14, 22 RB3/INT3/SEG10 ................................................. 14, 22 RB4/KBI0/SEG11 ................................................. 14, 22 RB5/KBI1 ............................................................. 14, 22 RB6/KBI2/PGC .................................................... 14, 22 RB7/KBI3/PGD .................................................... 14, 22 RC0/T1OSO/T13CKI ........................................... 15, 23 RC1/T1OSI/CCP2 ................................................ 15, 23 RC2/CCP1/SEG13 ............................................... 15, 23 RC3/SCK/SCL ..................................................... 15, 23 RC4/SDI/SDA ...................................................... 15, 23 RC5/SDO/SEG12 ................................................ 15, 23 RC6/TX1/CK1 ...................................................... 15, 23 RC7/RX1/DT1 ...................................................... 15, 23 RD0/SEG0 ........................................................... 16, 24 RD1/SEG1 ........................................................... 16, 24 RD2/SEG2 ........................................................... 16, 24 RD3/SEG3 ........................................................... 16, 24 RD4/SEG4 ........................................................... 16, 24 RD5/SEG5 ........................................................... 16, 24 RD6/SEG6 ........................................................... 16, 24 RD7/SEG7 ........................................................... 16, 24 RE4/COM1 ........................................................... 17, 25 RE5/COM2 ........................................................... 17, 25 RE6/COM3 ........................................................... 17, 25 RE7/CCP2/SEG31 ............................................... 17, 25 RF0/AN5/SEG18 .................................................. 18, 26 RF1/AN6/C2OUT/SEG19 .................................... 18, 26 RF2/AN7/C1OUT/SEG20 .................................... 18, 26 RF3/AN8/SEG21 .................................................. 18, 26 RF4/AN9/SEG22 .................................................. 18, 26 RF5/AN10/CVREF/SEG23 .................................... 18, 26 RF6/AN11/SEG24 ................................................ 18, 26 RF7/SS/SEG25 .................................................... 18, 26 RG0/SEG30 ......................................................... 19, 27 RG1/TX2/CK2/SEG29 ......................................... 19, 27 RG2/RX2/DT2/SEG28 ......................................... 19, 27 RG3/SEG27 ......................................................... 19, 27 RG4/SEG26 ......................................................... 19, 27 RG5 ...................................................................... 19, 27 RH0/SEG47 ............................................................... 28 RH1/SEG46 ............................................................... 28 RH2/SEG45 ............................................................... 28 RH3/SEG44 ............................................................... 28 RH4/SEG40 ............................................................... 28 RH5/SEG41 ............................................................... 28 RH6/SEG42 ............................................................... 28 RH7/SEG43 ............................................................... 28 RJ0/SEG32 ................................................................ 29 RJ1/SEG33 ................................................................ 29 RJ2/SEG34 ................................................................ 29 RJ3/SEG35 ................................................................ 29 RJ4/SEG39 ................................................................ 29 RJ5/SEG38 ................................................................ 29 RJ6/SEG37 ................................................................ 29 RJ7/SEG36 ................................................................ 29 VDD ............................................................................. 29 VDD ............................................................................. 19 VSS ............................................................................ 29 VSS ............................................................................ 19 Pinout I/O Descriptions PIC18F6X90 .............................................................. 12 PIC18F8X90 .............................................................. 20 PIR Registers ..................................................................... 98 PLL .................................................................................... 33 HSPLL Oscillator Mode ............................................. 33 Use with INTOSC ................................................ 33, 34 PLL Lock Time-out ............................................................. 55 POP ................................................................................. 324 POR. See Power-on Reset. PORTA Associated Registers ............................................... 111 LATA Register ......................................................... 109 PORTA Register ...................................................... 109 TRISA Register ........................................................ 109 PORTB Associated Registers ............................................... 114 LATB Register ......................................................... 112 PORTB Register ...................................................... 112 RB7:RB4 Interrupt-on-Change Flag (RBIF Bit) ......................................................... 112 TRISB Register ........................................................ 112 PORTC Associated Registers ............................................... 117 LATC Register ......................................................... 115 PORTC Register ...................................................... 115 RC3/SCK/SCL Pin ................................................... 171 TRISC Register ........................................................ 115 PORTD Associated Registers ............................................... 119 LATD Register ......................................................... 118 PORTD Register ...................................................... 118 TRISD Register ........................................................ 118 PORTE Associated Registers ............................................... 121 LATE Register ......................................................... 120 PORTE Register ...................................................... 120 TRISE Register ........................................................ 120 PORTF Associated Registers ............................................... 124 LATF Register .......................................................... 122 PORTF Register ...................................................... 122 TRISF Register ........................................................ 122 PORTG Associated Registers ............................................... 126 LATG Register ......................................................... 125 PORTG Register ...................................................... 125 TRISG Register ....................................................... 125 PORTH Associated Registers ............................................... 128 LATH Register ......................................................... 127 PORTH Register ...................................................... 127 TRISH Register ........................................................ 127 PORTJ Associated Registers ............................................... 130 LATJ Register .......................................................... 129 PORTJ Register ....................................................... 129 TRISJ Register ........................................................ 129 Postscaler, WDT Assignment (PSA Bit) .............................................. 133 Rate Select (T0PS2:T0PS0 Bits) ............................. 133 Switching Between Timer0 and WDT ...................... 133
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(c) 2007 Microchip Technology Inc.
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Power-Managed Modes ..................................................... 41 and Multiple Sleep Commands .................................. 42 Effects on Clock Sources ........................................... 39 Entering ...................................................................... 41 Exiting Idle and Sleep Modes by Reset ............................................................. 48 by WDT Time-out ............................................... 48 Without a Start-up Delay .................................... 48 Exiting Idle or Sleep Modes ....................................... 48 by Interrupt ......................................................... 48 Idle Modes ................................................................. 45 PRI_IDLE ........................................................... 46 Run Modes ................................................................. 42 PRI_RUN ........................................................... 42 RC_RUN ............................................................ 44 SEC_RUN .......................................................... 42 Selecting .................................................................... 41 Sleep Mode ................................................................ 45 Summary (table) ........................................................ 41 Power-on Reset (POR) .............................................. 53, 281 Oscillator Start-up Timer (OST) ................................. 55 Power-up Timer (PWRT) ................................... 55, 281 Time-out Sequence .................................................... 55 Power-up Delays ................................................................ 39 Power-up Timer (PWRT) ............................................. 39, 55 Prescaler, Capture ........................................................... 150 Prescaler, Timer0 ............................................................. 133 Assignment (PSA Bit) .............................................. 133 Rate Select (T0PS2:T0PS0 Bits) ............................. 133 Switching Between Timer0 and WDT ...................... 133 Prescaler, Timer2 ............................................................. 154 Program Counter ............................................................... 66 PCL, PCH and PCU Registers ................................... 66 PCLATH and PCLATU Registers .............................. 66 Program Memory and Extended Instruction Set ..................................... 84 Instructions ................................................................. 70 Two-Word .......................................................... 70 Interrupt Vector .......................................................... 65 Map and Stack (diagram) ........................................... 65 Reset Vector .............................................................. 65 Program Verification and Code Protection ....................... 292 Associated Registers ............................................... 292 Programming, Device Instructions ................................... 295 Pulse-Width Modulation. See PWM (CCP Module). PUSH ............................................................................... 324 PUSH and POP Instructions .............................................. 67 PUSHL ............................................................................. 340 PWM (CCP Module) Associated Registers ............................................... 155 Duty Cycle ................................................................ 154 Example Frequencies/Resolutions .......................... 154 Period ....................................................................... 153 Setup for PWM Operation ........................................ 155 TMR2 to PR2 Match ................................................ 153 Reader Response ............................................................ 410 Reading Program Memory and Other Locations ............. 292 Register File ....................................................................... 73 Register File Summary ................................................ 76-79 Registers ADCON0 (A/D Control 0) ......................................... 231 ADCON1 (A/D Control 1) ......................................... 232 ADCON2 (A/D Control 2) ......................................... 233 BAUDCON1 (Baud Rate Control 1) ......................... 200 CCPxCON (CCPx Control) ...................................... 147 CMCON (Comparator Control) ................................ 241 CONFIG1H (Configuration 1 High) .......................... 282 CONFIG2H (Configuration 2 High) .......................... 284 CONFIG2L (Configuration 2 Low) ........................... 283 CONFIG3H (Configuration 3 High) .......................... 284 CONFIG4L (Configuration 4 Low) ........................... 285 CONFIG5L (Configuration 5 Low) ........................... 285 CVRCON (Comparator Voltage Reference Control) .......................................... 247 DEVID1 (Device ID 1) .............................................. 286 DEVID2 (Device ID 2) .............................................. 286 HLVDCON (High/Low-Voltage Detect Control) ................................................ 251 INTCON (Interrupt Control) ....................................... 95 INTCON2 (Interrupt Control 2) .................................. 96 INTCON3 (Interrupt Control 3) .................................. 97 IPR1 (Peripheral Interrupt Priority 1) ....................... 104 IPR2 (Peripheral Interrupt Priority 2) ....................... 105 IPR3 (Peripheral Interrupt Priority 3) ....................... 106 LCDCON (LCD Control) .......................................... 258 LCDDATAx (LCD Datax) ......................................... 261 LCDPS (LCD Phase) ............................................... 259 LCDSEx (LCD Segmentx Enable) ........................... 260 OSCCON (Oscillator Control) .................................... 38 OSCTUNE (Oscillator Tuning) ................................... 35 PIE1 (Peripheral Interrupt Enable 1) ....................... 101 PIE2 (Peripheral Interrupt Enable 2) ....................... 102 PIE3 (Peripheral Interrupt Enable 3) ....................... 103 PIR1 (Peripheral Interrupt Request (Flag) 1) ............. 98 PIR2 (Peripheral Interrupt Request (Flag) 2) ............. 99 PIR3 (Peripheral Interrupt Request (Flag) 3) ........... 100 RCON (Reset Control) ....................................... 52, 107 RCSTA1 (EUSART Receive Status and Control) .......................................... 199 RCSTA2 (AUSART Receive Status and Control) .......................................... 219 SSPCON1 (MSSP Control 1, I2C Mode) ................. 168 SSPCON1 (MSSP Control 1, SPI Mode) ................ 159 SSPCON2 (MSSP Control 2, I2C Master Mode) ............................................ 169 SSPSTAT (MSSP Status, I2C Mode) ...................... 167 SSPSTAT (MSSP Status, SPI Mode) ...................... 158 STATUS .................................................................... 80 STKPTR (Stack Pointer) ............................................ 67 T0CON (Timer0 Control) ......................................... 131 T1CON (Timer1 Control) ......................................... 135 T2CON (Timer2 Control) ......................................... 141 T3CON (Timer3 Control) ......................................... 143 TXSTA1 (EUSART Transmit Status and Control) .......................................... 198 TXSTA2 (AUSART Transmit Status and Control) .......................................... 218 WDTCON (Watchdog Timer Control) ...................... 288 RESET ............................................................................. 325
Q
Q Clock ............................................................................ 154
R
RAM. See Data Memory. RC Oscillator ...................................................................... 33 RCIO Oscillator Mode ................................................ 33 RCALL ............................................................................. 325 RCON Register Bit Status During Initialization .................................... 58
(c) 2007 Microchip Technology Inc.
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Reset .................................................................................. 51 MCLR Reset, during Power-Managed Modes ........... 51 MCLR Reset, Normal Operation ................................ 51 Power-on Reset (POR) .............................................. 51 Programmable Brown-out Reset (BOR) .................... 51 Stack Full Reset ......................................................... 51 Stack Underflow Reset .............................................. 51 Watchdog Timer (WDT) Reset ................................... 51 Resets .............................................................................. 281 RETFIE ............................................................................ 326 RETLW ............................................................................. 326 RETURN .......................................................................... 327 Return Address Stack ........................................................ 66 Return Stack Pointer (STKPTR) ........................................ 67 Revision History ............................................................... 395 RLCF ................................................................................ 327 RLNCF ............................................................................. 328 RRCF ............................................................................... 328 RRNCF ............................................................................. 329 SUBULNK ........................................................................ 341 SUBWF ............................................................................ 331 SUBWFB ......................................................................... 332 SWAPF ............................................................................ 332
T
T0CON Register PSA Bit .................................................................... 133 T0CS Bit .................................................................. 132 T0PS2:T0PS0 Bits ................................................... 133 T0SE Bit .................................................................. 132 Table Pointer Operations (table) ........................................ 88 Table Reads ...................................................................... 68 TBLRD ............................................................................. 333 TBLWT ............................................................................. 334 Time-out in Various Situations (table) ................................ 55 Timer0 .............................................................................. 131 16-Bit Mode Timer Reads and Writes ...................... 132 Associated Registers ............................................... 133 Clock Source Edge Select (T0SE Bit) ..................... 132 Clock Source Select (T0CS Bit) ............................... 132 Operation ................................................................. 132 Overflow Interrupt .................................................... 133 Prescaler. See Prescaler, Timer0. Timer1 .............................................................................. 135 16-Bit Read/Write Mode .......................................... 137 Associated Registers ............................................... 139 Interrupt ................................................................... 138 Operation ................................................................. 136 Oscillator .......................................................... 135, 137 Layout Considerations ..................................... 138 Overflow Interrupt .................................................... 135 Resetting, Using a Special Event Trigger Output (CCP) ................................................... 138 TMR1H Register ...................................................... 135 TMR1L Register ....................................................... 135 Use as a Real-Time Clock ....................................... 138 Timer2 .............................................................................. 141 Associated Registers ............................................... 142 Interrupt ................................................................... 142 Operation ................................................................. 141 Output ...................................................................... 142 PR2 Register ........................................................... 153 TMR2 to PR2 Match Interrupt .................................. 153 Timer3 .............................................................................. 143 16-Bit Read/Write Mode .......................................... 145 Associated Registers ............................................... 145 Operation ................................................................. 144 Oscillator .......................................................... 143, 145 Overflow Interrupt ............................................ 143, 145 Special Event Trigger (CCP) ................................... 145 TMR3H Register ...................................................... 143 TMR3L Register ....................................................... 143 Timing Diagrams A/D Conversion ........................................................ 385 Acknowledge Sequence .......................................... 190 Asynchronous Reception ................................. 209, 225 Asynchronous Transmission ............................ 207, 223 Asynchronous Transmission (Back-to-Back) ......................................... 207, 223 Automatic Baud Rate Calculation ............................ 205 Auto-Wake-up Bit (WUE) During Normal Operation ............................................ 210 Auto-Wake-up Bit (WUE) During Sleep ................... 210 Baud Rate Generator with Clock Arbitration ............ 184 BRG Overflow Sequence ......................................... 205
S
SCK .................................................................................. 157 SDI ................................................................................... 157 SDO ................................................................................. 157 Serial Clock, SCK ............................................................. 157 Serial Data In (SDI) .......................................................... 157 Serial Data Out (SDO) ..................................................... 157 Serial Peripheral Interface. See SPI Mode. SETF ................................................................................ 329 Slave Select (SS) ............................................................. 157 SLEEP .............................................................................. 330 Sleep OSC1 and OSC2 Pin States ...................................... 39 Software Enabled BOR ...................................................... 54 Software Simulator (MPLAB SIM) .................................... 346 Special Event Trigger. See Compare (CCP Module). Special Features of the CPU ............................................ 281 Special Function Registers ................................................ 74 Map ...................................................................... 74-75 SPI Mode (MSSP) Associated Registers ............................................... 165 Bus Mode Compatibility ........................................... 165 Effects of a Reset ..................................................... 165 Enabling SPI I/O ...................................................... 161 Master Mode ............................................................ 162 Master/Slave Connection ......................................... 161 Operation ................................................................. 160 Serial Clock .............................................................. 157 Serial Data In ........................................................... 157 Serial Data Out ........................................................ 157 Slave Mode .............................................................. 163 Slave Select ............................................................. 157 Slave Select Synchronization .................................. 163 Sleep Operation ....................................................... 165 SPI Clock ................................................................. 162 Typical Connection .................................................. 161 SS .................................................................................... 157 SSPOV ............................................................................. 187 SSPOV Status Flag .......................................................... 187 SSPSTAT Register R/W Bit ............................................................. 170, 171 Stack Full/Underflow Resets .............................................. 68 STATUS Register ............................................................... 80 SUBFSR ........................................................................... 341 SUBFWB .......................................................................... 330 SUBLW ............................................................................ 331
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BRG Reset Due to SDA Arbitration During Start Condition ..................................... 193 Brown-out Reset (BOR) ........................................... 372 Bus Collision During a Repeated Start Condition (Case 1) .................................. 194 Bus Collision During a Repeated Start Condition (Case 2) .................................. 194 Bus Collision During a Start Condition (SCL = 0) ......................................... 193 Bus Collision During a Start Condition (SDA Only) ...................................... 192 Bus Collision During a Stop Condition (Case 1) ........................................... 195 Bus Collision During a Stop Condition (Case 2) ........................................... 195 Bus Collision for Transmit and Acknowledge ........... 191 Capture/Compare/PWM (All CCP Modules) ............ 374 CLKO and I/O .......................................................... 371 Clock Synchronization ............................................. 177 Clock/Instruction Cycle .............................................. 69 Example SPI Master Mode (CKE = 0) ..................... 375 Example SPI Master Mode (CKE = 1) ..................... 376 Example SPI Slave Mode (CKE = 0) ....................... 377 Example SPI Slave Mode (CKE = 1) ....................... 378 External Clock (All Modes Except PLL) ................... 369 Fail-Safe Clock Monitor ............................................ 291 High/Low-Voltage Detect Characteristics ................ 366 High-Voltage Detect Operation (VDIRMAG = 1) ...... 254 I2C Bus Data ............................................................ 379 I2C Bus Start/Stop Bits ............................................. 379 I2C Master Mode (7 or 10-Bit Transmission) ........... 188 I2C Master Mode (7-Bit Reception) .......................... 189 I2C Master Mode First Start Bit ................................ 185 I2C Slave Mode (10-Bit Reception, SEN = 0) .......... 174 I2C Slave Mode (10-Bit Reception, SEN = 1) .......... 179 I2C Slave Mode (10-Bit Transmission) ..................... 175 I2C Slave Mode (7-Bit Reception, SEN = 0) ............ 172 I2C Slave Mode (7-Bit Reception, SEN = 1) ............ 178 I2C Slave Mode (7-Bit Transmission) ....................... 173 I2C Slave Mode General Call Address Sequence (7 or 10-Bit Addressing Mode) ........ 180 I2C Stop Condition Receive or Transmit Mode ........ 190 LCD Interrupt Timing in Quarter-Duty Cycle Drive ... 276 LCD Sleep Entry/Exit When SLPEN = 1 or CS1:CS0 = 00 .................................................. 277 Low-Voltage Detect Operation (VDIRMAG = 0) ...... 253 Master SSP I2C Bus Data ........................................ 381 Master SSP I2C Bus Start/Stop Bits ........................ 381 PWM Output ............................................................ 153 Repeat Start Condition ............................................. 186 Reset, Watchdog Timer (WDT), Oscillator Start-up Timer (OST) and Power-up Timer (PWRT) ..... 372 Send Break Character Sequence ............................ 211 Slave Synchronization ............................................. 163 Slow Rise Time (MCLR Tied to VDD, VDD Rise > TPWRT) ............................................ 57 SPI Mode (Master Mode) ......................................... 162 SPI Mode (Slave Mode, CKE = 0) ........................... 164 SPI Mode (Slave Mode, CKE = 1) ........................... 164 Synchronous Reception (Master Mode, SREN) ............................. 214, 228 Synchronous Transmission .............................. 212, 226 Synchronous Transmission (Through TXEN) ...................................... 213, 227 Time-out Sequence on POR w/PLL Enabled (MCLR Tied to VDD) .......................................... 57 Time-out Sequence on Power-up MCLR Not Tied to VDD, Case 1 ......................... 56 MCLR Not Tied to VDD, Case 2 ......................... 56 MCLR Tied to VDD, VDD Rise < TPWRT ............. 56 Timer0 and Timer1 External Clock .......................... 373 Transition for Entry to PRI_IDLE Mode ..................... 46 Transition for Entry to SEC_RUN Mode .................... 43 Transition for Entry to Sleep Mode ............................ 45 Transition for Two-Speed Start-up (INTOSC to HSPLL) ........................................ 289 Transition for Wake from Idle to Run Mode ............... 46 Transition for Wake from Sleep (HSPLL) .................. 45 Transition from RC_RUN Mode to PRI_RUN Mode ................................................. 44 Transition from SEC_RUN Mode to PRI_RUN Mode (HSPLL) .................................. 43 Transition to RC_RUN Mode ..................................... 44 Type-A in 1/2 MUX, 1/2 Bias Drive .......................... 266 Type-A in 1/2 MUX, 1/3 Bias Drive .......................... 268 Type-A in 1/3 MUX, 1/2 Bias Drive .......................... 270 Type-A in 1/3 MUX, 1/3 Bias Drive .......................... 272 Type-A in 1/4 MUX, 1/3 Bias Drive .......................... 274 Type-A/Type-B in Static Drive ................................. 265 Type-B in 1/2 MUX, 1/2 Bias Drive .......................... 267 Type-B in 1/2 MUX, 1/3 Bias Drive .......................... 269 Type-B in 1/3 MUX, 1/2 Bias Drive .......................... 271 Type-B in 1/3 MUX, 1/3 Bias Drive .......................... 273 Type-B in 1/4 MUX, 1/3 Bias Drive .......................... 275 USART Synchronous Receive (Master/Slave) ........ 383 USART Synchronous Transmission (Master/Slave) ................................................. 383 Timing Diagrams and Specifications A/D Conversion Requirements ................................ 385 AC Characteristics - Internal RC Accuracy .............. 370 Capture/Compare/PWM Requirements (All CCP Modules) ........................................... 374 CLKO and I/O Requirements ................................... 371 Example SPI Mode Requirements (Master Mode, CKE = 0) .................................. 375 Example SPI Mode Requirements (Master Mode, CKE = 1) .................................. 376 Example SPI Mode Requirements (Slave Mode, CKE = 0) .................................... 377 Example SPI Slave Mode Requirements (CKE = 1) ......................................................... 378 External Clock Requirements .................................. 369 I2C Bus Data Requirements (Slave Mode) .............. 380 I2C Bus Start/Stop Bits Requirements (Slave Mode) ................................................... 379 Master SSP I2C Bus Data Requirements ................ 382 Master SSP I2C Bus Start/Stop Bits Requirements .................................................. 381 PLL Clock ................................................................ 370 Reset, Watchdog Timer, Oscillator Start-up Timer, Power-up Timer and Brown-out Reset Requirements ........................................ 372 Timer0 and Timer1 External Clock Requirements ........................................ 373 USART Synchronous Receive Requirements .................................................. 383 USART Synchronous Transmission Requirements .................................................. 383
(c) 2007 Microchip Technology Inc.
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Top-of-Stack Access .......................................................... 66 TSTFSZ ............................................................................ 335 Two-Speed Start-up ................................................. 281, 289 Two-Word Instructions Example Cases .......................................................... 70 TXSTA1 Register BRGH Bit ................................................................. 201 TXSTA2 Register BRGH Bit ................................................................. 220
W
Watchdog Timer (WDT) ........................................... 281, 287 Associated Registers ............................................... 288 Control Register ....................................................... 287 During Oscillator Failure .......................................... 290 Programming Considerations .................................. 287 WCOL ...................................................... 185, 186, 187, 190 WCOL Status Flag ................................... 185, 186, 187, 190 WWW Address ................................................................ 409 WWW, On-Line Support ...................................................... 5
V
Voltage Reference Specifications .................................... 365
X
XORLW ............................................................................ 335 XORWF ........................................................................... 336
DS39629C-page 408
(c) 2007 Microchip Technology Inc.
PIC18FXX90
THE MICROCHIP WEB SITE
Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information: * Product Support - Data sheets and errata, application notes and sample programs, design resources, user's guides and hardware support documents, latest software releases and archived software * General Technical Support - Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing * Business of Microchip - Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives
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Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales offices are also available to help customers. A listing of sales offices and locations is included in the back of this document. Technical support is available through the web site at: http://support.microchip.com
CUSTOMER CHANGE NOTIFICATION SERVICE
Microchip's customer notification service helps keep customers current on Microchip products. Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. To register, access the Microchip web site at www.microchip.com, click on Customer Change Notification and follow the registration instructions.
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DS39629C-page 409
PIC18FXX90
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. To: RE: Technical Publications Manager Reader Response Total Pages Sent ________
From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ Application (optional): Would you like a reply? Y N Literature Number: DS39629C FAX: (______) _________ - _________
Device: PIC18F6390/6490/8390/8490 Questions:
1. What are the best features of this document?
2. How does this document meet your hardware and software development needs?
3. Do you find the organization of this document easy to follow? If not, why?
4. What additions to the document do you think would enhance the structure and subject?
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DS39629C-page 410
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PIC18F6390/6490/8390/8490
PIC18F6390/6490/8390/8490 PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. Device X Temperature Range /XX Package XXX Pattern Examples:
a) b) Device(1), (2) PIC18F6390/6490/8390/8490, PIC18F6390/6490/8390/8490T; VDD range 4.2V to 5.5V PIC18LF6390/6490/8390/8490, PIC18LF6390/6490/8390/8490T; VDD range 2.0V to 5.5V I E = = -40C to +85C (Industrial) -40C to +125C (Extended) TQFP (Thin Quad Flatpack) c) PIC18LF6490-I/PT 301 = Industrial temp., TQFP package, Extended VDD limits, QTP pattern #301. PIC18F8490-I/PT = Industrial temp., TQFP package, normal VDD limits. PIC18F8490-E/PT = Extended temp., TQFP package, normal VDD limits.
Temperature Range
Package Pattern
PT =
Note 1: 2:
QTP, SQTP, Code or Special Requirements (blank otherwise)
F = Standard Voltage Range LF = Wide Voltage Range T = In tape and reel
(c) 2007 Microchip Technology Inc.
DS39629C-page 411
WORLDWIDE SALES AND SERVICE
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10/05/07
DS39629C-page 412
(c) 2007 Microchip Technology Inc.

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