View ST72361_4699192.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

ST72361
8-bit MCU with Flash or ROM, 10-bit ADC, 5 timers, SPI, 2x LINSCITM
Features

Memories - 16K to 60K High Density Flash (HDFlash) or ROM with read-out protection capability. InApplication Programming and In-Circuit Programming for HDFlash devices - 1.5 to 2K RAM - HDFlash endurance: 100 cycles, data retention 40 years at 85C Clock, Reset and Supply Management - Low power crystal/ceramic resonator oscillators and bypass for external clock - PLL for 2x frequency multiplication - 5 power saving modes: Halt, Auto Wake Up From Halt, Active Halt, Wait and Slow Interrupt Management - Nested interrupt controller - 14 interrupt vectors plus TRAP and RESET - TLI top level interrupt (on 64-pin devices) - Up to 21 external interrupt lines (on 4 vectors) Up to 48 I/O Ports - Up to 48 multifunctional bidirectional I/O lines - Up to 36 alternate function lines - Up to 6 high sink outputs 5 Timers - 16-bit timer with 2 input captures, 2 output compares, external clock input, PWM and pulse generator modes - 8-bit timer with 1 or 2 input captures, 1 or 2 output compares, PWM and pulse generator modes - 8-bit PWM auto-reload timer with 1 or 2 input captures, 2 or 4 independent PWM output channels, output compare and time base interrupt, external clock with event detector
LQFP32 7x7mm
LQFP44 10x10mm
LQFP64 10x10mm

- Main clock controller with real-time base and clock output - Window watchdog timer Up to 3 Communications Interfaces - SPI synchronous serial interface - Master/slave LINSCITM asynchronous serial interface - Master-only LINSCITM asynchronous serial interface Analog Peripheral (Low Current Coupling) - 10-bit A/D converter with up to 16 inputs - Up to 9 robust ports (low current coupling) Instruction Set - 8-bit data manipulation - 63 basic instructions - 17 main addressing modes - 8 x 8 unsigned multiply instruction Development Tools - Full hardware/software development package
Table 1. Device Summary
Features Program memory - bytes RAM (stack) - bytes Operating Supply CPU Frequency Max. Temp. Range Packages ST72361(AR/J/K)9 60K 2K (256) ST72361(AR/J/K)7 ST72361(AR/J/K)6 48K 32K 2K (256) 1.5K (256) 4.5V to 5.5 V External Resonator Osc. w/ PLLx2/8 MHz -40C to +125C LQFP64 10x10mm (AR), LQFP44 10x10mm (J), LQFP32 7x7mm (K)
Rev. 3
June 2007 1/224
1
Table of Contents
1 DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 PIN DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 REGISTER AND MEMORY MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4 FLASH PROGRAM MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.3 STRUCTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.4 ICC INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.5 ICP (IN-CIRCUIT PROGRAMMING) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.6 IAP (IN-APPLICATION PROGRAMMING) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.7 RELATED DOCUMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.8 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 5 CENTRAL PROCESSING UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.3 CPU REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 6 SUPPLY, RESET AND CLOCK MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 6.1 PHASE LOCKED LOOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 6.2 MULTI-OSCILLATOR (MO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6.3 RESET SEQUENCE MANAGER (RSM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 6.4 SYSTEM INTEGRITY MANAGEMENT (SI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 7 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7.2 MASKING AND PROCESSING FLOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7.3 INTERRUPTS AND LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 7.4 CONCURRENT & NESTED MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 7.5 INTERRUPT REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7.6 EXTERNAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 8 POWER SAVING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 8.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 8.2 SLOW MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 8.3 WAIT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 8.4 HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 8.5 ACTIVE HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 8.6 AUTO WAKE-UP FROM HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9 I/O PORTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.2 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.3 I/O PORT IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 9.4 LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 224 9.5 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 9.6 I/O PORT REGISTER CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2/224
2
Table of Contents
10 ON-CHIP PERIPHERALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 10.1 WINDOW WATCHDOG (WWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 10.2 MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK MCC/RTC . . . . . . . . . . . . . . . 58 10.3 PWM AUTO-RELOAD TIMER (ART) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 10.4 16-BIT TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 10.5 8-BIT TIMER (TIM8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 10.6 SERIAL PERIPHERAL INTERFACE (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 10.7 LINSCI SERIAL COMMUNICATION INTERFACE (LIN MASTER/SLAVE) . . . . . . . . . . . 120 10.8 LINSCI SERIAL COMMUNICATION INTERFACE (LIN MASTER ONLY) . . . . . . . . . . . . 151 10.9 10-BIT A/D CONVERTER (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 11 INSTRUCTION SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 11.1 CPU ADDRESSING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 11.2 INSTRUCTION GROUPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 12 ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 12.1 PARAMETER CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 12.2 ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 12.3 OPERATING CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 12.4 SUPPLY CURRENT CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 12.5 CLOCK AND TIMING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 12.6 AUTO WAKEUP FROM HALT OSCILLATOR (AWU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 12.7 MEMORY CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 12.8 EMC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 12.9 I/O PORT PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 12.10CONTROL PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 12.11TIMER PERIPHERAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 12.12COMMUNICATION INTERFACE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . 202 12.1310-BIT ADC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 13 PACKAGE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 13.1 PACKAGE MECHANICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 13.2 THERMAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 13.3 SOLDERING AND GLUEABILITY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 14 DEVICE CONFIGURATION AND ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . 210 14.1 FLASH OPTION BYTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 14.2 TRANSFER OF CUSTOMER CODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 15 DEVELOPMENT TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 16 IMPORTANT NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 16.1 ALL DEVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 16.2 FLASH/FASTROM DEVICES ONLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 16.3 ROM DEVICES ONLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 17 REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
3/224
ST72361
1 DESCRIPTION
The ST72361 devices are members of the ST7 microcontroller family designed for mid-range applications with LIN (Local Interconnect Network) interface. All devices are based on a common industrystandard 8-bit core, featuring an enhanced instruction set and are available with Flash or ROM program memory. The ST7 family architecture offers both power and flexibility to software developers, enabling the design of highly efficient and compact application code. Figure 1. Device Block Diagram
option
The on-chip peripherals include an A/D converter, a PWM Autoreload timer, 2 general purpose timers, 2 asynchronous serial interfaces, and an SPI interface. For power economy, microcontroller can switch dynamically into WAIT, SLOW, Active-Halt, Auto Wake-up from HALT (AWU) or HALT mode when the application is in idle or stand-by state. Typical applications are consumer, home, office and industrial products.
OSC1 OSC2
PLL x 2
OSC
PWM ART 8-Bit TIMER 16-Bit TIMER
/2
VDD VSS
POWER SUPPLY
PORT A PORT B PORT C PORT D PORT E PORT F SPI LINSCI2 (LIN master) LINSCI1 (LIN master/slave) WINDOW
ADDRESS AND DATA BUS
RESET TLI1
CONTROL 8-BIT CORE ALU
PA7:0 (8 bits)1 PB7:0 (8 bits)1 PC7:0 (8 bits)1 PD7:0 (8 bits)1 PE7:0 (8 bits)1 PF7:0 (8 bits)1
PROGRAM MEMORY (16 - 60 Kbytes)
RAM (1.5 - 2 Kbytes)
MCC (Clock Control)
WATCHDOG
1On
some devices only (see Device Summary on page 1)
4/224
3
ST72361
2 PIN DESCRIPTION
Figure 2. LQFP 64-Pin Package Pinout
OSC1 OSC2 ARTIC1 / PA0 PWM0 / PA1 PWM1 / (HS) PA2 PWM2 / PA3 PWM3 / PA4 VSS_3 VDD_3 ARTCLK / (HS) PA5 ARTIC2 / (HS) PA6 T8_OCMP2 / PA7 T8_ICAP2 / PB0 T8_OCMP1 / PB1 T8_ICAP1 / PB2 MCO / PB3
64 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
PF7 PF6 PD7 / AIN11 PD6 / AIN10 RESET PD5 / LINSCI2_TDO VDD_0 VDDA VSS_0 VSSA PD4 / LINSCI2_RDI PD3 (HS)/ LINSCI2_SCK PF5 TLI PF4 PF3 / AIN9 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 ei3 ei3 ei3 47 46 45 44 ei0 43 ei3 42 41 40 39 ei0 38 37 36 35 ei1 34 ei1 ei2 ei1 33 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
PD2 / LINSCI1_TDO PD1 / LINSCI1_RDI PF2 / AIN8 PF1 / AIN7 PF0 PE7 PD0 / SPI_SS / AIN6 VDD_1 VSS_1 PC7 / SPI_SCK PC6 / SPI_MOSI PC5 / SPI_MISO PE6 / AIN5 PE5 PC4 PC3
AIN12 / PE0 AIN13 / PE1 ICCCLK / AIN0 / PB4 AIN14 / PE2 AIN15 / PE3 ICCDATA / AIN1 / PB5 (*)T16_OCMP1 / AIN2 / PB6 VSS_2 VDD_2 (*)T16_OCMP2 / AIN3 / PB7 (*)T16_ICAP1 / AIN4 / PC0 (*)T16_ICAP2 / (HS) PC1 T16_EXTCLK / (HS) PC2 PE4 NC ICCSEL/VPP
(HS) 20mA high sink capability eix associated external interrupt vector
(*) : by option bit: T16_ICAP1 can be moved to PD4 T16_ICAP2 can be moved to PD1 T16_OCMP1 can be moved to PD3 T16_OCMP2 can be moved to PD5
5/224
ST72361
PIN DESCRIPTION (Cont'd) Figure 3. LQFP 44-Pin Package Pinout
OSC1 OSC2 PWM0 / PA1 PWM1 / (HS) PA2 PWM2 / PA3 PWM3 / PA4 ARTCLK / (HS) PA5 ARTIC2 / (HS) PA6 T8_OCMP1 / PB1 T8_ICAP1 / PB2 MCO / PB3
44 43 42 41 40 39 38 37 36 35 34 1 33 ei3 ei3 2 32 ei3 3 31 4 30 5 ei3 29 ei0 6 28 7 27 8 26 9 25 10 ei1 24 ei2 ei1 11 23 12 13 14 15 16 17 18 19 20 21 22 ICCCLK / AIN0 / PB4 ICCDATA / AIN1 / PB5 (*)T16_OCMP1 / AIN2 / PB6 VSS_2 VDD_2 (*)T16_OCMP2 / AIN3 / PB7 (*)T16_ICAP1 / AIN4 / PC0 (*)T16_ICAP2 / (HS) PC1 T16_EXTCLK / (HS) PC2 PE4 ICCSEL/VPP
PD7 / AIN11 PD6 / AIN10 RESET PD5 / LINSCI2_TDO 1 VDD_0 VDDA VSS_0 VSSA PD4 / LINSCI2_RDI PD3 (HS) / LINSCI2_SCK PF5
PD2 / LINSCI1_TDO PD1 / LINSCI1_RDI PF2 / AIN8 PF1 / AIN7 PD0 / SPI_SS / AIN6 PC7 / SPI_SCK PC6 / SPI_MOSI PC5 / SPI_MISO PE6 / AIN5 PC4 PC3
(HS) 20mA high sink capability eix associated external interrupt vector
(*) : by option bit: T16_ICAP1 can be moved to PD4 T16_ICAP2 can be moved to PD1 T16_OCMP1 can be moved to PD3 T16_OCMP2 can be moved to PD5
6/224
ST72361
PIN DESCRIPTION (Cont'd) Figure 4. LQFP 32-Pin Package Pinout
OSC1 OSC2 PWM0 / PA1 PWM1 / (HS) PA2 ARTCLK / (HS) PA5 T8_OCMP1 / PB1 T8_ICAP1 / PB2 MCO / PB3
1 2 3 4 5 6 7 8
32 31 30 29 28 27 26 25 24 ei3 23 ei3 22 21 ei0 20 19 18 ei1 ei2 ei1 17 9 10 11 12 13 14 15 16 ICCCLK / AIN0 / PB4 ICCDATA / AIN1 / PB5 T16_OCMP1 / AIN2 / PB6 T16_OCMP2 / AIN3 / PB7 T16_ICAP1 / AIN4 / PC0 T16_ICAP2 / (HS) PC1 T16_EXTCLK / (HS) PC2 ICCSEL/VPP
RESET PD5 / LINSCI2_TDO VDD_0 VDDA VSS_0 VSSA PD4 / LINSCI2_RDI PD3 (HS) / LINSCI2_SCK1
PD2 / LINSCI1_TDO PD1 / LINSCI1_RDI PD0 / SPI_SS / AIN6 PC7 / SPI_SCK PC6 / SPI_MOSI PC5 / SPI_MISO PC4 PC3
(HS) 20mA high sink capability eix associated external interrupt vector
(*) : by option bit: T16_ICAP1 can be moved to PD4 T16_ICAP2 can be moved to PD1 T16_OCMP1 can be moved to PD3 T16_OCMP2 can be moved to PD5
For external pin connection guidelines, refer to "ELECTRICAL CHARACTERISTICS" on page 178.
7/224
ST72361
PIN DESCRIPTION (Cont'd) For external pin connection guidelines, refer to "ELECTRICAL CHARACTERISTICS" on page 178. Legend / Abbreviations for Table 2: Type: I = input, O = output, S = supply In/Output level: CT= CMOS 0.3VDD/0.7VDD with Schmitt trigger TT= TTL 0.8V / 2V with Schmitt trigger Output level: HS = 20mA high sink (on N-buffer only) Port and control configuration: - Input: float = floating, wpu = weak pull-up, int = interrupt1), ana = analog, RB = robust - Output: OD = open drain, PP = push-pull Refer to "I/O PORTS" on page 45 for more details on the software configuration of the I/O ports. The RESET configuration of each pin is shown in bold which is valid as long as the device is in reset state. Table 2. Device Pin Description
Pin n LQFP64 LQFP44 LQFP32 Type Pin Name Level Output Input Port Input float wpu ana int Main Output function (after reset) OD PP
Alternate function
1 2 3 4 5 6 7 8 9 10 11 12 13 14
1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 -
OSC13) OSC23) PA0 / ARTIC1 PA1 / PWM0 PA2 (HS) / PWM1 PA3 / PWM2 PA4 / PWM3 VSS_3 VDD_3 PA5 (HS) / ARTCLK PA6 (HS) / ARTIC2 PA7 / T8_OCMP2 PB0 /T8_ICAP2 PB1 /T8_OCMP1 PB2 / T8_ICAP1 PB3 / MCO PE0 / AIN12 PE1 / AIN13 PB4 / AIN0 / ICCCLK PE2 / AIN14 PE3 / AIN15
I I/O I/O CT I/O CT I/O CT HS I/O CT I/O CT S S I/O CT HS I/O CT HS I/O CT I/O CT I/O CT I/O CT I/O CT I/O TT I/O TT I/O CT I/O TT I/O TT X X X X X X X X X X X X X X X ei1 X X ei0 ei0 ei0 ei1 ei1 ei1 ei1 X X X X X X X RB X RB X RB X RB X RB X ei1 RB X X X X X X X X X X X X X X X X X X X ei0 ei0 ei0 ei0 ei0 X X X X X X X X X X
External clock input or Resonator oscillator inverter input Resonator oscillator inverter output Port A0 Port A1 Port A2 Port A3 Port A4 ART Input Capture 1 ART PWM Output 0 ART PWM Output 1 ART PWM Output 2 ART PWM Output 3
Digital Ground Voltage Digital Main Supply Voltage Port A5 Port A6 Port A7 Port B0 Port B1 Port B2 Port B3 Port E0 Port E1 Port B4 Port E2 Port E3 Port B5 ART External Clock ART Input Capture 2 TIM8 Output Compare 2 TIM8 Input Capture 2 TIM8 Output Compare 1 TIM8 Input Capture 1 Main clock out (fOSC2) ADC Analog Input 12 ADC Analog Input 13 ICC Clock input ADC Analog Input 0
15 10 16 11 17 18 -
19 12 20 21 -
ADC Analog Input 14 ADC Analog Input 15 ICC Data in- ADC Analog put Input 1
22 13 10 PB5 / AIN1 / ICCDATA I/O CT
8/224
ST72361
Pin n LQFP64 LQFP44 LQFP32 Type Pin Name
Level Output Input
Port Input float wpu ana int
OD
PP
Main function Output (after reset)
Alternate function
23 14 11 24 15 25 16 -
PB6 / AIN2 / T16_OCMP1 VSS_2 VDD_2 PB7 /AIN3 / T16_OCMP2 PC0 / AIN4 / T16_ICAP1
I/O CT S S I/O CT I/O CT
X
X
RB X
X
Port B6
TIM16 Output Compare 1
ADC Analog Input 2
Digital Ground Voltage Digital Main Supply Voltage X X X X X X X X ei2 ei2 RB X RB X X X X X X X X X Port B7 Port C0 Port C1 Port C2 Port E4 Flash programming voltage. Must be tied low in user mode. X X X X X X X X X X X X X X X X X X X X X X X X X X Port C3 Port E5 Port E6 Port C5 Port C6 Port C7 ADC Analog Input 5 SPI Master In/Slave Out SPI Master Out/Slave In SPI Serial Clock X2) Port C4 TIM16 Output Compare 2 TIM16 Input Capture 1 ADC Analog Input 3 ADC Analog Input 4
26 17 12 27 18 13
28 19 14 PC1 (HS) / T16_ICAP2 I/O CT HS PC2 (HS) / 29 20 15 T16_EXTCLK 30 21 31 PE4 NC I I/O CT I/O CT I/O TT I/O TT I/O CT I/O CT I/O CT S S I/O CT I/O TT I/O TT I/O TT I/O TT I/O CT I/O CT I/O TT I/O TT I CT I/O TT I/O CT HS I/O CT HS I/O TT
TIM16 Input Capture 2 TIM16 External Clock input
Not Connected
32 22 16 VPP 33 23 17 PC3 34 24 18 PC4 35 PE5 PE6 / AIN5 36 25
37 26 19 PC5 /MISO 38 27 20 PC6 / MOSI 39 28 21 PC7 /SCK 40 41 VSS_1 VDD_1
Digital Ground Voltage Digital Main Supply Voltage X X X X X X X X X X X X X X X X X X X X X X X ei3 X X X X ei3 X X X X X X X X X X X X X X X X X X X X X Port D0 Port E7 Port F0 Port F1 Port F2 Port D1 Port D2 Port F3 Port F4 Top level interrupt input pin Port F5 Port D3 LINSCI2 Serial Clock Output ADC Analog Input 7 ADC Analog Input 8 LINSCI1 Receive Data input LINSCI1 Transmit Data output ADC Analog Input 9 SPI Slave Select ADC Analog Input 6
42 29 22 PD0 / SS/ AIN6 43 44 PE7 PF0 PF1 / AIN7 PF2 / AIN8
45 30 46 31
47 32 23 PD1 / SCI1_RDI 48 33 24 PD2 / SCI1_TDO 49 50 51 PF3 / AIN9 PF4 TLI PF5
52 34
53 35 25 PD3 (HS) / SCI2_SCK
9/224
ST72361
Pin n LQFP64 LQFP44 LQFP32 Type Pin Name
Level Output Input
Port Input float wpu ana int
OD
PP
Main function Output (after reset) X X Port D4
Alternate function
54 36 26 PD4 / SCI2_RDI 55 37 27 VSSA 56 38 28 VSS_0 57 39 29 VDDA 58 40 30 VDD_0 59 41 31 PD5 / SCI2_TDO 60 42 32 RESET 61 43 62 44 63 64 PD6 / AIN10 PD7 / AIN11 PF6 PF7
I/O CT S S I S I/O CT I/O CT I/O CT I/O CT I/O TT I/O TT
X
ei3
LINSCI2 Receive Data input
Analog Ground Voltage Digital Ground Voltage Analog Reference Voltage for ADC Digital Main Supply Voltage X X X X Port D5 LINSCI2 Transmit Data output ADC Analog Input 10 ADC Analog Input 11
Top priority non maskable interrupt. X X X X X X ei3 X X X X X X X X X Port D6 Port D7 Port F6 Port F7 ei3 X
Notes: 1. In the interrupt input column, "eiX" defines the associated external interrupt vector. If the weak pull-up column (wpu) is merged with the interrupt column (int), then the I/O configuration is pull-up interrupt input, else the configuration is floating interrupt input. 2. Input mode can be used for general purpose I/O, output mode cannot be used. 3. OSC1 and OSC2 pins connect a crystal/ceramic resonator, or an external source to the on-chip oscillator; see Section 6 and Section 12.5 "CLOCK AND TIMING CHARACTERISTICS" for more details. 4. On the chip, each I/O port has eight pads. Pads that are not bonded to external pins are in input pull-up configuration after reset. The configuration of these pads must be kept at reset state to avoid added current consumption.
10/224
ST72361
3 REGISTER AND MEMORY MAP
As shown in Figure 5, the MCU is capable of addressing 64 Kbytes of memories and I/O registers. The available memory locations consist of 128 bytes of register locations, up to 2 Kbytes of RAM and up to 60 Kbytes of user program memory. The RAM space includes up to 256 bytes for the stack from 0100h to 01FFh.The highest address bytes contain the user reset and interrupt vectors. IMPORTANT: Memory locations marked as "Reserved" must never be accessed. Accessing a reseved area can have unpredictable effects on the device.
Figure 5. Memory Map
0000h 007Fh 0080h
HW Registers (see Table 3)
0080h
Short Addressing RAM (zero page)
00FFh 0100h
RAM (2048/1536 bytes)
087Fh 0880h 01FFh 0200h
256 bytes Stack 16-bit Addressing RAM
067Fh or 087Fh
1000h
60 Kbytes
4000h 8000h
Reserved
0FFFh 1000h
48 Kbytes 32 Kbytes
Program Memory (60K, 48K, 32K, 16K)
FFDFh FFE0h FFFFh
C000h
Interrupt & Reset Vectors (see Table 9)
16 Kbytes
FFDFh
Table 3. Hardware Register Map
Address 0000h 0001h 0002h 0003h 0004h 0005h 0006h 0007h 0008h 0009h 000Ah 000Bh 000Ch 000Dh 000Eh Block Register Label PADR PADDR PAOR PBDR PBDDR PBOR PCDR PCDDR PCOR PDDR PDDDR PDOR PEDR PEDDR PEOR Register Name Port A Data Register Port A Data Direction Register Port A Option Register Port B Data Register Port B Data Direction Register Port B Option Register Port C Data Register Port C Data Direction Register Port C Option Register Port D Data Register Port D Data Direction Register Port D Option Register Port E Data Register Port E Data Direction Register Port E Option Register Reset Status 00h1) 00h 00h 00h1) 00h 00h 00h1) 00h 00h 00h1) 00h 00h 00h1) 00h 00h Remarks R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2)
Port A
Port B
Port C
Port D
Port E
11/224
ST72361
Address 000Fh 0010h 0011h 0012h to 0020h 0021h 0022h 0023h 0024h 0025h 0026h 0027h 0028h 0029h 002Ah 002Bh 002Ch 002Dh 002Eh 002Fh 0030h 0031h 0032h 0033h 0034h 0035h 0036h 0037h 0038h 0039h 003Ah 003Bh 003Ch 003Dh 003Eh 003Fh 0040h 0041h 0042h 0043h 0044h 0045h 0046h 0047h
Block
Register Label PFDR PFDDR PFOR
Register Name Port F Data Register Port F Data Direction Register Port F Option Register Reserved Area (15 bytes)
Reset Status 00h1) 00h 00h
Remarks R/W2) R/W2) R/W2)
Port F
SPI FLASH
SPIDR SPICR SPICSR FCSR ISPR0 ISPR1 ISPR2 ISPR3 EICR0 EICR1 AWUCSR AWUPR SICSR MCCSR WDGCR WDGWR PWMDCR3 PWMDCR2 PWMDCR1 PWMDCR0 PWMCR ARTCSR ARTCAR ARTARR ARTICCSR ARTICR1 ARTICR2 T8CR2 T8CR1 T8CSR T8IC1R T8OC1R T8CTR T8ACTR T8IC2R T8OC2R ADCCSR ADCDRH ADCDRL
SPI Data I/O Register SPI Control Register SPI Control/Status Register Flash Control/Status Register Interrupt Software Priority Register 0 Interrupt Software Priority Register 1 Interrupt Software Priority Register 2 Interrupt Software Priority Register 3 External Interrupt Control Register 0 External Interrupt Control Register 1 Auto Wake up f. Halt Control/Status Register Auto Wake Up From Halt Prescaler System Integrity Control / Status Register Main Clock Control / Status Register Watchdog Control Register Watchdog Window Register Pulse Width Modulator Duty Cycle Register 3 PWM Duty Cycle Register 2 PWM Duty Cycle Register 1 PWM Duty Cycle Register 0 PWM Control register Auto-Reload Timer Control/Status Register Auto-Reload Timer Counter Access Register Auto-Reload Timer Auto-Reload Register ART Input Capture Control/Status Register ART Input Capture Register 1 ART Input Capture register 2 Timer Control Register 2 Timer Control Register 1 Timer Control/Status Register Timer Input Capture 1 Register Timer Output Compare 1 Register Timer Counter Register Timer Alternate Counter Register Timer Input Capture 2 Register Timer Output Compare 2 Register Control/Status Register Data High Register Data Low Register
xxh 0xh 00h 00h FFh FFh FFh FFh 00h 00h 00h FFh 0xh 00h 7Fh 7Fh 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h xxh 00h FCh FCh xxh 00h 00h 00h 00h
R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W Read Only Read Only R/W R/W Read Only Read Only R/W Read Only Read Only Read Only R/W R/W Read Only Read Only
ITC
AWU CKCTRL WWDG
PWM ART
8-BIT TIMER
ADC
12/224
ST72361
Address 0048h 0049h 004Ah 004Bh 004Ch 004Dh 004Eh 004Fh 0050h 0051h 0052h 0053h 0054h 0055h 0056h 0057h 0058h 0059h 005Ah 005Bh 005Ch 005Dh 005Eh 005Fh 0060h 0061h 0062h 0063h 0064h 0065h 0066h 0067h 0068h to 007Fh
Block
Register Label SCI1ISR SCI1DR SCI1BRR SCI1CR1 SCI1CR2 SCI1CR3 SCI1ERPR SCI1ETPR
Register Name SCI1 Status Register SCI1 Data Register SCI1 Baud Rate Register SCI1 Control Register 1 SCI1 Control Register 2 SCI1Control Register 3 SCI1 Extended Receive Prescaler Register SCI1 Extended Transmit Prescaler Register Reserved Area (1 byte)
Reset Status C0h xxh 00h xxh 00h 00h 00h 00h
Remarks Read Only R/W R/W R/W R/W R/W R/W R/W
LINSCI1 (LIN Master/ Slave)
16-BIT TIMER
T16CR2 T16CR1 T16CSR T16IC1HR T16IC1LR T16OC1HR T16OC1LR T16CHR T16CLR T16ACHR T16ACLR T16IC2HR T16IC2LR T16OC2HR T16OC2LR SCI2SR SCI2DR SCI2BRR SCI2CR1 SCI2CR2 SCI2CR3 SCI2ERPR SCI2ETPR
Timer Control Register 2 Timer Control Register 1 Timer Control/Status Register Timer Input Capture 1 High Register Timer Input Capture 1 Low Register Timer Output Compare 1 High Register Timer Output Compare 1 Low Register Timer Counter High Register Timer Counter Low Register Timer Alternate Counter High Register Timer Alternate Counter Low Register Timer Input Capture 2 High Register Timer Input Capture 2 Low Register Timer Output Compare 2 High Register Timer Output Compare 2 Low Register SCI2 Status Register SCI2 Data Register SCI2 Baud Rate Register SCI2 Control Register 1 SCI2 Control Register 2 SCI2 Control Register 3 SCI2 Extended Receive Prescaler Register SCI2 Extended Transmit Prescaler Register
00h 00h 00h xxh xxh 80h 00h FFh FCh FFh FCh xxh xxh 80h 00h C0h xxh 00h xxh 00h 00h 00h 00h
R/W R/W R/W Read Only Read Only R/W R/W Read Only Read Only Read Only Read Only Read Only Read Only R/W R/W Read Only R/W R/W R/W R/W R/W R/W R/W
LINSCI2 (LIN Master)
Reserved area (24 bytes)
Legend: x = undefined, R/W = read/write
Notes: 1. The contents of the I/O port DR registers are readable only in output configuration. In input configuration, the values of the I/O pins are returned instead of the DR register contents. 2. The bits associated with unavailable pins must always keep their reset value.
13/224
ST72361
4 FLASH PROGRAM MEMORY
4.1 INTRODUCTION The ST7 dual voltage High Density Flash (HDFlash) is a non-volatile memory that can be electrically erased as a single block or by individual sectors and programmed on a Byte-by-Byte basis using an external VPP supply. The HDFlash devices can be programmed and erased off-board (plugged in a programming tool) or on-board using ICP (In-Circuit Programming) or IAP (In-Application Programming). The array matrix organisation allows each sector to be erased and reprogrammed without affecting other sectors. 4.2 MAIN FEATURES
Depending on the overall Flash memory size in the microcontroller device, there are up to three user sectors (see Table 3). Each of these sectors can be erased independently to avoid unnecessary erasing of the whole Flash memory when only a partial erasing is required. The first two sectors have a fixed size of 4 Kbytes (see Figure 6). They are mapped in the upper part of the ST7 addressing space so the reset and interrupt vectors are located in Sector 0 (F000hFFFFh). Table 4. Sectors available in Flash devices
Flash Size (bytes) 4K 8K > 8K Available Sectors Sector 0 Sectors 0,1 Sectors 0,1, 2

3 Flash programming modes: - Insertion in a programming tool. In this mode, all sectors including option bytes can be programmed or erased. - ICP (In-Circuit Programming). In this mode, all sectors including option bytes can be programmed or erased without removing the device from the application board. - IAP (In-Application Programming) In this mode, all sectors except Sector 0, can be programmed or erased without removing the device from the application board and while the application is running. ICT (In-Circuit Testing) for downloading and executing user application test patterns in RAM Read-out protection Register Access Security System (RASS) to prevent accidental programming or erasing
4.3 STRUCTURE The Flash memory is organised in sectors and can be used for both code and data storage. Figure 6. Memory Map and Sector Address
4K
1000h 3FFFh 7FFFh 9FFFh BFFFh D7FFh DFFFh EFFFh FFFFh
4.3.1 Read-out Protection Read-out protection, when selected, provides a protection against Program Memory content extraction and against write access to Flash memory. Even if no protection can be considered as totally unbreakable, the feature provides a very high level of protection for a general purpose microcontroller. In Flash devices, this protection is removed by reprogramming the option. In this case, the entire program memory is first automatically erased and the device can be reprogrammed. Read-out protection selection depends on the device type: - In Flash devices it is enabled and removed through the FMP_R bit in the option byte. - In ROM devices it is enabled by mask option specified in the Option List.
8K
10K
16K
24K
32K
48K
60K
FLASH MEMORY SIZE
SECTOR 2 2 Kbytes 8 Kbytes 16 Kbytes 24 Kbytes 40 Kbytes 52 Kbytes 4 Kbytes 4 Kbytes SECTOR 1 SECTOR 0
14/224
ST72361
FLASH PROGRAM MEMORY (Cont'd) 4.4 ICC INTERFACE ICC (In-Circuit Communication) needs a minimum of four and up to six pins to be connected to the programming tool (see Figure 7). These pins are: - RESET: device reset - VSS: device power supply ground Figure 7. Typical ICC Interface
PROGRAMMING TOOL ICC CONNECTOR ICC Cable APPLICATION BOARD (See Note 3) OPTIONAL (See Note 4) ICC CONNECTOR HE10 CONNECTOR TYPE 9 10 7 8 5 6 3 4 1 2 APPLICATION RESET SOURCE See Note 2 10k APPLICATION POWER SUPPLY CL2 CL1 See Note 1 APPLICATION I/O
- - - -
ICCCLK: ICC output serial clock pin ICCDATA: ICC input/output serial data pin ICCSEL/VPP: programming voltage OSC1(or OSCIN): main clock input for external source (optional) - VDD: application board power supply (see Figure 7, Note 3)
ST7
Notes: 1. If the ICCCLK or ICCDATA pins are only used as outputs in the application, no signal isolation is necessary. As soon as the Programming Tool is plugged to the board, even if an ICC session is not in progress, the ICCCLK and ICCDATA pins are not available for the application. If they are used as inputs by the application, isolation such as a serial resistor has to implemented in case another device forces the signal. Refer to the Programming Tool documentation for recommended resistor values. 2. During the ICC session, the programming tool must control the RESET pin. This can lead to conflicts between the programming tool and the application reset circuit if it drives more than 5mA at high level (push pull output or pull-up resistor<1K). A schottky diode can be used to isolate the application RESET circuit in this case. When using a classical RC network with R > 1K or a reset man-
agement IC with open drain output and pull-up resistor > 1K, no additional components are needed. In all cases the user must ensure that no external reset is generated by the application during the ICC session. 3. The use of Pin 7 of the ICC connector depends on the Programming Tool architecture. This pin must be connected when using most ST Programming Tools (it is used to monitor the application power supply). Please refer to the Programming Tool manual. 4. Pin 9 has to be connected to the OSC1 or OSCIN pin of the ST7 when the clock is not available in the application or if the selected clock option is not programmed in the option byte. ST7 devices with multi-oscillator capability need to have OSC2 grounded in this case.
ICCSEL/VPP
ICCDATA
RESET
ICCCLK
OSC2
OSC1
VDD
VSS
15/224
ST72361
FLASH PROGRAM MEMORY (Cont'd) 4.5 ICP (IN-CIRCUIT PROGRAMMING) To perform ICP the microcontroller must be switched to ICC (In-Circuit Communication) mode by an external controller or programming tool. Depending on the ICP code downloaded in RAM, Flash memory programming can be fully customized (number of bytes to program, program locations, or selection serial communication interface for downloading). When using an STMicroelectronics or third-party programming tool that supports ICP and the specific microcontroller device, the user needs only to implement the ICP hardware interface on the application board (see Figure 7). For more details on the pin locations, refer to the device pinout description. 4.6 IAP (IN-APPLICATION PROGRAMMING) This mode uses a BootLoader program previously stored in Sector 0 by the user (in ICP mode or by plugging the device in a programming tool). This mode is fully controlled by user software. This allows it to be adapted to the user application, (user-defined strategy for entering programming mode, choice of communications protocol used to fetch the data to be stored, etc.). For example, it is possible to download code from the SPI, SCI or other type of serial interface and program it in the Flash. IAP mode can be used to program any of the Flash sectors except Sector 0, which is write/ erase protected to allow recovery in case errors occur during the programming operation. 4.7 RELATED DOCUMENTATION For details on Flash programming and ICC protocol, refer to the ST7 Flash Programming Reference Manual and to the ST7 ICC Protocol Reference Manual. 4.8 REGISTER DESCRIPTION FLASH CONTROL/STATUS REGISTER (FCSR) Read / Write Reset Value: 0000 0000 (00h)
7 0 0 0 0 0 0 0 0 0
This register is reserved for use by Programming Tool software. It controls the Flash programming and erasing operations.
Table 5. Flash Control/Status Register Address and Reset Value
Address (Hex.) 0024h Register Label FCSR Reset Value 7 6 5 4 3 2 1 0
0
0
0
0
0
0
0
0
16/224
ST72361
5 CENTRAL PROCESSING UNIT
5.1 INTRODUCTION This CPU has a full 8-bit architecture and contains six internal registers allowing efficient 8-bit data manipulation. 5.2 MAIN FEATURES

5.3 CPU REGISTERS The six CPU registers shown in Figure 8 are not present in the memory mapping and are accessed by specific instructions. Accumulator (A) The Accumulator is an 8-bit general purpose register used to hold operands and the results of the arithmetic and logic calculations and to manipulate data. Index Registers (X and Y) These 8-bit registers are used to create effective addresses or as temporary storage areas for data manipulation. (The Cross-Assembler generates a precede instruction (PRE) to indicate that the following instruction refers to the Y register.) The Y register is not affected by the interrupt automatic procedures. Program Counter (PC) The program counter is a 16-bit register containing the address of the next instruction to be executed by the CPU. It is made of two 8-bit registers PCL (Program Counter Low which is the LSB) and PCH (Program Counter High which is the MSB).

Enable executing 63 basic instructions Fast 8-bit by 8-bit multiply 17 main addressing modes (with indirect addressing mode) Two 8-bit index registers 16-bit stack pointer Low power HALT and WAIT modes Priority maskable hardware interrupts Non-maskable software/hardware interrupts
Figure 8. CPU Registers
7 RESET VALUE = XXh 7 RESET VALUE = XXh 7 RESET VALUE = XXh 15 PCH 87 PCL 0 PROGRAM COUNTER RESET VALUE = RESET VECTOR @ FFFEh-FFFFh 7 0 CONDITION CODE REGISTER 1 1 I1 H I0 N Z C RESET VALUE = 1 1 1 X 1 X X X 15 87 0 STACK POINTER RESET VALUE = STACK HIGHER ADDRESS X = Undefined Value 0 Y INDEX REGISTER 0 X INDEX REGISTER 0 ACCUMULATOR
17/224
ST72361
CENTRAL PROCESSING UNIT (Cont'd) Condition Code Register (CC) Read/Write Reset Value: 111x1xxx
7
1 1 I1 H I0 N Z
Bit 1 = Z Zero. This bit is set and cleared by hardware. This bit indicates that the result of the last arithmetic, logical or data manipulation is zero. 0: The result of the last operation is different from zero. 1: The result of the last operation is zero. This bit is accessed by the JREQ and JRNE test instructions. Bit 0 = C Carry/borrow. This bit is set and cleared by hardware and software. It indicates an overflow or an underflow has occurred during the last arithmetic operation. 0: No overflow or underflow has occurred. 1: An overflow or underflow has occurred. This bit is driven by the SCF and RCF instructions and tested by the JRC and JRNC instructions. It is also affected by the "bit test and branch", shift and rotate instructions. Interrupt Management Bits Bit 5,3 = I1, I0 Interrupt The combination of the I1 and I0 bits gives the current interrupt software priority.
Interrupt Software Priority Level 0 (main) Level 1 Level 2 Level 3 (= interrupt disable) I1 1 0 0 1 I0 0 1 0 1
0 C
The 8-bit Condition Code register contains the interrupt masks and four flags representative of the result of the instruction just executed. This register can also be handled by the PUSH and POP instructions. These bits can be individually tested and/or controlled by specific instructions. Arithmetic Management Bits Bit 4 = H Half carry. This bit is set by hardware when a carry occurs between bits 3 and 4 of the ALU during an ADD or ADC instructions. It is reset by hardware during the same instructions. 0: No half carry has occurred. 1: A half carry has occurred. This bit is tested using the JRH or JRNH instruction. The H bit is useful in BCD arithmetic subroutines. Bit 2 = N Negative. This bit is set and cleared by hardware. It is representative of the result sign of the last arithmetic, logical or data manipulation. It's a copy of the result 7th bit. 0: The result of the last operation is positive or null. 1: The result of the last operation is negative (that is, the most significant bit is a logic 1). This bit is accessed by the JRMI and JRPL instructions.
These two bits are set/cleared by hardware when entering in interrupt. The loaded value is given by the corresponding bits in the interrupt software priority registers (IxSPR). They can be also set/ cleared by software with the RIM, SIM, IRET, HALT, WFI and PUSH/POP instructions. See the interrupt management chapter for more details.
18/224
ST72361
CENTRAL PROCESSING UNIT (Cont'd) Stack Pointer (SP) Read/Write Reset Value: 01 FFh
15 0 7
SP7 SP6 SP5 SP4 SP3 SP2 SP1
8 0 0 0 0 0 0 1 0 SP0
The Stack Pointer is a 16-bit register which is always pointing to the next free location in the stack. It is then decremented after data has been pushed onto the stack and incremented before data is popped from the stack (see Figure 9). Since the stack is 256 bytes deep, the 8 most significant bits are forced by hardware. Following an MCU Reset, or after a Reset Stack Pointer instruction (RSP), the Stack Pointer contains its reset value (the SP7 to SP0 bits are set) which is the stack higher address. Figure 9. Stack Manipulation Example
CALL Subroutine @ 0100h Interrupt Event PUSH Y
The least significant byte of the Stack Pointer (called S) can be directly accessed by a LD instruction. Note: When the lower limit is exceeded, the Stack Pointer wraps around to the stack upper limit, without indicating the stack overflow. The previously stored information is then overwritten and therefore lost. The stack also wraps in case of an underflow. The stack is used to save the return address during a subroutine call and the CPU context during an interrupt. The user may also directly manipulate the stack by means of the PUSH and POP instructions. In the case of an interrupt, the PCL is stored at the first location pointed to by the SP. Then the other registers are stored in the next locations as shown in Figure 9. - When an interrupt is received, the SP is decremented and the context is pushed on the stack. - On return from interrupt, the SP is incremented and the context is popped from the stack. A subroutine call occupies two locations and an interrupt five locations in the stack area.
POP Y
IRET
RET or RSP
SP SP CC A X PCH SP PCH @ 01FFh PCL PCL PCH PCL Y CC A X PCH PCL PCH PCL SP CC A X PCH PCL PCH PCL SP PCH PCL SP
Stack Higher Address = 01FFh Stack Lower Address = 0100h
19/224
ST72361
6 SUPPLY, RESET AND CLOCK MANAGEMENT
The device includes a range of utility features for securing the application in critical situations (for example, in case of a power brown-out), and reducing the number of external components. An overview is shown in Figure 11. For more details, refer to dedicated parametric section. Main features Optional PLL for multiplying the frequency by 2 Reset Sequence Manager (RSM) Multi-Oscillator Clock Management (MO) - 4 Crystal/Ceramic resonator oscillators System Integrity Management (SI) - Main supply Low voltage detection (LVD) - Auxiliary Voltage detector (AVD) with interrupt capability for monitoring the main supply Figure 11. Clock, Reset and Supply Block Diagram
/ 8000 8-BIT TIMER
6.1 PHASE LOCKED LOOP If the clock frequency input to the PLL is in the range 2 to 4 MHz, the PLL can be used to multiply the frequency by two to obtain an fOSC2 of 4 to 8 MHz. The PLL is enabled by option byte. If the PLL is disabled, then fOSC2 = fOSC/2. Caution: The PLL is not recommended for applications where timing accuracy is required. See "PLL Characteristics" on page 187. Figure 10. PLL Block Diagram
PLL x 2
fOSC 0 fOSC2 1
/2
PLL OPTION BIT
OSC2 OSC1
MULTIOSCILLATOR (MO)
fOSC PLL (option)
fOSC2
MAIN CLOCK CONTROLLER WITH REALTIME CLOCK (MCC/RTC) SYSTEM INTEGRITY MANAGEMENT
fCPU
RESET SEQUENCE RESET MANAGER (RSM)
AVD Interrupt Request SICSR AVD AVD LVD 0 F RF IE WDG RF
WATCHDOG TIMER (WDG)
0
0
0
LOW VOLTAGE VSS VDD DETECTOR (LVD)
AUXILIARY VOLTAGE DETECTOR (AVD)
20/224
ST72361
6.2 MULTI-OSCILLATOR (MO) The main clock of the ST7 can be generated by two different source types coming from the multioscillator block: an external source a crystal or ceramic resonator oscillator Each oscillator is optimized for a given frequency range in terms of consumption and is selectable through the option byte. The associated hardware configuration are shown in Table 6. Refer to the electrical characteristics section for more details. Caution: The OSC1 and/or OSC2 pins must not be left unconnected. For the purposes of Failure Mode and Effect Analysis, it should be noted that if the OSC1 and/or OSC2 pins are left unconnected, the ST7 main oscillator may start and, in this configuration, could generate an fOSC clock frequency in excess of the allowed maximum (> 16 MHz), putting the ST7 in an unsafe/undefined state. The product behavior must therefore be considered undefined when the OSC pins are left unconnected. External Clock Source In external clock mode, a clock signal (square, sinus or triangle) with ~50% duty cycle has to drive the OSC1 pin while the OSC2 pin is tied to ground. Crystal/Ceramic Oscillators This family of oscillators has the advantage of producing a very accurate rate on the main clock of the ST7. The selection within a list of five oscillators with different frequency ranges must be done by option byte in order to reduce consumption (refer to Section 14.1 on page 210 for more details on the frequency ranges). The resonator and the load capacitors must be placed as close as possible to the oscillator pins in order to minimize output distortion and start-up stabilization time. The loading capacitance values must be adjusted according to the selected oscillator. These oscillators are not stopped during the RESET phase to avoid losing time in the oscillator start-up phase. Table 6. ST7 Clock Sources
Hardware Configuration
External Clock
ST7 OSC1 OSC2
EXTERNAL SOURCE
Crystal/Ceramic Resonators
ST7 OSC1 OSC2
CL1
LOAD CAPACITORS
CL2
21/224
ST72361
6.3 RESET SEQUENCE MANAGER (RSM) 6.3.1 Introduction The reset sequence manager includes three RESET sources as shown in Figure 13: External RESET source pulse Internal LVD RESET (Low Voltage Detection) Internal WATCHDOG RESET These sources act on the RESET pin and it is always kept low during the delay phase. The RESET service routine vector is fixed at addresses FFFEh-FFFFh in the ST7 memory map. The basic RESET sequence consists of three phases as shown in Figure 12: Active Phase depending on the RESET source 256 or 4096 CPU clock cycle delay (selected by option byte) RESET vector fetch The 256 or 4096 CPU clock cycle delay allows the oscillator to stabilize and ensures that recovery has taken place from the Reset state. The shorter or longer clock cycle delay should be selected by option byte to correspond to the stabilization time of the external oscillator used in the application. Figure 13. Reset Block Diagram The RESET vector fetch phase duration is two clock cycles. Figure 12. RESET Sequence Phases
RESET
Active Phase INTERNAL RESET 256 or 4096 CLOCK CYCLES FETCH VECTOR
6.3.2 Asynchronous External RESET pin The RESET pin is both an input and an open-drain output with integrated RON weak pull-up resistor. This pull-up has no fixed value but varies in accordance with the input voltage. It can be pulled low by external circuitry to reset the device. See Electrical Characteristic section for more details. A RESET signal originating from an external source must have a duration of at least th(RSTL)in in order to be recognized (see Figure 14). This detection is asynchronous and therefore the MCU can enter reset state even in HALT mode.
VDD
RON
RESET
Filter INTERNAL RESET
PULSE GENERATOR
WATCHDOG RESET LVD RESET
22/224
ST72361
RESET SEQUENCE MANAGER (Cont'd) The RESET pin is an asynchronous signal which plays a major role in EMS performance. In a noisy environment, it is recommended to follow the guidelines mentioned in the electrical characteristics section. 6.3.3 External Power-On RESET If the LVD is disabled by option byte, to start up the microcontroller correctly, the user must ensure by means of an external reset circuit that the reset signal is held low until VDD is over the minimum level specified for the selected fOSC frequency. A proper reset signal for a slow rising VDD supply can generally be provided by an external RC network connected to the RESET pin. 6.3.4 Internal Low Voltage Detector (LVD) RESET Two different RESET sequences caused by the internal LVD circuitry can be distinguished: Power-On RESET Voltage Drop RESET The device RESET pin acts as an output that is pulled low when VDD < VIT+ (rising edge) or VDD < VIT- (falling edge) as shown in Figure 14. The LVD filters spikes on VDD larger than tg(VDD) to avoid parasitic resets. 6.3.5 Internal Watchdog RESET The RESET sequence generated by a internal Watchdog counter overflow is shown in Figure 14. Starting from the Watchdog counter underflow, the device RESET pin acts as an output that is pulled low during at least tw(RSTL)out.
Figure 14. RESET Sequences VDD
VIT+(LVD) VIT-(LVD)
LVD RESET
EXTERNAL RESET
WATCHDOG RESET
RUN
ACTIVE PHASE
RUN
ACTIVE PHASE
RUN
ACTIVE PHASE
RUN
th(RSTL)in
EXTERNAL RESET SOURCE
tw(RSTL)out
RESET PIN
WATCHDOG RESET WATCHDOG UNDERFLOW INTERNAL RESET (256 or 4096 TCPU) VECTOR FETCH
23/224
ST72361
6.4 SYSTEM INTEGRITY MANAGEMENT (SI) The System Integrity Management block contains the Low Voltage Detector (LVD) and Auxiliary Voltage Detector (AVD) functions. It is managed by the SICSR register. 6.4.1 Low Voltage Detector (LVD) The Low Voltage Detector function (LVD) generates a static reset when the VDD supply voltage is below a VIT-(LVD) reference value. This means that it secures the power-up as well as the power-down keeping the ST7 in reset. The VIT-(LVD) reference value for a voltage drop is lower than the VIT+(LVD) reference value for poweron in order to avoid a parasitic reset when the MCU starts running and sinks current on the supply (hysteresis). The LVD Reset circuitry generates a reset when VDD is below: - VIT+(LVD) when VDD is rising - VIT-(LVD) when VDD is falling The LVD function is illustrated in Figure 15. Provided the minimum VDD value (guaranteed for the oscillator frequency) is above VIT-(LVD), the MCU can only be in two modes: - under full software control - in static safe reset In these conditions, secure operation is always ensured for the application without the need for external reset hardware. During a Low Voltage Detector Reset, the RESET pin is held low, thus permitting the MCU to reset other devices. Notes: The LVD allows the device to be used without any external RESET circuitry. The LVD is an optional function which can be selected by option byte. It is recommended to make sure that the VDD supply voltage rises monotonously when the device is exiting from Reset, to ensure the application functions properly.
Figure 15. Low Voltage Detector vs Reset
VDD
Vhys VIT+(LVD) VIT-(LVD)
RESET
24/224
ST72361
SYSTEM INTEGRITY MANAGEMENT (Cont'd) 6.4.2 Auxiliary Voltage Detector (AVD) The Voltage Detector function (AVD) is based on an analog comparison between a VIT-(AVD) and VIT+(AVD) reference value and the VDD main supply. The VIT-(AVD) reference value for falling voltage is lower than the VIT+(AVD) reference value for rising voltage in order to avoid parasitic detection (hysteresis). The output of the AVD comparator is directly readable by the application software through a real time status bit (AVDF) in the SICSR register. This bit is read only. Caution: The AVD function is active only if the LVD is enabled through the option byte. 6.4.2.1 Monitoring the VDD Main Supply If the AVD interrupt is enabled, an interrupt is generated when the voltage crosses the VIT+(AVD) or VIT-(AVD) threshold (AVDF bit toggles). In the case of a drop in voltage, the AVD interrupt acts as an early warning, allowing software to shut Figure 16. Using the AVD to Monitor VDD VDD Early Warning Interrupt (Power has dropped, MCU not not yet in reset)
Vhyst
down safely before the LVD resets the microcontroller. See Figure 16. The interrupt on the rising edge is used to inform the application that the VDD warning state is over. If the voltage rise time trv is less than 256 or 4096 CPU cycles (depending on the reset delay selected by option byte), no AVD interrupt will be generated when VIT+(AVD) is reached. If trv is greater than 256 or 4096 cycles then: - If the AVD interrupt is enabled before the VIT+(AVD) threshold is reached, then two AVD interrupts will be received: The first when the AVDIE bit is set and the second when the threshold is reached. - If the AVD interrupt is enabled after the VIT+(AVD) threshold is reached, then only one AVD interrupt occurs.
VIT+(AVD) VIT-(AVD) VIT+(LVD) VIT-(LVD)
trv VOLTAGE RISE TIME
AVDF bit AVD INTERRUPT REQUEST IF AVDIE bit = 1
0
1
RESET VALUE
1
0
INTERRUPT PROCESS
INTERRUPT PROCESS
LVD RESET
25/224
ST72361
SYSTEM INTEGRITY MANAGEMENT (Cont'd) 6.4.3 Low Power Modes
Mode WAIT HALT Description No effect on SI. AVD interrupts cause the device to exit from Wait mode. The SICSR register is frozen.
6.4.3.1 Interrupts The AVD interrupt event generates an interrupt if the AVDIE bit is set and the interrupt mask in the CC register is reset (RIM instruction).
Interrupt Event AVD event Enable Event Control Flag Bit AVDF AVDIE Exit from Wait Yes Exit from Halt No
26/224
ST72361
SYSTEM INTEGRITY MANAGEMENT (Cont'd) 6.4.4 Register Description SYSTEM INTEGRITY (SI) CONTROL/STATUS REGISTER (SICSR) Read / Write Reset Value: 000x 000x (00h) Bits 3:1 = Reserved, must be kept cleared.
7 0 AVD IE AVD F LVD RF 0 0 0 0 WDG RF
Bit 7 = Reserved, must be kept cleared. Bit 6 = AVDIE Voltage Detector interrupt enable This bit is set and cleared by software. It enables an interrupt to be generated when the AVDF flag changes (toggles). The pending interrupt information is automatically cleared when software enters the AVD interrupt routine. 0: AVD interrupt disabled 1: AVD interrupt enabled Bit 5 = AVDF Voltage Detector flag This read-only bit is set and cleared by hardware. If the AVDIE bit is set, an interrupt request is generated when the AVDF bit changes value. Refer to Figure 16 and to Section 6.4.2.1 for additional details. 0: VDD over VIT+(AVD) threshold 1: VDD under VIT-(AVD) threshold Bit 4 = LVDRF LVD reset flag This bit indicates that the last Reset was generated by the LVD block. It is set by hardware (LVD reset) and cleared by software (writing zero). See WDGRF flag description for more details. When the LVD is disabled by OPTION BYTE, the LVDRF bit value is undefined.
Bit 0 = WDGRF Watchdog reset flag This bit indicates that the last Reset was generated by the Watchdog peripheral. It is set by hardware (watchdog reset) and cleared by software (writing zero) or an LVD Reset (to ensure a stable cleared state of the WDGRF flag when CPU starts). Combined with the LVDRF flag information, the flag description is given by the following table.
RESET Sources External RESET pin Watchdog LVD LVDRF 0 0 1 WDGRF 0 1 X
Application notes The LVDRF flag is not cleared when another RESET type occurs (external or watchdog), the LVDRF flag remains set to keep trace of the original failure. In this case, a watchdog reset can be detected by software while an external reset can not. CAUTION: When the LVD is not activated with the associated option byte, the WDGRF flag can not be used in the application.
27/224
ST72361
7 INTERRUPTS
7.1 INTRODUCTION The ST7 enhanced interrupt management provides the following features: Hardware interrupts Software interrupt (TRAP) Nested or concurrent interrupt management with flexible interrupt priority and level management: - Up to 4 software programmable nesting levels - Up to 16 interrupt vectors fixed by hardware - 2 non maskable events: RESET, TRAP - 1 maskable Top Level Event: TLI This interrupt management is based on: - Bit 5 and bit 3 of the CPU CC register (I1:0), - Interrupt software priority registers (ISPRx), - Fixed interrupt vector addresses located at the high addresses of the memory map (FFE0h to FFFFh) sorted by hardware priority order. This enhanced interrupt controller guarantees full upward compatibility with the standard (not nested) ST7 interrupt controller. 7.2 MASKING AND PROCESSING FLOW The interrupt masking is managed by the I1 and I0 bits of the CC register and the ISPRx registers which give the interrupt software priority level of Figure 17. Interrupt Processing Flowchart
RESET PENDING INTERRUPT N Y TLI Interrupt has the same or a lower software priority than current one N I1:0 Interrupt has a higher software priority than current one Y
each interrupt vector (see Table 6). The processing flow is shown in Figure 17. When an interrupt request has to be serviced: - Normal processing is suspended at the end of the current instruction execution. - The PC, X, A and CC registers are saved onto the stack. - I1 and I0 bits of CC register are set according to the corresponding values in the ISPRx registers of the serviced interrupt vector. - The PC is then loaded with the interrupt vector of the interrupt to service and the first instruction of the interrupt service routine is fetched (refer to "Interrupt Mapping" table for vector addresses). The interrupt service routine should end with the IRET instruction which causes the contents of the saved registers to be recovered from the stack. Note: As a consequence of the IRET instruction, the I1 and I0 bits will be restored from the stack and the program in the previous level will resume. Table 7. Interrupt Software Priority Levels
Interrupt software priority Level 0 (main) Level 1 Level 2 Level 3 (= interrupt disable) Level Low I1 1 0 High 1 I0 0 1 0 1
FETCH NEXT INSTRUCTION
THE INTERRUPT STAYS PENDING
Y
"IRET" N
RESTORE PC, X, A, CC FROM STACK
EXECUTE INSTRUCTION
STACK PC, X, A, CC LOAD I1:0 FROM INTERRUPT SW REG. LOAD PC FROM INTERRUPT VECTOR
28/224
ST72361
INTERRUPTS (Cont'd) Servicing Pending Interrupts As several interrupts can be pending at the same time, the interrupt to be taken into account is determined by the following two-step process: - the highest software priority interrupt is serviced, - if several interrupts have the same software priority then the interrupt with the highest hardware priority is serviced first. Figure 18 describes this decision process. Figure 18. Priority Decision Process
PENDING INTERRUPTS
TRAP (Non Maskable Software Interrupt) This software interrupt is serviced when the TRAP instruction is executed. It will be serviced according to the flowchart in Figure 17 as a TLI. Caution: TRAP can be interrupted by a TLI. RESET The RESET source has the highest priority in the ST7. This means that the first current routine has the highest software priority (level 3) and the highest hardware priority. See the RESET chapter for more details.
Same
SOFTWARE PRIORITY
Different
HIGHEST SOFTWARE PRIORITY SERVICED HIGHEST HARDWARE PRIORITY SERVICED
When an interrupt request is not serviced immediately, it is latched and then processed when its software priority combined with the hardware priority becomes the highest one. Note 1: The hardware priority is exclusive while the software one is not. This allows the previous process to succeed with only one interrupt. Note 2: RESET, TRAP and TLI can be considered as having the highest software priority in the decision process. Different Interrupt Vector Sources Two interrupt source types are managed by the ST7 interrupt controller: the non-maskable type (RESET, TRAP) and the maskable type (external or from internal peripherals). Non-Maskable Sources These sources are processed regardless of the state of the I1 and I0 bits of the CC register (see Figure 17). After stacking the PC, X, A and CC registers (except for RESET), the corresponding vector is loaded in the PC register and the I1 and I0 bits of the CC are set to disable interrupts (level 3). These sources allow the processor to exit HALT mode.
Maskable Sources Maskable interrupt vector sources can be serviced if the corresponding interrupt is enabled and if its own interrupt software priority (in ISPRx registers) is higher than the one currently being serviced (I1 and I0 in CC register). If any of these two conditions is false, the interrupt is latched and thus remains pending. TLI (Top Level Hardware Interrupt) This hardware interrupt occurs when a specific edge is detected on the dedicated TLI pin. Caution: A TRAP instruction must not be used in a TLI service routine. External Interrupts External interrupts allow the processor to exit from HALT low power mode. External interrupt sensitivity is software selectable through the External Interrupt Control register (EICR). External interrupt triggered on edge will be latched and the interrupt request automatically cleared upon entering the interrupt service routine. If several input pins of a group connected to the same interrupt line are selected simultaneously, these will be logically ORed. Peripheral Interrupts Usually the peripheral interrupts cause the MCU to exit from HALT mode except those mentioned in the "Interrupt Mapping" table. A peripheral interrupt occurs when a specific flag is set in the peripheral status registers and if the corresponding enable bit is set in the peripheral control register. The general sequence for clearing an interrupt is based on an access to the status register followed by a read or write to an associated register. Note: The clearing sequence resets the internal latch. A pending interrupt (that is, waiting for being serviced) will therefore be lost if the clear sequence is executed.
29/224
ST72361
INTERRUPTS (Cont'd) 7.3 INTERRUPTS AND LOW POWER MODES All interrupts allow the processor to exit the WAIT low power mode. On the contrary, only external and other specified interrupts allow the processor to exit from the HALT modes (see column "Exit from HALT" in "Interrupt Mapping" table). When several pending interrupts are present while exiting HALT mode, the first one serviced can only be an interrupt with exit from HALT mode capability and it is selected through the same decision process shown in Figure 18. Note: If an interrupt, that is not able to Exit from HALT mode, is pending with the highest priority when exiting HALT mode, this interrupt is serviced after the first one serviced. Figure 19. Concurrent Interrupt Management
SOFTWARE PRIORITY LEVEL IT2 IT1 IT4 IT3 TLI IT0 I1 I0
7.4 CONCURRENT & NESTED MANAGEMENT The following Figure 19 and Figure 20 show two different interrupt management modes. The first is called concurrent mode and does not allow an interrupt to be interrupted, unlike the nested mode in Figure 20. The interrupt hardware priority is given in this order from the lowest to the highest: MAIN, IT4, IT3, IT2, IT1, IT0, TLI. The software priority is given for each interrupt. Warning: A stack overflow may occur without notifying the software of the failure.
HARDWARE PRIORITY
TLI IT0 IT1 IT2 IT3 RIM IT4 MAIN MAIN IT1
3 3 3 3 3 3 3/0 10
11 11 11 11 11 11
11 / 10 Figure 20. Nested Interrupt Management
SOFTWARE PRIORITY LEVEL
TLI
IT0
IT2
IT1
IT4
IT3
I1
I0
HARDWARE PRIORITY
TLI IT0 IT1 IT2 IT3 RIM IT4 MAIN IT4 MAIN IT1 IT2
3 3 2 1 3 3 3/0 10
11 11 00 01 11 11
11 / 10
30/224
USED STACK = 20 BYTES
USED STACK = 10 BYTES
ST72361
INTERRUPTS (Cont'd) 7.5 INTERRUPT REGISTER DESCRIPTION CPU CC REGISTER INTERRUPT BITS Read / Write Reset Value: 111x 1010 (xAh)
7 1 1 I1 H I0 N Z 0 C ISPR1 I1_7 I0_7 I1_6 I0_6 I1_5 I0_5 I0_9 I1_4 I1_8 I0_4 I0_8
INTERRUPT SOFTWARE PRIORITY REGISTERS (ISPRX) Read/Write (bit 7:4 of ISPR3 are read only) Reset Value: 1111 1111 (FFh)
7 ISPR0 I1_3 I0_3 I1_2 I0_2 I1_1 I0_1 I1_0 0 I0_0
Bit 5, 3 = I1, I0 Software Interrupt Priority These two bits indicate the current interrupt software priority.
Interrupt Software Priority Level 0 (main) Level 1 Level 2 Level 3 (= interrupt disable*) Level Low I1 1 0 High 1 I0 0 1 0 1
ISPR2 ISPR3
I1_11 I0_11 I1_10 I0_10 I1_9 1 1 1 1
I1_13 I0_13 I1_12 I0_12
These two bits are set/cleared by hardware when entering in interrupt. The loaded value is given by the corresponding bits in the interrupt software priority registers (ISPRx). They can be also set/cleared by software with the RIM, SIM, HALT, WFI, IRET and PUSH/POP instructions (see "Interrupt Dedicated Instruction Set" table). *Note: TLI, TRAP and RESET events can interrupt a level 3 program.
These four registers contain the interrupt software priority of each interrupt vector. - Each interrupt vector (except RESET and TRAP) has corresponding bits in these registers where its own software priority is stored. This correspondence is shown in the following table.
Vector address FFFBh-FFFAh FFF9h-FFF8h ... FFE1h-FFE0h ISPRx bits I1_0 and I0_0 bits* I1_1 and I0_1 bits ... I1_13 and I0_13 bits
- Each I1_x and I0_x bit value in the ISPRx registers has the same meaning as the I1 and I0 bits in the CC register. - Level 0 cannot be written (I1_x = 1, I0_x = 0). In this case, the previously stored value is kept (Example: previous = CFh, write = 64h, result = 44h) The RESET, TRAP and TLI vectors have no software priorities. When one is serviced, the I1 and I0 bits of the CC register are both set. *Note: Bits in the ISPRx registers which correspond to the TLI can be read and written but they are not significant in the interrupt process management. Caution: If the I1_x and I0_x bits are modified while the interrupt x is executed the following behavior has to be considered: If the interrupt x is still pending (new interrupt or flag not cleared) and the new software priority is higher than the previous one, the interrupt x is re-entered. Otherwise, the software priority stays unchanged up to the next interrupt request (after the IRET of the interrupt x).
31/224
ST72361
INTERRUPTS (Cont'd)
Table 8. Dedicated Interrupt Instruction Set
Instruction HALT IRET JRM JRNM POP CC RIM SIM TRAP WFI New Description Entering Halt mode Interrupt routine return Jump if I1:0 = 11 (level 3) Jump if I1:0 <> 11 Pop CC from the Stack Enable interrupt (level 0 set) Disable interrupt (level 3 set) Software trap Wait for interrupt Pop CC, A, X, PC I1:0 = 11 ? I1:0 <> 11 ? Mem => CC Load 10 in I1:0 of CC Load 11 in I1:0 of CC Software NMI I1 1 1 1 1 H I0 0 1 1 0 N Z C Function/Example I1 1 I1 H H I0 0 I0 N Z C N Z C
Note: During the execution of an interrupt routine, the HALT, POPCC, RIM, SIM and WFI instructions change the current software priority up to the next IRET instruction or one of the previously mentioned instructions.
32/224
ST72361
INTERRUPTS (Cont'd) Table 9. Interrupt Mapping
N Source Block RESET TRAP 0 1 2 3 4 5 6 7 8 9 10 11 12 13 SPI TIMER8 TIMER16 LINSCI2 LINSCI1 PWM ART TLI MCC/RTC ei0/AWUFH ei1/AVD ei2 ei3 Reset Software interrupt External top level interrupt Main clock controller time base interrupt External interrupt ei0/ Auto wake-up from Halt External interrupt ei1/Auxiliary Voltage Detector External interrupt ei2 External interrupt ei3 not used not used SPI peripheral interrupts 8-bit TIMER peripheral interrupts 16-bit TIMER peripheral interrupts LINSCI2 Peripheral interrupts LINSCI1 Peripheral interrupts (LIN Master/ Slave) 8-bit PWM ART interrupts SPICSR T8_TCR1 TCR1 SCI2CR1 SCI1CR1 PWMCR Lowest Priority yes no no no no3) yes Description Register Label N/A EICR MCCSR EICR/ AWUCSR EICR/ SICSR EICR EICR yes2) Highest Priority Priority Order Exit from HALT1) yes no yes yes Address Vector FFFEh-FFFFh FFFCh-FFFDh FFFAh-FFFBh FFF8h-FFF9h FFF6h-FFF7h FFF4h-FFF5h FFF2h-FFF3h FFF0h-FFF1h FFEEh-FFEFh FFECh-FFEDh FFEAh-FFEBh FFE8h-FFE9h FFE6h-FFE7h FFE4h-FFE5h FFE2h-FFE3h FFE0h-FFE1h
Notes: 1. Valid for HALT and ACTIVE HALT modes except for the MCC/RTC interrupt source which exits from ACTIVE HALT mode only. 2. Except AVD interrupt 3. It is possible to exit from Halt using the external interrupt which is mapped on the RDI pin.
33/224
ST72361
INTERRUPTS (Cont'd) 7.6 EXTERNAL INTERRUPTS 7.6.1 I/O Port Interrupt Sensitivity The external interrupt sensitivity is controlled by the ISxx bits in the EICR register (Figure 21). This control allows up to four fully independent external interrupt source sensitivities. Each external interrupt source can be generated on four (or five) different events on the pin: Falling edge Rising edge Figure 21. External Interrupt Control Bits
PORT A [7:0] INTERRUPTS PAOR.0 PADDR.0 PA0 EICR IS00 IS01 PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7
Falling and rising edge Falling edge and low level To guarantee correct functionality, the sensitivity bits in the EICR register can be modified only when the I1 and I0 bits of the CC register are both set to 1 (level 3). This means that interrupts must be disabled before changing sensitivity. The pending interrupts are cleared by writing a different value in the ISx[1:0] of the EICR.

SENSITIVITY CONTROL
ei0 INTERRUPT SOURCE
PORT B [5:0] INTERRUPTS PBOR.0 PBDDR.0 PB0
EICR IS10 IS11
AWUFH Oscillator
/ AWUPR
To Timer Input Capture 1
PB0 PB1 PB2 PB3 PB4 PB5
SENSITIVITY CONTROL
ei1 INTERRUPT SOURCE
PORT C [2:1] INTERRUPTS PCOR.7 PCDDR.7 PC1
EICR IS20 IS21 PC1 PC2 ei2 INTERRUPT SOURCE
SENSITIVITY CONTROL
PORT D [7:6, 4, 1:0] INTERRUPTS PDOR.0 PDDDR.0 PD0
EICR IS30 IS31 PD0 PD1 PD4 PD6 PD7
SENSITIVITY CONTROL
ei3 INTERRUPT SOURCE
34/224
ST72361
INTERRUPTS (Cont'd) 7.6.2 Register Description EXTERNAL INTERRUPT CONTROL REGISTER 0 (EICR0) Read / Write Reset Value: 0000 0000 (00h)
7 IS31 IS30 IS21 IS20 IS11 IS10 IS01 0 IS00
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). Bits 1:0 = IS0[1:0] ei0 sensitivity The interrupt sensitivity, defined using the IS0[1:0] bits, is applied to the ei0 external interrupts:
IS01 IS00 0 0 1 1 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
Bits 7:6 = IS3[1:0] ei3 sensitivity The interrupt sensitivity, defined using the IS3[1:0] bits, is applied to the ei3 external interrupts:
IS31 IS30 0 0 1 1 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). EXTERNAL INTERUPT CONTROL REGISTER 1 (EICR1) Read / Write Reset Value: 0000 0000 (00h)
7 0 0 0 0 0 0 TLIS 0 TLIE
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). Bits 5:4 = IS2[1:0] ei2 sensitivity The interrupt sensitivity, defined using the IS2[1:0] bits, is applied to the ei2 external interrupts:
IS21 IS20 0 0 1 1 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
BIts 7:2 = Reserved Bit 1 = TLIS Top Level Interrupt sensitivity This bit configures the TLI edge sensitivity. It can be set and cleared by software only when TLIE bit is cleared. 0: Falling edge 1: Rising edge Bit 0 = TLIE Top Level Interrupt enable This bit allows to enable or disable the TLI capability on the dedicated pin. It is set and cleared by software. 0: TLI disabled 1: TLI enabled Notes: - A parasitic interrupt can be generated when clearing the TLIE bit. - In some packages, the TLI pin is not available. In this case, the TLIE bit must be kept low to avoid parasitic TLI interrupts.
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). Bits 3:2 = IS1[1:0] ei1 sensitivity The interrupt sensitivity, defined using the IS1[1:0] bits, is applied to the ei1 external interrupts:
IS11 IS10 0 0 1 1 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
35/224
ST72361
INTERRUPTS (Cont'd) Table 10. Nested Interrupts Register Map and Reset Values
Address (Hex.) 0025h Register Label ISPR0 Reset Value ISPR1 Reset Value ISPR2 Reset Value ISPR3 Reset Value EICR0 Reset Value EICR1 Reset Value 7 ei1 I1_3 1 I0_3 1 I1_2 1 6 5 ei0 I0_2 1 I1_1 1 ei3 0026h I1_7 I0_7 1 1 LINSCI 2 I1_11 I0_11 1 1 I1_6 I0_6 1 1 TIMER 16 I1_10 I0_10 1 1 I1_5 I0_5 1 1 TIMER 8 I1_9 I0_9 1 1 ART I1_13 I0_13 1 1 IS11 IS10 0 0 0 0 I1_4 1 4 3 CLKM I0_1 1 1 ei2 I0_4 1 2 1 TLI 1 0
0027h
0028h 0029h 002Ah
1 IS31 0 0
1 IS30 0 0
1 IS21 0 0
1 IS20 0 0
SPI I1_8 I0_8 1 1 LINSCI 1 I1_12 I0_12 1 1 IS01 IS00 0 0 TLIS TLIE 0 0
36/224
ST72361
8 POWER SAVING MODES
8.1 INTRODUCTION To give a large measure of flexibility to the application in terms of power consumption, five main power saving modes are implemented in the ST7 (see Figure 22): Slow Wait (and Slow-Wait) Active Halt Auto Wake-up From Halt (AWUFH) Halt After a RESET the normal operating mode is selected by default (RUN mode). This mode drives the device (CPU and embedded peripherals) by means of a master clock which is based on the main oscillator frequency divided or multiplied by 2 (fOSC2). From RUN mode, the different power saving modes may be selected by setting the relevant register bits or by calling the specific ST7 software instruction whose action depends on the oscillator status. Figure 22. Power Saving Mode Transitions
MCCSR
8.2 SLOW MODE This mode has two targets: - To reduce power consumption by decreasing the internal clock in the device, - To adapt the internal clock frequency (fCPU) to the available supply voltage. SLOW mode is controlled by three bits in the MCCSR register: the SMS bit which enables or disables Slow mode and two CPx bits which select the internal slow frequency (fCPU). In this mode, the master clock frequency (fOSC2) can be divided by 2, 4, 8 or 16. The CPU and peripherals are clocked at this lower frequency (fCPU). Note: SLOW-WAIT mode is activated by entering WAIT mode while the device is in SLOW mode. Figure 23. SLOW Mode Clock Transitions
fOSC2/2 fCPU fOSC2/4 fOSC2
fOSC2 CP1:0 SMS 00 01
High RUN SLOW WAIT SLOW WAIT ACTIVE HALT AUTO WAKE-UP FROM HALT HALT Low POWER CONSUMPTION
NEW SLOW FREQUENCY REQUEST
NORMAL RUN MODE REQUEST
37/224
ST72361
POWER SAVING MODES (Cont'd) 8.3 WAIT MODE WAIT mode places the MCU in a low power consumption mode by stopping the CPU. This power saving mode is selected by calling the `WFI' instruction. All peripherals remain active. During WAIT mode, the I[1:0] bits of the CC register are forced to `10', to enable all interrupts. All other registers and memory remain unchanged. The MCU remains in WAIT mode until an interrupt or RESET occurs, whereupon the Program Counter branches to the starting address of the interrupt or Reset service routine. The MCU will remain in WAIT mode until a Reset or an Interrupt occurs, causing it to wake up. Refer to Figure 24 Figure 24. WAIT Mode Flow-chart
OSCILLATOR PERIPHERALS CPU I[1:0] BITS ON ON OFF 10
WFI INSTRUCTION
N RESET N INTERRUPT Y OSCILLATOR PERIPHERALS CPU I[1:0] BITS ON OFF ON 10 Y
256 OR 4096 CPU CLOCK CYCLE DELAY
OSCILLATOR PERIPHERALS CPU I[1:0] BITS
ON ON ON XX 1)
FETCH RESET VECTOR OR SERVICE INTERRUPT
Note: 1. Before servicing an interrupt, the CC register is pushed on the stack. The I[1:0] bits of the CC register are set to the current software priority level of the interrupt routine and recovered when the CC register is popped.
38/224
ST72361
POWER SAVING MODES (Cont'd) 8.4 HALT MODE The HALT mode is the lowest power consumption mode of the MCU. It is entered by executing the `HALT' instruction when the OIE bit of the Main Clock Controller Status register (MCCSR) is cleared (see Section 10.2 on page 58 for more details on the MCCSR register) and when the AWUEN bit in the AWUCSR register is cleared. The MCU can exit HALT mode on reception of either a specific interrupt (see Table 9, "Interrupt Mapping," on page 33) or a RESET. When exiting HALT mode by means of a RESET or an interrupt, the oscillator is immediately turned on and the 256 or 4096 CPU cycle delay is used to stabilize the oscillator. After the start up delay, the CPU resumes operation by servicing the interrupt or by fetching the reset vector which woke it up (see Figure 26). When entering HALT mode, the I[1:0] bits in the CC register are forced to `10b' to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes up immediately. In HALT mode, the main oscillator is turned off causing all internal processing to be stopped, including the operation of the on-chip peripherals. All peripherals are not clocked except the ones which get their clock supply from another clock generator (such as an external or auxiliary oscillator). The compatibility of Watchdog operation with HALT mode is configured by the "WDGHALT" option bit of the option byte. The HALT instruction when executed while the Watchdog system is enabled, can generate a Watchdog RESET (see Section 10.1 on page 52 for more details). Figure 25. HALT Timing Overview
RUN HALT 256 OR 4096 CPU CYCLE DELAY RESET OR INTERRUPT FETCH VECTOR RUN
Figure 26. HALT Mode Flow-chart
HALT INSTRUCTION (MCCSR.OIE=0) (AWUCSR.AWUEN=0) ENABLE WDGHALT 1) 1 WATCHDOG RESET OSCILLATOR OFF PERIPHERALS 2) OFF CPU OFF I[1:0] BITS 10 0 WATCHDOG DISABLE
N RESET N Y INTERRUPT 3) Y OSCILLATOR ON PERIPHERALS OFF CPU ON I[1:0] BITS XX 4) 256 OR 4096 CPU CLOCK CYCLE DELAY OSCILLATOR ON PERIPHERALS ON CPU ON I[1:0] BITS XX 4) FETCH RESET VECTOR OR SERVICE INTERRUPT
HALT INSTRUCTION [MCCSR.OIE=0]
Notes: 1. WDGHALT is an option bit. See option byte section for more details. 2. Peripheral clocked with an external clock source can still be active. 3. Only some specific interrupts can exit the MCU from HALT mode (such as external interrupt). Refer to Table 9, "Interrupt Mapping," on page 33 for more details. 4. Before servicing an interrupt, the CC register is pushed on the stack. The I[1:0] bits of the CC register are set to the current software priority level of the interrupt routine and recovered when the CC register is popped.
39/224
ST72361
POWER SAVING MODES (Cont'd) Halt Mode Recommendations - Make sure that an external event is available to wake up the microcontroller from Halt mode. - When using an external interrupt to wake up the microcontroller, reinitialize the corresponding I/O as "Input Pull-up with Interrupt" before executing the HALT instruction. The main reason for this is that the I/O may be wrongly configured due to external interference or by an unforeseen logical condition. - For the same reason, reinitialize the level sensitiveness of each external interrupt as a precautionary measure. - The opcode for the HALT instruction is 0x8E. To avoid an unexpected HALT instruction due to a program counter failure, it is advised to clear all occurrences of the data value 0x8E from memory. For example, avoid defining a constant in ROM with the value 0x8E. - As the HALT instruction clears the interrupt mask in the CC register to allow interrupts, the user may choose to clear all pending interrupt bits before executing the HALT instruction. This avoids entering other peripheral interrupt routines after executing the external interrupt routine corresponding to the wake-up event (reset or external interrupt). 8.5 ACTIVE HALT MODE ACTIVE HALT mode is the lowest power consumption mode of the MCU with a real time clock available. It is entered by executing the `HALT' instruction when MCC/RTC interrupt enable flag (OIE bit in MCCSR register) is set and when the AWUEN bit in the AWUCSR register is cleared (See "Register Description" on page 44.)
MCCSR OIE bit 0 1 Power Saving Mode entered when HALT instruction is executed HALT mode ACTIVE HALT mode
The MCU can exit ACTIVE HALT mode on reception of the RTC interrupt and some specific interrupts (see Table 9, "Interrupt Mapping," on page 33) or a RESET. When exiting ACTIVE HALT mode by means of a RESET a 4096 or 256 CPU cycle delay occurs (depending on the option byte). After the start up delay, the CPU resumes operation by servicing the interrupt or by fetching the reset vector which woke it up (see Figure 28). When entering ACTIVE HALT mode, the I[1:0] bits in the CC register are are forced to `10b' to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes up immediately. In ACTIVE HALT mode, only the main oscillator and its associated counter (MCC/RTC) are running to keep a wake-up time base. All other peripherals are not clocked except those which get their clock supply from another clock generator (such as external or auxiliary oscillator). The safeguard against staying locked in ACTIVE HALT mode is provided by the oscillator interrupt. Note: As soon as active halt is enabled, executing a HALT instruction while the Watchdog is active does not generate a RESET. This means that the device cannot spend more than a defined delay in this power saving mode.
40/224
ST72361
POWER SAVING MODES (Cont'd) Figure 27. ACTIVE HALT Timing Overview
RUN ACTIVE 256 OR 4096 CYCLE HALT DELAY (AFTER RESET) RUN RESET OR INTERRUPT
HALT INSTRUCTION (Active Halt enabled)
FETCH VECTOR
Figure 28. ACTIVE HALT Mode Flow-chart
HALT INSTRUCTION (MCCSR.OIE=1) (AWUCSR.AWUEN=0) OSCILLATOR ON PERIPHERALS 2) OFF CPU OFF 10 I[1:0] BITS N RESET N INTERRUPT 3) Y OSCILLATOR ON PERIPHERALS OFF CPU ON I[1:0] BITS XX 4) 256 OR 4096 CPU CLOCK CYCLE DELAY OSCILLATOR ON PERIPHERALS ON CPU ON I[1:0] BITS XX 4) FETCH RESET VECTOR OR SERVICE INTERRUPT Y
Notes: 1. This delay occurs only if the MCU exits ACTIVE HALT mode by means of a RESET. 2. Peripheral clocked with an external clock source can still be active. 3. Only the RTC interrupt and some specific interrupts can exit the MCU from ACTIVE HALT mode (such as external interrupt). Refer to Table 9, "Interrupt Mapping," on page 33 for more details. 4. Before servicing an interrupt, the CC register is pushed on the stack. The I[1:0] bits in the CC register are set to the current software priority level of the interrupt routine and restored when the CC register is popped.
41/224
ST72361
POWER SAVING MODES (Cont'd) 8.6 AUTO WAKE-UP FROM HALT MODE Auto Wake-Up From Halt (AWUFH) mode is similar to Halt mode with the addition of an internal RC oscillator for wake-up. Compared to ACTIVE HALT mode, AWUFH has lower power consumption because the main clock is not kept running, but there is no accurate realtime clock available. It is entered by executing the HALT instruction when the AWUEN bit in the AWUCSR register has been set and the OIE bit in the MCCSR register is cleared (see Section 10.2 on page 58 for more details). Figure 29. AWUFH Mode Block Diagram AWU RC oscillator fAWU_RC to Timer input capture and a 256 or 4096 cycle delay is used to stabilize it. After this start-up delay, the CPU resumes operation by servicing the AWUFH interrupt. The AWU flag and its associated interrupt are cleared by software reading the AWUCSR register. To compensate for any frequency dispersion of the AWU RC oscillator, it can be calibrated by measuring the clock frequency fAWU_RC and then calculating the right prescaler value. Measurement mode is enabled by setting the AWUM bit in the AWUCSR register in Run mode. This connects fAWU_RC to the ICAP1 input of the 16-bit timer, allowing the fAWU_RC to be measured using the main oscillator clock as a reference timebase. Similarities with Halt mode The following AWUFH mode behavior is the same as normal Halt mode: - The MCU can exit AWUFH mode by means of any interrupt with exit from Halt capability or a reset (see Section 8.4 "HALT MODE"). - When entering AWUFH mode, the I[1:0] bits in the CC register are forced to 10b to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes up immediately. - In AWUFH mode, the main oscillator is turned off causing all internal processing to be stopped, including the operation of the on-chip peripherals. None of the peripherals are clocked except those which get their clock supply from another clock generator (such as an external or auxiliary oscillator like the AWU oscillator). - The compatibility of Watchdog operation with AWUFH mode is configured by the WDGHALT option bit in the option byte. Depending on this setting, the HALT instruction when executed while the Watchdog system is enabled, can generate a Watchdog RESET.
/64 divider
AWUFH prescaler /1 .. 255
AWUFH interrupt (ei0 source)
As soon as HALT mode is entered, and if the AWUEN bit has been set in the AWUCSR register, the AWU RC oscillator provides a clock signal (fAWU_RC). Its frequency is divided by a fixed divider and a programmable prescaler controlled by the AWUPR register. The output of this prescaler provides the delay time. When the delay has elapsed the AWUF flag is set by hardware and an interrupt wakes up the MCU from Halt mode. At the same time the main oscillator is immediately turned on Figure 30. AWUF Halt Timing Diagram tAWU RUN MODE
fCPU fAWU_RC
HALT MODE
256 or 4096 tCPU
RUN MODE
Clear by software
AWUFH interrupt
42/224
ST72361
POWER SAVING MODES (Cont'd) Figure 31. AWUFH Mode Flow-chart
HALT INSTRUCTION (MCCSR.OIE=0) (AWUCSR.AWUEN=1) ENABLE WDGHALT 1) 1 WATCHDOG RESET AWU RC OSC ON MAIN OSC OFF PERIPHERALS 2) OFF CPU OFF I[1:0] BITS 10 0 WATCHDOG DISABLE
Notes: 1. WDGHALT is an option bit. See option byte section for more details. 2. Peripheral clocked with an external clock source can still be active. 3. Only an AWUFH interrupt and some specific interrupts can exit the MCU from HALT mode (such as external interrupt). Refer to Table 9, "Interrupt Mapping," on page 33 for more details. 4. Before servicing an interrupt, the CC register is pushed on the stack. The I[1:0] bits of the CC register are set to the current software priority level of the interrupt routine and recovered when the CC register is popped.
N RESET N Y INTERRUPT 3) Y AWU RC OSC OFF MAIN OSC ON PERIPHERALS OFF CPU ON I[1:0] BITS XX 4) 256 OR 4096 CPU CLOCK CYCLE DELAY AWU RC OSC OFF MAIN OSC ON PERIPHERALS ON CPU ON I[1:0] BITS XX 4) FETCH RESET VECTOR OR SERVICE INTERRUPT
43/224
ST72361
POWER SAVING MODES (Cont'd) 8.6.1 Register Description AWUFH CONTROL/STATUS REGISTER (AWUCSR) Read / Write (except bit 2 read only) Reset Value: 0000 0000 (00h)
7 0 0 0 0 0 0 AWU AWU AWU F M EN
0: AWUFH (Auto Wake-Up From Halt) mode disabled 1: AWUFH (Auto Wake-Up From Halt) mode enabled AWUFH PRESCALER REGISTER (AWUPR) Read / Write Reset Value: 1111 1111 (FFh)
7 0
Bits 7:3 = Reserved. Bit 2 = AWUF Auto Wake-Up Flag This bit is set by hardware when the AWU module generates an interrupt and cleared by software on reading AWUCSR. 0: No AWU interrupt occurred 1: AWU interrupt occurred Bit 1 = AWUM Auto Wake-Up Measurement This bit enables the AWU RC oscillator and connects its output to the ICAP1 input of the 16-bit timer. This allows the timer to be used to measure the AWU RC oscillator dispersion and then compensate this dispersion by providing the right value in the AWUPR register. 0: Measurement disabled 1: Measurement enabled Bit 0 = AWUEN Auto Wake-Up From Halt Enabled This bit enables the Auto Wake-Up From Halt feature: once HALT mode is entered, the AWUFH wakes up the microcontroller after a time delay defined by the AWU prescaler value. It is set and cleared by software. Table 11. AWU Register Map and Reset Values
Address (Hex.) 002Bh 002Ch Register Label 7 6 5
AWU AWU AWU AWU AWU AWU AWU AWU PR7 PR6 PR5 PR4 PR3 PR2 PR1 PR0
Bits 7:0 = AWUPR[7:0] Auto Wake-Up Prescaler These 8 bits define the AWUPR Dividing factor (as explained below:
AWUPR[7:0] 00h 01h ... FEh FFh Dividing factor Forbidden (See note) 1 ... 254 255
In AWU mode, the period that the MCU stays in Halt Mode (tAWU in Figure 30) is defined by
t
AWU
1 = 64 x AWUPR x ------------------------- + t RCSTRT f AWURC
This prescaler register can be programmed to modify the time that the MCU stays in Halt mode before waking up automatically. Note: If 00h is written to AWUPR, depending on the product, an interrupt is generated immediately after a HALT instruction or the AWUPR remains unchanged.
4
3
2
1
0
AWUCSR AWUF AWUM AWUEN 0 0 0 0 0 Reset Value 0 0 0 AWUPR AWUPR7 AWUPR6 AWUPR5 AWUPR4 AWUPR3 AWUPR2 AWUPR1 AWUPR0 Reset Value 1 1 1 1 1 1 1 1
44/224
ST72361
9 I/O PORTS
9.1 INTRODUCTION The I/O ports offer different functional modes: - transfer of data through digital inputs and outputs and for specific pins: - external interrupt generation - alternate signal input/output for the on-chip peripherals. An I/O port contains up to 8 pins. Each pin can be programmed independently as digital input (with or without interrupt generation) or digital output. 9.2 FUNCTIONAL DESCRIPTION Each port has two main registers: - Data Register (DR) - Data Direction Register (DDR) and one optional register: - Option Register (OR) Each I/O pin may be programmed using the corresponding register bits in the DDR and OR registers: Bit X corresponding to pin X of the port. The same correspondence is used for the DR register. The following description takes into account the OR register, (for specific ports which do not provide this register refer to the I/O Port Implementation section). The generic I/O block diagram is shown in Figure 32 9.2.1 Input Modes The input configuration is selected by clearing the corresponding DDR register bit. In this case, reading the DR register returns the digital value applied to the external I/O pin. Different input modes can be selected by software through the OR register. Notes: 1. Writing the DR register modifies the latch value but does not affect the pin status. 2. When switching from input to output mode, the DR register has to be written first to drive the correct level on the pin as soon as the port is configured as an output. 3. Do not use read/modify/write instructions (BSET or BRES) to modify the DR register as this might corrupt the DR content for I/Os configured as input. External interrupt function When an I/O is configured as Input with Interrupt, an event on this I/O can generate an external interrupt request to the CPU. Each pin can independently generate an interrupt request. The interrupt sensitivity is independently programmable using the sensitivity bits in the EICR register. Each external interrupt vector is linked to a dedicated group of I/O port pins (see pinout description and interrupt section). If several input pins are selected simultaneously as interrupt sources, these are first detected according to the sensitivity bits in the EICR register and then logically ORed. The external interrupts are hardware interrupts, which means that the request latch (not accessible directly by the application) is automatically cleared when the corresponding interrupt vector is fetched. To clear an unwanted pending interrupt by software, the sensitivity bits in the EICR register must be modified. 9.2.2 Output Modes The output configuration is selected by setting the corresponding DDR register bit. In this case, writing the DR register applies this digital value to the I/O pin through the latch. Then reading the DR register returns the previously stored value. Two different output modes can be selected by software through the OR register: Output push-pull and open-drain. DR register value and output pin status:
DR 0 1 Push-pull VSS VDD Open-drain Vss Floating
9.2.3 Alternate Functions When an on-chip peripheral is configured to use a pin, the alternate function is automatically selected. This alternate function takes priority over the standard I/O programming. When the signal is coming from an on-chip peripheral, the I/O pin is automatically configured in output mode (push-pull or open drain according to the peripheral). When the signal is going to an on-chip peripheral, the I/O pin must be configured in input mode. In this case, the pin state is also digitally readable by addressing the DR register. Note: Input pull-up configuration can cause unexpected value at the input of the alternate peripheral input. When an on-chip peripheral use a pin as input and output, this pin has to be configured in input floating mode.
45/224
ST72361
I/O PORTS (Cont'd) Figure 32. I/O Port General Block Diagram
ALTERNATE OUTPUT
REGISTER ACCESS
1 0
VDD
P-BUFFER (see table below) PULL-UP (see table below) VDD
ALTERNATE ENABLE DR
DDR PULL-UP CONDITION If implemented OR SEL N-BUFFER DDR SEL CMOS SCHMITT TRIGGER ANALOG INPUT DIODES (see table below) PAD
OR
EXTERNAL INTERRUPT SOURCE (eix)
Table 12. I/O Port Mode Options
Configuration Mode Input Floating with/without Interrupt Pull-up with/without Interrupt Push-pull Open Drain (logic level) True Open Drain Pull-Up Off On Off NI P-Buffer Off On Off NI On On Diodes to VDD to VSS
Output
Legend: NI - not implemented Off - implemented not activated On - implemented and activated
46/224
DATA BUS
DR SEL
1 0
ALTERNATE INPUT
NI (see note)
Note: The diode to VDD is not implemented in the true open drain pads. A local protection between the pad and VSS is implemented to protect the device against positive stress.
ST72361
I/O PORTS (Cont'd) Table 13. I/O Port Configurations
Hardware Configuration
NOT IMPLEMENTED IN TRUE OPEN DRAIN I/O PORTS VDD RPU PAD PULL-UP CONDITION DR REGISTER ACCESS
DR REGISTER
W DATA BUS R
INPUT 1)
ALTERNATE INPUT EXTERNAL INTERRUPT SOURCE (eix) INTERRUPT CONDITION ANALOG INPUT NOT IMPLEMENTED IN TRUE OPEN DRAIN I/O PORTS
OPEN-DRAIN OUTPUT 2)
VDD RPU
DR REGISTER ACCESS
PAD
DR REGISTER
R/W
DATA BUS
ALTERNATE ENABLE
ALTERNATE OUTPUT
PUSH-PULL OUTPUT 2)
NOT IMPLEMENTED IN TRUE OPEN DRAIN I/O PORTS
VDD RPU
DR REGISTER ACCESS
PAD
DR REGISTER
R/W
DATA BUS
ALTERNATE ENABLE
ALTERNATE OUTPUT
Notes: 1. When the I/O port is in input configuration and the associated alternate function is enabled as an output, reading the DR register will read the alternate function output status. 2. When the I/O port is in output configuration and the associated alternate function is enabled as an input, the alternate function reads the pin status given by the DR register content.
47/224
ST72361
I/O PORTS (Cont'd) CAUTION: The alternate function must not be activated as long as the pin is configured as input with interrupt, in order to avoid generating spurious interrupts. Analog alternate function When the pin is used as an ADC input, the I/O must be configured as floating input. The analog multiplexer (controlled by the ADC registers) switches the analog voltage present on the selected pin to the common analog rail which is connected to the ADC input. It is recommended not to change the voltage level or loading on any port pin while conversion is in progress. Furthermore it is recommended not to have clocking pins located close to a selected analog pin. WARNING: The analog input voltage level must be within the limits stated in the absolute maximum ratings. 9.3 I/O PORT IMPLEMENTATION The hardware implementation on each I/O port depends on the settings in the DDR and OR registers and specific feature of the I/O port such as ADC Input or true open drain. Switching these I/O ports from one state to another should be done in a sequence that prevents unwanted side effects. Recommended safe transitions are illustrated in Figure 33 on page 49. Other transitions are potentially risky and should be avoided, since they are likely to present unwanted side-effects such as spurious interrupt generation.
Figure 33. Interrupt I/O Port State Transitions
01
INPUT floating/pull-up interrupt
00
INPUT floating (reset state)
10
OUTPUT open-drain
11
OUTPUT push-pull
XX
= DDR, OR
9.4 LOW POWER MODES
Mode WAIT HALT Description No effect on I/O ports. External interrupts cause the device to exit from WAIT mode. No effect on I/O ports. External interrupts cause the device to exit from HALT mode.
9.5 INTERRUPTS The external interrupt event generates an interrupt if the corresponding configuration is selected with DDR and OR registers and the interrupt mask in the CC register is not active (RIM instruction).
Interrupt Event External interrupt on selected external event Enable Event Control Flag Bit DDRx ORx Exit from Wait Exit from Halt
Yes
48/224
ST72361
I/O PORTS (Cont'd) 9.6 I/O PORT REGISTER CONFIGURATIONS The I/O port register configurations are summarized as follows. 9.6.1 Standard Ports PB7:6, PC0, PC3, PC7:5, PD3:2, PD5, PE7:0, PF7:0
MODE floating input pull-up input open drain output push-pull output DDR 0 0 1 1 OR 0 1 0 1
PA1,3,5,7; PB1,3,5; PC2; PD1,4,7 (without pull-up)
MODE floating input floating interrupt input open drain output push-pull output DDR 0 0 1 1 OR 0 1 0 1
9.6.3 Pull-up Input Port PC4
MODE pull-up input
9.6.2 Interrupt Ports PA0,2,4,6; PB0,2,4; PC1; PD0,6 (with pull-up)
MODE floating input pull-up interrupt input open drain output push-pull output DDR 0 0 1 1 OR 0 1 0 1
The PC4 port cannot operate as a general purpose output. If DDR = 1 it is still possible to read the port through the DR register.
49/224
ST72361
I/O PORTS (Cont'd) Table 14. Port Configuration
Port Pin name
PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7 PB0 PB1 PB2 PB3 PB4 PB5 PC0 PC1 PC2 PC3 PC4 PC7:5 PD0 PD1 PD3:2 PD4 PD5 PD6 PD7 PE7:0 PF7:0
Input OR = 0 OR = 1
pull-up interrupt (ei0) floating interrupt (ei0) pull-up interrupt (ei0) floating interrupt (ei0) pull-up interrupt (ei0) floating interrupt (ei0) pull-up interrupt (ei0) floating interrupt (ei0) pull-up interrupt (ei1) floating interrupt (ei1) pull-up interrupt (ei1) floating interrupt (ei1) pull-up interrupt (ei1) floating interrupt (ei1) pull-up pull-up interrupt (ei2) floating interrupt (ei2) pull-up pull-up pull-up pull-up interrupt (ei3) floating interrupt (ei3) pull-up floating interrupt (ei3) pull-up pull-up interrupt (ei3) floating interrupt (ei3) pull-up (TTL) pull-up (TTL)
Output OR = 0 OR = 1
Port A
floating
open drain
push-pull
Port B
floating
open drain
push-pull
floating
open drain
push-pull
Port C
N/A open drain push-pull
floating
Port D
floating
open drain
push-pull
Port E Port F
floating (TTL) floating (TTL)
open drain open drain
push-pull push-pull
50/224
ST72361
I/O PORTS (Cont'd) Table 15. I/O Port Register Map and Reset Values
Address (Hex.) Register Label 7 0 6 0 5 0 4 0 3 0 2 0 1 0 0 0
Reset Value of all IO port registers 0000h PADR 0001h PADDR 0002h PAOR 0003h PBDR 0004h PBDDR 0005h PBOR 0006h PCDR 0007h PCDDR 0008h PCOR 0009h PDDR 000Ah PDDDR 000Bh PDOR 000Ch PEDR 000Dh PEDDR 000Eh PEOR 000Fh PFDR 0010h PFDDR 0011h PFOR
MSB
LSB
MSB
LSB
MSB
LSB
MSB
LSB
MSB
LSB
MSB
LSB
51/224
ST72361
10 ON-CHIP PERIPHERALS
10.1 WINDOW WATCHDOG (WWDG) 10.1.1 Introduction The Window Watchdog is used to detect the occurrence of a software fault, usually generated by external interference or by unforeseen logical conditions, which causes the application program to abandon its normal sequence. The Watchdog circuit generates an MCU reset on expiry of a programmed time period, unless the program refreshes the contents of the downcounter before the T6 bit becomes cleared. An MCU reset is also generated if the 7-bit downcounter value (in the control register) is refreshed before the downcounter has reached the window register value. This implies that the counter must be refreshed in a limited window. 10.1.2 Main Features Programmable free-running downcounter Conditional reset - Reset (if watchdog activated) when the downcounter value becomes less than 40h - Reset (if watchdog activated) if the downFigure 34. Watchdog Block Diagram
RESET W6 WATCHDOG WINDOW REGISTER (WDGWR) W5 W4 W3 W2 W1 W0
counter is reloaded outside the window (see Figure 37) Hardware/Software Watchdog activation (selectable by option byte) Optional reset on HALT instruction (configurable by option byte) 10.1.3 Functional Description The counter value stored in the WDGCR register (bits T[6:0]), is decremented every 16384 fOSC2 cycles (approx.), and the length of the timeout period can be programmed by the user in 64 increments. If the watchdog is activated (the WDGA bit is set) and when the 7-bit downcounter (T[6:0] bits) rolls over from 40h to 3Fh (T6 becomes cleared), it initiates a reset cycle pulling low the reset pin for typically 30s. If the software reloads the counter while the counter is greater than the value stored in the window register, then a reset is generated.
comparator = 1 when T6:0 > W6:0 CMP Write WDGCR WATCHDOG CONTROL REGISTER (WDGCR) WDGA T6 T5 T4 T3 T2 T1 T0
MCC/RTC fOSC2
DIV 64
6-BIT DOWNCOUNTER (CNT)
WDG PRESCALER DIV 4 12-BIT MCC RTC COUNTER MSB
11 65
LSB
0
TB[1:0] bits (MCCSR Register)
52/224
ST72361
WINDOW WATCHDOG (Cont'd) The application program must write in the WDGCR register at regular intervals during normal operation to prevent an MCU reset. This operation must occur only when the counter value is lower than the window register value. The value to be stored in the WDGCR register must be between FFh and C0h (see Figure 35): - Enabling the watchdog: When Software Watchdog is selected (by option byte), the watchdog is disabled after a reset. It is enabled by setting the WDGA bit in the WDGCR register, then it cannot be disabled again except by a reset. When Hardware Watchdog is selected (by option byte), the watchdog is always active and the WDGA bit is not used. - Controlling the downcounter: This downcounter is free-running: It counts down even if the watchdog is disabled. When the watchdog is enabled, the T6 bit must be set to prevent generating an immediate reset. The T[5:0] bits contain the number of increments which represents the time delay before the watchdog produces a reset (see Figure 35. Approximate Timeout Duration). The timing varies
between a minimum and a maximum value due to the unknown status of the prescaler when writing to the WDGCR register (see Figure 36). The window register (WDGWR) contains the high limit of the window: To prevent a reset, the downcounter must be reloaded when its value is lower than the window register value and greater than 3Fh. Figure 37 describes the window watchdog process. Note: The T6 bit can be used to generate a software reset (the WDGA bit is set and the T6 bit is cleared). - Watchdog Reset on Halt option If the watchdog is activated and the watchdog reset on halt option is selected, then the HALT instruction will generate a Reset. 10.1.4 Using Halt Mode with the WDG If Halt mode with Watchdog is enabled by option byte (no watchdog reset on HALT instruction), it is recommended before executing the HALT instruction to refresh the WDG counter, to avoid an unexpected WDG reset immediately after waking up the microcontroller.
53/224
ST72361
WINDOW WATCHDOG (Cont'd) 10.1.5 How to Program the Watchdog Timeout Figure 35 shows the linear relationship between the 6-bit value to be loaded in the Watchdog Counter (CNT) and the resulting timeout duration in milliseconds. This can be used for a quick calculation without taking the timing variations into account. If Figure 35. Approximate Timeout Duration 3F 38 30
more precision is needed, use the formulae in Figure 36. Caution: When writing to the WDGCR register, always write 1 in the T6 bit to avoid generating an immediate reset.
CNT Value (hex.)
28 20 18
10 08 00 1.5 18 34 50 65 82 98 114 128 Watchdog timeout (ms) @ 8 MHz fOSC2
54/224
ST72361
WINDOW WATCHDOG (Cont'd) Figure 36. Exact Timeout Duration (tmin and tmax) WHERE: tmin0 = (LSB + 128) x 64 x tOSC2 tmax0 = 16384 x tOSC2 tOSC2 = 125ns if fOSC2 = 8 MHz CNT = Value of T[5:0] bits in the WDGCR register (6 bits) MSB and LSB are values from the table below depending on the timebase selected by the TB[1:0] bits in the MCCSR register
TB1 Bit TB0 Bit (MCCSR Reg.) (MCCSR Reg.) 0 0 0 1 1 0 1 1 Selected MCCSR Timebase 2ms 4ms 10ms 25ms MSB 4 8 20 49 LSB 59 53 35 54
To calculate the minimum Watchdog Timeout (tmin): IF CNT < MSB ------------4
THEN t min = t min0 + 16384 x CNT x tosc2 ELSE t min = t min0 + 16384 x CNT - 4CNT + ( 192 + LSB ) x 64 x 4CNT ------------------------------ MSB MSB
x t osc2
To calculate the maximum Watchdog Timeout (tmax): IF CNT MSB ------------4
THEN t max = t max0 + 16384 x CNT x t osc2 ELSE t max = t max0 + 16384 x CNT - 4CNT + ( 192 + LSB ) x 64 x 4CNT ------------------------------ MSB MSB
x t osc2
Note: In the above formulae, division results must be rounded down to the next integer value. Example: With 2ms timeout selected in MCCSR register
Value of T[5:0] Bits in WDGCR Register (Hex.) 00 3F Min. Watchdog Timeout (ms) tmin 1.496 128 Max. Watchdog Timeout (ms) tmax 2.048 128.552
55/224
ST72361
WINDOW WATCHDOG (Cont'd) Figure 37. Window Watchdog Timing Diagram
T[5:0] CNT downcounter
WDGWR
3Fh
Refresh not allowed Refresh Window
time (step = 16384/fOSC2)
T6 bit Reset
10.1.6 Low Power Modes Mode SLOW WAIT Description No effect on Watchdog: The downcounter continues to decrement at normal speed. No effect on Watchdog: The downcounter continues to decrement.
OIE bit in MCCSR register WDGHALT bit in Option Byte No Watchdog reset is generated. The MCU enters Halt mode. The Watchdog counter is decremented once and then stops counting and is no longer able to generate a watchdog reset until the MCU receives an external interrupt or a reset. 0 0 If an interrupt is received (refer to interrupt table mapping to see interrupts which can occur in halt mode), the Watchdog restarts counting after 256 or 4096 CPU clocks. If a reset is generated, the Watchdog is disabled (reset state) unless Hardware Watchdog is selected by option byte. For application recommendations see Section 10.1.8 below. A reset is generated instead of entering halt mode. No reset is generated. The MCU enters Active Halt mode. The Watchdog counter is not decremented. It stop counting. When the MCU receives an oscillator interrupt or external interrupt, the Watchdog restarts counting immediately. When the MCU receives a reset the Watchdog restarts counting after 256 or 4096 CPU clocks.
HALT
0
1
ACTIVE HALT
1
x
10.1.7 Hardware Watchdog Option If Hardware Watchdog is selected by option byte, the watchdog is always active and the WDGA bit in the WDGCR is not used. Refer to the Option Byte description.
10.1.8 Using Halt Mode with the WDG (WDGHALT option) The following recommendation applies if Halt mode is used when the watchdog is enabled. - Before executing the HALT instruction, refresh the WDG counter, to avoid an unexpected WDG reset immediately after waking up the microcontroller.
56/224
ST72361
WINDOW WATCHDOG (Cont'd) 10.1.9 Interrupts None. 10.1.10 Register Description CONTROL REGISTER (WDGCR) Read / Write Reset Value: 0111 1111 (7F h)
7 WDGA T6 T5 T4 T3 T2 T1 0 T0
WINDOW REGISTER (WDGWR) Read/Write Reset Value: 0111 1111 (7Fh)
7 W6 W5 W4 W3 W2 W1 0 W0
Bit 7 = Reserved Bits 6:0 = W[6:0] 7-bit window value These bits contain the window value to be compared to the downcounter.
Bit 7 = WDGA Activation bit. This bit is set by software and only cleared by hardware after a reset. When WDGA = 1, the watchdog can generate a reset. 0: Watchdog disabled 1: Watchdog enabled Note: This bit is not used if the hardware watchdog option is enabled by option byte. Bits 6:0 = T[6:0] 7-bit counter (MSB to LSB). These bits contain the value of the watchdog counter. It is decremented every 16384 fOSC2 cycles (approx.). A reset is produced when it rolls over from 40h to 3Fh (T6 becomes cleared).
Figure 38. Watchdog Timer Register Map and Reset Values
Address (Hex.) 2F 30 Register Label WDGCR Reset Value WDGWR Reset Value 7 WDGA 0 0 6 T6 1 W6 1 5 T5 1 W5 1 4 T4 1 W4 1 3 T3 1 W3 1 2 T2 1 W2 1 1 T1 1 W1 1 0 T0 1 W0 1
57/224
ST72361
ON-CHIP PERIPHERALS (Cont'd) 10.2 MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK MCC/RTC The Main Clock Controller consists of three different functions: a programmable CPU clock prescaler a clock-out signal to supply external devices a real time clock timer with interrupt capability Each function can be used independently and simultaneously. 10.2.1 Programmable CPU Clock Prescaler The programmable CPU clock prescaler supplies the clock for the ST7 CPU and its internal peripherals. It manages SLOW power saving mode (See Section 8.2 "SLOW MODE" for more details). The prescaler selects the fCPU main clock frequency and is controlled by three bits in the MCCSR register: CP[1:0] and SMS. 10.2.2 Clock-out Capability The clock-out capability is an alternate function of an I/O port pin that outputs a fOSC2 clock to drive external devices. It is controlled by the MCO bit in the MCCSR register. 10.2.3 Real Time Clock Timer (RTC) The counter of the real time clock timer allows an interrupt to be generated based on an accurate real time clock. Four different time bases depending directly on fOSC2 are available. The whole functionality is controlled by 4 bits of the MCCSR register: TB[1:0], OIE and OIF. When the RTC interrupt is enabled (OIE bit set), the ST7 enters ACTIVE HALT mode when the HALT instruction is executed. See Section 8.5 "ACTIVE HALT MODE" for more details.
Figure 39. Main Clock Controller (MCC/RTC) Block Diagram
fOSC2
MCO
RTC COUNTER
TO WATCHDOG TIMER
MCO CP1 CP0 SMS TB1 TB0 OIE MCCSR
OIF MCC/RTC INTERRUPT
DIV 2, 4, 8, 16
fCPU
CPU CLOCK TO CPU AND PERIPHERALS
58/224
ST72361
MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK (Cont'd) 10.2.4 Low Power Modes Bits 6:5 = CP[1:0] CPU clock prescaler Mode Description These bits select the CPU clock prescaler which is No effect on MCC/RTC peripheral. applied in the different slow modes. Their action is WAIT MCC/RTC interrupt cause the device to conditioned by the setting of the SMS bit. These exit from WAIT mode. two bits are set and cleared by software
No effect on MCC/RTC counter (OIE bit is set), the registers are frozen. ACTIVE HALT MCC/RTC interrupt cause the device to exit from ACTIVE HALT mode. MCC/RTC counter and registers are froHALT zen. and MCC/RTC operation resumes when the AWUF HALT MCU is woken up by an interrupt with "exit from HALT" capability. fCPU in SLOW mode fOSC2 / 2 fOSC2 / 4 fOSC2/ 8 fOSC2 / 16 CP1 0 0 1 1 CP0 0 1 0 1
10.2.5 Interrupts The MCC/RTC interrupt event generates an interrupt if the OIE bit of the MCCSR register is set and the interrupt mask in the CC register is not active (RIM instruction).
Interrupt Event Time base overflow event Enable Event Control Flag Bit OIF OIE Exit from Wait Yes Exit from Halt No1)
Bit 4 = SMS Slow mode select This bit is set and cleared by software. 0: Normal mode. fCPU = fOSC2 1: Slow mode. fCPU is given by CP1, CP0 See Section 8.2 "SLOW MODE" and Section 10.2 "MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK MCC/RTC" for more details. Bits 3:2 = TB[1:0] Time base control These bits select the programmable divider time base. They are set and cleared by software.
Time Base Counter Prescaler f OSC2 =4 MHz fOSC2=8 MHz 16000 32000 80000 200000 4ms 8ms 20ms 50ms 2ms 4ms 10ms 25ms TB1 0 0 1 1 TB0 0 1 0 1
Note: The MCC/RTC interrupt wakes up the MCU from ACTIVE HALT mode, not from HALT or AWUF HALT mode. 10.2.6 Register Description MCC CONTROL/STATUS REGISTER (MCCSR) Read / Write Reset Value: 0000 0000 (00h)
7 MCO CP1 CP0 SMS TB1 TB0 OIE 0 OIF
A modification of the time base is taken into account at the end of the current period (previously set) to avoid an unwanted time shift. This allows to use this time base as a real time clock. Bit 1 = OIE Oscillator interrupt enable This bit set and cleared by software. 0: Oscillator interrupt disabled 1: Oscillator interrupt enabled This interrupt can be used to exit from ACTIVE HALT mode. When this bit is set, calling the ST7 software HALT instruction enters the ACTIVE HALT power saving mode.
Bit 7 = MCO Main clock out selection This bit enables the MCO alternate function on the corresponding I/O port. It is set and cleared by software. 0: MCO alternate function disabled (I/O pin free for general-purpose I/O) 1: MCO alternate function enabled (fOSC2 on I/O port)
59/224
ST72361
MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK (Cont'd) Bit 0 = OIF Oscillator interrupt flag This bit is set by hardware and cleared by software reading the CSR register. It indicates when set that the main oscillator has reached the selected elapsed time (TB1:0). 0: Timeout not reached 1: Timeout reached CAUTION: The BRES and BSET instructions must not be used on the MCCSR register to avoid unintentionally clearing the OIF bit.
Table 16. Main Clock Controller Register Map and Reset Values
Address (Hex.) 002Dh 002Eh Register Label SICSR Reset Value MCCSR Reset Value 7 0 MCO 0 6 AVDIE CP1 0 5 AVDF CP0 0 4 LVDRF SMS 0 3 0 TB1 0 2 1 0 WDGRF x OIF 0
0 TB0 0
0 OIE 0
60/224
ST72361
ON-CHIP PERIPHERALS (Cont'd) 10.3 PWM AUTO-RELOAD TIMER (ART) 10.3.1 Introduction The Pulse Width Modulated Auto-Reload Timer on-chip peripheral consists of an 8-bit auto reload counter with compare/capture capabilities and of a 7-bit prescaler clock source. These resources allow five possible operating modes: - Generation of up to four independent PWM signals Figure 40. PWM Auto-Reload Timer Block Diagram
PWMCR OEx OPx OCRx REGISTER LOAD PWMx PORT ALTERNATE FUNCTION POLARITY CONTROL COMPARE DCRx REGISTER
- Output compare and Time base interrupt - Up to two input capture functions - External event detector - Up to two external interrupt sources The three first modes can be used together with a single counter frequency. The timer can be used to wake up the MCU from WAIT and HALT modes.
ARR REGISTER
8-BIT COUNTER (CAR REGISTER)
LOAD
ARTICx
INPUT CAPTURE CONTROL
LOAD
ICRx REGISTER
ICSx
ICIEx
ICFx
ICCSR
ARTCLK
fEXT fCPU fCOUNTER
ICx INTERRUPT
MUX fINPUT
PROGRAMMABLE PRESCALER
EXCL
CC2
CC1
CC0
TCE
FCRL
OIE
OVF
ARTCSR
OVF INTERRUPT
61/224
ST72361
PWM AUTO-RELOAD TIMER (Cont'd) 10.3.2 Functional Description Counter The free running 8-bit counter is fed by the output of the prescaler, and is incremented on every rising edge of the clock signal. It is possible to read or write the contents of the counter on the fly by reading or writing the Counter Access register (ARTCAR). When a counter overflow occurs, the counter is automatically reloaded with the contents of the ARTARR register (the prescaler is not affected). Counter clock and prescaler The counter clock frequency is given by: fCOUNTER = fINPUT / 2CC[2:0] The timer counter's input clock (fINPUT) feeds the 7-bit programmable prescaler, which selects one of the eight available taps of the prescaler, as defined by CC[2:0] bits in the Control/Status Register (ARTCSR). Thus the division factor of the prescaler can be set to 2n (where n = 0, 1,..7). This fINPUT frequency source is selected through the EXCL bit of the ARTCSR register and can be either the fCPU or an external input frequency fEXT. The clock input to the counter is enabled by the TCE (Timer Counter Enable) bit in the ARTCSR register. When TCE is reset, the counter is stopped and the prescaler and counter contents are frozen. When TCE is set, the counter runs at the rate of the selected clock source. Figure 41. Output Compare Control
fCOUNTER ARTARR=FDh COUNTER FDh FEh FFh FDh FEh FFh FDh FEh FFh
Counter and Prescaler Initialization After RESET, the counter and the prescaler are cleared and fINPUT = fCPU. The counter can be initialized by: - Writing to the ARTARR register and then setting the FCRL (Force Counter Re-Load) and the TCE (Timer Counter Enable) bits in the ARTCSR register. - Writing to the ARTCAR counter access register, In both cases the 7-bit prescaler is also cleared, whereupon counting will start from a known value. Direct access to the prescaler is not possible. Output compare control The timer compare function is based on four different comparisons with the counter (one for each PWMx output). Each comparison is made between the counter value and an output compare register (OCRx) value. This OCRx register can not be accessed directly, it is loaded from the duty cycle register (PWMDCRx) at each overflow of the counter. This double buffering method avoids glitch generation when changing the duty cycle on the fly.
OCRx
FDh
FEh
PWMDCRx
FDh
FEh
PWMx
62/224
ST72361
PWM AUTO-RELOAD TIMER (Cont'd) Independent PWM signal generation This mode allows up to four Pulse Width Modulated signals to be generated on the PWMx output pins with minimum core processing overhead. This function is stopped during HALT mode. Each PWMx output signal can be selected independently using the corresponding OEx bit in the PWM Control register (PWMCR). When this bit is set, the corresponding I/O pin is configured as output push-pull alternate function. The PWM signals all have the same frequency which is controlled by the counter period and the ARTARR register value. fPWM = fCOUNTER / (256 - ARTARR) When a counter overflow occurs, the PWMx pin level is changed depending on the corresponding OPx (output polarity) bit in the PWMCR register. Figure 42. PWM Auto-reload Timer Function
255 DUTY CYCLE REGISTER (PWMDCRx)
When the counter reaches the value contained in one of the output compare register (OCRx) the corresponding PWMx pin level is restored. It should be noted that the reload values will also affect the value and the resolution of the duty cycle of the PWM output signal. To obtain a signal on a PWMx pin, the contents of the OCRx register must be greater than the contents of the ARTARR register. The maximum available resolution for the PWMx duty cycle is: Resolution = 1 / (256 - ARTARR) Note: To get the maximum resolution (1/256), the ARTARR register must be 0. With this maximum resolution, 0% and 100% can be obtained by changing the polarity.
COUNTER
AUTO-RELOAD REGISTER (ARTARR) 000
t
PWMx OUTPUT
WITH OEx=1 AND OPx=0 WITH OEx=1 AND OPx=1
Figure 43. PWM Signal from 0% to 100% Duty Cycle
fCOUNTER ARTARR=FDh COUNTER FDh FEh FFh FDh FEh FFh FDh FEh
OCRx=FCh PWMx OUTPUT WITH OEx=1 AND OPx=0 OCRx=FDh OCRx=FEh OCRx=FFh
t
63/224
ST72361
PWM AUTO-RELOAD TIMER (Cont'd) Output compare and Time base interrupt On overflow, the OVF flag of the ARTCSR register is set and an overflow interrupt request is generated if the overflow interrupt enable bit, OIE, in the ARTCSR register, is set. The OVF flag must be reset by the user software. This interrupt can be used as a time base in the application. External clock and event detector mode Using the fEXT external prescaler input clock, the auto-reload timer can be used as an external clock event detector. In this mode, the ARTARR register is used to select the nEVENT number of events to be counted before setting the OVF flag. nEVENT = 256 - ARTARR Caution: The external clock function is not available in HALT mode. If HALT mode is used in the application, prior to executing the HALT instruction, the counter must be disabled by clearing the TCE bit in the ARTCSR register to avoid spurious counter increments.
Figure 44. External Event Detector Example (3 counts)
fEXT=fCOUNTER ARTARR=FDh
COUNTER
FDh
FEh
FFh
FDh
FEh
FFh
FDh
OVF
ARTCSR READ INTERRUPT IF OIE=1 INTERRUPT IF OIE=1
ARTCSR READ
t
64/224
ST72361
PWM AUTO-RELOAD TIMER (Cont'd) Input Capture Function Input Capture mode allows the measurement of external signal pulse widths through ARTICRx registers. Each input capture can generate an interrupt independently on a selected input signal transition. This event is flagged by a set of the corresponding CFx bits of the Input Capture Control/Status register (ARTICCSR). These input capture interrupts are enabled through the CIEx bits of the ARTICCSR register. The active transition (falling or rising edge) is software programmable through the CSx bits of the ARTICCSR register. The read only input capture registers (ARTICRx) are used to latch the auto-reload counter value when a transition is detected on the ARTICx pin (CFx bit set in ARTICCSR register). After fetching the interrupt vector, the CFx flags can be read to identify the interrupt source. Note: After a capture detection, data transfer in the ARTICRx register is inhibited until the next read (clearing the CFx bit). The timer interrupt remains pending while the CFx flag is set when the interrupt is enabled (CIEx bit set). This means, the ARTICRx register has to be read at each capture event to clear the CFx flag. The timing resolution is given by auto-reload counter cycle time (1/fCOUNTER). Note: During HALT mode, input capture is inhibited (the ARTICRx is never reloaded) and only the external interrupt capability can be used. Note: The ARTICx signal is synchronized on CPU clock. It takes two rising edges until ARTICRx is latched with the counter value. Depending on the prescaler value and the time when the ICAP event occurs, the value loaded in the ARTICRx register may be different. If the counter is clocked with the CPU clock, the value latched in ARTICRx is always the next counter value after the event on ARTICx occurred (Figure 45). If the counter clock is prescaled, it depends on the position of the ARTICx event within the counter cycle (Figure 46).
Figure 45. Input Capture Timing Diagram, fCOUNTER = fCPU
fCPU
fCOUNTER
COUNTER
01h
02h
03h
04h
05h
06h
07h INTERRUPT
ARTICx PIN ICAP SAMPLED CFx FLAG xxh ICAP SAMPLED
05h t
65/224
ST72361
PWM AUTO-RELOAD TIMER (Cont'd) Figure 46. input Capture Timing Diagram, fCOUNTER = fCPU / 4
fCPU
fCOUNTER
COUNTER
03h
04h
05h
ARTICx PIN ICAP SAMPLED CFx FLAG xxh ICRx REGISTER 04h
INTERRUPT
t
fCPU
fCOUNTER
COUNTER
03h
04h
05h
ARTICx PIN ICAP SAMPLED CFx FLAG xxh ICRx REGISTER
INTERRUPT
05h t
External Interrupt Capability This mode allows the Input capture capabilities to be used as external interrupt sources. The interrupts are generated on the edge of the ARTICx signal. The edge sensitivity of the external interrupts is programmable (CSx bit of ARTICCSR register) and they are independently enabled through CIEx bits of the ARTICCSR register. After fetching the interrupt vector, the CFx flags can be read to identify the interrupt source. During HALT mode, the external interrupts can be used to wake up the micro (if the CIEx bit is set). In
this case, the interrupt synchronization is done directly on the ARTICx pin edge (Figure 47). Figure 47. ART External Interrupt in Halt Mode
ARTICx PIN CFx FLAG INTERRUPT t
66/224
ST72361
ON-CHIP PERIPHERALS (Cont'd) 10.3.3 Register Description CONTROL / STATUS REGISTER (ARTCSR) Read / Write Reset Value: 0000 0000 (00h)
7 EXCL CC2 CC1 CC0 TCE FCRL OIE 0 OVF 7 0 CA6 CA5 CA4 CA3 CA2 CA1 CA0
0: New transition not yet reached 1: Transition reached COUNTER ACCESS REGISTER (ARTCAR) Read / Write Reset Value: 0000 0000 (00h)
Bit 7 = EXCL External Clock This bit is set and cleared by software. It selects the input clock for the 7-bit prescaler. 0: CPU clock. 1: External clock. Bit 6:4 = CC[2:0] Counter Clock Control These bits are set and cleared by software. They determine the prescaler division ratio from fINPUT.
fCOUNTER fINPUT fINPUT / 2 fINPUT / 4 fINPUT / 8 fINPUT / 16 fINPUT / 32 fINPUT / 64 fINPUT / 128 With fINPUT=8 MHz CC2 CC1 CC0 8 MHz 4 MHz 2 MHz 1 MHz 500 kHz 250 kHz 125 kHz 62.5 kHz 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1
CA7
Bit 7:0 = CA[7:0] Counter Access Data These bits can be set and cleared either by hardware or by software. The ARTCAR register is used to read or write the auto-reload counter "on the fly" (while it is counting).
AUTO-RELOAD REGISTER (ARTARR) Read / Write Reset Value: 0000 0000 (00h)
7 AR7 AR6 AR5 AR4 AR3 AR2 AR1 0 AR0
Bit 3 = TCE Timer Counter Enable This bit is set and cleared by software. It puts the timer in the lowest power consumption mode. 0: Counter stopped (prescaler and counter frozen). 1: Counter running. Bit 2 = FCRL Force Counter Re-Load This bit is write-only and any attempt to read it will yield a logical zero. When set, it causes the contents of ARTARR register to be loaded into the counter, and the content of the prescaler register to be cleared in order to initialize the timer before starting to count. Bit 1 = OIE Overflow Interrupt Enable This bit is set and cleared by software. It allows to enable/disable the interrupt which is generated when the OVF bit is set. 0: Overflow Interrupt disable. 1: Overflow Interrupt enable. Bit 0 = OVF Overflow Flag This bit is set by hardware and cleared by software reading the ARTCSR register. It indicates the transition of the counter from FFh to the ARTARR value.
Bit 7:0 = AR[7:0] Counter Auto-Reload Data These bits are set and cleared by software. They are used to hold the auto-reload value which is automatically loaded in the counter when an overflow occurs. At the same time, the PWM output levels are changed according to the corresponding OPx bit in the PWMCR register. This register has two PWM management functions: - Adjusting the PWM frequency - Setting the PWM duty cycle resolution PWM Frequency vs Resolution:
ARTARR value 0 [ 0..127 ] [ 128..191 ] [ 192..223 ] [ 224..239 ] Resolution Min 8-bit > 7-bit > 6-bit > 5-bit > 4-bit ~0.244 kHz ~0.244 kHz ~0.488 kHz ~0.977 kHz ~1.953 kHz fPWM Max 31.25 kHz 62.5 kHz 125 kHz 250 kHz 500 kHz
67/224
ST72361
ON-CHIP PERIPHERALS (Cont'd) PWM CONTROL REGISTER (PWMCR) Read / Write Reset Value: 0000 0000 (00h)
7 OE3 OE2 OE1 OE0 OP3 OP2 OP1 0 OP0
DUTY CYCLE REGISTERS (PWMDCRx) Read / Write Reset Value: 0000 0000 (00h)
7 DC7 DC6 DC5 DC4 DC3 DC2 DC1 0 DC0
Bit 7:4 = OE[3:0] PWM Output Enable These bits are set and cleared by software. They enable or disable the PWM output channels independently acting on the corresponding I/O pin. 0: PWM output disabled. 1: PWM output enabled. Bit 3:0 = OP[3:0] PWM Output Polarity These bits are set and cleared by software. They independently select the polarity of the four PWM output signals.
PWMx output level OPx Counter <= OCRx 1 0 Counter > OCRx 0 1 0 1
Bit 7:0 = DC[7:0] Duty Cycle Data These bits are set and cleared by software. A PWMDCRx register is associated with the OCRx register of each PWM channel to determine the second edge location of the PWM signal (the first edge location is common to all channels and given by the ARTARR register). These PWMDCR registers allow the duty cycle to be set independently for each PWM channel.
Note: When an OPx bit is modified, the PWMx output signal polarity is immediately reversed.
68/224
ST72361
ON-CHIP PERIPHERALS (Cont'd) INPUT CAPTURE CONTROL / STATUS REGISTER (ARTICCSR) Read / Write Reset Value: 0000 0000 (00h)
7 0 0 CS2 CS1 CIE2 CIE1 CF2 0 IC7 CF1 IC6 IC5 IC4 IC3 IC2 IC1 IC0
INPUT CAPTURE REGISTERS (ARTICRx) Read only Reset Value: 0000 0000 (00h)
7 0
Bit 7:6 = Reserved, always read as 0. Bit 5:4 = CS[2:1] Capture Sensitivity These bits are set and cleared by software. They determine the trigger event polarity on the corresponding input capture channel. 0: Falling edge triggers capture on channel x. 1: Rising edge triggers capture on channel x. Bit 3:2 = CIE[2:1] Capture Interrupt Enable These bits are set and cleared by software. They enable or disable the Input capture channel interrupts independently. 0: Input capture channel x interrupt disabled. 1: Input capture channel x interrupt enabled. Bit 1:0 = CF[2:1] Capture Flag These bits are set by hardware and cleared by software reading the corresponding ARTICRx register. Each CFx bit indicates that an input capture x has occurred. 0: No input capture on channel x. 1: An input capture has occurred on channel x.
Bit 7:0 = IC[7:0] Input Capture Data These read only bits are set and cleared by hardware. An ARTICRx register contains the 8-bit auto-reload counter value transferred by the input capture channel x event.
69/224
ST72361
PWM AUTO-RELOAD TIMER (Cont'd) Table 17. PWM Auto-Reload Timer Register Map and Reset Values
Address (Hex.) 0031h Register Label PWMDCR3 Reset Value PWMDCR2 Reset Value PWMDCR1 Reset Value PWMDCR0 Reset Value PWMCR Reset Value ARTCSR Reset Value ARTCAR Reset Value ARTARR Reset Value ARTICCSR Reset Value ARTICR1 Reset Value ARTICR2 Reset Value 0 IC7 0 IC7 0 0 IC6 0 IC6 0 7 DC7 0 DC7 0 DC7 0 DC7 0 OE3 0 EXCL 0 CA7 0 AR7 0 6 DC6 0 DC6 0 DC6 0 DC6 0 OE2 0 CC2 0 CA6 0 AR6 0 5 DC5 0 DC5 0 DC5 0 DC5 0 OE1 0 CC1 0 CA5 0 AR5 0 CE2 0 IC5 0 IC5 0 4 DC4 0 DC4 0 DC4 0 DC4 0 OE0 0 CC0 0 CA4 0 AR4 0 CE1 0 IC4 0 IC4 0 3 DC3 0 DC3 0 DC3 0 DC3 0 OP3 0 TCE 0 CA3 0 AR3 0 CS2 0 IC3 0 IC3 0 2 DC2 0 DC2 0 DC2 0 DC2 0 OP2 0 FCRL 0 CA2 0 AR2 0 CS1 0 IC2 0 IC2 0 1 DC1 0 DC1 0 DC1 0 DC1 0 OP1 0 RIE 0 CA1 0 AR1 0 CF2 0 IC1 0 IC1 0 0 DC0 0 DC0 0 DC0 0 DC0 0 OP0 0 OVF 0 CA0 0 AR0 0 CF1 0 IC0 0 IC0 0
0032h
0033h
0034h
0035h
0036h
0037h
0038h
0039h
003Ah
003Bh
70/224
ST72361
10.4 16-BIT TIMER 10.4.1 Introduction The timer consists of a 16-bit free-running counter driven by a programmable prescaler. It may be used for a variety of purposes, including pulse length measurement of up to two input signals (input capture) or generation of up to two output waveforms (output compare and PWM). Pulse lengths and waveform periods can be modulated from a few microseconds to several milliseconds using the timer prescaler and the CPU clock prescaler. Some ST7 devices have two on-chip 16-bit timers. They are completely independent, and do not share any resources. They are synchronized after a MCU reset as long as the timer clock frequencies are not modified. This description covers one or two 16-bit timers. In ST7 devices with two timers, register names are prefixed with TA (Timer A) or TB (Timer B). 10.4.2 Main Features Programmable prescaler: fCPU divided by 2, 4 or 8 Overflow status flag and maskable interrupt External clock input (must be at least four times slower than the CPU clock speed) with the choice of active edge 1 or 2 Output Compare functions each with: - 2 dedicated 16-bit registers - 2 dedicated programmable signals - 2 dedicated status flags - 1 dedicated maskable interrupt 1 or 2 Input Capture functions each with: - 2 dedicated 16-bit registers - 2 dedicated active edge selection signals - 2 dedicated status flags - 1 dedicated maskable interrupt Pulse width modulation mode (PWM) One Pulse mode Reduced Power Mode 5 alternate functions on I/O ports (ICAP1, ICAP2, OCMP1, OCMP2, EXTCLK)* The Block Diagram is shown in Figure 48. *Note: Some timer pins may not be available (not bonded) in some ST7 devices. Refer to the device pin out description. When reading an input signal on a non-bonded pin, the value will always be `1'. 10.4.3 Functional Description 10.4.3.1 Counter The main block of the Programmable Timer is a 16-bit free running upcounter and its associated 16-bit registers. The 16-bit registers are made up of two 8-bit registers called high and low. Counter Register (CR): - Counter High Register (CHR) is the most significant byte (MS Byte). - Counter Low Register (CLR) is the least significant byte (LS Byte). Alternate Counter Register (ACR) - Alternate Counter High Register (ACHR) is the most significant byte (MS Byte). - Alternate Counter Low Register (ACLR) is the least significant byte (LS Byte). These two read-only 16-bit registers contain the same value but with the difference that reading the ACLR register does not clear the TOF bit (Timer overflow flag), located in the Status register, (SR), (see note at the end of paragraph titled 16-bit read sequence). Writing in the CLR register or ACLR register resets the free running counter to the FFFCh value. Both counters have a reset value of FFFCh (this is the only value which is reloaded in the 16-bit timer). The reset value of both counters is also FFFCh in One Pulse mode and PWM mode. The timer clock depends on the clock control bits of the CR2 register, as illustrated in Table 17 Clock Control Bits. The value in the counter register repeats every 131072, 262144 or 524288 CPU clock cycles depending on the CC[1:0] bits. The timer frequency can be fCPU/2, fCPU/4, fCPU/8 or an external frequency.
71/224
ST72361
16-BIT TIMER (Cont'd) Figure 48. Timer Block Diagram
ST7 INTERNAL BUS fCPU MCU-PERIPHERAL INTERFACE 8 low 8-bit buffer EXEDG 16 1/2 1/4 1/8 EXTCLK pin COUNTER REGISTER ALTERNATE COUNTER REGISTER 16 CC[1:0] TIMER INTERNAL BUS 16 16 OVERFLOW DETECT CIRCUIT OUTPUT COMPARE REGISTER 1 OUTPUT COMPARE REGISTER 2 INPUT CAPTURE REGISTER 1 16 INPUT CAPTURE REGISTER 2 16 8 high low 8 high 8 low 8 high 8 low 8 high 8 low 8
8 high
OUTPUT COMPARE CIRCUIT 6
EDGE DETECT CIRCUIT1
ICAP1 pin
EDGE DETECT CIRCUIT2
ICAP2 pin
LATCH1
ICF1 OCF1 TOF ICF2 OCF2 TIMD
OCMP1 pin OCMP2 pin
0
0 LATCH2
(Control/Status Register) CSR
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1
OC1E OC2E OPM PWM
CC1
CC0 IEDG2 EXEDG
(Control Register 1) CR1
(Control Register 2) CR2
(See note) TIMER INTERRUPT
Note: If IC, OC and TO interrupt requests have separate vectors then the last OR is not present (See device Interrupt Vector Table)
72/224
ST72361
16-BIT TIMER (Cont'd) 16-bit read sequence: (from either the Counter Register or the Alternate Counter Register). Beginning of the sequence At t0 Read MS Byte Other instructions Read At t0 +t LS Byte Sequence completed The user must read the MS Byte first, then the LS Byte value is buffered automatically. This buffered value remains unchanged until the 16-bit read sequence is completed, even if the user reads the MS Byte several times. After a complete reading sequence, if only the CLR register or ACLR register are read, they return the LS Byte of the count value at the time of the read. Whatever the timer mode used (input capture, output compare, One Pulse mode or PWM mode) an overflow occurs when the counter rolls over from FFFFh to 0000h then: - The TOF bit of the SR register is set. - A timer interrupt is generated if: - TOIE bit of the CR1 register is set and - I bit of the CC register is cleared. If one of these conditions is false, the interrupt remains pending to be issued as soon as they are both true.
Returns the buffered
LS Byte is buffered
LS Byte value at t0
Clearing the overflow interrupt request is done in two steps: 1. Reading the SR register while the TOF bit is set. 2. An access (read or write) to the CLR register. Notes: The TOF bit is not cleared by accesses to ACLR register. The advantage of accessing the ACLR register rather than the CLR register is that it allows simultaneous use of the overflow function and reading the free running counter at random times (for example, to measure elapsed time) without the risk of clearing the TOF bit erroneously. The timer is not affected by WAIT mode. In HALT mode, the counter stops counting until the mode is exited. Counting then resumes from the previous count (MCU awakened by an interrupt) or from the reset count (MCU awakened by a Reset). 10.4.3.2 External Clock The external clock (where available) is selected if CC0 = 1 and CC1 = 1 in the CR2 register. The status of the EXEDG bit in the CR2 register determines the type of level transition on the external clock pin EXTCLK that will trigger the free running counter. The counter is synchronized with the falling edge of the internal CPU clock. A minimum of four falling edges of the CPU clock must occur between two consecutive active edges of the external clock; thus the external clock frequency must be less than a quarter of the CPU clock frequency.
73/224
ST72361
16-BIT TIMER (Cont'd) Figure 49. Counter Timing Diagram, Internal Clock Divided by 2
CPU CLOCK INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FFFD FFFE FFFF 0000 0001 0002 0003
Figure 50. Counter Timing Diagram, Internal Clock Divided by 4
CPU CLOCK INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FFFC FFFD 0000 0001
Figure 51. Counter Timing Diagram, Internal Clock Divided By 8
CPU CLOCK INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FFFC FFFD 0000
Note: The MCU is in reset state when the internal reset signal is high, when it is low the MCU is running.
74/224
ST72361
16-BIT TIMER (Cont'd) 10.4.3.3 Input Capture In this section, the index, i, may be 1 or 2 because there are two input capture functions in the 16-bit timer. The two 16-bit input capture registers (IC1R and IC2R) are used to latch the value of the free running counter after a transition is detected on the ICAPi pin (see Figure 52).
ICiR MS Byte ICiHR LS Byte ICiLR
ICiR register is a read-only register. The active transition is software programmable through the IEDGi bit of Control Registers (CRi). Timing resolution is one count of the free running counter: (fCPU/CC[1:0]). Procedure: To use the input capture function select the following in the CR2 register: - Select the timer clock (CC[1:0]) (see Table 17 Clock Control Bits). - Select the edge of the active transition on the ICAP2 pin with the IEDG2 bit (the ICAP2 pin must be configured as floating input or input with pull-up without interrupt if this configuration is available). And select the following in the CR1 register: - Set the ICIE bit to generate an interrupt after an input capture coming from either the ICAP1 pin or the ICAP2 pin - Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the ICAP1pin must be configured as floating input or input with pullup without interrupt if this configuration is available).
When an input capture occurs: - ICFi bit is set. - The ICiR register contains the value of the free running counter on the active transition on the ICAPi pin (see Figure 53). - A timer interrupt is generated if the ICIE bit is set and the I bit is cleared in the CC register. Otherwise, the interrupt remains pending until both conditions become true. Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two steps: 1. Reading the SR register while the ICFi bit is set. 2. An access (read or write) to the ICiLR register. Notes: 1. After reading the ICiHR register, transfer of input capture data is inhibited and ICFi will never be set until the ICiLR register is also read. 2. The ICiR register contains the free running counter value which corresponds to the most recent input capture. 3. The two input capture functions can be used together even if the timer also uses the two output compare functions. 4. In One Pulse mode and PWM mode only Input Capture 2 can be used. 5. The alternate inputs (ICAP1 and ICAP2) are always directly connected to the timer. So any transitions on these pins activates the input capture function. Moreover if one of the ICAPi pins is configured as an input and the second one as an output, an interrupt can be generated if the user toggles the output pin and if the ICIE bit is set. This can be avoided if the input capture function i is disabled by reading the ICiHR (see note 1). 6. The TOF bit can be used with interrupt generation in order to measure events that go beyond the timer range (FFFFh).
75/224
ST72361
16-BIT TIMER (Cont'd) Figure 52. Input Capture Block Diagram
ICAP1 pin ICAP2 pin EDGE DETECT CIRCUIT2 EDGE DETECT CIRCUIT1
ICIE
(Control Register 1) CR1
IEDG1
(Status Register) SR IC2R Register IC1R Register
ICF1 ICF2 0 0 0
16-BIT 16-BIT FREE RUNNING COUNTER
(Control Register 2) CR2
CC1 CC0 IEDG2
Figure 53. Input Capture Timing Diagram
TIMER CLOCK COUNTER REGISTER ICAPi PIN ICAPi FLAG ICAPi REGISTER Note: The rising edge is the active edge. FF03 FF01 FF02 FF03
76/224
ST72361
16-BIT TIMER (Cont'd) 10.4.3.4 Output Compare In this section, the index, i, may be 1 or 2 because there are two output compare functions in the 16bit timer. This function can be used to control an output waveform or indicate when a period of time has elapsed. When a match is found between the Output Compare register and the free running counter, the output compare function: - Assigns pins with a programmable value if the OCiE bit is set - Sets a flag in the status register - Generates an interrupt if enabled Two 16-bit registers Output Compare Register 1 (OC1R) and Output Compare Register 2 (OC2R) contain the value to be compared to the counter register each timer clock cycle.
OCiR MS Byte OCiHR LS Byte OCiLR
- The OCMPi pin takes OLVLi bit value (OCMPi pin latch is forced low during reset). - A timer interrupt is generated if the OCIE bit is set in the CR1 register and the I bit is cleared in the CC register (CC). The OCiR register value required for a specific timing application can be calculated using the following formula:
OCiR =
Where:
t * fCPU
PRESC
t
= Output compare period (in seconds) = CPU clock frequency (in hertz) PRESC = Timer prescaler factor (2, 4 or 8 depending on CC[1:0] bits, see Table 17 Clock Control Bits) fCPU If the timer clock is an external clock, the formula is:
These registers are readable and writable and are not affected by the timer hardware. A reset event changes the OCiR value to 8000h. Timing resolution is one count of the free running counter: (fCPU/CC[1:0]). Procedure: To use the output compare function, select the following in the CR2 register: - Set the OCiE bit if an output is needed then the OCMPi pin is dedicated to the output compare i signal. - Select the timer clock (CC[1:0]) (see Table 17 Clock Control Bits). And select the following in the CR1 register: - Select the OLVLi bit to applied to the OCMPi pins after the match occurs. - Set the OCIE bit to generate an interrupt if it is needed. When a match is found between OCiR register and CR register: - OCFi bit is set.
OCiR = t * fEXT
Where:
t
fEXT
= Output compare period (in seconds) = External timer clock frequency (in hertz)
Clearing the output compare interrupt request (that is, clearing the OCFi bit) is done by: 1. Reading the SR register while the OCFi bit is set. 2. An access (read or write) to the OCiLR register. The following procedure is recommended to prevent the OCFi bit from being set between the time it is read and the write to the OCiR register: - Write to the OCiHR register (further compares are inhibited). - Read the SR register (first step of the clearance of the OCFi bit, which may be already set). - Write to the OCiLR register (enables the output compare function and clears the OCFi bit).
77/224
ST72361
16-BIT TIMER (Cont'd) Notes: 1. After a processor write cycle to the OCiHR register, the output compare function is inhibited until the OCiLR register is also written. 2. If the OCiE bit is not set, the OCMPi pin is a general I/O port and the OLVLi bit will not appear when a match is found but an interrupt could be generated if the OCIE bit is set. 3. In both internal and external clock modes, OCFi and OCMPi are set while the counter value equals the OCiR register value (see Figure 55 on page 80 for an example with fCPU/2 and Figure 56 on page 80 for an example with fCPU/4). This behavior is the same in OPM or PWM mode. 4. The output compare functions can be used both for generating external events on the OCMPi pins even if the input capture mode is also used. 5. The value in the 16-bit OCiR register and the OLVi bit should be changed after each successful comparison in order to control an output waveform or establish a new elapsed timeout. Figure 54. Output Compare Block Diagram
Forced Compare Output capability When the FOLVi bit is set by software, the OLVLi bit is copied to the OCMPi pin. The OLVi bit has to be toggled in order to toggle the OCMPi pin when it is enabled (OCiE bit = 1). The OCFi bit is then not set by hardware, and thus no interrupt request is generated. The FOLVLi bits have no effect in both One Pulse mode and PWM mode.
16 BIT FREE RUNNING COUNTER 16-bit OUTPUT COMPARE CIRCUIT 16-bit 16-bit
OC1E OC2E
CC1
CC0
(Control Register 2) CR2 (Control Register 1) CR1
OCIE FOLV2 FOLV1 OLVL2 OLVL1 Latch 1
OCMP1 Pin OCMP2 Pin
OC1R Register
OCF1 OCF2 0 0 0
Latch 2
OC2R Register (Status Register) SR
78/224
ST72361
16-BIT TIMER (Cont'd) Figure 55. Output Compare Timing Diagram, fTIMER = fCPU/2
INTERNAL CPU CLOCK TIMER CLOCK COUNTER REGISTER OUTPUT COMPARE REGISTER i (OCRi) OUTPUT COMPARE FLAG i (OCFi) OCMPi PIN (OLVLi = 1) 2ECF 2ED0 2ED1 2ED2 2ED3 2ED4 2ED3
Figure 56. Output Compare Timing Diagram, fTIMER = fCPU/4
INTERNAL CPU CLOCK TIMER CLOCK COUNTER REGISTER OUTPUT COMPARE REGISTER i (OCRi) OUTPUT COMPARE FLAG i (OCFi) OCMPi PIN (OLVLi = 1) 2ECF 2ED0 2ED1 2ED2 2ED3 2ED4 2ED3
79/224
ST72361
16-BIT TIMER (Cont'd) 10.4.3.5 One Pulse Mode One Pulse mode enables the generation of a pulse when an external event occurs. This mode is selected via the OPM bit in the CR2 register. The One Pulse mode uses the Input Capture1 function and the Output Compare1 function. Procedure: To use One Pulse mode: 1. Load the OC1R register with the value corresponding to the length of the pulse (see the formula in the opposite column). 2. Select the following in the CR1 register: - Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after the pulse. - Using the OLVL2 bit, select the level to be applied to the OCMP1 pin during the pulse. - Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the ICAP1 pin must be configured as floating input). 3. Select the following in the CR2 register: - Set the OC1E bit, the OCMP1 pin is then dedicated to the Output Compare 1 function. - Set the OPM bit. - Select the timer clock CC[1:0] (see Table 17 Clock Control Bits). One Pulse mode cycle When event occurs on ICAP1 ICR1 = Counter OCMP1 = OLVL2 Counter is reset to FFFCh ICF1 bit is set When Counter = OC1R
Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two steps: 1. Reading the SR register while the ICFi bit is set. 2. An access (read or write) to the ICiLR register. The OC1R register value required for a specific timing application can be calculated using the following formula: OCiR Value =
t * fCPU
PRESC
-5
Where: t = Pulse period (in seconds) fCPU = CPU clock frequency (in hertz) PRESC = Timer prescaler factor (2, 4 or 8 depending on the CC[1:0] bits, see Table 17 Clock Control Bits) If the timer clock is an external clock the formula is: OCiR = t * fEXT -5 Where: t = Pulse period (in seconds) fEXT = External timer clock frequency (in hertz) When the value of the counter is equal to the value of the contents of the OC1R register, the OLVL1 bit is output on the OCMP1 pin, (See Figure 57). Notes: 1. The OCF1 bit cannot be set by hardware in One Pulse mode but the OCF2 bit can generate an Output Compare interrupt. 2. When the Pulse Width Modulation (PWM) and One Pulse mode (OPM) bits are both set, the PWM mode is the only active one. 3. If OLVL1 = OLVL2 a continuous signal will be seen on the OCMP1 pin. 4. The ICAP1 pin can not be used to perform input capture. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset each time a valid edge occurs on the ICAP1 pin and ICF1 can also generates interrupt if ICIE is set. 5. When One Pulse mode is used OC1R is dedicated to this mode. Nevertheless OC2R and OCF2 can be used to indicate a period of time has been elapsed but cannot generate an output waveform because the level OLVL2 is dedicated to the One Pulse mode.
OCMP1 = OLVL1
Then, on a valid event on the ICAP1 pin, the counter is initialized to FFFCh and OLVL2 bit is loaded on the OCMP1 pin, the ICF1 bit is set and the value FFFDh is loaded in the IC1R register. Because the ICF1 bit is set when an active edge occurs, an interrupt can be generated if the ICIE bit is set.
80/224
ST72361
16-BIT TIMER (Cont'd) Figure 57. One Pulse Mode Timing Example
IC1R COUNTER ICAP1 OCMP1 OLVL2 01F8 FFFC FFFD FFFE
01F8 2ED0 2ED1 2ED2 2ED3
2ED3 FFFC FFFD
OLVL1
OLVL2
compare1
Note: IEDG1 = 1, OC1R = 2ED0h, OLVL1 = 0, OLVL2 = 1
Figure 58. Pulse Width Modulation Mode Timing Example with 2 Output Compare Functions
COUNTER 34E2 FFFC FFFD FFFE OCMP1 OLVL2
2ED0 2ED1 2ED2
34E2
FFFC
OLVL1
OLVL2
compare2
compare1
compare2
Note: OC1R = 2ED0h, OC2R = 34E2, OLVL1 = 0, OLVL2 = 1
Note: On timers with only one Output Compare register, a fixed frequency PWM signal can be generated using the output compare and the counter overflow to define the pulse length.
81/224
ST72361
16-BIT TIMER (Cont'd) 10.4.3.6 Pulse Width Modulation Mode Pulse Width Modulation (PWM) mode enables the generation of a signal with a frequency and pulse length determined by the value of the OC1R and OC2R registers. Pulse Width Modulation mode uses the complete Output Compare 1 function plus the OC2R register, and so this functionality can not be used when PWM mode is activated. In PWM mode, double buffering is implemented on the output compare registers. Any new values written in the OC1R and OC2R registers are taken into account only at the end of the PWM period (OC2) to avoid spikes on the PWM output pin (OCMP1). Procedure To use Pulse Width Modulation mode: 1. Load the OC2R register with the value corresponding to the period of the signal using the formula in the opposite column. 2. Load the OC1R register with the value corresponding to the period of the pulse if (OLVL1 = 0 and OLVL2 = 1) using the formula in the opposite column. 3. Select the following in the CR1 register: - Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after a successful comparison with the OC1R register. - Using the OLVL2 bit, select the level to be applied to the OCMP1 pin after a successful comparison with the OC2R register. 4. Select the following in the CR2 register: - Set OC1E bit: the OCMP1 pin is then dedicated to the output compare 1 function. - Set the PWM bit. - Select the timer clock (CC[1:0]) (see Table 17 Clock Control Bits). Pulse Width Modulation cycle When Counter = OC1R
If OLVL1 = 1 and OLVL2 = 0 the length of the positive pulse is the difference between the OC2R and OC1R registers. If OLVL1 = OLVL2 a continuous signal will be seen on the OCMP1 pin. The OCiR register value required for a specific timing application can be calculated using the following formula: OCiR Value =
t * fCPU
PRESC
-5
Where: t = Signal or pulse period (in seconds) fCPU = CPU clock frequency (in hertz) PRESC = Timer prescaler factor (2, 4 or 8 depending on CC[1:0] bits, see Table 17 Clock Control Bits) If the timer clock is an external clock the formula is: OCiR = t * fEXT -5 Where: t = Signal or pulse period (in seconds) fEXT = External timer clock frequency (in hertz) The Output Compare 2 event causes the counter to be initialized to FFFCh (See Figure 58) Notes: 1. After a write instruction to the OCiHR register, the output compare function is inhibited until the OCiLR register is also written. 2. The OCF1 and OCF2 bits cannot be set by hardware in PWM mode therefore the Output Compare interrupt is inhibited. 3. The ICF1 bit is set by hardware when the counter reaches the OC2R value and can produce a timer interrupt if the ICIE bit is set and the I bit is cleared. 4. In PWM mode the ICAP1 pin can not be used to perform input capture because it is disconnected to the timer. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset each period and ICF1 can also generates interrupt if ICIE is set. 5. When the Pulse Width Modulation (PWM) and One Pulse mode (OPM) bits are both set, the PWM mode is the only active one.
OCMP1 = OLVL1
When Counter = OC2R
OCMP1 = OLVL2 Counter is reset to FFFCh ICF1 bit is set
82/224
ST72361
16-BIT TIMER (Cont'd) 10.4.4 Low Power Modes
Mode WAIT Description No effect on 16-bit Timer. Timer interrupts cause the device to exit from WAIT mode. 16-bit Timer registers are frozen. In HALT mode, the counter stops counting until Halt mode is exited. Counting resumes from the previous count when the MCU is woken up by an interrupt with "exit from HALT mode" capability or from the counter reset value when the MCU is woken up by a RESET. If an input capture event occurs on the ICAPi pin, the input capture detection circuitry is armed. Consequently, when the MCU is woken up by an interrupt with "exit from HALT mode" capability, the ICFi bit is set, and the counter value present when exiting from HALT mode is captured into the ICiR register.
HALT
10.4.5 Interrupts
Interrupt Event Input Capture 1 event/Counter reset in PWM mode Input Capture 2 event Output Compare 1 event (not available in PWM mode) Output Compare 2 event (not available in PWM mode) Timer Overflow event Event Flag ICF1 ICF2 OCF1 OCF2 TOF Enable Control Bit ICIE OCIE TOIE Yes No Exit from Wait Exit from Halt
Note: The 16-bit Timer interrupt events are connected to the same interrupt vector (see Interrupts chapter). These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction). 10.4.6 Summary of Timer Modes
MODES Input Capture (1 and/or 2) Output Compare (1 and/or 2) One Pulse Mode PWM Mode Input Capture 1 Yes No TIMER RESOURCES Input Capture 2 Output Compare 1 Output Compare 2 Yes Not Recommended Not Recommended3)
1)
Yes No
Yes Partially 2) No
1) See note 4 in Section 10.4.3.5 "One Pulse Mode" 2) See note 5 in Section 10.4.3.5 "One Pulse Mode" 3) See note 4 in Section 10.4.3.6 "Pulse Width Modulation Mode"
83/224
ST72361
16-BIT TIMER (Cont'd) 10.4.7 Register Description Each Timer is associated with three control and status registers, and with six pairs of data registers (16-bit values) relating to the two input captures, the two output compares, the counter and the alternate counter. CONTROL REGISTER 1 (CR1) Read/Write Reset Value: 0000 0000 (00h)
7 0
Bit 4 = FOLV2 Forced Output Compare 2. This bit is set and cleared by software. 0: No effect on the OCMP2 pin. 1: Forces the OLVL2 bit to be copied to the OCMP2 pin, if the OC2E bit is set and even if there is no successful comparison. Bit 3 = FOLV1 Forced Output Compare 1. This bit is set and cleared by software. 0: No effect on the OCMP1 pin. 1: Forces OLVL1 to be copied to the OCMP1 pin, if the OC1E bit is set and even if there is no successful comparison. Bit 2 = OLVL2 Output Level 2. This bit is copied to the OCMP2 pin whenever a successful comparison occurs with the OC2R register and OCxE is set in the CR2 register. This value is copied to the OCMP1 pin in One Pulse mode and Pulse Width Modulation mode. Bit 1 = IEDG1 Input Edge 1. This bit determines which type of level transition on the ICAP1 pin will trigger the capture. 0: A falling edge triggers the capture. 1: A rising edge triggers the capture. Bit 0 = OLVL1 Output Level 1. The OLVL1 bit is copied to the OCMP1 pin whenever a successful comparison occurs with the OC1R register and the OC1E bit is set in the CR2 register.
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1
Bit 7 = ICIE Input Capture Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is generated whenever the ICF1 or ICF2 bit of the SR register is set. Bit 6 = OCIE Output Compare Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is generated whenever the OCF1 or OCF2 bit of the SR register is set. Bit 5 = TOIE Timer Overflow Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is enabled whenever the TOF bit of the SR register is set.
84/224
ST72361
16-BIT TIMER (Cont'd) CONTROL REGISTER 2 (CR2) Read/Write Reset Value: 0000 0000 (00h)
7 0
OC1E OC2E OPM PWM CC1 CC0 IEDG2 EXEDG
Bit 4 = PWM Pulse Width Modulation. 0: PWM mode is not active. 1: PWM mode is active, the OCMP1 pin outputs a programmable cyclic signal; the length of the pulse depends on the value of OC1R register; the period depends on the value of OC2R register. Bit 3, 2 = CC[1:0] Clock Control. The timer clock mode depends on these bits: Table 18. Clock Control Bits
Timer Clock fCPU / 4 fCPU / 2 fCPU / 8 External Clock (where available) CC1 0 1 CC0 0 1 0 1
Bit 7 = OC1E Output Compare 1 Pin Enable. This bit is used only to output the signal from the timer on the OCMP1 pin (OLV1 in Output Compare mode, both OLV1 and OLV2 in PWM and one-pulse mode). Whatever the value of the OC1E bit, the Output Compare 1 function of the timer remains active. 0: OCMP1 pin alternate function disabled (I/O pin free for general-purpose I/O). 1: OCMP1 pin alternate function enabled. Bit 6 = OC2E Output Compare 2 Pin Enable. This bit is used only to output the signal from the timer on the OCMP2 pin (OLV2 in Output Compare mode). Whatever the value of the OC2E bit, the Output Compare 2 function of the timer remains active. 0: OCMP2 pin alternate function disabled (I/O pin free for general-purpose I/O). 1: OCMP2 pin alternate function enabled. Bit 5 = OPM One Pulse Mode. 0: One Pulse mode is not active. 1: One Pulse mode is active, the ICAP1 pin can be used to trigger one pulse on the OCMP1 pin; the active transition is given by the IEDG1 bit. The length of the generated pulse depends on the contents of the OC1R register.
Note: If the external clock pin is not available, programming the external clock configuration stops the counter. Bit 1 = IEDG2 Input Edge 2. This bit determines which type of level transition on the ICAP2 pin will trigger the capture. 0: A falling edge triggers the capture. 1: A rising edge triggers the capture. Bit 0 = EXEDG External Clock Edge. This bit determines which type of level transition on the external clock pin EXTCLK will trigger the counter register. 0: A falling edge triggers the counter register. 1: A rising edge triggers the counter register.
85/224
ST72361
16-BIT TIMER (Cont'd) CONTROL/STATUS REGISTER (CSR) Read/Write (bits 7:3 read only) Reset Value: xxxx x0xx (xxh)
7 ICF1 OCF1 TOF ICF2 OCF2 TIMD 0 0 0
Note: Reading or writing the ACLR register does not clear TOF. Bit 4 = ICF2 Input Capture Flag 2. 0: No input capture (reset value). 1: An input capture has occurred on the ICAP2 pin. To clear this bit, first read the SR register, then read or write the low byte of the IC2R (IC2LR) register. Bit 3 = OCF2 Output Compare Flag 2. 0: No match (reset value). 1: The content of the free running counter has matched the content of the OC2R register. To clear this bit, first read the SR register, then read or write the low byte of the OC2R (OC2LR) register. Bit 2 = TIMD Timer disable. This bit is set and cleared by software. When set, it freezes the timer prescaler and counter and disabled the output functions (OCMP1 and OCMP2 pins) to reduce power consumption. Access to the timer registers is still available, allowing the timer configuration to be changed, or the counter reset, while it is disabled. 0: Timer enabled 1: Timer prescaler, counter and outputs disabled Bits 1:0 = Reserved, must be kept cleared.
Bit 7 = ICF1 Input Capture Flag 1. 0: No input capture (reset value). 1: An input capture has occurred on the ICAP1 pin or the counter has reached the OC2R value in PWM mode. To clear this bit, first read the SR register, then read or write the low byte of the IC1R (IC1LR) register. Bit 6 = OCF1 Output Compare Flag 1. 0: No match (reset value). 1: The content of the free running counter has matched the content of the OC1R register. To clear this bit, first read the SR register, then read or write the low byte of the OC1R (OC1LR) register. Bit 5 = TOF Timer Overflow Flag. 0: No timer overflow (reset value). 1: The free running counter rolled over from FFFFh to 0000h. To clear this bit, first read the SR register, then read or write the low byte of the CR (CLR) register.
86/224
ST72361
16-BIT TIMER (Cont'd) INPUT CAPTURE 1 HIGH REGISTER (IC1HR) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the high part of the counter value (transferred by the input capture 1 event).
7 MSB 0 LSB
OUTPUT COMPARE 1 HIGH REGISTER (OC1HR) Read/Write Reset Value: 1000 0000 (80h) This is an 8-bit register that contains the high part of the value to be compared to the CHR register.
7 MSB 0 LSB
INPUT CAPTURE 1 LOW REGISTER (IC1LR) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the low part of the counter value (transferred by the input capture 1 event).
7 MSB 0 LSB
OUTPUT COMPARE 1 LOW REGISTER (OC1LR) Read/Write Reset Value: 0000 0000 (00h) This is an 8-bit register that contains the low part of the value to be compared to the CLR register.
7 MSB 0 LSB
87/224
ST72361
16-BIT TIMER (Cont'd) OUTPUT COMPARE 2 HIGH REGISTER (OC2HR) Read/Write Reset Value: 1000 0000 (80h) This is an 8-bit register that contains the high part of the value to be compared to the CHR register.
7 MSB 0 LSB
ALTERNATE COUNTER HIGH REGISTER (ACHR) Read Only Reset Value: 1111 1111 (FFh) This is an 8-bit register that contains the high part of the counter value.
7 MSB 0 LSB
OUTPUT COMPARE 2 LOW REGISTER (OC2LR) Read/Write Reset Value: 0000 0000 (00h) This is an 8-bit register that contains the low part of the value to be compared to the CLR register.
7 MSB 0 LSB
ALTERNATE COUNTER LOW REGISTER (ACLR) Read Only Reset Value: 1111 1100 (FCh) This is an 8-bit register that contains the low part of the counter value. A write to this register resets the counter. An access to this register after an access to CSR register does not clear the TOF bit in the CSR register.
7 0 LSB
COUNTER HIGH REGISTER (CHR) Read Only Reset Value: 1111 1111 (FFh) This is an 8-bit register that contains the high part of the counter value.
7 MSB 0 LSB
MSB
INPUT CAPTURE 2 HIGH REGISTER (IC2HR) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the high part of the counter value (transferred by the Input Capture 2 event).
7 0 LSB
COUNTER LOW REGISTER (CLR) Read Only Reset Value: 1111 1100 (FCh) This is an 8-bit register that contains the low part of the counter value. A write to this register resets the counter. An access to this register after accessing the CSR register clears the TOF bit.
7 MSB 0 LSB
MSB
INPUT CAPTURE 2 LOW REGISTER (IC2LR) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the low part of the counter value (transferred by the Input Capture 2 event).
7 MSB 0 LSB
88/224
ST72361
16-BIT TIMER (Cont'd) Table 19. 16-Bit Timer Register Map
Address (Hex.) 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F Register Name CR2 CR1 CSR IC1HR IC1LR OC1HR OC1LR CHR CLR ACHR ACLR IC2HR IC2LR OC2HR OC2LR 7 OC1E ICIE ICF1 MSB MSB MSB MSB MSB MSB MSB MSB MSB MSB MSB MSB 6 OC2E OCIE OCF1 5 OPM TOIE TOF 4 PWM FOLV2 ICF2 3 CC1 FOLV1 OCF2 2 CC0 OLVL2 TIMD LSB LSB LSB LSB LSB LSB LSB LSB LSB LSB LSB LSB 1 IEDG2 IEDG1 0 EXEDG OLVL1
89/224
ST72361
10.5 8-BIT TIMER (TIM8) 10.5.1 Introduction The timer consists of a 8-bit free-running counter driven by a programmable prescaler. It may be used for a variety of purposes, including pulse length measurement of up to two input signals (input capture) or generation of up to two output waveforms (output compare and PWM). Pulse lengths and waveform periods can be modulated from a few microseconds to several milliseconds using the timer prescaler and the clock prescaler. 10.5.2 Main Features Programmable prescaler: fCPU divided by 2, 4 , 8 or fOSC2 divided by 8000. Overflow status flag and maskable interrupt Output compare functions with - 2 dedicated 8-bit registers - 2 dedicated programmable signals - 2 dedicated status flags - 1 dedicated maskable interrupt Input capture functions with - 2 dedicated 8-bit registers - 2 dedicated active edge selection signals - 2 dedicated status flags - 1 dedicated maskable interrupt Pulse width modulation mode (PWM) One pulse mode Reduced Power Mode 4 alternate functions on I/O ports (ICAP1, ICAP2, OCMP1, OCMP2)* The Block Diagram is shown in Figure 59. *Note: Some timer pins may not be available (not bonded) in some ST7 devices. Refer to the device pin out description. When reading an input signal on a non-bonded pin, the value will always be `1'. 10.5.3 Functional Description 10.5.3.1 Counter The main block of the Programmable Timer is a 8bit free running upcounter and its associated 8-bit registers. These two read-only 8-bit registers contain the same value but with the difference that reading the ACTR register does not clear the TOF bit (Timer overflow flag), located in the Status register, (SR). Writing in the CTR register or ACTR register resets the free running counter to the FCh value. Both counters have a reset value of FCh (this is the only value which is reloaded in the 8-bit timer). The reset value of both counters is also FCh in One Pulse mode and PWM mode. The timer clock depends on the clock control bits of the CR2 register, as shown in Table 19 Clock Control Bits. The value in the counter register repeats every 512, 1024, 2048 or 20480000 fCPU clock cycles depending on the CC[1:0] bits. The timer frequency can be fCPU/2, fCPU/4, fCPU/8 or fOSC2 /8000. For example, if fOSC2/8000 is selected, and fOSC2 = 8 MHz, the timer frequency will be 1 ms. Refer to Table 19 on page 105.
90/224
ST72361
8-BIT TIMER (Cont'd) Figure 59. Timer Block Diagram
ST7 INTERNAL BUS
fCPU
MCU-PERIPHERAL INTERFACE
8
8
8
8
8
1/2 1/4 1/8
COUNTER REGISTER ALTERNATE COUNTER REGISTER 8
fOSC2
1/8000
OUTPUT COMPARE REGISTER 1
OUTPUT COMPARE REGISTER 2
INPUT CAPTURE REGISTER 1 8
INPUT CAPTURE REGISTER 2 8
CC[1:0] TIMER INTERNAL BUS 8 8 OVERFLOW DETECT CIRCUIT
OUTPUT COMPARE CIRCUIT 6
EDGE DETECT CIRCUIT1
ICAP1 pin
EDGE DETECT CIRCUIT2
ICAP2 pin
LATCH1
ICF1 OCF1 TOF ICF2 OCF2 TIMD
OCMP1 pin OCMP2 pin
0
0
0 LATCH2
(Control/Status Register) CSR
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1
OC1E OC2E OPM PWM
CC1
CC0 IEDG2
(Control Register 1) CR1
(Control Register 2) CR2
(See note) TIMER INTERRUPT
Note: If IC, OC and TO interrupt requests have separate vectors then the last OR is not present (See device Interrupt Vector Table)
91/224
ST72361
8-BIT TIMER (Cont'd) Whatever the timer mode used (input capture, output compare, one pulse mode or PWM mode) an overflow occurs when the counter rolls over from FFh to 00h then: - The TOF bit of the SR register is set. - A timer interrupt is generated if: - TOIE bit of the CR1 register is set and - I bit of the CC register is cleared. If one of these conditions is false, the interrupt remains pending to be issued as soon as they are both true. Clearing the overflow interrupt request is done in two steps: 1. Reading the SR register while the TOF bit is set. 2. An access (read or write) to the CTR register.
Notes: The TOF bit is not cleared by accesses to ACTR register. The advantage of accessing the ACTR register rather than the CTR register is that it allows simultaneous use of the overflow function and reading the free running counter at random times (for example, to measure elapsed time) without the risk of clearing the TOF bit erroneously. The timer is not affected by WAIT mode. In HALT mode, the counter stops counting until the mode is exited. Counting then resumes from the previous count (MCU awakened by an interrupt) or from the reset count (MCU awakened by a Reset).
92/224
ST72361
8-BIT TIMER (Cont'd) Figure 60. Counter Timing Diagram, Internal Clock Divided by 2 fCPU CLOCK
INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FD FE FF 00 01 02 03
Figure 61. Counter Timing Diagram, Internal Clock Divided by 4 fCPU CLOCK
INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FC FD 00 01
Figure 62. Counter Timing Diagram, Internal Clock Divided by 8 fCPU CLOCK
INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FC FD 00
Note: The MCU is in reset state when the internal reset signal is high, when it is low the MCU is running.
93/224
ST72361
8-BIT TIMER (Cont'd) 10.5.3.2 Input Capture In this section, the index, i, may be 1 or 2 because there are two input capture functions in the 8-bit timer. The two 8-bit input capture registers (IC1R and IC2R) are used to latch the value of the free running counter after a transition is detected on the ICAPi pin (see Figure 63). ICiR register is a read-only register. The active transition is software programmable through the IEDGi bit of Control Registers (CRi). Timing resolution is one count of the free running counter (see Table 19 Clock Control Bits). Procedure: To use the input capture function select the following in the CR2 register: - Select the timer clock (CC[1:0]) (see Table 19 Clock Control Bits). - Select the edge of the active transition on the ICAP2 pin with the IEDG2 bit (the ICAP2 pin must be configured as floating input or input with pull-up without interrupt if this configuration is available). And select the following in the CR1 register: - Set the ICIE bit to generate an interrupt after an input capture coming from either the ICAP1 pin or the ICAP2 pin - Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the ICAP1 pin must be configured as floating input or input with pull-up without interrupt if this configuration is available).
When an input capture occurs: - ICFi bit is set. - The ICiR register contains the value of the free running counter on the active transition on the ICAPi pin (see Figure 64). - A timer interrupt is generated if the ICIE bit is set and the interrrupt mask is cleared in the CC register. Otherwise, the interrupt remains pending until both conditions become true. Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two steps: 1. Reading the SR register while the ICFi bit is set. 2. An access (read or write) to the ICiR register. Notes: 1. The ICiR register contains the free running counter value which corresponds to the most recent input capture. 2. The two input capture functions can be used together even if the timer also uses the two output compare functions. 3. Once the ICIE bit is set both input capture features may trigger interrupt requests. If only one is needed in the application, the interrupt routine software needs to discard the unwanted capture interrupt. This can be done by checking the ICF1 and ICF2 flags and resetting them both. 4. In One pulse Mode and PWM mode only Input Capture 2 can be used. 5. The alternate inputs (ICAP1 and ICAP2) are always directly connected to the timer. So any transitions on these pins activates the input capture function. Moreover if one of the ICAPi pins is configured as an input and the second one as an output, an interrupt can be generated if the user toggles the output pin and if the ICIE bit is set. 6. The TOF bit can be used with interrupt generation in order to measure events that go beyond the timer range (FFh).
94/224
ST72361
8-BIT TIMER (Cont'd) Figure 63. Input Capture Block Diagram
ICAP1 pin ICAP2 pin EDGE DETECT CIRCUIT2 EDGE DETECT CIRCUIT1
ICIE
(Control Register 1) CR1
IEDG1
(Status Register) SR IC2R Register IC1R Register
ICF1 ICF2 0 0 0
8-bit 8-bit FREE RUNNING COUNTER
(Control Register 2) CR2
CC1 CC0 IEDG2
Figure 64. Input Capture Timing Diagram
TIMER CLOCK COUNTER REGISTER ICAPi PIN ICAPi FLAG ICAPi REGISTER Note: The rising edge is the active edge. 03 01 02 03
95/224
ST72361
8-BIT TIMER (Cont'd) 10.5.3.3 Output Compare In this section, the index, i, may be 1 or 2 because there are two output compare functions in the 8-bit timer. This function can be used to control an output waveform or indicate when a period of time has elapsed. When a match is found between the Output Compare register and the free running counter, the output compare function: - Assigns pins with a programmable value if the OCiE bit is set - Sets a flag in the status register - Generates an interrupt if enabled Two 8-bit registers Output Compare Register 1 (OC1R) and Output Compare Register 2 (OC2R) contain the value to be compared to the counter register each timer clock cycle. These registers are readable and writable and are not affected by the timer hardware. A reset event changes the OCiR value to 00h. Timing resolution is one count of the free running counter: (fCPU/CC[1:0]). Procedure: To use the output compare function, select the following in the CR2 register: - Set the OCiE bit if an output is needed then the OCMPi pin is dedicated to the output compare i signal. - Select the timer clock (CC[1:0]) (see Table 19 Clock Control Bits). And select the following in the CR1 register:
- Select the OLVLi bit to applied to the OCMPi pins after the match occurs. - Set the OCIE bit to generate an interrupt if it is needed. When a match is found between OCRi register and CR register: - OCFi bit is set. - The OCMPi pin takes OLVLi bit value (OCMPi pin latch is forced low during reset). - A timer interrupt is generated if the OCIE bit is set in the CR1 register and the I bit is cleared in the CC register (CC). The OCiR register value required for a specific timing application can be calculated using the following formula:
OCiR =
Where:
t * fCPU
PRESC
t
= Output compare period (in seconds) fCPU = PLL output x2 clock frequency in hertz (or fOSC/2 if PLL is not enabled) PRESC = Timer prescaler factor (2, 4, 8 or 8000 depending on CC[1:0] bits, see Table 19 Clock Control Bits) Clearing the output compare interrupt request (that is, clearing the OCFi bit) is done by: 1. Reading the SR register while the OCFi bit is set. 2. An access (read or write) to the OCiR register.
96/224
ST72361
8-BIT TIMER (Cont'd) Notes: 1. Once the OCIE bit is set both output compare features may trigger interrupt requests. If only one is needed in the application, the interrupt routine software needs to discard the unwanted compare interrupt. This can be done by checking the OCF1 and OCF2 flags and resetting them both. 2. If the OCiE bit is not set, the OCMPi pin is a general I/O port and the OLVLi bit will not appear when a match is found but an interrupt could be generated if the OCIE bit is set. 3. When the timer clock is fCPU/2, OCFi and OCMPi are set while the counter value equals the OCiR register value (see Figure 66 on page 99). This behaviour is the same in OPM or PWM mode. When the timer clock is fCPU/4, fCPU/8 or fCPU/ 8000, OCFi and OCMPi are set while the counter value equals the OCiR register value plus 1 (see Figure 67 on page 99). 4. The output compare functions can be used both for generating external events on the OCMPi pins even if the input capture mode is also used. 5. The value in the 8-bit OCiR register and the OLVi bit should be changed after each sucFigure 65. Output Compare Block Diagram
cessful comparison in order to control an output waveform or establish a new elapsed timeout. Forced Compare Output capability When the FOLVi bit is set by software, the OLVLi bit is copied to the OCMPi pin. The OLVi bit has to be toggled in order to toggle the OCMPi pin when it is enabled (OCiE bit = 1). The OCFi bit is then not set by hardware, and thus no interrupt request is generated. The FOLVLi bits have no effect in both one pulse mode and PWM mode.
8 BIT 8-bit
FREE RUNNING COUNTER
OC1E OC2E
CC1
CC0
(Control Register 2) CR2 (Control Register 1) CR1
OUTPUT COMPARE CIRCUIT 8-bit 8-bit
OCIE
FOLV2 FOLV1 OLVL2
OLVL1
Latch 1
OCMP1 Pin OCMP2 Pin
OC1R Register
OCF1 OCF2 0 0 0
Latch 2
OC2R Register (Status Register) SR
97/224
ST72361
8-BIT TIMER (Cont'd) Figure 66. Output Compare Timing Diagram, fTIMER = fCPU/2
fCPU CLOCK
TIMER CLOCK COUNTER REGISTER OUTPUT COMPARE REGISTER i (OCRi) OUTPUT COMPARE FLAG i (OCFi) OCMPi PIN (OLVLi = 1) CF D0 D1 D3 D2 D3 D4
Figure 67. Output Compare Timing Diagram, fTIMER = fCPU/4
fCPU CLOCK
TIMER CLOCK COUNTER REGISTER OUTPUT COMPARE REGISTER i (OCRi) COMPARE REGISTER i LATCH OUTPUT COMPARE FLAG i (OCFi) OCMPi PIN (OLVLi = 1) CF D0 D1 D3 D2 D3 D4
98/224
ST72361
8-BIT TIMER (Cont'd) 10.5.3.4 One Pulse Mode One Pulse mode enables the generation of a pulse when an external event occurs. This mode is selected via the OPM bit in the CR2 register. The one pulse mode uses the Input Capture1 function and the Output Compare1 function. Procedure: To use one pulse mode: 1. Load the OC1R register with the value corresponding to the length of the pulse (see the formula in the opposite column). 2. Select the following in the CR1 register: - Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after the pulse. - Using the OLVL2 bit, select the level to be applied to the OCMP1 pin during the pulse. - Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the ICAP1 pin must be configured as floating input). 3. Select the following in the CR2 register: - Set the OC1E bit, the OCMP1 pin is then dedicated to the Output Compare 1 function. - Set the OPM bit. - Select the timer clock CC[1:0] (see Table 19 Clock Control Bits). One pulse mode cycle When event occurs on ICAP1 ICR1 = Counter OCMP1 = OLVL2 Counter is reset to FCh ICF1 bit is set When Counter = OC1R
Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two steps: 1. Reading the SR register while the ICFi bit is set. 2. An access (read or write) to the ICiLR register. The OC1R register value required for a specific timing application can be calculated using the following formula: t * fCPU - 5 OCiR Value =
PRESC
Where: t = Pulse period (in seconds) fCPU = PLL output x2 clock frequency in hertz (or fOSC/2 if PLL is not enabled) PRESC = Timer prescaler factor (2, 4, 8 or 8000 depending on the CC[1:0] bits, see Table 19 Clock Control Bits) When the value of the counter is equal to the value of the contents of the OC1R register, the OLVL1 bit is output on the OCMP1 pin, (See Figure 68). Notes: 1. The OCF1 bit cannot be set by hardware in one pulse mode but the OCF2 bit can generate an Output Compare interrupt. 2. When the Pulse Width Modulation (PWM) and One Pulse Mode (OPM) bits are both set, the PWM mode is the only active one. 3. If OLVL1=OLVL2 a continuous signal will be seen on the OCMP1 pin. 4. The ICAP1 pin can not be used to perform input capture. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset each time a valid edge occurs on the ICAP1 pin and ICF1 can also generates interrupt if ICIE is set. 5. When one pulse mode is used OC1R is dedicated to this mode. Nevertheless OC2R and OCF2 can be used to indicate a period of time has been elapsed but cannot generate an output waveform because the level OLVL2 is dedicated to the one pulse mode.
OCMP1 = OLVL1
Then, on a valid event on the ICAP1 pin, the counter is initialized to FCh and OLVL2 bit is loaded on the OCMP1 pin, the ICF1 bit is set and the value FFFDh is loaded in the IC1R register. Because the ICF1 bit is set when an active edge occurs, an interrupt can be generated if the ICIE bit is set.
99/224
ST72361
8-BIT TIMER (Cont'd) Figure 68. One Pulse Mode Timing Example
IC1R COUNTER ICAP1 OCMP1 OLVL2 F8 FC FD FE
F8 D0 D1 D2 D3
D3 FC FD
OLVL1
OLVL2
compare1
Note: IEDG1 = 1, OC1R = D0h, OLVL1 = 0, OLVL2 = 1
Figure 69. Pulse Width Modulation Mode Timing Example
COUNTER E2 OCMP1
FC
FD
FE OLVL2
D0
D1
D2
E2
FC OLVL2
OLVL1
compare2
compare1
compare2
Note: OC1R = D0h, OC2R = E2, OLVL1 = 0, OLVL2 = 1
100/224
ST72361
8-BIT TIMER (Cont'd) 10.5.3.5 Pulse Width Modulation Mode Pulse Width Modulation (PWM) mode enables the generation of a signal with a frequency and pulse length determined by the value of the OC1R and OC2R registers. Pulse Width Modulation mode uses the complete Output Compare 1 function plus the OC2R register, and so this functionality can not be used when PWM mode is activated. In PWM mode, double buffering is implemented on the output compare registers. Any new values written in the OC1R and OC2R registers are taken into account only at the end of the PWM period (OC2) to avoid spikes on the PWM output pin (OCMP1). Procedure To use pulse width modulation mode: 1. Load the OC2R register with the value corresponding to the period of the signal using the formula in the opposite column. 2. Load the OC1R register with the value corresponding to the period of the pulse if (OLVL1 = 0 and OLVL2 = 1) using the formula in the opposite column. 3. Select the following in the CR1 register: - Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after a successful comparison with the OC1R register. - Using the OLVL2 bit, select the level to be applied to the OCMP1 pin after a successful comparison with the OC2R register. 4. Select the following in the CR2 register: - Set OC1E bit: the OCMP1 pin is then dedicated to the output compare 1 function. - Set the PWM bit. - Select the timer clock (CC[1:0]) (see Table 19 Clock Control Bits). Pulse Width Modulation cycle When Counter = OC1R
If OLVL1 = 1 and OLVL2 = 0 the length of the positive pulse is the difference between the OC2R and OC1R registers. If OLVL1 = OLVL2 a continuous signal will be seen on the OCMP1 pin. The OCiR register value required for a specific timing application can be calculated using the following formula: t * fCPU - 5 OCiR Value =
PRESC
Where: t = Signal or pulse period (in seconds) fCPU = PLL output x2 clock frequency in hertz (or fOSC/2 if PLL is not enabled) PRESC = Timer prescaler factor (2, 4, 8 or 8000 depending on CC[1:0] bits, see Table 19 Clock Control Bits) The Output Compare 2 event causes the counter to be initialized to FCh (See Figure 69) Notes: 1. The OCF1 and OCF2 bits cannot be set by hardware in PWM mode therefore the Output Compare interrupt is inhibited. 2. The ICF1 bit is set by hardware when the counter reaches the OC2R value and can produce a timer interrupt if the ICIE bit is set and the I bit is cleared. 3. In PWM mode the ICAP1 pin can not be used to perform input capture because it is disconnected to the timer. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset each period and ICF1 can also generates interrupt if ICIE is set. 4. When the Pulse Width Modulation (PWM) and One Pulse Mode (OPM) bits are both set, the PWM mode is the only active one.
OCMP1 = OLVL1
When Counter = OC2R
OCMP1 = OLVL2 Counter is reset to FCh ICF1 bit is set
101/224
ST72361
8-BIT TIMER (Cont'd) 10.5.4 Low Power Modes
Mode WAIT Description No effect on 8-bit Timer. Timer interrupts cause the device to exit from WAIT mode. 8-bit Timer registers are frozen. In HALT mode, the counter stops counting until Halt mode is exited. Counting resumes from the previous count when the MCU is woken up by an interrupt with "exit from HALT mode" capability or from the counter reset value when the MCU is woken up by a RESET. If an input capture event occurs on the ICAPi pin, the input capture detection circuitry is armed. Consequently, when the MCU is woken up by an interrupt with "exit from HALT mode" capability, the ICFi bit is set, and the counter value present when exiting from HALT mode is captured into the ICiR register.
HALT
10.5.5 Interrupts
Interrupt Event Input Capture 1 event/Counter reset in PWM mode Input Capture 2 event Output Compare 1 event (not available in PWM mode) Output Compare 2 event (not available in PWM mode) Timer Overflow event Event Flag ICF1 ICF2 OCF1 OCF2 TOF Enable Control Bit ICIE OCIE TOIE Yes No Exit from Wait Exit from Halt
Note: The 8-bit Timer interrupt events are connected to the same interrupt vector (see Interrupts chapter). These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction). 10.5.6 Summary of Timer modes
MODES Input Capture (1 and/or 2) Output Compare (1 and/or 2) One Pulse Mode PWM Mode Input Capture 1 Yes No AVAILABLE RESOURCES Input Capture 2 Output Compare 1 Output Compare 2 Yes Not Recommended Not Recommended3)
1)
Yes No
Yes Partially 2) No
1) See note 4 in "One Pulse Mode" on page 100 2) See note 5 in "One Pulse Mode" on page 100 3) See note 4 in "Pulse Width Modulation Mode" on page 102
102/224
ST72361
8-BIT TIMER (Cont'd) 10.5.7 Register Description Each Timer is associated with three control and status registers, and with six data registers (8-bit values) relating to the two input captures, the two output compares, the counter and the alternate counter. CONTROL REGISTER 1 (CR1) Read/Write Reset Value: 0000 0000 (00h)
7 0
Bit 4 = FOLV2 Forced Output Compare 2. This bit is set and cleared by software. 0: No effect on the OCMP2 pin. 1: Forces the OLVL2 bit to be copied to the OCMP2 pin, if the OC2E bit is set and even if there is no successful comparison. Bit 3 = FOLV1 Forced Output Compare 1. This bit is set and cleared by software. 0: No effect on the OCMP1 pin. 1: Forces OLVL1 to be copied to the OCMP1 pin, if the OC1E bit is set and even if there is no successful comparison. Bit 2 = OLVL2 Output Level 2. This bit is copied to the OCMP2 pin whenever a successful comparison occurs with the OC2R register and OCxE is set in the CR2 register. This value is copied to the OCMP1 pin in One Pulse Mode and Pulse Width Modulation mode. Bit 1 = IEDG1 Input Edge 1. This bit determines which type of level transition on the ICAP1 pin will trigger the capture. 0: A falling edge triggers the capture. 1: A rising edge triggers the capture. Bit 0 = OLVL1 Output Level 1. The OLVL1 bit is copied to the OCMP1 pin whenever a successful comparison occurs with the OC1R register and the OC1E bit is set in the CR2 register.
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1
Bit 7 = ICIE Input Capture Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is generated whenever the ICF1 or ICF2 bit of the SR register is set. Bit 6 = OCIE Output Compare Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is generated whenever the OCF1 or OCF2 bit of the SR register is set. Bit 5 = TOIE Timer Overflow Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is enabled whenever the TOF bit of the SR register is set.
103/224
ST72361
8-BIT TIMER (Cont'd) CONTROL REGISTER 2 (CR2) Read/Write Reset Value: 0000 0000 (00h)
7 OC1E OC2E OPM PWM CC1 CC0 IEDG2 0 0
Bit 4 = PWM Pulse Width Modulation. 0: PWM mode is not active. 1: PWM mode is active, the OCMP1 pin outputs a programmable cyclic signal; the length of the pulse depends on the value of OC1R register; the period depends on the value of OC2R register. Bit 3, 2 = CC[1:0] Clock Control. The timer clock mode depends on these bits: Table 20. Clock Control Bits
Timer Clock fCPU / 4 fCPU / 2 fCPU / 8 fOSC2 / 8000* CC1 0 0 1 1 CC0 0 1 0 1
Bit 7 = OC1E Output Compare 1 Pin Enable. This bit is used only to output the signal from the timer on the OCMP1 pin (OLV1 in Output Compare mode, both OLV1 and OLV2 in PWM and one-pulse mode). Whatever the value of the OC1E bit, the Output Compare 1 function of the timer remains active. 0: OCMP1 pin alternate function disabled (I/O pin free for general-purpose I/O). 1: OCMP1 pin alternate function enabled. Bit 6 = OC2E Output Compare 2 Pin Enable. This bit is used only to output the signal from the timer on the OCMP2 pin (OLV2 in Output Compare mode). Whatever the value of the OC2E bit, the Output Compare 2 function of the timer remains active. 0: OCMP2 pin alternate function disabled (I/O pin free for general-purpose I/O). 1: OCMP2 pin alternate function enabled. Bit 5 = OPM One Pulse Mode. 0: One Pulse Mode is not active. 1: One Pulse Mode is active, the ICAP1 pin can be used to trigger one pulse on the OCMP1 pin; the active transition is given by the IEDG1 bit. The length of the generated pulse depends on the contents of the OC1R register.
* Not available in Slow mode in ST72F561. Bit 1 = IEDG2 Input Edge 2. This bit determines which type of level transition on the ICAP2 pin will trigger the capture. 0: A falling edge triggers the capture. 1: A rising edge triggers the capture. Bit 0 = Reserved, must be kept at 0.
104/224
ST72361
8-BIT TIMER (Cont'd) CONTROL/STATUS REGISTER (CSR) Read Only (except bit 2 R/W) Reset Value: 0000 0000 (00h)
7 ICF1 OCF1 TOF ICF2 OCF2 TIMD 0 0 0
Note: Reading or writing the ACTR register does not clear TOF. Bit 4 = ICF2 Input Capture Flag 2. 0: No input capture (reset value). 1: An input capture has occurred on the ICAP2 pin. To clear this bit, first read the SR register, then read or write the IC2R register. Bit 3 = OCF2 Output Compare Flag 2. 0: No match (reset value). 1: The content of the free running counter has matched the content of the OC2R register. To clear this bit, first read the SR register, then read or write the OC2R register. Bit 2 = TIMD Timer disable. This bit is set and cleared by software. When set, it freezes the timer prescaler and counter and disabled the output functions (OCMP1 and OCMP2 pins) to reduce power consumption. Access to the timer registers is still available, allowing the timer configuration to be changed, or the counter reset, while it is disabled. 0: Timer enabled 1: Timer prescaler, counter and outputs disabled Bits 1:0 = Reserved, must be kept cleared.
Bit 7 = ICF1 Input Capture Flag 1. 0: No input capture (reset value). 1: An input capture has occurred on the ICAP1 pin or the counter has reached the OC2R value in PWM mode. To clear this bit, first read the SR register, then read or write the the IC1R register. Bit 6 = OCF1 Output Compare Flag 1. 0: No match (reset value). 1: The content of the free running counter has matched the content of the OC1R register. To clear this bit, first read the SR register, then read or write the OC1R register. Bit 5 = TOF Timer Overflow Flag. 0: No timer overflow (reset value). 1: The free running counter rolled over from FFh to 00h. To clear this bit, first read the SR register, then read or write the CTR register.
105/224
ST72361
8-BIT TIMER (Cont'd) INPUT CAPTURE 1 REGISTER (IC1R) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the counter value (transferred by the input capture 1 event).
7 MSB 0 LSB
COUNTER REGISTER (CTR) Read Only Reset Value: 1111 1100 (FCh) This is an 8-bit register that contains the counter value. A write to this register resets the counter. An access to this register after accessing the CSR register clears the TOF bit.
7 MSB 0 LSB
OUTPUT COMPARE 1 REGISTER (OC1R) Read/Write Reset Value: 0000 0000 (00h) This is an 8-bit register that contains the value to be compared to the CTR register.
7 MSB 0 LSB
ALTERNATE COUNTER REGISTER (ACTR) Read Only Reset Value: 1111 1100 (FCh) This is an 8-bit register that contains the counter value. A write to this register resets the counter. An access to this register after an access to CSR register does not clear the TOF bit in the CSR register.
7 0 LSB
OUTPUT COMPARE 2 REGISTER (OC2R) Read/Write Reset Value: 0000 0000 (00h) This is an 8-bit register that contains the value to be compared to the CTR register.
7 MSB 0 LSB
MSB
INPUT CAPTURE 2 REGISTER (IC2R) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the counter value (transferred by the Input Capture 2 event).
7 MSB 0 LSB
106/224
ST72361
8-BIT TIMER (Cont'd) 10.5.8 8-bit Timer Register Map
Address (Hex.) 3C 3D 3E 3F 40 41 42 43 44 Register Name CR2 CR1 CSR IC1R OC1R CTR ACTR IC2R OC2R 7 OC1E ICIE ICF1 MSB MSB MSB MSB MSB MSB 6 OC2E OCIE OCF1 5 OPM TOIE TOF 4 PWM FOLV2 ICF2 3 CC1 FOLV1 OCF2 2 CC0 OLVL2 TIMD LSB LSB LSB LSB LSB LSB 1 IEDG2 IEDG1 0 0 OLVL1
107/224
ST72361
ON-CHIP PERIPHERALS (cont'd) 10.6 SERIAL PERIPHERAL INTERFACE (SPI) 10.6.1 Introduction The Serial Peripheral Interface (SPI) allows fullduplex, synchronous, serial communication with external devices. An SPI system may consist of a master and one or more slaves or a system in which devices may be either masters or slaves. 10.6.2 Main Features Full duplex synchronous transfers (on three lines) Simplex synchronous transfers (on two lines) Master or slave operation 6 master mode frequencies (fCPU/4 max.) fCPU/2 max. slave mode frequency (see note) SS Management by software or hardware Programmable clock polarity and phase End of transfer interrupt flag Write collision, Master Mode Fault and Overrun flags Note: In slave mode, continuous transmission is not possible at maximum frequency due to the software overhead for clearing status flags and to initiate the next transmission sequence. 10.6.3 General Description Figure 70 on page 110 shows the serial peripheral interface (SPI) block diagram. There are three registers: - SPI Control Register (SPICR) - SPI Control/Status Register (SPICSR) - SPI Data Register (SPIDR) The SPI is connected to external devices through four pins: - MISO: Master In / Slave Out data - MOSI: Master Out / Slave In data - SCK: Serial Clock out by SPI masters and input by SPI slaves - SS: Slave select: This input signal acts as a `chip select' to let the SPI master communicate with slaves individually and to avoid contention on the data lines. Slave SS inputs can be driven by standard I/O ports on the master Device.
108/224
ST72361
SERIAL PERIPHERAL INTERFACE (SPI) (cont'd) Figure 70. Serial Peripheral Interface Block Diagram
Data/Address Bus SPIDR Read Read Buffer Interrupt request
MOSI MISO
8-bit Shift Register
7 SPIF WCOL OVR MODF 0
SPICSR
SOD SSM
0 SSI
SOD bit
Write
SS
SPI STATE CONTROL
7 SPIE
1 0
SCK
SPICR
0
SPE SPR2 MSTR CPOL CPHA SPR1 SPR0
MASTER CONTROL SERIAL CLOCK GENERATOR
SS
109/224
ST72361
SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.3.1 Functional Description A basic example of interconnections between a single master and a single slave is illustrated in Figure 71. The MOSI pins are connected together and the MISO pins are connected together. In this way data is transferred serially between master and slave (most significant bit first). The communication is always initiated by the master. When the master device transmits data to a slave device via MOSI pin, the slave device responds by sending data to the master device via Figure 71. Single Master/ Single Slave Application
MASTER MSBit LSBit MISO
the MISO pin. This implies full duplex communication with both data out and data in synchronized with the same clock signal (which is provided by the master device via the SCK pin). To use a single data line, the MISO and MOSI pins must be connected at each node (in this case only simplex communication is possible). Four possible data/clock timing relationships may be chosen (see Figure 74 on page 114) but master and slave must be programmed with the same timing mode.
SLAVE MSBit MISO LSBit
8-bit SHIFT REGISTER
8-bit SHIFT REGISTER
MOSI
MOSI
SPI CLOCK GENERATOR
SCK SS +5V
SCK SS Not used if SS is managed by software
110/224
ST72361
SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.3.2 Slave Select Management As an alternative to using the SS pin to control the Slave Select signal, the application can choose to manage the Slave Select signal by software. This is configured by the SSM bit in the SPICSR register (see Figure 73). In software management, the external SS pin is free for other application uses and the internal SS signal level is driven by writing to the SSI bit in the SPICSR register. In Master mode: - SS internal must be held high continuously
In Slave Mode: There are two cases depending on the data/clock timing relationship (see Figure 72): If CPHA = 1 (data latched on second clock edge): - SS internal must be held low during the entire transmission. This implies that in single slave applications the SS pin either can be tied to VSS, or made free for standard I/O by managing the SS function by software (SSM = 1 and SSI = 0 in the in the SPICSR register) If CPHA = 0 (data latched on first clock edge): - SS internal must be held low during byte transmission and pulled high between each byte to allow the slave to write to the shift register. If SS is not pulled high, a Write Collision error will occur when the slave writes to the shift register (see Section 10.6.5.3).
Figure 72. Generic SS Timing Diagram
MOSI/MISO Master SS Slave SS (if CPHA = 0) Slave SS (if CPHA = 1)
Byte 1
Byte 2
Byte 3
Figure 73. Hardware/Software Slave Select Management SSM bit
SSI bit SS external pin
1 0
SS internal
111/224
ST72361
SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.3.3 Master Mode Operation In master mode, the serial clock is output on the SCK pin. The clock frequency, polarity and phase are configured by software (refer to the description of the SPICSR register). Note: The idle state of SCK must correspond to the polarity selected in the SPICSR register (by pulling up SCK if CPOL = 1 or pulling down SCK if CPOL = 0). How to operate the SPI in master mode To operate the SPI in master mode, perform the following steps in order: 1. Write to the SPICR register: - Select the clock frequency by configuring the SPR[2:0] bits. - Select the clock polarity and clock phase by configuring the CPOL and CPHA bits. Figure 74 shows the four possible configurations. Note: The slave must have the same CPOL and CPHA settings as the master. 2. Write to the SPICSR register: - Either set the SSM bit and set the SSI bit or clear the SSM bit and tie the SS pin high for the complete byte transmit sequence. 3. Write to the SPICR register: - Set the MSTR and SPE bits Note: MSTR and SPE bits remain set only if SS is high). Important note: if the SPICSR register is not written first, the SPICR register setting (MSTR bit) may be not taken into account. The transmit sequence begins when software writes a byte in the SPIDR register. 10.6.3.4 Master Mode Transmit Sequence When software writes to the SPIDR register, the data byte is loaded into the 8-bit shift register and then shifted out serially to the MOSI pin most significant bit first. When data transfer is complete: - The SPIF bit is set by hardware. - An interrupt request is generated if the SPIE bit is set and the interrupt mask in the CCR register is cleared. Clearing the SPIF bit is performed by the following software sequence: 1. An access to the SPICSR register while the SPIF bit is set 2. A read to the SPIDR register
Note: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read. 10.6.3.5 Slave Mode Operation In slave mode, the serial clock is received on the SCK pin from the master device. To operate the SPI in slave mode: 1. Write to the SPICSR register to perform the following actions: - Select the clock polarity and clock phase by configuring the CPOL and CPHA bits (see Figure 74). Note: The slave must have the same CPOL and CPHA settings as the master. - Manage the SS pin as described in Section 10.6.3.2 and Figure 72. If CPHA = 1 SS must be held low continuously. If CPHA = 0 SS must be held low during byte transmission and pulled up between each byte to let the slave write in the shift register. 2. Write to the SPICR register to clear the MSTR bit and set the SPE bit to enable the SPI I/O functions. 10.6.3.6 Slave Mode Transmit Sequence When software writes to the SPIDR register, the data byte is loaded into the 8-bit shift register and then shifted out serially to the MISO pin most significant bit first. The transmit sequence begins when the slave device receives the clock signal and the most significant bit of the data on its MOSI pin. When data transfer is complete: - The SPIF bit is set by hardware. - An interrupt request is generated if SPIE bit is set and interrupt mask in the CCR register is cleared. Clearing the SPIF bit is performed by the following software sequence: 1. An access to the SPICSR register while the SPIF bit is set 2. A write or a read to the SPIDR register Notes: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read. The SPIF bit can be cleared during a second transmission; however, it must be cleared before the second SPIF bit in order to prevent an Overrun condition (see Section 10.6.5.2).
112/224
ST72361
SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.4 Clock Phase and Clock Polarity Four possible timing relationships may be chosen by software, using the CPOL and CPHA bits (See Figure 74). Note: The idle state of SCK must correspond to the polarity selected in the SPICSR register (by pulling up SCK if CPOL = 1 or pulling down SCK if CPOL = 0). The combination of the CPOL clock polarity and CPHA (clock phase) bits selects the data capture clock edge. Figure 74. Data Clock Timing Diagram
Figure 74 shows an SPI transfer with the four combinations of the CPHA and CPOL bits. The diagram may be interpreted as a master or slave timing diagram where the SCK pin, the MISO pin and the MOSI pin are directly connected between the master and the slave device. Note: If CPOL is changed at the communication byte boundaries, the SPI must be disabled by resetting the SPE bit.
CPHA = 1
SCK (CPOL = 1) SCK (CPOL = 0)
MISO (from master) MOSI (from slave) SS (to slave)
CAPTURE STROBE
MSBit
Bit 6
Bit 5
Bit 4
Bit3
Bit 2
Bit 1
LSBit
MSBit
Bit 6
Bit 5
Bit 4
Bit3
Bit 2
Bit 1
LSBit
CPHA = 0
SCK (CPOL = 1) SCK (CPOL = 0)
MISO (from master) MOSI (from slave) SS (to slave)
CAPTURE STROBE
MSBit
Bit 6
Bit 5
Bit 4
Bit3
Bit 2
Bit 1
LSBit
MSBit
Bit 6
Bit 5
Bit 4
Bit3
Bit 2
Bit 1
LSBit
Note: This figure should not be used as a replacement for parametric information. Refer to the Electrical Characteristics chapter.
113/224
ST72361
SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.5 Error Flags 10.6.5.1 Master Mode Fault (MODF) Master mode fault occurs when the master device's SS pin is pulled low. When a Master mode fault occurs: - The MODF bit is set and an SPI interrupt request is generated if the SPIE bit is set. - The SPE bit is reset. This blocks all output from the device and disables the SPI peripheral. - The MSTR bit is reset, thus forcing the device into slave mode. Clearing the MODF bit is done through a software sequence: 1. A read access to the SPICSR register while the MODF bit is set. 2. A write to the SPICR register. Notes: To avoid any conflicts in an application with multiple slaves, the SS pin must be pulled high during the MODF bit clearing sequence. The SPE and MSTR bits may be restored to their original state during or after this clearing sequence. Hardware does not allow the user to set the SPE and MSTR bits while the MODF bit is set except in the MODF bit clearing sequence. In a slave device, the MODF bit can not be set, but in a multimaster configuration the device can be in slave mode with the MODF bit set. The MODF bit indicates that there might have been a multimaster conflict and allows software to handle this using an interrupt routine and either perform a reset or return to an application default state.
10.6.5.2 Overrun Condition (OVR) An overrun condition occurs when the master device has sent a data byte and the slave device has not cleared the SPIF bit issued from the previously transmitted byte. When an Overrun occurs: - The OVR bit is set and an interrupt request is generated if the SPIE bit is set. In this case, the receiver buffer contains the byte sent after the SPIF bit was last cleared. A read to the SPIDR register returns this byte. All other bytes are lost. The OVR bit is cleared by reading the SPICSR register. 10.6.5.3 Write Collision Error (WCOL) A write collision occurs when the software tries to write to the SPIDR register while a data transfer is taking place with an external device. When this happens, the transfer continues uninterrupted and the software write will be unsuccessful. Write collisions can occur both in master and slave mode. See also Section 10.6.3.2 "Slave Select Management". Note: A "read collision" will never occur since the received data byte is placed in a buffer in which access is always synchronous with the CPU operation. The WCOL bit in the SPICSR register is set if a write collision occurs. No SPI interrupt is generated when the WCOL bit is set (the WCOL bit is a status flag only). Clearing the WCOL bit is done through a software sequence (see Figure 75).
Figure 75. Clearing the WCOL Bit (Write Collision Flag) Software Sequence
Clearing sequence after SPIF = 1 (end of a data byte transfer) 1st Step Read SPICSR
2nd Step
Read SPIDR
RESULT SPIF = 0 WCOL = 0
Clearing sequence before SPIF = 1 (during a data byte transfer) 1st Step Read SPICSR RESULT 2nd Step Read SPIDR WCOL = 0 Note: Writing to the SPIDR register instead of reading it does not reset the WCOL bit.
114/224
ST72361
SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.5.4 Single Master and Multimaster Configurations There are two types of SPI systems: - Single Master System - Multimaster System Single Master System A typical single master system may be configured using a device as the master and four devices as slaves (see Figure 76). The master device selects the individual slave devices by using four pins of a parallel port to control the four SS pins of the slave devices. The SS pins are pulled high during reset since the master device ports will be forced to be inputs at that time, thus disabling the slave devices. Note: To prevent a bus conflict on the MISO line, the master allows only one active slave device during a transmission.
For more security, the slave device may respond to the master with the received data byte. Then the master will receive the previous byte back from the slave device if all MISO and MOSI pins are connected and the slave has not written to its SPIDR register. Other transmission security methods can use ports for handshake lines or data bytes with command fields. Multimaster System A multimaster system may also be configured by the user. Transfer of master control could be implemented using a handshake method through the I/O ports or by an exchange of code messages through the serial peripheral interface system. The multimaster system is principally handled by the MSTR bit in the SPICR register and the MODF bit in the SPICSR register.
Figure 76. Single Master / Multiple Slave Configuration
SS SCK Slave Device MOSI MISO SCK Slave Device MOSI
SS SCK Slave Device MOSI
SS SCK Slave Device MOSI
SS
MISO
MISO
MISO
MOSI MISO Ports SCK Master Device 5V SS
115/224
ST72361
SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.6 Low Power Modes
Mode WAIT Description No effect on SPI. SPI interrupt events cause the device to exit from WAIT mode. SPI registers are frozen. In HALT mode, the SPI is inactive. SPI operation resumes when the device is woken up by an interrupt with "exit from HALT mode" capability. The data received is subsequently read from the SPIDR register when the software is running (interrupt vector fetching). If several data are received before the wakeup event, then an overrun error is generated. This error can be detected after the fetch of the interrupt routine that woke up the Device.
HALT
the SPI from HALT mode state to normal state. If the SPI exits from Slave mode, it returns to normal state immediately. Caution: The SPI can wake up the device from HALT mode only if the Slave Select signal (external SS pin or the SSI bit in the SPICSR register) is low when the device enters HALT mode. So, if Slave selection is configured as external (see Section 10.6.3.2), make sure the master drives a low level on the SS pin when the slave enters HALT mode. 10.6.7 Interrupts
Interrupt Event SPI End of Transfer Event Master Mode Fault Event Overrun Error Event Flag SPIF MODF OVR SPIE Yes No Enable Control Bit Exit from Wait Exit from Halt Yes
10.6.6.1 Using the SPI to wake up the device from Halt mode In slave configuration, the SPI is able to wake up the device from HALT mode through a SPIF interrupt. The data received is subsequently read from the SPIDR register when the software is running (interrupt vector fetch). If multiple data transfers have been performed before software clears the SPIF bit, then the OVR bit is set by hardware. Note: When waking up from HALT mode, if the SPI remains in Slave mode, it is recommended to perform an extra communications cycle to bring
Note: The SPI interrupt events are connected to the same interrupt vector (see Interrupts chapter). They generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction).
116/224
ST72361
10.6.8 Register Description SPI CONTROL REGISTER (SPICR) Read/Write Reset Value: 0000 xxxx (0xh)
7
SPIE SPE SPR2 MSTR CPOL CPHA SPR1
0
SPR0
Bit 7 = SPIE Serial Peripheral Interrupt Enable This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SPI interrupt is generated whenever an End of Transfer event, Master Mode Fault or Overrun error occurs (SPIF = 1, MODF = 1 or OVR = 1 in the SPICSR register) Bit 6 = SPE Serial Peripheral Output Enable This bit is set and cleared by software. It is also cleared by hardware when, in master mode, SS = 0 (see Section 10.6.5.1 "Master Mode Fault (MODF)"). The SPE bit is cleared by reset, so the SPI peripheral is not initially connected to the external pins. 0: I/O pins free for general purpose I/O 1: SPI I/O pin alternate functions enabled Bit 5 = SPR2 Divider Enable This bit is set and cleared by software and is cleared by reset. It is used with the SPR[1:0] bits to set the baud rate. Refer to Table 20 SPI Master Mode SCK Frequency. 0: Divider by 2 enabled 1: Divider by 2 disabled Note: This bit has no effect in slave mode. Bit 4 = MSTR Master Mode This bit is set and cleared by software. It is also cleared by hardware when, in master mode, SS = 0 (see Section 10.6.5.1 "Master Mode Fault (MODF)"). 0: Slave mode 1: Master mode. The function of the SCK pin changes from an input to an output and the functions of the MISO and MOSI pins are reversed.
Bit 3 = CPOL Clock Polarity This bit is set and cleared by software. This bit determines the idle state of the serial Clock. The CPOL bit affects both the master and slave modes. 0: SCK pin has a low level idle state 1: SCK pin has a high level idle state Note: If CPOL is changed at the communication byte boundaries, the SPI must be disabled by resetting the SPE bit. Bit 2 = CPHA Clock Phase This bit is set and cleared by software. 0: The first clock transition is the first data capture edge. 1: The second clock transition is the first capture edge. Note: The slave must have the same CPOL and CPHA settings as the master. Bits 1:0 = SPR[1:0] Serial Clock Frequency These bits are set and cleared by software. Used with the SPR2 bit, they select the baud rate of the SPI serial clock SCK output by the SPI in master mode. Note: These 2 bits have no effect in slave mode. Table 21. SPI Master Mode SCK Frequency
Serial Clock fCPU/4 fCPU/8 fCPU/16 fCPU/32 fCPU/64 fCPU/128 SPR2 1 0 1 0 1 0 SPR1 SPR0 0 1 0 1
117/224
ST72361
SERIAL PERIPHERAL INTERFACE (cont'd) SPI CONTROL/STATUS REGISTER (SPICSR) Read/Write (some bits Read Only) Reset Value: 0000 0000 (00h)
7 SPIF WCOL OVR MODF SOD SSM 0 SSI
Bit 2 = SOD SPI Output Disable This bit is set and cleared by software. When set, it disables the alternate function of the SPI output (MOSI in master mode / MISO in slave mode) 0: SPI output enabled (if SPE = 1) 1: SPI output disabled Bit 1 = SSM SS Management This bit is set and cleared by software. When set, it disables the alternate function of the SPI SS pin and uses the SSI bit value instead. See Section 10.6.3.2 "Slave Select Management". 0: Hardware management (SS managed by external pin) 1: Software management (internal SS signal controlled by SSI bit. External SS pin free for general-purpose I/O) Bit 0 = SSI SS Internal Mode This bit is set and cleared by software. It acts as a `chip select' by controlling the level of the SS slave select signal when the SSM bit is set. 0: Slave selected 1: Slave deselected SPI DATA I/O REGISTER (SPIDR) Read/Write Reset Value: Undefined
7 D7 D6 D5 D4 D3 D2 D1 0 D0
Bit 7 = SPIF Serial Peripheral Data Transfer Flag (Read only) This bit is set by hardware when a transfer has been completed. An interrupt is generated if SPIE = 1 in the SPICR register. It is cleared by a software sequence (an access to the SPICSR register followed by a write or a read to the SPIDR register). 0: Data transfer is in progress or the flag has been cleared. 1: Data transfer between the device and an external device has been completed. Note: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read. Bit 6 = WCOL Write Collision status (Read only) This bit is set by hardware when a write to the SPIDR register is done during a transmit sequence. It is cleared by a software sequence (see Figure 75). 0: No write collision occurred 1: A write collision has been detected Bit 5 = OVR SPI Overrun error (Read only) This bit is set by hardware when the byte currently being received in the shift register is ready to be transferred into the SPIDR register while SPIF = 1 (See Section 10.6.5.2). An interrupt is generated if SPIE = 1 in the SPICR register. The OVR bit is cleared by software reading the SPICSR register. 0: No overrun error 1: Overrun error detected Bit 4 = MODF Mode Fault flag (Read only) This bit is set by hardware when the SS pin is pulled low in master mode (see Section 10.6.5.1 "Master Mode Fault (MODF)"). An SPI interrupt can be generated if SPIE = 1 in the SPICR register. This bit is cleared by a software sequence (An access to the SPICSR register while MODF = 1 followed by a write to the SPICR register). 0: No master mode fault detected 1: A fault in master mode has been detected Bit 3 = Reserved, must be kept cleared.
The SPIDR register is used to transmit and receive data on the serial bus. In a master device, a write to this register will initiate transmission/reception of another byte. Notes: During the last clock cycle the SPIF bit is set, a copy of the received data byte in the shift register is moved to a buffer. When the user reads the serial peripheral data I/O register, the buffer is actually being read. While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read. Warning: A write to the SPIDR register places data directly into the shift register for transmission. A read to the SPIDR register returns the value located in the buffer and not the content of the shift register (see Figure 70).
118/224
ST72361
SERIAL PERIPHERAL INTERFACE (Cont'd) Table 22. SPI Register Map and Reset Values
Address (Hex.) 21 22 23 Register Label SPIDR Reset Value SPICR Reset Value SPICSR Reset Value 7 MSB x SPIE 0 SPIF 0 6 5 4 3 2 1 0 LSB x SPR0 x SSI 0
x SPE 0 WCOL 0
x SPR2 0 OVR 0
x MSTR 0 MODF 0
x CPOL x 0
x CPHA x SOD 0
x SPR1 x SSM 0
119/224
ST72361
10.7 LINSCI SERIAL COMMUNICATION INTERFACE (LIN MASTER/SLAVE) 10.7.1 Introduction The Serial Communications Interface (SCI) offers a flexible means of full-duplex data exchange with external equipment requiring an industry standard NRZ asynchronous serial data format. The SCI offers a very wide range of baud rates using two baud rate generator systems. The LIN-dedicated features support the LIN (Local Interconnect Network) protocol for both master and slave nodes. This chapter is divided into SCI Mode and LIN mode sections. For information on general SCI communications, refer to the SCI mode section. For LIN applications, refer to both the SCI mode and LIN mode sections. 10.7.2 SCI Features Full duplex, asynchronous communications NRZ standard format (Mark/Space) Independently programmable transmit and receive baud rates up to 500K baud Programmable data word length (8 or 9 bits) Receive buffer full, Transmit buffer empty and End of Transmission flags 2 receiver wake-up modes: - Address bit (MSB) - Idle line Muting function for multiprocessor configurations Separate enable bits for Transmitter and Receiver Overrun, Noise and Frame error detection 6 interrupt sources - Transmit data register empty - Transmission complete - Receive data register full - Idle line received - Overrun error - Parity interrupt Parity control: - Transmits parity bit - Checks parity of received data byte Reduced power consumption mode 10.7.3 LIN Features - LIN Master - 13-bit LIN Synch Break generation - LIN Slave - Automatic Header Handling - Automatic baud rate resynchronization based on recognition and measurement of the LIN Synch Field (for LIN slave nodes) - Automatic baud rate adjustment (at CPU frequency precision) - 11-bit LIN Synch Break detection capability - LIN Parity check on the LIN Identifier Field (only in reception) - LIN Error management - LIN Header Timeout - Hot plugging support
120/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (cont'd) 10.7.4 General Description - A conventional type for commonly-used baud rates The interface is externally connected to another - An extended type with a prescaler offering a very device by two pins: wide range of baud rates even with non-standard - TDO: Transmit Data Output. When the transmitoscillator frequencies ter is disabled, the output pin returns to its I/O - A LIN baud rate generator with automatic resynport configuration. When the transmitter is enabled and nothing is to be transmitted, the TDO chronization pin is at high level. - RDI: Receive Data Input is the serial data input. Oversampling techniques are used for data recovery by discriminating between valid incoming data and noise. Through these pins, serial data is transmitted and received as characters comprising: - An Idle Line prior to transmission or reception - A start bit - A data word (8 or 9 bits) least significant bit first - A Stop bit indicating that the character is complete This interface uses three types of baud rate generator:
121/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) Figure 77. SCI Block Diagram (in Conventional Baud Rate Generator Mode)
Write
Read
(DATA REGISTER) SCIDR
Transmit Data Register (TDR) TDO Transmit Shift Register RDI
Received Data Register (RDR)
Receive Shift Register
SCICR1
R8 T8 SCID M
WAKE PCE
PS PIE
TRANSMIT CONTROL
WAKE UP UNIT
RECEIVER CONTROL
RECEIVER CLOCK
SCICR2
TIE TCIE RIE ILIE TE RE RWU SBK OR/ TDRE TC RDRF IDLE LHE NF FE
SCISR
PE
SCI INTERRUPT CONTROL TRANSMITTER CLOCK TRANSMITTER RATE
fCPU
CONTROL
/16
/PR SCIBRR
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1SCR0
RECEIVER RATE CONTROL CONVENTIONAL BAUD RATE GENERATOR
122/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5 SCI Mode - Functional Description 10.7.5.1 Serial Data Format Conventional Baud Rate Generator Mode Word length may be selected as being either 8 or 9 bits by programming the M bit in the SCICR1 regThe block diagram of the Serial Control Interface ister (see Figure 78). in conventional baud rate generator mode is The TDO pin is in low state during the start bit. shown in Figure 77. It uses four registers: The TDO pin is in high state during the stop bit. - 2 control registers (SCICR1 and SCICR2) An Idle character is interpreted as a continuous logic high level for 10 (or 11) full bit times. - A status register (SCISR) A Break character is a character with a sufficient - A baud rate register (SCIBRR) number of low level bits to break the normal data Extended Prescaler Mode format followed by an extra "1" bit to acknowledge the start bit. Two additional prescalers are available in extended prescaler mode. They are shown in Figure 79. - An extended prescaler receiver register (SCIERPR) - An extended prescaler transmitter register (SCIETPR) Figure 78. Word Length Programming 9-bit Word length (M bit is set) Data Character
Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Possible Parity Bit Bit8
Next Data Character
Next Stop Start Bit Bit Start Bit
Idle Line
Break Character
Extra '1'
Start Bit
8-bit Word length (M bit is reset) Data Character
Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6
Possible Parity Bit Bit7 Stop Bit
Next Data Character
Next Start Bit Start Bit Extra Start Bit '1'
Idle Line Break Character
123/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5.2 Transmitter When no transmission is taking place, a write instruction to the SCIDR register places the data diThe transmitter can send data words of either 8 or rectly in the shift register, the data transmission 9 bits depending on the M bit status. When the M starts, and the TDRE bit is immediately set. bit is set, word length is 9 bits and the 9th bit (the When a character transmission is complete (after MSB) has to be stored in the T8 bit in the SCICR1 the stop bit) the TC bit is set and an interrupt is register. generated if the TCIE is set and the I[1:0] bits are Character Transmission cleared in the CCR register. During an SCI transmission, data shifts out least Clearing the TC bit is performed by the following significant bit first on the TDO pin. In this mode, software sequence: the SCIDR register consists of a buffer (TDR) be1. An access to the SCISR register tween the internal bus and the transmit shift regis2. A write to the SCIDR register ter (see Figure 77). Note: The TDRE and TC bits are cleared by the Procedure same software sequence. - Select the M bit to define the word length. Break Characters - Select the desired baud rate using the SCIBRR Setting the SBK bit loads the shift register with a and the SCIETPR registers. break character. The break character length de- Set the TE bit to send a preamble of 10 (M = 0) pends on the M bit (see Figure 78). or 11 (M = 1) consecutive ones (Idle Line) as first As long as the SBK bit is set, the SCI sends break transmission. characters to the TDO pin. After clearing this bit by - Access the SCISR register and write the data to software, the SCI inserts a logic 1 bit at the end of send in the SCIDR register (this sequence clears the last break character to guarantee the recognithe TDRE bit). Repeat this sequence for each tion of the start bit of the next character. data to be transmitted. Idle Line Clearing the TDRE bit is always performed by the Setting the TE bit drives the SCI to send a preamfollowing software sequence: ble of 10 (M = 0) or 11 (M = 1) consecutive `1's 1. An access to the SCISR register (idle line) before the first character. 2. A write to the SCIDR register In this case, clearing and then setting the TE bit The TDRE bit is set by hardware and it indicates: during a transmission sends a preamble (idle line) - The TDR register is empty. after the current word. Note that the preamble duration (10 or 11 consecutive `1's depending on the - The data transfer is beginning. M bit) does not take into account the stop bit of the - The next data can be written in the SCIDR regisprevious character. ter without overwriting the previous data. Note: Resetting and setting the TE bit causes the This flag generates an interrupt if the TIE bit is set data in the TDR register to be lost. Therefore the and the I[|1:0] bits are cleared in the CCR register. best time to toggle the TE bit is when the TDRE bit When a transmission is taking place, a write inis set, that is, before writing the next byte in the struction to the SCIDR register stores the data in SCIDR. the TDR register and which is copied in the shift register at the end of the current transmission.
124/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5.3 Receiver - The OR bit is set. The SCI can receive data words of either 8 or 9 - The RDR content will not be lost. bits. When the M bit is set, word length is 9 bits - The shift register will be overwritten. and the MSB is stored in the R8 bit in the SCICR1 - An interrupt is generated if the RIE bit is set and register. the I[|1:0] bits are cleared in the CCR register. Character reception The OR bit is reset by an access to the SCISR regDuring a SCI reception, data shifts in least signifiister followed by a SCIDR register read operation. cant bit first through the RDI pin. In this mode, the Noise Error SCIDR register consists or a buffer (RDR) between the internal bus and the received shift regisOversampling techniques are used for data recovter (see Figure 77). ery by discriminating between valid incoming data and noise. Procedure When noise is detected in a character: - Select the M bit to define the word length. - The NF bit is set at the rising edge of the RDRF - Select the desired baud rate using the SCIBRR bit. and the SCIERPR registers. - Data is transferred from the Shift register to the - Set the RE bit, this enables the receiver which SCIDR register. begins searching for a start bit. - No interrupt is generated. However this bit rises When a character is received: at the same time as the RDRF bit which itself - The RDRF bit is set. It indicates that the content generates an interrupt. of the shift register is transferred to the RDR. The NF bit is reset by a SCISR register read oper- An interrupt is generated if the RIE bit is set and ation followed by a SCIDR register read operation. the I[1:0] bits are cleared in the CCR register. Framing Error - The error flags can be set if a frame error, noise A framing error is detected when: or an overrun error has been detected during reception. - The stop bit is not recognized on reception at the expected time, following either a desynchronizaClearing the RDRF bit is performed by the following tion or excessive noise. software sequence done by: - A break is received. 1. An access to the SCISR register When the framing error is detected: 2. A read to the SCIDR register. - the FE bit is set by hardware The RDRF bit must be cleared before the end of the reception of the next character to avoid an overrun - Data is transferred from the Shift register to the error. SCIDR register. Idle Line - No interrupt is generated. However this bit rises at the same time as the RDRF bit which itself When an idle line is detected, there is the same generates an interrupt. procedure as a data received character plus an interrupt if the ILIE bit is set and the I[|1:0] bits are The FE bit is reset by a SCISR register read opercleared in the CCR register. ation followed by a SCIDR register read operation. Overrun Error Break Character An overrun error occurs when a character is re- When a break character is received, the SCI ceived when RDRF has not been reset. Data can handles it as a framing error. To differentiate a not be transferred from the shift register to the break character from a framing error, it is necesTDR register as long as the RDRF bit is not sary to read the SCIDR. If the received value is cleared. 00h, it is a break character. Otherwise it is a framing error. When an overrun error occurs:
125/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5.4 Conventional Baud Rate Generation 10.7.5.5 Extended Baud Rate Generation The baud rates for the receiver and transmitter (Rx The extended prescaler option gives a very fine and Tx) are set independently and calculated as tuning on the baud rate, using a 255 value prescaler, whereas the conventional Baud Rate Generafollows: tor retains industry standard software compatibilifCPU fCPU ty. Rx = Tx = The extended baud rate generator block diagram (16*PR)*RR (16*PR)*TR is described in Figure 79. with: The output clock rate sent to the transmitter or to PR = 1, 3, 4 or 13 (see SCP[1:0] bits) the receiver will be the output from the 16 divider divided by a factor ranging from 1 to 255 set in the TR = 1, 2, 4, 8, 16, 32, 64,128 SCIERPR or the SCIETPR register. (see SCT[2:0] bits) Note: The extended prescaler is activated by setRR = 1, 2, 4, 8, 16, 32, 64,128 ting the SCIETPR or SCIERPR register to a value (see SCR[2:0] bits) other than zero. The baud rates are calculated as follows: All these bits are in the SCIBRR register. Example: If fCPU is 8 MHz (normal mode) and if fCPU fCPU PR = 13 and TR = RR = 1, the transmit and reRx = Tx = ceive baud rates are 38400 baud. 16*ERPR*(PR*RR) 16*ETPR*(PR*TR) Note: The baud rate registers MUST NOT be changed while the transmitter or the receiver is enwith: abled. ETPR = 1, ..., 255 (see SCIETPR register) ERPR = 1, ..., 255 (see SCIERPR register)
126/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) Figure 79. SCI Baud Rate and Extended Prescaler Block Diagram
TRANSMITTER CLOCK EXTENDED PRESCALER TRANSMITTER RATE CONTROL
SCIETPR
EXTENDED TRANSMITTER PRESCALER REGISTER
SCIERPR
EXTENDED RECEIVER PRESCALER REGISTER RECEIVER CLOCK EXTENDED PRESCALER RECEIVER RATE CONTROL EXTENDED PRESCALER
fCPU
TRANSMITTER RATE CONTROL
/16
/PR SCIBRR
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1SCR0
RECEIVER RATE CONTROL CONVENTIONAL BAUD RATE GENERATOR
127/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5.6 Receiver Muting and Wake-up Feature ceived an address character (most significant bit = '1'), the receivers are waken up. The receivers In multiprocessor configurations it is often desirawhich are not addressed set RWU bit to enter in ble that only the intended message recipient mute mode. Consequently, they will not treat the should actively receive the full message contents, next characters constituting the next part of the thus reducing redundant SCI service overhead for message. all non-addressed receivers. 10.7.5.7 Parity Control The non-addressed devices may be placed in Hardware byte Parity control (generation of parity sleep mode by means of the muting function. bit in transmission and parity checking in recepSetting the RWU bit by software puts the SCI in tion) can be enabled by setting the PCE bit in the sleep mode: SCICR1 register. Depending on the character forAll the reception status bits can not be set. mat defined by the M bit, the possible SCI character formats are as listed in Table 22. All the receive interrupts are inhibited. Note: In case of wake-up by an address mark, the A muted receiver may be woken up in one of the MSB bit of the data is taken into account and not following ways: the parity bit - by Idle Line detection if the WAKE bit is reset, Table 23. Character Formats - by Address Mark detection if the WAKE bit is set. Idle Line Detection M bit PCE bit Character format 0 | SB | 8 bit data | STB | Receiver wakes up by Idle Line detection when the 0 Receive line has recognized an Idle Line. Then the 1 | SB | 7-bit data | PB | STB | RWU bit is reset by hardware but the IDLE bit is 0 | SB | 9-bit data | STB | 1 not set. 1 | SB | 8-bit data | PB | STB | This feature is useful in a multiprocessor system Legend: SB = Start Bit, STB = Stop Bit, when the first characters of the message deterPB = Parity Bit mine the address and when each message ends Even parity: The parity bit is calculated to obtain by an idle line: As soon as the line becomes idle, an even number of "1s" inside the character made every receivers is waken up and analyse the first of the 7 or 8 LSB bits (depending on whether M is characters of the message which indicates the adequal to 0 or 1) and the parity bit. dressed receiver. The receivers which are not addressed set RWU bit to enter in mute mode. ConExample: data = 00110101; 4 bits set => parity bit sequently, they will not treat the next characters will be 0 if even parity is selected (PS bit = 0). constituting the next part of the message. At the Odd parity: The parity bit is calculated to obtain end of the message, an idle line is sent by the an odd number of "1s" inside the character made transmitter: this wakes up every receivers which of the 7 or 8 LSB bits (depending on whether M is are ready to analyse the addressing characters of equal to 0 or 1) and the parity bit. the new message. Example: data = 00110101; 4 bits set => parity bit In such a system, the inter-characters space must will be 1 if odd parity is selected (PS bit = 1). be smaller than the idle time. Transmission mode: If the PCE bit is set then the Address Mark Detection MSB bit of the data written in the data register is Receiver wakes up by Address Mark detection not transmitted but is changed by the parity bit. when it received a "1" as the most significant bit of Reception mode: If the PCE bit is set then the ina word, thus indicating that the message is an adterface checks if the received data byte has an dress. The reception of this particular word wakes even number of "1s" if even parity is selected up the receiver, resets the RWU bit and sets the (PS = 0) or an odd number of "1s" if odd parity is RDRF bit, which allows the receiver to receive this selected (PS = 1). If the parity check fails, the PE word normally and to use it as an address word. flag is set in the SCISR register and an interrupt is This feature is useful in a multiprocessor system generated if PCIE is set in the SCICR1 register. when the most significant bit of each character (except for the break character) is reserved for Address Detection. As soon as the receivers re-
128/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.6 Low Power Modes 10.7.7 Interrupts
Mode WAIT Description No effect on SCI. SCI interrupts cause the device to exit from Wait mode. SCI registers are frozen. In Halt mode, the SCI stops transmitting/receiving until Halt mode is exited. Interrupt Event Enable Exit Event Control from Flag Bit Wait TIE TCIE Exit from Halt
HALT
Transmit Data Register TDRE Empty Transmission ComTC plete Received Data Ready RDRF to be Read Overrun Error or LIN OR/ Synch Error Detected LHE Idle Line Detected IDLE Parity Error PE LIN Header Detection LHDF
RIE ILIE PIE LHIE
Yes
No
The SCI interrupt events are connected to the same interrupt vector (see Interrupts chapter). These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction).
129/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.8 SCI Mode Register Description STATUS REGISTER (SCISR) Bit 3 = OR Overrun error Read Only The OR bit is set by hardware when the word curReset Value: 1100 0000 (C0h) rently being received in the shift register is ready to be transferred into the RDR register whereas 7 0 RDRF is still set. An interrupt is generated if RIE = 1 in the SCICR2 register. It is cleared by a 1) 1) 1) 1) TDRE TC RDRF IDLE OR NF FE PE software sequence (an access to the SCISR register followed by a read to the SCIDR register). 0: No Overrun error Bit 7 = TDRE Transmit data register empty 1: Overrun error detected This bit is set by hardware when the content of the TDR register has been transferred into the shift Note: When this bit is set, RDR register contents register. An interrupt is generated if the TIE = 1 in will not be lost but the shift register will be overwritthe SCICR2 register. It is cleared by a software seten. quence (an access to the SCISR register followed by a write to the SCIDR register). 0: Data is not transferred to the shift register Bit 2 = NF Character Noise flag 1: Data is transferred to the shift register This bit is set by hardware when noise is detected on a received character. It is cleared by a software sequence (an access to the SCISR register folBit 6 = TC Transmission complete lowed by a read to the SCIDR register). This bit is set by hardware when transmission of a 0: No noise character containing Data is complete. An inter1: Noise is detected rupt is generated if TCIE = 1 in the SCICR2 regisNote: This bit does not generate interrupt as it apter. It is cleared by a software sequence (an acpears at the same time as the RDRF bit which itcess to the SCISR register followed by a write to self generates an interrupt. the SCIDR register). 0: Transmission is not complete 1: Transmission is complete Bit 1 = FE Framing error Note: TC is not set after the transmission of a PreThis bit is set by hardware when a desynchronizaamble or a Break. tion, excessive noise or a break character is detected. It is cleared by a software sequence (an access to the SCISR register followed by a read to Bit 5 = RDRF Received data ready flag the SCIDR register). This bit is set by hardware when the content of the 0: No Framing error RDR register has been transferred to the SCIDR 1: Framing error or break character detected register. An interrupt is generated if RIE = 1 in the Note: This bit does not generate an interrupt as it SCICR2 register. It is cleared by a software seappears at the same time as the RDRF bit which itquence (an access to the SCISR register followed self generates an interrupt. If the word currently by a read to the SCIDR register). being transferred causes both a frame error and 0: Data is not received an overrun error, it will be transferred and only the 1: Received data is ready to be read OR bit will be set. Bit 4 = IDLE Idle line detected This bit is set by hardware when an Idle Line is detected. An interrupt is generated if the ILIE = 1 in the SCICR2 register. It is cleared by a software sequence (an access to the SCISR register followed by a read to the SCIDR register). 0: No Idle Line is detected 1: Idle Line is detected Note: The IDLE bit will not be set again until the RDRF bit has been set itself (that is, a new idle line occurs). Bit 0 = PE Parity error This bit is set by hardware when a byte parity error occurs (if the PCE bit is set) in receiver mode. It is cleared by a software sequence (a read to the status register followed by an access to the SCIDR data register). An interrupt is generated if PIE = 1 in the SCICR1 register. 0: No parity error 1: Parity error detected
130/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) CONTROL REGISTER 1 (SCICR1) Read/Write Bit 3 = WAKE Wake-Up method Reset Value: x000 0000 (x0h) This bit determines the SCI Wake-Up method, it is set or cleared by software. 7 0 0: Idle Line 1: Address Mark 1) R8 T8 SCID M WAKE PCE PS PIE Note: If the LINE bit is set, the WAKE bit is deactivated and replaced by the LHDM bit. 1)
This bit has a different function in LIN mode, please refer to the LIN mode register description.
Bit 7 = R8 Receive data bit 8 This bit is used to store the 9th bit of the received word when M = 1. Bit 6 = T8 Transmit data bit 8 This bit is used to store the 9th bit of the transmitted word when M = 1. Bit 5 = SCID Disabled for low power consumption When this bit is set the SCI prescalers and outputs are stopped and the end of the current byte transfer in order to reduce power consumption.This bit is set and cleared by software. 0: SCI enabled 1: SCI prescaler and outputs disabled Bit 4 = M Word length This bit determines the word length. It is set or cleared by software. 0: 1 Start bit, 8 Data bits, 1 Stop bit 1: 1 Start bit, 9 Data bits, 1 Stop bit Note: The M bit must not be modified during a data transfer (both transmission and reception).
Bit 2 = PCE Parity control enable This bit is set and cleared by software. It selects the hardware parity control (generation and detection for byte parity, detection only for LIN parity). 0: Parity control disabled 1: Parity control enabled Bit 1 = PS Parity selection This bit selects the odd or even parity when the parity generation/detection is enabled (PCE bit set). It is set and cleared by software. The parity will be selected after the current byte. 0: Even parity 1: Odd parity Bit 0 = PIE Parity interrupt enable This bit enables the interrupt capability of the hardware parity control when a parity error is detected (PE bit set). The parity error involved can be a byte parity error (if bit PCE is set and bit LPE is reset) or a LIN parity error (if bit PCE is set and bit LPE is set). 0: Parity error interrupt disabled 1: Parity error interrupt enabled
131/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) CONTROL REGISTER 2 (SCICR2) 1: Receiver is enabled and begins searching for a Read/Write start bit Reset Value: 0000 0000 (00 h) Bit 1 = RWU Receiver wake-up 7 0 This bit determines if the SCI is in mute mode or not. It is set and cleared by software and can be 1) SBK1) TIE TCIE RIE ILIE TE RE RWU cleared by hardware when a wake-up sequence is recognized. 1) 0: Receiver in active mode This bit has a different function in LIN mode, please 1: Receiver in mute mode refer to the LIN mode register description. Notes: Bit 7 = TIE Transmitter interrupt enable This bit is set and cleared by software. - Before selecting Mute mode (by setting the RWU 0: Interrupt is inhibited bit) the SCI must first receive a data byte, other1: In SCI interrupt is generated whenever wise it cannot function in Mute mode with wakeTDRE = 1 in the SCISR register up by Idle line detection. - In Address Mark Detection Wake-Up configuraBit 6 = TCIE Transmission complete interrupt enation (WAKE bit = 1) the RWU bit cannot be modble ified by software while the RDRF bit is set. This bit is set and cleared by software. 0: Interrupt is inhibited Bit 0 = SBK Send break 1: An SCI interrupt is generated whenever TC = 1 This bit set is used to send break characters. It is in the SCISR register set and cleared by software. 0: No break character is transmitted Bit 5 = RIE Receiver interrupt enable 1: Break characters are transmitted This bit is set and cleared by software. Note: If the SBK bit is set to "1" and then to "0", the 0: Interrupt is inhibited transmitter will send a BREAK word at the end of 1: An SCI interrupt is generated whenever OR = 1 the current word. or RDRF = 1 in the SCISR register Bit 4 = ILIE Idle line interrupt enable This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever IDLE = 1 in the SCISR register. Bit 3 = TE Transmitter enable This bit enables the transmitter. It is set and cleared by software. 0: Transmitter is disabled 1: Transmitter is enabled Notes: - During transmission, a "0" pulse on the TE bit ("0" followed by "1") sends a preamble (idle line) after the current word. - When TE is set there is a 1 bit-time delay before the transmission starts. Bit 2 = RE Receiver enable This bit enables the receiver. It is set and cleared by software. 0: Receiver is disabled in the SCISR register DATA REGISTER (SCIDR) Read/Write Reset Value: Undefined Contains the Received or Transmitted data character, depending on whether it is read from or written to.
7
DR7 DR6 DR5 DR4 DR3 DR2 DR1
0
DR0
The Data register performs a double function (read and write) since it is composed of two registers, one for transmission (TDR) and one for reception (RDR). The TDR register provides the parallel interface between the internal bus and the output shift register (see Figure 77). The RDR register provides the parallel interface between the input shift register and the internal bus (see Figure 77).
132/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) BAUD RATE REGISTER (SCIBRR) TR dividing factor Read/Write 1 Reset Value: 0000 0000 (00h)
2 7
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2
SCT2
SCT1 0
SCT0 0 1 0 1 0 1 0 1
0
SCR1 SCR0
4 8 16 32 64 128
0 1 0 1 1
Note: When LIN slave mode is disabled, the SCIBRR register controls the conventional baud rate generator. Bits 7:6 = SCP[1:0] First SCI Prescaler These 2 prescaling bits allow several standard clock division ranges:
PR Prescaling factor 1 3 4 13 SCP1 0 1 SCP0 0 1 0 1
Bits 2:0 = SCR[2:0] SCI Receiver rate divider These 3 bits, in conjunction with the SCP[1:0] bits define the total division applied to the bus clock to yield the receive rate clock in conventional Baud Rate Generator mode.
RR dividing factor 1 2 4 8 16 32 64 128 1 1 0 1 0 SCR2 SCR1 0 SCR0 0 1 0 1 0 1 0 1
Bits 5:3 = SCT[2:0] SCI Transmitter rate divisor These 3 bits, in conjunction with the SCP1 and SCP0 bits define the total division applied to the bus clock to yield the transmit rate clock in conventional Baud Rate Generator mode.
133/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) EXTENDED RECEIVE PRESCALER DIVISION EXTENDED TRANSMIT PRESCALER DIVISION REGISTER (SCIERPR) REGISTER (SCIETPR) Read/Write Read/Write Reset Value: 0000 0000 (00 h) Reset Value:0000 0000 (00 h)
7 0 7
ETPR 7 ETPR 6 ETPR 5 ETPR 4 ETPR 3 ETPR 2
0
ETPR ETPR 1 0
ERPR ERPR ERPR ERPR ERPR ERPR ERPR ERPR 7 6 5 4 3 2 1 0
Bits 7:0 = ERPR[7:0] 8-bit Extended Receive Prescaler Register The extended Baud Rate Generator is activated when a value other than 00h is stored in this register. The clock frequency from the 16 divider (see Figure 79) is divided by the binary factor set in the SCIERPR register (in the range 1 to 255). The extended baud rate generator is not active after a reset.
Bits 7:0 = ETPR[7:0] 8-bit Extended Transmit Prescaler Register The extended Baud Rate Generator is activated when a value other than 00h is stored in this register. The clock frequency from the 16 divider (see Figure 79) is divided by the binary factor set in the SCIETPR register (in the range 1 to 255). The extended baud rate generator is not active after a reset. Note: In LIN slave mode, the Conventional and Extended Baud Rate Generators are disabled.
134/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) 10.7.9 LIN Mode - Functional Description. Slave The block diagram of the Serial Control Interface, Set the LSLV bit in the SCICR3 register to enter in LIN slave mode is shown in Figure 81. LIN slave mode. In this case, setting the SBK bit will have no effect. It uses six registers: In LIN Slave mode the LIN baud rate generator is - 3 control registers: SCICR1, SCICR2 and selected instead of the Conventional or Extended SCICR3 Prescaler. The LIN baud rate generator is com- 2 status registers: the SCISR register and the mon to the transmitter and the receiver. LHLR register mapped at the SCIERPR address Then the baud rate can be programmed using - A baud rate register: LPR mapped at the SCILPR and LPRF registers. BRR address and an associated fraction register Note: It is mandatory to set the LIN configuration LPFR mapped at the SCIETPR address first before programming LPR and LPRF, because The bits dedicated to LIN are located in the the LIN configuration uses a different baud rate SCICR3. Refer to the register descriptions in Secgenerator from the standard one. tion 10.7.10for the definitions of each bit. 10.7.9.1 Entering LIN Mode 10.7.9.2 LIN Transmission To use the LINSCI in LIN mode the following conIn LIN mode the same procedure as in SCI mode figuration must be set in SCICR3 register: has to be applied for a LIN transmission. - Clear the M bit to configure 8-bit word length. To transmit the LIN Header the proceed as fol- Set the LINE bit. lows: Master - First set the SBK bit in the SCICR2 register to start transmitting a 13-bit LIN Synch Break To enter master mode the LSLV bit must be reset In this case, setting the SBK bit will send 13 low - reset the SBK bit bits. - Load the LIN Synch Field (0x55) in the SCIDR Then the baud rate can programmed using the register to request Synch Field transmission SCIBRR, SCIERPR and SCIETPR registers. - Wait until the SCIDR is empty (TDRE bit set in In LIN master mode, the Conventional and / or Exthe SCISR register) tended Prescaler define the baud rate (as in stand- Load the LIN message Identifier in the SCIDR ard SCI mode) register to request Identifier transmission.
135/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) Figure 80. LIN Characters 8-bit Word length (M bit is reset) Next Data Character Next Start Stop Start Bit Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit Idle Line LIN Synch Break = 13 low bits Start Bit LIN Synch Field Extra Start `1' Bit Data Character
LIN Synch Field Next Start Stop Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit Bit Measurement for baud rate autosynchronization
136/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) Figure 81. SCI Block Diagram in LIN Slave Mode
Write Read
(DATA REGISTER) SCIDR
Transmit Data Register (TDR)
Received Data Register (RDR)
TDO
Transmit Shift Register
Receive Shift Register
RDI
SCICR1
R8 T8 SCID M
WAKE PCE
PS
PIE
TRANSMIT CONTROL
WAKE UP UNIT
RECEIVER CONTROL
RECEIVER CLOCK
SCICR2
TIE TCIE RIE ILIE TE RE RWU SBK TDRE TC RDRF IDLE OR/ LHE NF FE
SCISR
PE
SCI INTERRUPT CONTROL TRANSMITTER CLOCK
fCPU
LIN SLAVE BAUD RATE AUTO SYNCHRONIZATION UNIT
SCICR3
LDUM LINE LSLV LASE LHDM LHIE LHDF LSF
SCIBRR
LPR7 LPR0 CONVENTIONAL BAUD RATE GENERATOR + EXTENDED PRESCALER 0
fCPU
/ LDIV
/16
1
LIN SLAVE BAUD RATE GENERATOR
137/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.3 LIN Reception Note: In LIN mode the reception of a byte is the same as In LIN slave mode, the FE bit detects all frame error which does not correspond to a break. in SCI mode but the LINSCI has features for handling the LIN Header automatically (identifier deIdentifier Detection (LHDM = 1): tection) or semiautomatically (Synch Break detecThis case is the same as the previous one except tion) depending on the LIN Header detection that the LHDF and the RDRF flags are set only afmode. The detection mode is selected by the ter the entire header has been received (this is LHDM bit in the SCICR3. true whether automatic resynchronization is enaAdditionally, an automatic resynchronization feabled or not). This indicates that the LIN Identifier is ture can be activated to compensate for any clock available in the SCIDR register. deviation, for more details please refer to Section Notes: 10.7.9.5 "LIN Baud Rate". During LIN Synch Field measurement, the SCI LIN Header Handling by a Slave state machine is switched off: No characters are Depending on the LIN Header detection method transferred to the data register. the LINSCI will signal the detection of a LIN HeadLIN Slave parity er after the LIN Synch Break or after the Identifier has been successfully received. In LIN Slave mode (LINE and LSLV bits are set) LIN parity checking can be enabled by setting the Note: PCE bit. It is recommended to combine the Header detecIn this case, the parity bits of the LIN Identifier tion function with Mute mode. Putting the LINSCI Field are checked. The identifier character is recin Mute mode allows the detection of Headers only ognized as the third received character after a and prevents the reception of any other characbreak character (included): ters. This mode can be used to wait for the next Header parity bits without being interrupted by the data bytes of the current message in case this message is not relevant for the application. Synch Break Detection (LHDM = 0): When a LIN Synch Break is received: LIN Synch LIN Synch Identifier - The RDRF bit in the SCISR register is set. It inField Break Field dicates that the content of the shift register is transferred to the SCIDR register, a value of 0x00 is expected for a Break. The bits involved are the two MSB positions (7th and 8th bits if M = 0; 8th and 9th bits if M = 0) of - The LHDF flag in the SCICR3 register indicates the identifier character. The check is performed as that a LIN Synch Break Field has been detected. specified by the LIN specification: - An interrupt is generated if the LHIE bit in the SCICR3 register is set and the I[1:0] bits are cleared in the CCR register. parity bits stop bit start bit - Then the LIN Synch Field is received and measidentifier bits ured. ID0 ID1 ID2 ID3 ID4 ID5 P0 P1 - If automatic resynchronization is enabled (LASE bit = 1), the LIN Synch Field is not transIdentifier Field ferred to the shift register: There is no need to clear the RDRF bit. P0 = ID0 ID1 ID2 ID4 M=0 - If automatic resynchronization is disabled (LAP1 = ID1 ID3 ID4 ID5 SE bit = 0), the LIN Synch Field is received as a normal character and transferred to the SCIDR register and RDRF is set.
138/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.4 LIN Error Detection edge of the Synch Field. Let us refer to this period deviation as D: LIN Header Error Flag If the LHE flag is set, it means that: The LIN Header Error Flag indicates that an invalid D > 15.625% LIN Header has been detected. When a LIN Header Error occurs: If LHE flag is not set, it means that: - The LHE flag is set D < 16.40625% - An interrupt is generated if the RIE bit is set and If 15.625% D < 16.40625%, then the flag can the I[1:0] bits are cleared in the CCR register. be either set or reset depending on the dephasing between the signal on the RDI line and the If autosynchronization is enabled (LASE bit = 1), CPU clock. this can mean that the LIN Synch Field is corrupted, and that the SCI is in a blocked state (LSF bit is - The second check is based on the measurement set). The only way to recover is to reset the LSF bit of each bit time between both edges of the Synch and then to clear the LHE bit. Field: this checks that each of these bit times is large enough compared to the bit time of the cur- The LHE bit is reset by an access to the SCISR rent baud rate. register followed by a read of the SCIDR register. When LHE is set due to this error then the SCI LHE/OVR Error Conditions goes into a blocked state (LSF bit is set). When Auto Resynchronization is disabled (LASE LIN Header Time-out Error bit = 0), the LHE flag detects: When the LIN Identifier Field Detection Method is - That the received LIN Synch Field is not equal to used (by configuring LHDM to 1) or when LIN 55h. auto-resynchronization is enabled (LASE bit = 1), - That an overrun occurred (as in standard SCI the LINSCI automatically monitors the mode) THEADER_MAX condition given by the LIN protocol. - Furthermore, if LHDM is set it also detects that a If the entire Header (up to and including the STOP LIN Header Reception Timeout occurred (only if bit of the LIN Identifier Field) is not received within LHDM is set). the maximum time limit of 57 bit times then a LIN Header Error is signalled and the LHE bit is set in When the LIN auto-resynchronization is enabled the SCISR register. (LASE bit = 1), the LHE flag detects: - That the deviation error on the Synch Field is outside the LIN specification which allows up to +/-15.5% of period deviation between the slave and master oscillators. - A LIN Header Reception Timeout occurred. If THEADER > THEADER_MAX then the LHE flag is set. Refer to Figure 82. (only if LHDM is set to 1) - An overflow during the Synch Field Measurement, which leads to an overflow of the divider registers. If LHE is set due to this error then the SCI goes into a blocked state (LSF bit is set). - That an overrun occurred on Fields other than the Synch Field (as in standard SCI mode) Deviation Error on the Synch Field The deviation error is checking by comparing the current baud rate (relative to the slave oscillator) with the received LIN Synch Field (relative to the master oscillator). Two checks are performed in parallel: - The first check is based on a measurement between the first falling edge and the last falling Figure 82. LIN Header Reception Timeout
LIN Synch Break
LIN Synch Field
Identifier Field
THEADER The time-out counter is enabled at each break detection. It is stopped in the following conditions: - A LIN Identifier Field has been received - An LHE error occurred (other than a timeout error). - A software reset of LSF bit (transition from high to low) occurred during the analysis of the LIN Synch Field or If LHE bit is set due to this error during the LIN Synchr Field (if LASE bit = 1) then the SCI goes into a blocked state (LSF bit is set).
139/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) If LHE bit is set due to this error during Fields other LIN Header Length than LIN Synch Field or if LASE bit is reset then Even if no timeout occurs on the LIN Header, it is the current received Header is discarded and the possible to have access to the effective LIN headSCI searches for a new Break Field. er Length (THEADER) through the LHL register. Note on LIN Header Time-out Limit This allows monitoring at software level the TFRAME_MAX condition given by the LIN protocol. According to the LIN specification, the maximum This feature is only available when LHDM bit = 1 length of a LIN Header which does not cause a or when LASE bit = 1. timeout is equal to 1.4 * (34 + 1) = 49 TBIT_MASTER. Mute Mode and Errors TBIT_MASTER refers to the master baud rate. In mute mode when LHDM bit = 1, if an LHE error When checking this timeout, the slave node is deoccurs during the analysis of the LIN Synch Field synchronized for the reception of the LIN Break or if a LIN Header Time-out occurs then the LHE and Synch fields. Consequently, a margin must be bit is set but it does not wake up from mute mode. allowed, taking into account the worst case: This In this case, the current header analysis is discarded. If needed, the software has to reset LSF bit. occurs when the LIN identifier lasts exactly 10 Then the SCI searches for a new LIN header. TBIT_MASTER periods. In this case, the LIN Break and Synch fields last 49 - 10 = 39TBIT_MASTER peIn mute mode, if a framing error occurs on a data riods. (which is not a break), it is discarded and the FE bit Assuming the slave measures these first 39 bits is not set. with a desynchronized clock of 15.5%. This leads When LHDM bit = 1, any LIN header which reto a maximum allowed Header Length of: spects the following conditions causes a wake-up 39 x (1/0.845) TBIT_MASTER + 10TBIT_MASTER from mute mode: = 56.15 TBIT_SLAVE - A valid LIN Break Field (at least 11 dominant bits followed by a recessive bit) A margin is provided so that the time-out occurs - A valid LIN Synch Field (without deviation error) when the header length is greater than 57 TBIT_SLAVE periods. If it is less than or equal to 57 - A LIN Identifier Field without framing error. Note TBIT_SLAVE periods, then no timeout occurs. that a LIN parity error on the LIN Identifier Field does not prevent wake-up from mute mode. - No LIN Header Time-out should occur during Header reception. Figure 83. LIN Synch Field Measurement
TCPU = CPU period TBR = Baud Rate period TBR = 16.LP.TCPU
SM = Synch Measurement Register (15 bits) TBR LIN Synch Break Extra `1' LIN Synch Field Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Stop Bit Next Start Bit
Measurement = 8.TBR = SM.TCPU LPR(n) LPR = TBR / (16.TCPU) = Rounding (SM / 128) LPR(n+1)
140/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.5 LIN Baud Rate mitter are both set to the same value, depending on the LIN Slave baud rate generator: Baud rate programming is done by writing a value in the LPR prescaler or performing an automatic resynchronization as described below. fCPU Automatic Resynchronization Tx = Rx = (16*LDIV) To automatically adjust the baud rate based on measurement of the LIN Synch Field: with: - Write the nominal LIN Prescaler value (usually LDIV is an unsigned fixed point number. The mandepending on the nominal baud rate) in the tissa is coded on 8 bits in the LPR register and the LPFR / LPR registers. fraction is coded on 4 bits in the LPFR register. - Set the LASE bit to enable the Auto SynchroniIf LASE bit = 1 then LDIV is automatically updated zation Unit. at the end of each LIN Synch Field. When Auto Synchronization is enabled, after each Three registers are used internally to manage the LIN Synch Break, the time duration between five auto-update of the LIN divider (LDIV): falling edges on RDI is sampled on fCPU and the - LDIV_NOM (nominal value written by software at result of this measurement is stored in an internal LPR/LPFR addresses) 15-bit register called SM (not user accessible) (see Figure 83). Then the LDIV value (and its as- LDIV_MEAS (results of the Field Synch meassociated LPFR and LPR registers) are automatiurement) cally updated at the end of the fifth falling edge. - LDIV (used to generate the local baud rate) During LIN Synch field measurement, the SCI The control and interactions of these registers, exstate machine is stopped and no data is transplained in Figure 84 and Figure 85, depend on the ferred to the data register. LDUM bit setting (LIN Divider Update Method). 10.7.9.6 LIN Slave Baud Rate Generation Note: In LIN mode, transmission and reception are drivAs explained in Figure 84 and Figure 85, LDIV can en by the LIN baud rate generator be updated by two concurrent actions: a transfer Note: LIN Master mode uses the Extended or from LDIV_MEAS at the end of the LIN Sync Field Conventional prescaler register to generate the and a transfer from LDIV_NOM due to a software baud rate. write of LPR. If both operations occur at the same If LINE bit = 1 and LSLV bit = 1 then the Conventime, the transfer from LDIV_NOM has priority. tional and Extended Baud Rate Generators are disabled: the baud rate for the receiver and trans-
141/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) Figure 84. LDIV Read / Write Operations When LDUM = 0 Write LPR Write LPFR LIN Sync Field Measurement
MANT(7:0) FRAC(3:0)
LDIV_NOM
Write LPR MANT(7:0) FRAC(3:0) LDIV_MEAS Update at end of Synch Field
MANT(7:0) FRAC(3:0) LDIV
Baud Rate Generation
Read LPR
Read LPFR
Figure 85. LDIV Read / Write Operations When LDUM = 1 Write LPR Write LPFR LIN Sync Field Measurement
MANT(7:0) FRAC(3:0)
LDIV_NOM
RDRF = 1 MANT(7:0) FRAC(3:0) LDIV_MEAS Update at end of Synch Field
MANT(7:0) FRAC(3:0) LDIV
Baud Rate Generation
Read LPR
Read LPFR
142/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.7 LINSCI Clock Tolerance Consequently, the clock frequency should not vary more than 6/16 (37.5%) within one bit. LINSCI Clock Tolerance when unsynchronized The sampling clock is resynchronized at each start When LIN slaves are unsynchronized (meaning no bit, so that when receiving 10 bits (one start bit, 1 characters have been transmitted for a relatively data byte, 1 stop bit), the clock deviation should long time), the maximum tolerated deviation of the not exceed 3.75%. LINSCI clock is +/-15%. 10.7.9.8 Clock Deviation Causes If the deviation is within this range then the LIN The causes which contribute to the total deviation Synch Break is detected properly when a new reception occurs. are: This is made possible by the fact that masters - DTRA: Deviation due to transmitter error. Note: The transmitter can be either a master send 13 low bits for the LIN Synch Break, which or a slave (in case of a slave listening to the can be interpreted as 11 low bits (13 bits -15% = response of another slave). 11.05) by a "fast" slave and then considered as a LIN Synch Break. According to the LIN specifica- DMEAS: Error due to the LIN Synch measuretion, a LIN Synch Break is valid when its duration ment performed by the receiver. is greater than tSBRKTS = 10. This means that the - DQUANT: Error due to the baud rate quantizaLIN Synch Break must last at least 11 low bits. tion of the receiver. Note: If the period desynchronization of the slave - DREC: Deviation of the local oscillator of the is +15% (slave too slow), the character "00h" receiver: This deviation can occur during the which represents a sequence of 9 low bits must reception of one complete LIN message asnot be interpreted as a break character (9 bits + suming that the deviation has been compen15% = 10.35). Consequently, a valid LIN Synch sated at the beginning of the message. break must last at least 11 low bits. - DTCL: Deviation due to the transmission line LINSCI Clock Tolerance when Synchronized (generally due to the transceivers) When synchronization has been performed, folAll the deviations of the system should be added lowing reception of a LIN Synch Break, the LINSand compared to the LINSCI clock tolerance: CI, in LIN mode, has the same clock deviation tolDTRA + DMEAS +DQUANT + DREC + DTCL < 3.75% erance as in SCI mode, which is explained below: During reception, each bit is oversampled 16 times. The mean of the 8th, 9th and 10th samples is considered as the bit value. Figure 86.Bit Sampling in Reception Mode
RDI LINE sampled values Sample clock 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
6/16 7/16 One bit time 7/16
143/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.9 Error due to LIN Synch measurement Consequently, at a given CPU frequency, the maximum possible nominal baud rate (LPRMIN) The LIN Synch Field is measured over eight bit should be chosen with respect to the maximum toltimes. erated deviation given by the equation: This measurement is performed using a counter DTRA + 2 / (128*LDIVMIN) + 1 / (2*16*LDIVMIN) clocked by the CPU clock. The edge detections + DREC + DTCL < 3.75% are performed using the CPU clock cycle. This leads to a precision of 2 CPU clock cycles for the measurement which lasts 16*8*LDIV clock cyExample: cles. A nominal baud rate of 20Kbits/s at TCPU = 125ns Consequently, this error (DMEAS) is equal to: (8 MHz) leads to LDIVNOM = 25d. 2 / (128*LDIVMIN). LDIVMIN = 25 - 0.15*25 = 21.25 LDIVMIN corresponds to the minimum LIN prescalDMEAS = 2 / (128*LDIVMIN) * 100 = 0.00073% er content, leading to the maximum baud rate, takDQUANT = 1 / (2*16*LDIVMIN) * 100 = 0.0015% ing into account the maximum deviation of +/-15%. 10.7.9.10 Error due to Baud Rate Quantization The baud rate can be adjusted in steps of 1 / (16 * LDIV). The worst case occurs when the "real" baud rate is in the middle of the step. This leads to a quantization error (DQUANT) equal to 1 / (2*16*LDIVMIN). 10.7.9.11 Impact of Clock Deviation on Maximum Baud Rate The choice of the nominal baud rate (LDIVNOM) will influence both the quantization error (DQUANT) and the measurement error (DMEAS). The worst case occurs for LDIVMIN. LIN Slave systems For LIN Slave systems (the LINE and LSLV bits are set), receivers wake up by LIN Synch Break or LIN Identifier detection (depending on the LHDM bit). Hot Plugging Feature for LIN Slave Nodes In LIN Slave Mute Mode (the LINE, LSLV and RWU bits are set) it is possible to hot plug to a network during an ongoing communication flow. In this case the SCI monitors the bus on the RDI line until 11 consecutive dominant bits have been detected and discards all the other bits received.
144/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.10 LIN Mode Register Description framing error is detected (if the stop bit is dominant (0) and at least one of the other bits is recessive STATUS REGISTER (SCISR) (1). It is not set when a break occurs, the LHDF bit Read Only is used instead as a break flag (if the LHDM Reset Value: 1100 0000 (C0h) bit = 0). It is cleared by a software sequence (an access to the SCISR register followed by a read to 7 0 the SCIDR register). 0: No Framing error TDRE TC RDRF IDLE LHE NF FE PE 1: Framing error detected Bits 7:4 = Same function as in SCI mode; please refer to Section 10.7.8 "SCI Mode Register Description". Bit 3 = LHE LIN Header Error. During LIN Header this bit signals three error types: - The LIN Synch Field is corrupted and the SCI is blocked in LIN Synch State (LSF bit = 1). - A timeout occurred during LIN Header reception - An overrun error was detected on one of the header field (see OR bit description in Section 10.7.8 "SCI Mode Register Description"). An interrupt is generated if RIE = 1 in the SCICR2 register. If blocked in the LIN Synch State, the LSF bit must first be reset (to exit LIN Synch Field state and then to be able to clear LHE flag). Then it is cleared by the following software sequence: An access to the SCISR register followed by a read to the SCIDR register. 0: No LIN Header error 1: LIN Header error detected Note: Apart from the LIN Header this bit signals an Overrun Error as in SCI mode (see description in Section 10.7.8 "SCI Mode Register Description"). Bit 2 = NF Noise flag In LIN Master mode (LINE bit = 1 and LSLV bit = 0), this bit has the same function as in SCI mode; please refer to Section 10.7.8 "SCI Mode Register Description". In LIN Slave mode (LINE bit = 1 and LSLV bit = 1) this bit has no meaning. Bit 1 = FE Framing error. In LIN slave mode, this bit is set only when a real Bit 0 = PE Parity error. This bit is set by hardware when a LIN parity error occurs (if the PCE bit is set) in receiver mode. It is cleared by a software sequence (a read to the status register followed by an access to the SCIDR data register). An interrupt is generated if PIE = 1 in the SCICR1 register. 0: No LIN parity error 1: LIN Parity error detected CONTROL REGISTER 1 (SCICR1) Read/Write Reset Value: x000 0000 (x0h)
7
R8 T8 SCID M WAKE PCE PS
0
PIE
Bits 7:3 = Same function as in SCI mode; please refer to Section 10.7.8 "SCI Mode Register Description". Bit 2 = PCE Parity control enable. This bit is set and cleared by software. It selects the hardware parity control for LIN identifier parity check. 0: Parity control disabled 1: Parity control enabled When a parity error occurs, the PE bit in the SCISR register is set. Bit 1 = Reserved Bit 0 = Same function as in SCI mode; please refer to Section 10.7.8 "SCI Mode Register Description".
145/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) CONTROL REGISTER 2 (SCICR2) 1: LDIV is updated at the next received character Read/Write (when RDRF = 1) after a write to the LPR regisReset Value: 0000 0000 (00 h) ter Notes: 7 0 - If no write to LPR is performed between the setting of LDUM bit and the reception of the next TIE TCIE RIE ILIE TE RE RWU SBK character, LDIV will be updated with the old value. - After LDUM has been set, it is possible to reset Bits 7:2 Same function as in SCI mode; please rethe LDUM bit by software. In this case, LDIV can fer to Section 10.7.8 "SCI Mode Register Descripbe modified by writing into LPR / LPFR registers. tion". Bit 1 = RWU Receiver wake-up. This bit determines if the SCI is in mute mode or not. It is set and cleared by software and can be cleared by hardware when a wake-up sequence is recognized. 0: Receiver in active mode 1: Receiver in mute mode Notes: - Mute mode is recommended for detecting only the Header and avoiding the reception of any other characters. For more details, please refer to Section 10.7.9.3 "LIN Reception". - In LIN slave mode, when RDRF is set, the software can not set or clear the RWU bit. Bit 0 = SBK Send break. This bit set is used to send break characters. It is set and cleared by software. 0: No break character is transmitted 1: Break characters are transmitted Note: If the SBK bit is set to "1" and then to "0", the transmitter will send a BREAK word at the end of the current word. CONTROL REGISTER 3 (SCICR3) Read/Write Reset Value: 0000 0000 (00h)
7
LDUM LINE LSLV LASE LHDM LHIE LHDF
Bits 6:5 = LINE, LSLV LIN Mode Enable Bits. These bits configure the LIN mode:
LINE 0 1 LSLV x 0 1 Meaning LIN mode disabled LIN Master Mode LIN Slave Mode
The LIN Master configuration enables: The capability to send LIN Synch Breaks (13 low bits) using the SBK bit in the SCICR2 register. The LIN Slave configuration enables: - The LIN Slave Baud Rate generator. The LIN Divider (LDIV) is then represented by the LPR and LPFR registers. The LPR and LPFR registers are read/write accessible at the address of the SCIBRR register and the address of the SCIETPR register - Management of LIN Headers. - LIN Synch Break detection (11-bit dominant). - LIN Wake-Up method (see LHDM bit) instead of the normal SCI Wake-Up method. - Inhibition of Break transmission capability (SBK has no effect) - LIN Parity Checking (in conjunction with the PCE bit) Bit 4 = LASE LIN Auto Synch Enable. This bit enables the Auto Synch Unit (ASU). It is set and cleared by software. It is only usable in LIN Slave mode. 0: Auto Synch Unit disabled 1: Auto Synch Unit enabled. Bit 3 = LHDM LIN Header Detection Method This bit is set and cleared by software. It is only usable in LIN Slave mode. It enables the Header Detection Method. In addition if the RWU bit in the
0
LSF
Bit 7 = LDUM LIN Divider Update Method. This bit is set and cleared by software and is also cleared by hardware (when RDRF = 1). It is only used in LIN Slave mode. It determines how the LIN Divider can be updated by software. 0: LDIV is updated as soon as LPR is written (if no Auto Synchronization update occurs at the same time).
146/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) SCICR2 register is set, the LHDM bit selects the Figure 87. LSF Bit Set and Clear Wake-Up method (replacing the WAKE bit). 11 dominant bits parity bits 0: LIN Synch Break Detection Method 1: LIN Identifier Field Detection Method Bit 2 = LHIE LIN Header Interrupt Enable This bit is set and cleared by software. It is only usable in LIN Slave mode. 0: LIN Header Interrupt is inhibited. 1: An SCI interrupt is generated whenever LHDF = 1. Bit 1 = LHDF LIN Header Detection Flag This bit is set by hardware when a LIN Header is detected and cleared by a software sequence (an access to the SCISR register followed by a read of the SCICR3 register). It is only usable in LIN Slave mode. 0: No LIN Header detected. 1: LIN Header detected. Notes: The header detection method depends on the LHDM bit: - If LHDM = 0, a header is detected as a LIN Synch Break. - If LHDM = 1, a header is detected as a LIN Identifier, meaning that a LIN Synch Break Field + a LIN Synch Field + a LIN Identifier Field have been consecutively received. Bit 0 = LSF LIN Synch Field State This bit indicates that the LIN Synch Field is being analyzed. It is only used in LIN Slave mode. In Auto Synchronization Mode (LASE bit = 1), when the SCI is in the LIN Synch Field State it waits or counts the falling edges on the RDI line. It is set by hardware as soon as a LIN Synch Break is detected and cleared by hardware when the LIN Synch Field analysis is finished (see Figure 87). This bit can also be cleared by software to exit LIN Synch State and return to idle mode. 0: The current character is not the LIN Synch Field 1: LIN Synch Field State (LIN Synch Field undergoing analysis)
LSF bit LIN Synch Break LIN Synch Field Identifier Field
LIN DIVIDER REGISTERS LDIV is coded using the two registers LPR and LPFR. In LIN Slave mode, the LPR register is accessible at the address of the SCIBRR register and the LPFR register is accessible at the address of the SCIETPR register. LIN PRESCALER REGISTER (LPR) Read/Write Reset Value: 0000 0000 (00h)
7
LPR7 LPR6 LPR5 LPR4 LPR3 LPR2 LPR1
0
LPR0
LPR[7:0] LIN Prescaler (mantissa of LDIV) These 8 bits define the value of the mantissa of the LIN Divider (LDIV):
LPR[7:0] 00h 01h ... FEh FFh Rounded Mantissa (LDIV) SCI clock disabled 1 ... 254 255
Caution: LPR and LPFR registers have different meanings when reading or writing to them. Consequently bit manipulation instructions (BRES or BSET) should never be used to modify the LPR[7:0] bits, or the LPFR[3:0] bits.
147/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) LIN PRESCALER FRACTION REGISTER will effectively update LDIV and so the clock gen(LPFR) eration. Read/Write 2. In LIN Slave mode, if the LPR[7:0] register is Reset Value: 00 00 0000 (00h) equal to 00h, the transceiver and receiver input clocks are switched off. 7 0
0 0 0 0 LPFR 3 LPFR 2 LPFR 1 LPFR 0
Bits 7:4 = Reserved. Bits 3:0 = LPFR[3:0] Fraction of LDIV These 4 bits define the fraction of the LIN Divider (LDIV):
LPFR[3:0] 0h 1h ... Eh Fh Fraction (LDIV) 0 1/16 ... 14/16 15/16
Examples of LDIV coding: Example 1: LPR = 27d and LPFR = 12d This leads to: Mantissa (LDIV) = 27d Fraction (LDIV) = 12/16 = 0.75d Therefore LDIV = 27.75d Example 2: LDIV = 25.62d This leads to: LPFR = rounded(16*0.62d) = rounded(9.92d) = 10d = Ah LPR = mantissa (25.620d) = 25d = 1Bh Example 3: LDIV = 25.99d This leads to: LPFR = rounded(16*0.99d) = rounded(15.84d) = 16d
1. When initializing LDIV, the LPFR register must be written first. Then, the write to the LPR register
148/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) LIN HEADER LENGTH REGISTER (LHLR) LHL[1:0] Read Only 0h Reset Value: 0000 0000 (00 h).
1h 7
LHL7 LHL6 LHL5 LHL4 LHL3 LHL2 LHL1
Fraction (57 - THEADER) 0 1/4 1/2 3/4
0
LHL0
2h 3h
Note: In LIN Slave mode when LASE = 1 or LHDM = 1, the LHLR register is accessible at the address of the SCIERPR register. Otherwise this register is always read as 00h. Bits 7:0 = LHL[7:0] LIN Header Length. This is a read-only register, which is updated by hardware if one of the following conditions occurs: - After each break detection, it is loaded with "FFh". - If a timeout occurs on THEADER, it is loaded with 00h. - After every successful LIN Header reception (at the same time than the setting of LHDF bit), it is loaded with a value (LHL) which gives access to the number of bit times of the LIN header length (THEADER). The coding of this value is explained below: LHL Coding: THEADER_MAX = 57 LHL(7:2) represents the mantissa of (57 - THEADER) LHL(1:0) represents the fraction (57 - THEADER)
LHL[7:2] 0h 1h ... 39h 3Ah 3Bh ... 3Eh 3Fh Mantissa (57 - THEADER) 0 1 ... 56 57 58 ... 62 63 Mantissa (THEADER) 57 56 ... 1 0 Never Occurs ... Never Occurs Initial value
Example of LHL coding: Example 1: LHL = 33h = 001100 11b LHL(7:3) = 1100b = 12d LHL(1:0) = 11b = 3d This leads to: Mantissa (57 - THEADER) = 12d Fraction (57 - THEADER) = 3/4 = 0.75 Therefore: (57 - THEADER) = 12.75d and THEADER = 44.25d Example 2: 57 - THEADER = 36.21d LHL(1:0) = rounded(4*0.21d) = 1d LHL(7:2) = Mantissa (36.21d) = 36d = 24h Therefore LHL(7:0) = 10010001 = 91h Example 3: 57 - THEADER = 36.90d LHL(1:0) = rounded(4*0.90d) = 4d The carry must be propagated to the matissa: LHL(7:2) = Mantissa (36.90d) + 1 = 37d = Therefore LHL(7:0) = 10110000 = A0h
149/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master/Slave) (Cont'd)
Table 24. LINSCI1 Register Map and Reset Values
Addr. (Hex. ) 48 49 Register Name SCI1SR Reset Value SCI1DR Reset Value SCI1BRR LPR (LIN Slave Mode) Reset Value SCI1CR1 Reset Value SCI1CR2 Reset Value SCI1CR3 Reset Value SCI1ERPR LHLR (LIN Slave Mode) Reset Value SCI1ETPR LPFR (LIN Slave Mode) Reset Value 7 TDRE 1 DR7 SCP1 LPR7 0 R8 x TIE 0 LDUM 0 ERPR7 LHL7 0 ETPR7 0 0 6 TC 1 DR6 SCP0 LPR6 0 T8 0 TCIE 0 LINE 0 ERPR6 LHL6 0 ETPR6 0 0 5 RDRF 0 DR5 SCT2 LPR5 0 SCID 0 RIE 0 LSLV 0 ERPR5 LHL5 0 ETPR5 0 0 4 IDLE 0 DR4 SCT1 LPR4 0 M 0 ILIE 0 LASE 0 ERPR4 LHL4 0 ETPR4 0 0 3 OR/LHE 0 DR3 SCT0 LPR3 0 WAKE 0 TE 0 LHDM 0 ERPR3 LHL3 0 ETPR3 LPFR3 0 2 NF 0 DR2 SCR2 LPR2 0 PCE 0 RE 0 LHIE 0 ERPR2 LHL2 0 ETPR2 LPFR2 0 1 FE 0 DR1 SCR1 LPR1 0 PS 0 RWU 0 LHDF 0 ERPR1 LHL1 0 ETPR1 LPFR1 0 0 PE 0 DR0 SCR0 LPR0 0 PIE 0 SBK 0 LSF 0 ERPR0 LHL0 0 ETPR0 LPFR0 0
4A
4B 4C 4D
4E
4F
150/224
ST72361
10.8 LINSCI SERIAL COMMUNICATION INTERFACE (LIN Master Only) 10.8.1 Introduction The Serial Communications Interface (SCI) offers a flexible means of full-duplex data exchange with external equipment requiring an industry standard NRZ asynchronous serial data format. The SCI offers a very wide range of baud rates using two baud rate generator systems. 10.8.2 Main Features Full duplex, asynchronous communications NRZ standard format (Mark/Space) Dual baud rate generator systems Independently programmable transmit and receive baud rates up to 500K baud. Programmable data word length (8 or 9 bits) Receive buffer full, Transmit buffer empty and End of Transmission flags 2 receiver wake-up modes: - Address bit (MSB) - Idle line Muting function for multiprocessor configurations Separate enable bits for Transmitter and Receiver 4 error detection flags: - Overrun error - Noise error - Frame error - Parity error 5 interrupt sources with flags: - Transmit data register empty - Transmission complete - Receive data register full - Idle line received - Overrun error detected Transmitter clock output Parity control: - Transmits parity bit - Checks parity of received data byte Reduced power consumption mode LIN Synch Break send capability 10.8.3 General Description The interface is externally connected to another device by three pins (see Figure 88 on page 153). Any SCI bidirectional communication requires a minimum of two pins: Receive Data In (RDI) and Transmit Data Out (TDO): - SCLK: Transmitter clock output. This pin outputs the transmitter data clock for synchronous transmission (no clock pulses on start bit and stop bit, and a software option to send a clock pulse on the last data bit). This can be used to control peripherals that have shift registers (e.g. LCD drivers). The clock phase and polarity are software programmable. - TDO: Transmit Data Output. When the transmitter is disabled, the output pin returns to its I/O port configuration. When the transmitter is enabled and nothing is to be transmitted, the TDO pin is at high level. - RDI: Receive Data Input is the serial data input. Oversampling techniques are used for data recovery by discriminating between valid incoming data and noise. Through these pins, serial data is transmitted and received as frames comprising: - An Idle Line prior to transmission or reception - A start bit - A data word (8 or 9 bits) least significant bit first - A Stop bit indicating that the frame is complete. This interface uses two types of baud rate generator: - A conventional type for commonly-used baud rates, - An extended type with a prescaler offering a very wide range of baud rates even with non-standard oscillator frequencies.
151/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) Figure 88. SCI Block Diagram
Write Read
(DATA REGISTER) SCIDR
Transmit Data Register (TDR) TDO Transmit Shift Register RDI
LINE
Received Data Register (RDR)
Received Shift Register
-
-
CLKEN CPOL CPHA LBCL
SCICR3
CLOCK EXTRACTION
SCLK
PHASE AND POLARITY CONTROL
R8 T8 SCID
M
WAKE PCE
PS
PIE
SCICR1
TRANSMIT CONTROL
WAKE UP UNIT
RECEIVER CONTROL
RECEIVER CLOCK
SCICR2
TIE TCIE RIE ILIE TE RE RWU SBK TDRE TC RDRF IDLE OR NF FE
SCISR
PE
SCI INTERRUPT CONTROL TRANSMITTER CLOCK TRANSMITTER RATE
fCPU
CONTROL
/16
/PR SCIBRR
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1SCR0
RECEIVER RATE CONTROL CONVENTIONAL BAUD RATE GENERATOR
152/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.4 Functional Description 10.8.4.1 Serial Data Format The block diagram of the Serial Control Interface, Word length may be selected as being either 8 or 9 is shown in Figure 88 on page 153. It contains sevbits by programming the M bit in the SCICR1 regen dedicated registers: ister (see Figure 89). - Three control registers (SCICR1, SCICR2 and The TDO pin is in low state during the start bit. SCICR3) The TDO pin is in high state during the stop bit. - A status register (SCISR) An Idle character is interpreted as an entire frame - A baud rate register (SCIBRR) of "1"s followed by the start bit of the next frame which contains data. - An extended prescaler receiver register (SCIERPR) A Break character is interpreted on receiving "0"s for some multiple of the frame period. At the end of - An extended prescaler transmitter register (SCIthe last break frame the transmitter inserts an exETPR) tra "1" bit to acknowledge the start bit. Refer to the register descriptions in Section Transmission and reception are driven by their 10.7.8for the definitions of each bit. own baud rate generator. Figure 89. Word Length Programming 9-bit Word length (M bit is set) Data Frame
Start Bit CLOCK Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Possible Parity Bit Bit8 ** Start Bit Extra '1' Start Bit
Next Data Frame
Next Stop Start Bit Bit
Idle Frame Break Frame
** LBCL bit controls last data clock pulse
8-bit Word length (M bit is reset)
Data Frame
Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Possible Parity Bit Bit7 Stop Bit
Next Data Frame
Next Start Bit
CLOCK
**** **
Idle Frame Break Frame
Start Bit Extra Start Bit '1' ** LBCL bit controls last data clock pulse
153/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.4.2 Transmitter When a frame transmission is complete (after the stop bit or after the break frame) the TC bit is set The transmitter can send data words of either 8 or and an interrupt is generated if the TCIE is set and 9 bits depending on the M bit status. When the M the I bit is cleared in the CCR register. bit is set, word length is 9 bits and the 9th bit (the Clearing the TC bit is performed by the following MSB) has to be stored in the T8 bit in the SCICR1 software sequence: register. 1. An access to the SCISR register When the transmit enable bit (TE) is set, the data 2. A write to the SCIDR register in the transmit shift register is output on the TDO Note: The TDRE and TC bits are cleared by the pin and the corresponding clock pulses are output same software sequence. on the SCLK pin. Character Transmission Break Characters During an SCI transmission, data shifts out least Setting the SBK bit loads the shift register with a significant bit first on the TDO pin. In this mode, break character. The break frame length depends the SCIDR register consists of a buffer (TDR) beon the M bit (see Figure 89). tween the internal bus and the transmit shift regisAs long as the SBK bit is set, the SCI send break ter (see Figure 89). frames to the TDO pin. After clearing this bit by Procedure software the SCI insert a logic 1 bit at the end of the last break frame to guarantee the recognition - Select the M bit to define the word length. of the start bit of the next frame. - Select the desired baud rate using the SCIBRR Idle Characters and the SCIETPR registers. Setting the TE bit drives the SCI to send an idle - Set the TE bit to send an idle frame as first transframe before the first data frame. mission. Clearing and then setting the TE bit during a trans- Access the SCISR register and write the data to mission sends an idle frame after the current word. send in the SCIDR register (this sequence clears Note: Resetting and setting the TE bit causes the the TDRE bit). Repeat this sequence for each data in the TDR register to be lost. Therefore the data to be transmitted. best time to toggle the TE bit is when the TDRE bit Clearing the TDRE bit is always performed by the is set, that is, before writing the next byte in the following software sequence: SCIDR. 1. An access to the SCISR register 2. A write to the SCIDR register LIN Transmission The TDRE bit is set by hardware and it indicates: The same procedure has to be applied for LIN Master transmission with the following differences: - The TDR register is empty. - Clear the M bit to configure 8-bit word length. - The data transfer is beginning. - Set the LINE bit to enter LIN master mode. In this - The next data can be written in the SCIDR regiscase, setting the SBK bit sends 13 low bits. ter without overwriting the previous data. This flag generates an interrupt if the TIE bit is set and the I bit is cleared in the CCR register. When a transmission is taking place, a write instruction to the SCIDR register stores the data in the TDR register and which is copied in the shift register at the end of the current transmission. When no transmission is taking place, a write instruction to the SCIDR register places the data directly in the shift register, the data transmission starts, and the TDRE bit is immediately set.
154/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.4.3 Receiver Overrun Error The SCI can receive data words of either 8 or 9 An overrun error occurs when a character is received when RDRF has not been reset. Data canbits. When the M bit is set, word length is 9 bits not be transferred from the shift register to the and the MSB is stored in the R8 bit in the SCICR1 RDR register until the RDRF bit is cleared. register. Character reception When a overrun error occurs: During a SCI reception, data shifts in least signifi- The OR bit is set. cant bit first through the RDI pin. In this mode, the - The RDR content is not lost. SCIDR register consists or a buffer (RDR) be- The shift register is overwritten. tween the internal bus and the received shift register (see Figure 88 on page 153). - An interrupt is generated if the RIE bit is set and the I bit is cleared in the CCR register. Procedure The OR bit is reset by an access to the SCISR reg- Select the M bit to define the word length. ister followed by a SCIDR register read operation. - Select the desired baud rate using the SCIBRR Noise Error and the SCIERPR registers. Oversampling techniques are used for data recov- Set the RE bit, this enables the receiver which ery by discriminating between valid incoming data begins searching for a start bit. and noise. When a character is received: When noise is detected in a frame: - The RDRF bit is set. It indicates that the content - The NF is set at the rising edge of the RDRF bit. of the shift register is transferred to the RDR. - Data is transferred from the Shift register to the - An interrupt is generated if the RIE bit is set and SCIDR register. the I bit is cleared in the CCR register. - No interrupt is generated. However this bit rises - The error flags can be set if a frame error, noise at the same time as the RDRF bit which itself or an overrun error has been detected during regenerates an interrupt. ception. The NF bit is reset by a SCISR register read operClearing the RDRF bit is performed by the following ation followed by a SCIDR register read operation. software sequence done by: Framing Error 1. An access to the SCISR register A framing error is detected when: 2. A read to the SCIDR register. - The stop bit is not recognized on reception at the The RDRF bit must be cleared before the end of the expected time, following either a de-synchronireception of the next character to avoid an overrun zation or excessive noise. error. - A break is received. Break Character When the framing error is detected: When a break character is received, the SCI handles it as a framing error. - the FE bit is set by hardware Idle Character - Data is transferred from the Shift register to the SCIDR register. When an idle frame is detected, there is the same procedure as a data received character plus an in- No interrupt is generated. However this bit rises terrupt if the ILIE bit is set and the I bit is cleared in at the same time as the RDRF bit which itself the CCR register. generates an interrupt. The FE bit is reset by a SCISR register read operation followed by a SCIDR register read operation.
155/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) Figure 90. SCI Baud Rate and Extended Prescaler Block Diagram
TRANSMITTER CLOCK EXTENDED PRESCALER TRANSMITTER RATE CONTROL
SCIETPR
EXTENDED TRANSMITTER PRESCALER REGISTER
SCIERPR
EXTENDED RECEIVER PRESCALER REGISTER RECEIVER CLOCK EXTENDED PRESCALER RECEIVER RATE CONTROL EXTENDED PRESCALER
fCPU
TRANSMITTER RATE CONTROL
/16
/PR SCIBRR
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1SCR0
RECEIVER RATE CONTROL CONVENTIONAL BAUD RATE GENERATOR
156/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) other than zero. The baud rates are calculated as 10.8.4.4 Conventional Baud Rate Generation follows: The baud rates for the receiver and transmitter (Rx and Tx) are set independently and calculated as fCPU fCPU follows Rx = Tx = : 16*ERPR*(PR*RR) 16 ETPR*(PR*TR)
*
Tx =
fCPU (16*PR)*TR
Rx =
fCPU (16*PR)*RR with: ETPR = 1, ..., 255 (see SCIETPR register) ERPR = 1, ..., 255 (see SCIERPR register) 10.8.4.6 Receiver Muting and Wake-up Feature In multiprocessor configurations it is often desirable that only the intended message recipient should actively receive the full message contents, thus reducing redundant SCI service overhead for all non addressed receivers. The non addressed devices may be placed in sleep mode by means of the muting function. Setting the RWU bit by software puts the SCI in sleep mode: All the reception status bits cannot be set. All the receive interrupts are inhibited. A muted receiver may be awakened by one of the following two ways: - by Idle Line detection if the WAKE bit is reset, - by Address Mark detection if the WAKE bit is set. Receiver wakes-up by Idle Line detection when the Receive line has recognized an Idle Frame. Then the RWU bit is reset by hardware but the IDLE bit is not set. Receiver wakes-up by Address Mark detection when it received a "1" as the most significant bit of a word, thus indicating that the message is an address. The reception of this particular word wakes up the receiver, resets the RWU bit and sets the RDRF bit, which allows the receiver to receive this word normally and to use it as an address word.
with: PR = 1, 3, 4 or 13 (see SCP[1:0] bits) TR = 1, 2, 4, 8, 16, 32, 64, 128 (see SCT[2:0] bits) RR = 1, 2, 4, 8, 16, 32, 64, 128 (see SCR[2:0] bits) All these bits are in the SCIBRR register. Example: If fCPU is 8 MHz (normal mode) and if PR = 13 and TR = RR = 1, the transmit and receive baud rates are 38400 baud. Note: The baud rate registers MUST NOT be changed while the transmitter or the receiver is enabled. 10.8.4.5 Extended Baud Rate Generation The extended prescaler option gives a very fine tuning on the baud rate, using a 255 value prescaler, whereas the conventional Baud Rate Generator retains industry standard software compatibility. The extended baud rate generator block diagram is described in the Figure 90. The output clock rate sent to the transmitter or to the receiver is the output from the 16 divider divided by a factor ranging from 1 to 255 set in the SCIERPR or the SCIETPR register. Note: The extended prescaler is activated by setting the SCIETPR or SCIERPR register to a value
157/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) even number of "1s" if even parity is selected 10.8.4.7 Parity control (PS = 0) or an odd number of "1s" if odd parity is Parity control (generation of parity bit in transmisselected (PS = 1). If the parity check fails, the PE sion and parity checking in reception) can be enaflag is set in the SCISR register and an interrupt is bled by setting the PCE bit in the SCICR1 register. generated if PIE is set in the SCICR1 register. Depending on the frame length defined by the M bit, the possible SCI frame formats are as listed in Table 24. 10.8.5 Low Power Modes Table 25. Frame Formats
M bit 0 1 PCE bit 0 1 0 1 SCI frame | SB | 8 bit data | STB | | SB | 7-bit data | PB | STB | | SB | 9-bit data | STB | | SB | 8-bit data PB | STB | Mode WAIT Description No effect on SCI. SCI interrupts cause the device to exit from Wait mode. SCI registers are frozen. In Halt mode, the SCI stops transmitting/receiving until Halt mode is exited.
HALT
Legend: SB: Start Bit STB: Stop Bit PB: Parity Bit Note: In case of wake up by an address mark, the MSB bit of the data is taken into account and not the parity bit Even parity: The parity bit is calculated to obtain an even number of "1s" inside the frame made of the 7 or 8 LSB bits (depending on whether M is equal to 0 or 1) and the parity bit. Example: data = 00110101; 4 bits set => parity bit is 0 if even parity is selected (PS bit = 0). Odd parity: The parity bit is calculated to obtain an odd number of "1s" inside the frame made of the 7 or 8 LSB bits (depending on whether M is equal to 0 or 1) and the parity bit. Example: data = 00110101; 4 bits set => parity bit is 1 if odd parity is selected (PS bit = 1). Transmission mode: If the PCE bit is set then the MSB bit of the data written in the data register is not transmitted but is changed by the parity bit. Reception mode: If the PCE bit is set then the interface checks if the received data byte has an
10.8.6 Interrupts
Interrupt Event Enable Exit Event Control from Flag Bit Wait TIE TCIE Yes RIE ILIE PIE No Exit from Halt
Transmit Data Register TDRE Empty Transmission ComTC plete Received Data Ready RDRF to be Read Overrun Error DetectOR ed Idle Line Detected IDLE Parity Error PE
The SCI interrupt events are connected to the same interrupt vector. These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction).
158/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.7 SCI Synchronous Transmission These options allow the user to serially control peripherals which consist of shift registers, without The SCI transmitter allows the user to control a losing any functions of the SCI transmitter which one way synchronous serial transmission. The can still talk to other SCI receivers. These options SCLK pin is the output of the SCI transmitter clock. do not affect the SCI receiver which is independNo clock pulses are sent to the SCLK pin during ent from the transmitter. start bit and stop bit. Depending on the state of the Note: The SCLK pin works in conjunction with the LBCL bit in the SCICR3 register, clock pulses are TDO pin. When the SCI transmitter is disabled (TE or are not be generated during the last valid data and RE = 0), the SCLK and TDO pins go into high bit (address mark). The CPOL bit in the SCICR3 impedance state. register allows the user to select the clock polarity, and the CPHA bit in the SCICR3 register allows Note: The LBCL, CPOL and CPHA bits have to be the user to select the phase of the external clock selected before enabling the transmitter to ensure (see Figure 91, Figure 92 and Figure 93). that the clock pulses function correctly. These bits During idle, preamble and send break, the external should not be changed while the transmitter is enabled. SCLK clock is not activated. Figure 91. SCI Example of Synchronous and Asynchronous Transmission
RDI TDO SCI SCLK Output port
Data out Data in
Asynchronous (e.g. modem)
Data in Clock Enable
Synchronous (e.g. shift register)
159/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) Figure 92. SCI Data Clock Timing Diagram (M = 0)
Idle or preceding Start transmission Clock (CPOL=0, CPHA=0) Clock (CPOL=0, CPHA=1)
Idle or next
M = 0 (8 data bits)
Stop
transmission
* *
Clock (CPOL=1, CPHA=0)
* *
0 1 2 3 4 5 6 7
Clock (CPOL=1, CPHA=1)
Data Start
LSB
MSB Stop * LBCL bit controls last data clock pulse
Figure 93. SCI Data Clock Timing Diagram (M = 1)
Idle or preceding Start transmission Clock (CPOL=0, CPHA=0) Clock (CPOL=0, CPHA=1) M = 1 (9 data bits) Stop Idle or next transmission
* *
Clock (CPOL=1, CPHA=0)
* *
0 1 2 3 4 5 6 7 8
Clock (CPOL=1, CPHA=1)
Data Start
LSB
MSB Stop * LBCL bit controls last data clock pulse
160/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.8 Register Description Note: The IDLE bit is not be set again until the RDRF bit has been set itself (that is, a new idle line STATUS REGISTER (SCISR) occurs). Read Only Reset Value: 1100 0000 (C0h) Bit 3 = OR Overrun error. 7 0 This bit is set by hardware when the word currently being received in the shift register is ready to be TDRE TC RDRF IDLE OR NF FE PE transferred into the RDR register while RDRF = 1. An interrupt is generated if RIE = 1 in the SCICR2 register. It is cleared by a software sequence (an Bit 7 = TDRE Transmit data register empty. access to the SCISR register followed by a read to This bit is set by hardware when the content of the the SCIDR register). TDR register has been transferred into the shift 0: No Overrun error register. An interrupt is generated if the TIE bit = 1 1: Overrun error is detected in the SCICR2 register. It is cleared by a software sequence (an access to the SCISR register folNote: When this bit is set, the RDR register conlowed by a write to the SCIDR register). tent is not lost but the shift register is overwritten. 0: Data is not transferred to the shift register 1: Data is transferred to the shift register Bit 2 = NF Noise flag. Note: Data is not be transferred to the shift register This bit is set by hardware when noise is detected until the TDRE bit is cleared. on a received frame. It is cleared by a software sequence (an access to the SCISR register followed by a read to the SCIDR register). Bit 6 = TC Transmission complete. 0: No noise is detected This bit is set by hardware when transmission of a 1: Noise is detected frame containing Data is complete. An interrupt is generated if TCIE = 1 in the SCICR2 register. It is Note: This bit does not generate interrupt as it apcleared by a software sequence (an access to the pears at the same time as the RDRF bit which itSCISR register followed by a write to the SCIDR self generates an interrupt. register). 0: Transmission is not complete 1: Transmission is complete Bit 1 = FE Framing error. This bit is set by hardware when a de-synchronizaNote: TC is not set after the transmission of a Pretion, excessive noise or a break character is deamble or a Break. tected. It is cleared by a software sequence (an access to the SCISR register followed by a read to Bit 5 = RDRF Received data ready flag. the SCIDR register). This bit is set by hardware when the content of the 0: No Framing error is detected RDR register has been transferred to the SCIDR 1: Framing error or break character is detected register. An interrupt is generated if RIE = 1 in the Note: This bit does not generate an interrupt as it SCICR2 register. It is cleared by a software seappears at the same time as the RDRF bit which itquence (an access to the SCISR register followed self generates an interrupt. If the word currently by a read to the SCIDR register). being transferred causes both frame error and 0: Data is not received overrun error, it is transferred and only the OR bit 1: Received data is ready to be read is set. Bit 4 = IDLE Idle line detect. This bit is set by hardware when an Idle Line is detected. An interrupt is generated if the ILIE = 1 in the SCICR2 register. It is cleared by a software sequence (an access to the SCISR register followed by a read to the SCIDR register). 0: No Idle Line is detected 1: Idle Line is detected Bit 0 = PE Parity error. This bit is set by hardware when a parity error occurs in receiver mode. It is cleared by a software sequence (a read to the status register followed by an access to the SCIDR data register). An interrupt is generated if PIE = 1 in the SCICR1 register. 0: No parity error 1: Parity error
161/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) CONTROL REGISTER 1 (SCICR1) Read/Write Bit 3 = WAKE Wake-Up method. This bit determines the SCI Wake-Up method, it is Reset Value: x000 0000 (x0h) set or cleared by software. 0: Idle Line 7 0 1: Address Mark
R8 T8 SCID M WAKE PCE PS
PIE
Bit 7 = R8 Receive data bit 8. This bit is used to store the 9th bit of the received word when M = 1. Bit 6 = T8 Transmit data bit 8. This bit is used to store the 9th bit of the transmitted word when M = 1. Bit 5 = SCID Disabled for low power consumption When this bit is set the SCI prescalers and outputs are stopped and the end of the current byte transfer in order to reduce power consumption.This bit is set and cleared by software. 0: SCI enabled 1: SCI prescaler and outputs disabled Bit 4 = M Word length. This bit determines the word length. It is set or cleared by software. 0: 1 Start bit, 8 Data bits, 1 Stop bit 1: 1 Start bit, 9 Data bits, 1 Stop bit Note: The M bit must not be modified during a data transfer (both transmission and reception).
Bit 2 = PCE Parity control enable. This bit selects the hardware parity control (generation and detection). When the parity control is enabled, the computed parity is inserted at the MSB position (9th bit if M = 1; 8th bit if M = 0) and parity is checked on the received data. This bit is set and cleared by software. Once it is set, PCE is active after the current byte (in reception and in transmission). 0: Parity control disabled 1: Parity control enabled Bit 1 = PS Parity selection. This bit selects the odd or even parity when the parity generation/detection is enabled (PCE bit set). It is set and cleared by software. The parity is selected after the current byte. 0: Even parity 1: Odd parity Bit 0 = PIE Parity interrupt enable. This bit enables the interrupt capability of the hardware parity control when a parity error is detected (PE bit set). It is set and cleared by software. 0: Parity error interrupt disabled 1: Parity error interrupt enabled
162/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) CONTROL REGISTER 2 (SCICR2) Read/Write Bit 2 = RE Receiver enable. This bit enables the receiver. It is set and cleared Reset Value: 0000 0000 (00 h) by software. 0: Receiver is disabled 7 0 1: Receiver is enabled and begins searching for a start bit TIE TCIE RIE ILIE TE RE RWU SBK Bit 7 = TIE Transmitter interrupt enable. This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever TDRE = 1 in the SCISR register Bit 6 = TCIE Transmission complete interrupt enable This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever TC = 1 in the SCISR register Bit 5 = RIE Receiver interrupt enable. This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever OR = 1 or RDRF = 1 in the SCISR register Bit 4 = ILIE Idle line interrupt enable. This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever IDLE = 1 in the SCISR register. Bit 3 = TE Transmitter enable. This bit enables the transmitter. It is set and cleared by software. 0: Transmitter is disabled 1: Transmitter is enabled Notes: - During transmission, a "0" pulse on the TE bit ("0" followed by "1") sends a preamble (idle line) after the current word. - When TE is set there is a 1 bit-time delay before the transmission starts. Bit 1 = RWU Receiver wake-up. This bit determines if the SCI is in mute mode or not. It is set and cleared by software and can be cleared by hardware when a wake-up sequence is recognized. 0: Receiver in active mode 1: Receiver in mute mode Notes: - Before selecting Mute mode (by setting the RWU bit) the SCI must first receive a data byte, otherwise it cannot function in Mute mode with wakeup by Idle line detection. - In Address Mark Detection Wake-Up configuration (WAKE bit = 1) the RWU bit cannot be modified by software while the RDRF bit is set. Bit 0 = SBK Send break. This bit set is used to send break characters. It is set and cleared by software. 0: No break character is transmitted 1: Break characters are transmitted Note: If the SBK bit is set to "1" and then to "0", the transmitter sends a BREAK word at the end of the current word.
163/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) CONTROL REGISTER 3 (SCICR3) 0: Steady low value on SCLK pin outside transmission window. Read/Write 1: Steady high value on SCLK pin outside transReset Value: 0000 0000 (00h) mission window.
7
LINE -
0
CLKEN CPOL CPHA LBCL
Bit 7 = Reserved, must be kept cleared. Bit 6 = LINE LIN Mode Enable. This bit is set and cleared by software. 0: LIN Mode disabled 1: LIN Master mode enabled The LIN Master mode enables the capability to send LIN Synch Breaks (13 low bits) using the SBK bit in the SCICR2 register .In transmission, the LIN Synch Break low phase duration is shown as below:
LINE 0 1 M 0 1 0 1 Number of low bits sent during a LIN Synch Break 10 11 13 14
Bit 1 = CPHA Clock Phase. This bit allows the user to select the phase of the clock output on the SCLK pin. It works in conjunction with the CPOL bit to produce the desired clock/data relationship (see Figure 92 and Figure 93) 0: SCLK clock line activated in middle of data bit. 1: SCLK clock line activated at beginning of data bit. Bit 0 = LBCL Last bit clock pulse. This bit allows the user to select whether the clock pulse associated with the last data bit transmitted (MSB) has to be output on the SCLK pin. 0: The clock pulse of the last data bit is not output to the SCLK pin. 1: The clock pulse of the last data bit is output to the SCLK pin. Note: The last bit is the 8th or 9th data bit transmitted depending on the 8 or 9 bit format selected by the M bit in the SCICR1 register. Table 26. SCI clock on SCLK pin
Bits 5:4 = Reserved, forced by hardware to 0. These bits are not used. Bit 3 = CLKEN Clock Enable. This bit allows the user to enable the SCLK pin. 0: SLK pin disabled 1: SLK pin enabled Bit 2 = CPOL Clock Polarity. This bit allows the user to select the polarity of the clock output on the SCLK pin. It works in conjunction with the CPHA bit to produce the desired clock/data relationship (see Figure 92 and Figure 93).
Data format 8 bit 9 bit
M bit 0 1
LBCL bit 0 1 0 1
Number of clock pulses on SCLK 7 8 8 9
Note: These 3 bits (CPOL, CPHA, LBCL) should not be written while the transmitter is enabled.
164/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) DATA REGISTER (SCIDR) Bits 5:3 = SCT[2:0] SCI Transmitter rate divisor These 3 bits, in conjunction with the SCP1 and Read/Write SCP0 bits define the total division applied to the Reset Value: Undefined bus clock to yield the transmit rate clock in conventional Baud Rate Generator mode. Contains the Received or Transmitted data character, depending on whether it is read from or writTR dividing factor SCT2 SCT1 SCT0 ten to.
1 7
DR7 DR6 DR5 DR4 DR3 DR2 DR1
0
DR0
2 4 8 16 32 64 128
0 0 1 0 1 1
0 1 0 1 0 1 0 1
The Data register performs a double function (read and write) since it is composed of two registers, one for transmission (TDR) and one for reception (RDR). The TDR register provides the parallel interface between the internal bus and the output shift register (see Figure 88 on page 153). The RDR register provides the parallel interface between the input shift register and the internal bus (see Figure 88). BAUD RATE REGISTER (SCIBRR) Read/Write Reset Value: 00 00 0000 (00h)
7
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2
Note: This TR factor is used only when the ETPR fine tuning factor is equal to 00h; otherwise, TR is replaced by the (TR*ETPR) dividing factor. Bits 2:0 = SCR[2:0] SCI Receiver rate divisor. These 3 bits, in conjunction with the SCP1 and SCP0 bits define the total division applied to the bus clock to yield the receive rate clock in conventional Baud Rate Generator mode.
0
SCR1 SCR0
RR dividing factor 1 2 4 8 16 32 64 128
SCR2
SCR1 0
SCR0 0 1 0 1 0 1 0 1
0 1 0 1 1
Bits 7:6 = SCP[1:0] First SCI Prescaler These 2 prescaling bits allow several standard clock division ranges:
PR Prescaling factor 1 3 4 13 SCP1 0 1 SCP0 0 1 0 1
Note: This RR factor is used only when the ERPR fine tuning factor is equal to 00h; otherwise, RR is replaced by the (RR*ERPR) dividing factor.
165/224
ST72361
LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) EXTENDED RECEIVE PRESCALER DIVISION EXTENDED TRANSMIT PRESCALER DIVISION REGISTER (SCIERPR) REGISTER (SCIETPR) Read/Write Read/Write Reset Value: 0000 0000 (00 h) Reset Value:0000 0000 (00 h)
7 0 7
ETPR 7 ETPR 6 ETPR 5 ETPR 4 ETPR 3 ETPR 2
0
ETPR ETPR 1 0
ERPR ERPR ERPR ERPR ERPR ERPR ERPR ERPR 7 6 5 4 3 2 1 0
Bits 7:0 = ERPR[7:0] 8-bit Extended Receive Prescaler Register. The extended Baud Rate Generator is activated when a value other than 00h is stored in this register. The clock frequency from the 16 divider (see Figure 90) is divided by the binary factor set in the SCIERPR register (in the range 1 to 255). The extended baud rate generator is not active after a reset. Table 27. Baud Rate Selection
Bits 7:0 = ETPR[7:0] 8-bit Extended Transmit Prescaler Register. The extended Baud Rate Generator is activated when a value other than 00h is stored in this register. The clock frequency from the 16 divider (see Figure 90) is divided by the binary factor set in the SCIETPR register (in the range 1 to 255). The extended baud rate generator is not active after a reset.
Conditions Symbol Parameter fCPU Accuracy vs. Standard Prescaler Conventional Mode TR (or RR) = 128, PR = 13 TR (or RR) = 32, PR = 13 TR (or RR) = 16, PR =13 TR (or RR) = 8, PR = 13 TR (or RR) = 4, PR = 13 TR (or RR) = 16, PR = 3 TR (or RR) = 2, PR = 13 TR (or RR) = 1, PR =13 Extended Mode ETPR (or ERPR) = 35, TR (or RR) = 1, PR = 1 Standard
Baud Rate
Unit
~0.16% fTx fRx Communication frequency 8 MHz
300 ~300.48 1200 ~1201.92 2400 ~2403.84 4800 ~4807.69 9600 ~9615.38 10400 ~10416.67 19200 ~19230.77 38400 ~38461.54 14400 ~14285.71
Hz
~0.79%
166/224
ST72361
LINSCITM SERIAL COMMUNICATIONS INTERFACE (LIN Master) (Cont'd)
Table 28. LINSCI2 Register Map and Reset Values
Address (Hex.) 60 61 62 63 64 65 66 67 Register Name SCI2SR Reset Value SCI2DR Reset Value SCI2BRR Reset Value SCI2CR1 Reset Value SCI2CR2 Reset Value SCI2CR3 Reset Value SCI2ERPR Reset Value SCI2ETPR Reset Value 7 TDRE 1 DR7 SCP1 0 R8 TIE 0 0 ERPR7 0 ETPR7 0 6 TC 1 DR6 SCP0 0 T8 TCIE 0 LINE 0 ERPR6 0 ETPR6 0 5 RDRF 0 DR5 SCT2 0 SCID RIE 0 0 ERPR5 0 ETPR5 0 4 IDLE 0 DR4 SCT1 0 M ILIE 0 0 ERPR4 0 ETPR4 0 3 OR 0 DR3 SCT0 0 WAKE TE 0 CLKEN 0 ERPR3 0 ETPR3 0 2 NF 0 DR2 SCR2 0 PCE RE 0 CPOL 0 ERPR2 0 ETPR2 0 1 FE 0 DR1 SCR1 0 PS RWU 0 CPHA 0 ERPR1 0 ETPR1 0 0 PE 0 DR0 SCR0 0 PIE SBK 0 LBCL 0 ERPR0 0 ETPR0 0
167/224
ST72361
10.9 10-BIT A/D CONVERTER (ADC) 10.9.1 Introduction The on-chip Analog to Digital Converter (ADC) peripheral is a 10-bit, successive approximation converter with internal sample and hold circuitry. This peripheral has up to 16 multiplexed analog input channels (refer to device pin out description) that allow the peripheral to convert the analog voltage levels from up to 16 different sources. The result of the conversion is stored in a 10-bit Data Register. The A/D converter is controlled through a Control/Status Register. 10.9.2 Main Features 10-bit conversion Up to 16 channels with multiplexed input Linear successive approximation Data register (DR) which contains the results Conversion complete status flag On/off bit (to reduce consumption) The block diagram is shown in Figure 94. Figure 94. ADC Block Diagram fCPU fCPU, fCPU/2, fCPU/4 fADC 10.9.3 Functional Description 10.9.3.1 Digital A/D Conversion Result The conversion is monotonic, meaning that the result never decreases if the analog input does not and never increases if the analog input does not. If the input voltage (VAIN) is greater than VDDA (high-level voltage reference) then the conversion result is FFh in the ADCDRH register and 03h in the ADCDRL register (without overflow indication). If the input voltage (VAIN) is lower than VSSA (lowlevel voltage reference) then the conversion result in the ADCDRH and ADCDRL registers is 00 00h. The A/D converter is linear and the digital result of the conversion is stored in the ADCDRH and ADCDRL registers. The accuracy of the conversion is described in the Electrical Characteristics Section. RAIN is the maximum recommended impedance for an analog input signal. If the impedance is too high, this will result in a loss of accuracy due to leakage and sampling not being completed in the allotted time.
EOC SPEED ADON SLOW CH3
CH2
CH1
CH0
ADCCSR
4
AIN0
AIN1
ANALOG MUX
AINx
ANALOG TO DIGITAL CONVERTER
ADCDRH
D9
D8
D7
D6
D5
D4
D3
D2
ADCDRL
0
0
0
0
0
0
D1
D0
168/224
ST72361
10-BIT A/D CONVERTER (ADC) (Cont'd) 10.9.3.2 A/D Conversion The analog input ports must be configured as input, no pull-up, no interrupt. Refer to the "I/O ports" chapter. Using these pins as analog inputs does not affect the ability of the port to be read as a logic input. In the ADCCSR register: - Select the CS[3:0] bits to assign the analog channel to convert. ADC Conversion mode In the ADCCSR register: - Set the ADON bit to enable the A/D converter and to start the conversion. From this time on, the ADC performs a continuous conversion of the selected channel. When a conversion is complete: - The EOC bit is set by hardware. - The result is in the ADCDR registers. A read to the ADCDRH resets the EOC bit. To read the 10 bits, perform the following steps: 1. Poll EOC bit 2. Read the ADCDRL register 3. Read the ADCDRH register. This clears EOC automatically. To read only 8 bits, perform the following steps: 1. Poll EOC bit 2. Read the ADCDRH register. This clears EOC automatically. 10.9.3.3 Changing the conversion channel The application can change channels during conversion. When software modifies the CH[3:0] bits in the ADCCSR register, the current conversion is stopped, the EOC bit is cleared, and the A/D converter starts converting the newly selected channel. 10.9.3.4 ADCDR consistency If an End Of Conversion event occurs after software has read the ADCDRLSB but before it has read the ADCDRMSB, there would be a risk that the two values read would belong to different samples. To guarantee consistency: - The ADCDRL and the ADCDRH registers are locked when the ADCCRL is read - The ADCDRL and the ADCDRH registers are unlocked when the ADCDRH register is read or when ADON is reset. This is important, as the ADCDR register will not be updated until the ADCDRH register is read. 10.9.4 Low Power Modes Note: The A/D converter may be disabled by resetting the ADON bit. This feature allows reduced power consumption when no conversion is needed and between single shot conversions. Mode WAIT Description No effect on A/D Converter A/D Converter disabled. After wakeup from Halt mode, the A/D Converter requires a stabilization time tSTAB (see Electrical Characteristics) before accurate conversions can be performed.
HALT
10.9.5 Interrupts None.
169/224
ST72361
10-BIT A/D CONVERTER (ADC) (Cont'd) 10.9.6 Register Description CONTROL/STATUS REGISTER (ADCCSR) Read / Write (Except bit 7 read only) Reset Value: 0000 0000 (00h)
7
EOC SPEED ADON SLOW CH3 CH2 CH1
Channel Pin* AIN0 AIN1 AIN2 AIN3 AIN4 AIN5 AIN6 AIN7 AIN8 AIN9 AIN10 AIN11 AIN12 AIN13 AIN14 AIN15
CH3 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
CH2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
CH1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1
CH0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0
CH0
Bit 7 = EOC End of Conversion This bit is set by hardware. It is cleared by software reading the ADCDRH register or writing to any bit of the ADCCSR register. 0: Conversion is not complete 1: Conversion complete Bit 6 = SPEED A/D clock selection This bit is set and cleared by software. Table 29. A/D Clock Selection
fADC fCPU/2 fCPU (where fCPU <= 4 MHz) fCPU/4 fCPU/2 (same frequency as SLOW=0, SPEED=0) SLOW 0 0 1 1 SPEED 0 1 0 1
DATA REGISTER (ADCDRH) Read Only Reset Value: 0000 0000 (00h)
7
D9 D8 D7 D6 D5 D4 D3
0
D2
Bit 5 = ADON A/D Converter on This bit is set and cleared by software. 0: Disable ADC and stop conversion 1: Enable ADC and start conversion Bit 4 = SLOW A/D Clock Selection This bit is set and cleared by software. It works together with the SPEED bit. Refer to Table 29. Bits 3:0 = CH[3:0] Channel Selection These bits are set and cleared by software. They select the analog input to convert.
*The number of channels is device dependent. Refer to the device pinout description.
Bits 7:0 = D[9:2] MSB of Analog Converted Value DATA REGISTER (ADCDRL) Read Only Reset Value: 0000 0000 (00h)
7
0 0 0 0 0 0 D1
0
D0
Bits 7:2 = Reserved. Forced by hardware to 0. Bits 1:0 = D[1:0] LSB of Analog Converted Value
170/224
ST72361
10-BIT A/D CONVERTER (ADC) (Cont'd) Table 30. ADC Register Map and Reset Values
Address (Hex.) 45h 46h 47h Register Label ADCCSR Reset Value ADCDRH Reset Value ADCDRL Reset Value 7 EOC 0 D9 0 0 0 6 SPEED 0 D8 0 0 0 5 ADON 0 D7 0 0 0 4 SLOW 0 D6 0 0 0 3 CH3 0 D5 0 0 0 2 CH2 0 D4 0 0 0 1 CH1 0 D3 0 D1 0 0 CH0 0 D2 0 D0 0
171/224
ST72361
11 INSTRUCTION SET
11.1 CPU ADDRESSING MODES The CPU features 17 different addressing modes which can be classified in seven main groups:
Addressing Mode Inherent Immediate Direct Indexed Indirect Relative Bit operation Example nop ld A,#$55 ld A,$55 ld A,($55,X) ld A,([$55],X) jrne loop bset byte,#5
The CPU Instruction set is designed to minimize the number of bytes required per instruction: To do Table 31. CPU Addressing Mode Overview
Mode Inherent Immediate Short Long No Offset Short Long Short Long Short Long Relative Relative Bit Bit Bit Bit Direct Direct Direct Direct Direct Indirect Indirect Indirect Indirect Direct Indirect Direct Indirect Direct Indirect Relative Relative Indexed Indexed Indexed Indexed Indexed nop ld A,#$55 ld A,$10 ld A,$1000 ld A,(X) ld A,($10,X) ld A,($1000,X) ld A,[$10] ld A,[$10.w] ld A,([$10],X) ld A,([$10.w],X) jrne loop jrne [$10] bset $10,#7 bset [$10],#7 btjt $10,#7,skip btjt [$10],#7,skip Syntax
so, most of the addressing modes may be subdivided in two submodes called long and short: - Long addressing mode is more powerful because it can use the full 64 Kbyte address space, however it uses more bytes and more CPU cycles. - Short addressing mode is less powerful because it can generally only access page zero (0000h 00FFh range), but the instruction size is more compact, and faster. All memory to memory instructions use short addressing modes only (CLR, CPL, NEG, BSET, BRES, BTJT, BTJF, INC, DEC, RLC, RRC, SLL, SRL, SRA, SWAP) The ST7 Assembler optimizes the use of long and short addressing modes.
Destination
Pointer Address (Hex.)
Pointer Size (Hex.)
Length (Bytes) +0 +1
00..FF 0000..FFFF 00..FF 00..1FE 0000..FFFF 00..FF 0000..FFFF 00..1FE 0000..FFFF PC+/-127 PC+/-127 00..FF 00..FF 00..FF 00..FF 00..FF byte 00..FF byte 00..FF byte 00..FF 00..FF 00..FF 00..FF byte word byte word
+1 +2 +0 +1 +2 +2 +2 +2 +2 +1 +2 +1 +2 +2 +3
172/224
ST72361
INSTRUCTION SET OVERVIEW (Cont'd) 11.1.1 Inherent All Inherent instructions consist of a single byte. The opcode fully specifies all the required information for the CPU to process the operation.
Inherent Instruction NOP TRAP WFI HALT RET IRET SIM RIM SCF RCF RSP LD CLR PUSH/POP INC/DEC TNZ CPL, NEG MUL SLL, SRL, SRA, RLC, RRC SWAP Function No operation S/W Interrupt Wait For Interrupt (Low Power Mode) Halt Oscillator (Lowest Power Mode) Sub-routine Return Interrupt Sub-routine Return Set Interrupt Mask (level 3) Reset Interrupt Mask (level 0) Set Carry Flag Reset Carry Flag Reset Stack Pointer Load Clear Push/Pop to/from the stack Increment/Decrement Test Negative or Zero 1 or 2 Complement Byte Multiplication Shift and Rotate Operations Swap Nibbles
11.1.3 Direct In Direct instructions, the operands are referenced by their memory address. The direct addressing mode consists of two submodes: Direct (short) The address is a byte, thus requires only one byte after the opcode, but only allows 00 - FF addressing space. Direct (long) The address is a word, thus allowing 64 Kbyte addressing space, but requires 2 bytes after the opcode. 11.1.4 Indexed (No Offset, Short, Long) In this mode, the operand is referenced by its memory address, which is defined by the unsigned addition of an index register (X or Y) with an offset. The indirect addressing mode consists of three submodes: Indexed (No Offset) There is no offset, (no extra byte after the opcode), and allows 00 - FF addressing space. Indexed (Short) The offset is a byte, thus requires only one byte after the opcode and allows 00 - 1FE addressing space. Indexed (long) The offset is a word, thus allowing 64 Kbyte addressing space and requires 2 bytes after the opcode. 11.1.5 Indirect (Short, Long) The required data byte to do the operation is found by its memory address, located in memory (pointer). The pointer address follows the opcode. The indirect addressing mode consists of two submodes: Indirect (short) The pointer address is a byte, the pointer size is a byte, thus allowing 00 - FF addressing space, and requires 1 byte after the opcode. Indirect (long) The pointer address is a byte, the pointer size is a word, thus allowing 64 Kbyte addressing space, and requires 1 byte after the opcode.
11.1.2 Immediate Immediate instructions have 2 bytes, the first byte contains the opcode, the second byte contains the operand value.
Immediate Instruction LD CP BCP AND, OR, XOR ADC, ADD, SUB, SBC Load Compare Bit Compare Logical Operations Arithmetic Operations Function
173/224
ST72361
INSTRUCTION SET OVERVIEW (Cont'd) 11.1.6 Indirect Indexed (Short, Long) This is a combination of indirect and short indexed addressing modes. The operand is referenced by its memory address, which is defined by the unsigned addition of an index register value (X or Y) with a pointer value located in memory. The pointer address follows the opcode. The indirect indexed addressing mode consists of two submodes: Indirect Indexed (Short) The pointer address is a byte, the pointer size is a byte, thus allowing 00 - 1FE addressing space, and requires 1 byte after the opcode. Indirect Indexed (Long) The pointer address is a byte, the pointer size is a word, thus allowing 64 Kbyte addressing space, and requires 1 byte after the opcode. Table 32. Instructions Supporting Direct, Indexed, Indirect and Indirect Indexed Addressing Modes
Long and Short Instructions LD CP AND, OR, XOR ADC, ADD, SUB, SBC BCP Load Compare Logical Operations Arithmetic Additions/Substractions operations Bit Compare Function
11.1.7 Relative mode (Direct, Indirect) This addressing mode is used to modify the PC register value, by adding an 8-bit signed offset to it.
Available Relative Direct/Indirect Instructions JRxx CALLR Function Conditional Jump Call Relative
The relative addressing mode consists of two submodes: Relative (Direct) The offset is following the opcode. Relative (Indirect) The offset is defined in memory, which address follows the opcode.
Short Instructions Only CLR INC, DEC TNZ CPL, NEG BSET, BRES BTJT, BTJF SLL, SRL, SRA, RLC, RRC SWAP CALL, JP Clear
Function Increment/Decrement Test Negative or Zero 1 or 2 Complement Bit Operations Bit Test and Jump Operations Shift and Rotate Operations Swap Nibbles Call or Jump subroutine
174/224
ST72361
INSTRUCTION SET OVERVIEW (Cont'd) 11.2 INSTRUCTION GROUPS The ST 7 family devices use an Instruction Set consisting of 63 instructions. The instructions may
Load and Transfer Stack operation Increment/Decrement Compare and Tests Logical operations Bit Operation Conditional Bit Test and Branch Arithmetic operations Shift and Rotates Unconditional Jump or Call Conditional Branch Interruption management Condition Code Flag modification LD PUSH INC CP AND BSET BTJT ADC SLL JRA JRxx TRAP SIM WFI RIM HALT SCF IRET RCF CLR POP DEC TNZ OR BRES BTJF ADD SRL JRT SUB SRA JRF SBC RLC JP MUL RRC CALL SWAP CALLR SLA NOP RET BCP XOR CPL NEG RSP
be subdivided into 13 main groups as illustrated in the following table:
Using a prebyte The instructions are described with one to four opcodes. In order to extend the number of available opcodes for an 8-bit CPU (256 opcodes), three different prebyte opcodes are defined. These prebytes modify the meaning of the instruction they precede. The whole instruction becomes: PC-2 End of previous instruction PC-1 Prebyte PC Opcode PC+1 Additional word (0 to 2) according to the number of bytes required to compute the effective address
These prebytes enable instruction in Y as well as indirect addressing modes to be implemented. They precede the opcode of the instruction in X or the instruction using direct addressing mode. The prebytes are: PDY 90 Replace an X based instruction using immediate, direct, indexed, or inherent addressing mode by a Y one. PIX 92 Replace an instruction using direct, direct bit, or direct relative addressing mode to an instruction using the corresponding indirect addressing mode. It also changes an instruction using X indexed addressing mode to an instruction using indirect X indexed addressing mode. PIY 91 Replace an instruction using X indirect indexed addressing mode by a Y one.
175/224
ST72361
INSTRUCTION SET OVERVIEW (Cont'd)
Mnemo ADC ADD AND BCP BRES BSET BTJF BTJT CALL CALLR CLR CP CPL DEC HALT IRET INC JP JRA JRT JRF JRIH JRIL JRH JRNH JRM JRNM JRMI JRPL JREQ JRNE JRC JRNC JRULT JRUGE JRUGT Description Add with Carry Addition Logical And Bit compare A, Memory Bit Reset Bit Set Jump if bit is false (0) Jump if bit is true (1) Call subroutine Call subroutine relative Clear Arithmetic Compare One Complement Decrement Halt Interrupt routine return Increment Absolute Jump Jump relative always Jump relative Never jump Jump if ext. INT pin = 1 Jump if ext. INT pin = 0 Jump if H = 1 Jump if H = 0 Jump if I1:0 = 11 Jump if I1:0 <> 11 Jump if N = 1 (minus) Jump if N = 0 (plus) Jump if Z = 1 (equal) Jump if Z = 0 (not equal) Jump if C = 1 Jump if C = 0 Jump if C = 1 Jump if C = 0 Jump if (C + Z = 0) jrf * (ext. INT pin high) (ext. INT pin low) H=1? H=0? I1:0 = 11 ? I1:0 <> 11 ? N=1? N=0? Z=1? Z=0? C=1? C=0? Unsigned < Jmp if unsigned >= Unsigned > Pop CC, A, X, PC inc X jp [TBL.w] reg, M tst(Reg - M) A = FFH-A dec Y reg, M reg reg, M reg, M 1 I1 H 0 I0 N N Z Z C M 0 N N N 1 Z Z Z C 1 Function/Example A=A+M+C A=A+M A=A.M tst (A . M) bres Byte, #3 bset Byte, #3 btjf Byte, #3, Jmp1 btjt Byte, #3, Jmp1 A A A A M M M M C C Dst Src M M M M I1 H H H I0 N N N N N Z Z Z Z Z C C C
176/224
ST72361
INSTRUCTION SET OVERVIEW (Cont'd)
Mnemo JRULE LD MUL NEG NOP OR POP PUSH RCF RET RIM RLC RRC RSP SBC SCF SIM SLA SLL SRL SRA SUB SWAP TNZ TRAP WFI XOR Description Jump if (C + Z = 1) Load Multiply Negate (2's compl) No Operation OR operation Pop from the Stack Push onto the Stack Reset carry flag Subroutine Return Enable Interrupts Rotate left true C Rotate right true C Reset Stack Pointer Substract with Carry Set carry flag Disable Interrupts Shift left Arithmetic Shift left Logic Shift right Logic Shift right Arithmetic Substraction SWAP nibbles Test for Neg & Zero S/W trap Wait for Interrupt Exclusive OR A = A XOR M A M I1:0 = 10 (level 0) C <= A <= C C => A => C S = Max allowed A=A-M-C C=1 I1:0 = 11 (level 3) C <= A <= 0 C <= A <= 0 0 => A => C A7 => A => C A=A-M A7-A4 <=> A3-A0 tnz lbl1 S/W interrupt 1 1 1 0 N Z reg, M reg, M reg, M reg, M A reg, M M 1 1 N N 0 N N N N Z Z Z Z Z Z Z C C C C C A M N Z C 1 reg, M reg, M 1 0 N N Z Z C C A=A+M pop reg pop CC push Y C=0 A reg CC M M M M reg, CC 0 I1 H I0 N Z C N Z Function/Example Unsigned <= dst <= src X,A = X * A neg $10 reg, M A, X, Y reg, M M, reg X, Y, A 0 N Z N Z 0 C Dst Src I1 H I0 N Z C
177/224
ST72361
12 ELECTRICAL CHARACTERISTICS
12.1 PARAMETER CONDITIONS Unless otherwise specified, all voltages are referred to VSS. 12.1.1 Minimum and Maximum Values Unless otherwise specified the minimum and maximum values are guaranteed in the worst conditions of ambient temperature, supply voltage and frequencies by tests in production on 100% of the devices with an ambient temperature at TA = 25C and TA = TAmax (given by the selected temperature range). Data based on characterization results, design simulation and/or technology characteristics are indicated in the table footnotes and are not tested in production. Based on characterization, the minimum and maximum values refer to sample tests and represent the mean value plus or minus three times the standard deviation (mean3). 12.1.2 Typical Values Unless otherwise specified, typical data is based VDD = 5V (for the on TA = 25C, 4.5V VDD 5.5V voltage range). They are given only as design guidelines and are not tested. Typical ADC accuracy values are determined by characterization of a batch of samples from a standard diffusion lot over the full temperature range, where 95% of the devices have an error less than or equal to the value indicated (mean2). 12.1.3 Typical Curves Unless otherwise specified, all typical curves are given only as design guidelines and are not tested. 12.1.4 Loading Capacitor The loading conditions used for pin parameter measurement are shown in Figure 95. Figure 95. Pin Loading Conditions 12.1.5 Pin Input Voltage The input voltage measurement on a pin of the device is described in Figure 96. Figure 96. Pin input voltage
ST7 PIN
VIN
ST7 PIN
CL
178/224
ST72361
12.2 ABSOLUTE MAXIMUM RATINGS Stresses above those listed as "absolute maximum ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these condi12.2.1 Voltage Characteristics
Symbol VDD - VSS VPP - VSS VIN |VDDx| and |VSSx| |VSSA - VSSx| VESD(HBM) VESD(MM) Supply voltage Programming Voltage Input voltage on any pin1)2) Variations between different digital power pins Variations between digital and analog ground pins Electro-static discharge voltage (Human Body Model) Electro-static discharge voltage (Machine Model) Ratings
tions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.
Maximum value 6.5 13 VSS - 0.3 to VDD + 0.3 50 50
Unit V
mV
see Section 12.8.3 on page 192
12.2.2 Current Characteristics
Symbol IVDD IVSS IIO Ratings Total current into VDD power lines (source)
3)
Maximum value 150 25 50 - 25
Unit
Total current out of VSS ground lines (sink)3) Output current sunk by any standard I/O and control pin Output current sunk by any high sink I/O pin Output current source by any I/Os and control pin Injected current on VPP pin Injected current on RESET pin
mA 5 +5 5
5)
IINJ(PIN)2)4)
Injected current on OSC1 and OSC2 pins Injected current on PB3 (on Flash devices) Injected current on any other pin5)
IINJ(PIN)2)
Total injected current (sum of all I/O and control pins)
25
12.2.3 Thermal Characteristics
Symbol TSTG TJ Ratings Storage temperature range Value -65 to +150 Unit C
Maximum junction temperature (see Section 13.2 "THERMAL CHARACTERISTICS")
Notes: 1. Directly connecting the RESET and I/O pins to VDD or VSS could damage the device if an unintentional internal reset is generated or an unexpected change of the I/O configuration occurs (for example, due to a corrupted program counter). To guarantee safe operation, this connection has to be done through a pull-up or pull-down resistor (typical: 4.7k for RESET, 10k for I/Os). Unused I/O pins must be tied in the same way to VDD or VSS according to their reset configuration. 2. IINJ(PIN) must never be exceeded. This is implicitly insured if VIN maximum is respected. If VIN maximum cannot be respected, the injection current must be limited externally to the IINJ(PIN) value. A positive injection is induced by VIN>VDD while a negative injection is induced by VIN < VSS. For true open-drain pads, there is no positive injection current, and the corresponding VIN maximum must always be respected 3. All power (VDD) and ground (VSS) lines must always be connected to the external supply. 4. Negative injection disturbs the analog performance of the device. See note in "10-BIT ADC CHARACTERISTICS" on page 204. 5. When several inputs are submitted to a current injection, the maximum IINJ(PIN) is the absolute sum of the positive and negative injected currents (instantaneous values). These results are based on characterization with IINJ(PIN) maximum current injection on four I/O port pins of the device.
179/224
ST72361
12.3 OPERATING CONDITIONS 12.3.1 General Operating Conditions
Symbol fCPU Parameter Internal clock frequency Extended Operating voltage VDD Standard Operating Voltage Operating Voltage for Flash Write/Erase VPP = 11.4 to 12.6V 1 Suffix Version 5 Suffix Version TA Ambient temperature range 6 Suffix Version 7 Suffix Version 3 Suffix Version -40 No Flash Write/Erase. Analog parameters not guaranteed. Conditions Min 0 3.8 4.5 4.5 0 -10 Max 8 4.5 5.5 5.5 70 85 85 105 125 C Unit MHz V
Figure 97. fCPU Maximum vs VDD
fCPU [MHz]
FUNCTIONALITY GUARANTEED IN THIS AREA UNLESS OTHERWISE SPECIFIED IN THE TABLES OF PARAMETRIC DATA FUNCTIONALITY GUARANTEED IN THIS AREA
8 FUNCTIONALITY NOT GUARANTEED IN THIS AREA
6
4 2 1 0 3.5 3.8 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE [V]
180/224
ST72361
12.3.2 Operating Conditions with Low Voltage Detector (LVD) Subject to general operating conditions for TA.
Symbol VIT+(LVD) VIT-(LVD) Vhys(LVD) VtPOR tg(VDD) Parameter Reset release threshold (VDD rise) Reset generation threshold (VDD fall) LVD voltage threshold hysteresis1) VDD rise time rate1) VDD glitches filtered (not detected) by Measured at VIT-(LVD) LVD1) VIT+(LVD)-VIT-(LVD) Conditions Min 4.01) 3.8 150 6 100 40 Typ 4.2 4.0 200 Max 4.5 4.251) 250 Unit V mV s/V ms/V ns
Notes: 1. Data based on characterization results, not tested in production.
12.3.3 Auxiliary Voltage Detector (AVD) Thresholds Subject to general operating conditions for TA.
Symbol VIT+(AVD) VIT-(AVD) Vhys(AVD) VITParameter 10 AVDF flag toggle threshold (VDD rise) 01 AVDF flag toggle threshold (VDD fall) AVD voltage threshold hysteresis Voltage drop between AVD flag set and LVD reset activated VIT+(AVD)-VIT-(AVD) VIT-(AVD)-VIT-(LVD) Conditions Min 4.41) 4.2 Typ 4.6 4.4 250 450 mV Max 4.9 V 4.651) Unit
1. Data based on characterization results, not tested in production.
Figure 98. LVD Startup Behavior
5V VIT+ LVD RESET
VD
D
2V Reset state not defined in this area t
Note: When the LVD is enabled, the MCU reaches its authorized operating voltage from a reset state. However, in some devices, the reset signal may be undefined until VDD is approximately 2V. As a consequence, the I/Os may toggle when VDD is below this voltage. Because Flash write access is impossible below this voltage, the Flash memory contents will not be corrupted.
181/224
ST72361
12.4 SUPPLY CURRENT CHARACTERISTICS The following current consumption specified for the ST7 functional operating modes over temperature range does not take into account the clock source current consumption. To get the total deSymbol Parameter
vice consumption, the two current values must be added (except for HALT mode for which the clock is stopped).
Flash Devices ROM Devices Typ 1) 1.8 3.2 6 10 0.5 0.6 0.85 1.25 1 1.8 3.4 6.4 0.4 0.5 0.6 0.8 <1 0.5 Max2) 3 5 8 15 2.7 3 3.6 4 3 4 5 7 1.2 1.3 1.8 2 10 50 1.2 30 70 Typ 1 1.1 2.2 4.4 8.9 0.1 0.2 0.4 0.8 0.7 1.4 2.9 5.7 0.07 0.14 0.28 0.56 <1 0.18 25 Max2) 2 3.5 6 12 0.2 0.4 0.8 1.5 3 4 5 7 0.12 0.25 0.5 1 10 50 0.25 30 70 A mA A
Conditions fOSC = 2 MHz, fCPU = 1 MHz fOSC = 4 MHz, fCPU = 2 MHz fOSC = 8 MHz, fCPU = 4 MHz fOSC = 16 MHz, fCPU = 8 MHz fOSC = 2 MHz, fCPU = 62.5kHz fOSC = 4 MHz, fCPU = 125 kHz fOSC = 8 MHz, fCPU = 250 kHz fOSC = 16 MHz, fCPU = 500 kHz fOSC = 2 MHz, fCPU = 1 MHz fOSC = 4 MHz, fCPU = 2 MHz fOSC = 8 MHz, fCPU = 4 MHz fOSC = 16 MHz, fCPU = 8 MHz fOSC = 2 MHz, fCPU = 62.5 kHz fOSC = 4 MHz, fCPU = 125 kHz fOSC = 8 MHz, fCPU = 250 kHz fOSC = 16 MHz, fCPU = 500 kHz VDD = 5.5V -40C TA +85C -40C TA +125C
Unit
Supply current in RUN mode
3)
Supply current in SLOW mode3)
mA
Supply current in WAIT mode3) IDD Supply current in SLOW WAIT mode2) Supply current in HALT mode4) Supply current in ACTIVE HALT mode4)5) Supply current in AWUFH mode4)5)
VDD = 5.5V
-40C TA +85C -40C TA +125C
25
Notes: 1. Typical data are based on TA = 25C, VDD = 5V (4.5V VDD 5.5V range). 2. Data based on characterization results, tested in production at VDD max., fCPU max. and TA max. 3. Measurements are done in the following conditions: - Program executed from Flash, CPU running with Flash (for flash devices). - All I/O pins in input mode with a static value at VDD or VSS (no load) - All peripherals in reset state. - Clock input (OSC1) driven by external square wave. - In SLOW and SLOW WAIT mode, fCPU is based on fOSC divided by 32. To obtain the total current consumption of the device, add the clock source (Section 12.5.3) and the peripheral power consumption (Section 12.4.2). 4. All I/O pins in input mode with a static value at VDD or VSS (no load). Data based on characterization results, tested in production at VDD max., fCPU max. and TA max. 5. This consumption refers to the Halt period only and not the associated run period which is software dependent.
182/224
ST72361
SUPPLY CURRENT CHARACTERISTICS (Cont'd) 12.4.1 Supply and Clock Managers The previous current consumption specified for the ST7 functional operating modes over temperature range does not take into account the clock
Symbol IDD(RES) IDD(PLL) IDD(LVD) Parameter Supply current of resonator oscillator PLL supply current LVD supply current
2)3)
source current consumption. To obtain the total device consumption, the two current values must be added (except for HALT mode).
Conditions Typ 360 150 300 Max1) Unit A
See Section 12.5.3 on page 186 VDD = 5V HALT mode, VDD = 5V
Notes: 1. Data based on characterization results, not tested in production. 2. Data based on characterization results done with the external components specified in Section 12.5.3, not tested in production. 3. As the oscillator is based on a current source, the consumption does not depend on the voltage.
183/224
ST72361
12.4.2 On-Chip Peripherals TA = 25C, fCPU = 8 MHz.
Symbol IDD(TIM) IDD(TIM8) IDD(ART) IDD(SPI) IDD(SCI) IDD(ADC) Parameter 16-bit Timer supply current1) 8-bit Timer supply current 1) ART PWM supply current2) SPI supply current3) SCI supply current4) ADC supply current when converting
5)
Conditions
Typ 50 75
Unit
VDD = 5.0V 400
A
Notes: 1. Data based on a differential IDD measurement between reset configuration (timer counter running at fCPU/4) and timer counter stopped (only TIMD bit set). Data valid for one timer. 2. Data based on a differential IDD measurement between reset configuration (timer stopped) and timer counter enabled (only TCE bit set). 3. Data based on a differential IDD measurement between reset configuration (SPI disabled) and a permanent SPI master communication at maximum speed (data sent equal to 55h).This measurement includes the pad toggling consumption. 4. Data based on a differential IDD measurement between SCI low power state (SCID = 1) and a permanent SCI data transmit sequence. Data valid for one SCI. 5. Data based on a differential IDD measurement between reset configuration and continuous A/D conversions.
184/224
ST72361
12.5 CLOCK AND TIMING CHARACTERISTICS Subject to general operating conditions for VDD, fOSC, and TA. 12.5.1 General Timings
Symbol tc(INST) tv(IT) Parameter Instruction cycle time Interrupt reaction time tv(IT) = tc(INST) + 10
2)
Conditions fCPU = 8 MHz fCPU = 8 MHz
Min 2 250 10 1.25
Typ1) 3 375
Max 12 1500 22 2.75
Unit tCPU ns tCPU s
12.5.2 External Clock Source
Symbol VOSC1H VOSC1L tw(OSC1H) tw(OSC1L) tr(OSC1) tf(OSC1) IL Parameter OSC1 input pin high level voltage OSC1 input pin low level voltage OSC1 high or low time3) OSC1 rise or fall time3) OSCx Input leakage current VSS VIN VDD see Figure 99 Conditions Min 0.7 x VDD VSS 25 ns 5 1 A Typ Max VDD 0.3 x VDD Unit V
Figure 99. Typical Application with an External Clock Source
90% VOSC1H 10%
VOSC1L tr(OSC1) tf(OSC1) tw(OSC1H) tw(OSC1L)
OSC2
Not connected internally fOSC
EXTERNAL CLOCK SOURCE
OSC1
IL ST72XXX
Notes: 1. Data based on typical application software. 2. Time measured between interrupt event and interrupt vector fetch. tc(INST) is the number of tCPU cycles needed to finish the current instruction execution. 3. Data based on design simulation and/or technology characteristics, not tested in production.
185/224
ST72361
CLOCK AND TIMING CHARACTERISTICS (Cont'd) 12.5.3 Crystal and Ceramic Resonator Oscillators The ST7 internal clock can be supplied with four different Crystal/Ceramic resonator oscillators. All the information given in this paragraph is based on characterization results with specified typical external components. In the application, the resonator and the load capacitors have to be placed as
Symbol fOSC RF CL1 CL2 Parameter Oscillator Frequency3) Feedback resistor Recommended load capacitance versus equivalent serial resistance of the crystal or ceramic resonator (RS) Parameter OSC2 driving current
close as possible to the oscillator pins in order to minimize output distortion and start-up stabilization time. Refer to the crystal/ceramic resonator manufacturer for more details (frequency, package, accuracy...). 1)2)
Conditions Min 1 >2 >4 >8 20 22 22 18 15 Typ 80 160 310 610 Max 2 4 8 16 40 56 46 33 33 Max 150 250 460 910 Unit MHz k pF
LP: Low power oscillator MP: Medium power oscillator MS: Medium speed oscillator HS: High speed oscillator RS = 200 RS = 200 RS = 200 RS = 100 LP oscillator MP oscillator MS oscillator HS oscillator
Symbol i2
Conditions VDD = 5V VIN = VSS LP oscillator MP oscillator MS oscillator HS oscillator
Unit A
Figure 100. Typical Application with a Crystal or Ceramic Resonator
WHEN RESONATOR WITH INTEGRATED CAPACITORS
i2
fOSC OSC1
CL1
RESONATOR CL2 OSC2
RF ST72XXX
Notes: 1. Resonator characteristics given by the crystal/ceramic resonator manufacturer. 2. tSU(OSC) is the typical oscillator start-up time measured between VDD = 2.8V and the fetch of the first instruction (with a quick VDD ramp-up from 0 to 5V (< 50s). 3. The oscillator selection can be optimized in terms of supply current using an high quality resonator with small RS value. Refer to crystal/ceramic resonator manufacturer for more details.
186/224
ST72361
CLOCK CHARACTERISTICS (Cont'd) 12.5.4 PLL Characteristics Operating conditions: VDD 3.8 to 5.5V @ TA 0 to 70C1) or VDD 4.5 to 5.5V @ TA -40 to 125C
Symbol VDD(PLL) fOSC fCPU/fCPU Parameter PLL Voltage Range PLL input frequency range PLL jitter1) fOSC = 4 MHz, VDD = 4.5 to 5.5V fOSC = 2 MHz, VDD = 4.5 to 5.5V Conditions TA = 0 to +70C TA = -40 to +125C Min 3.8 4.5 2 Note 2 Typ Max 5.5 4 MHz % Unit
Notes: 1. Data characterized but not tested. 2. Under characterization
Figure 101. PLL Jitter vs Signal Frequency1)
0.8 0.7 0.6 +/-Jitter (%) 0.5 0.4 0.3 0.2 0.1 0 2000 1000 500 250 125 Application Signal Frequency (KHz) PLL ON PLL OFF
The user must take the PLL jitter into account in the application (for example in serial communication or sampling of high frequency signals). The PLL jitter is a periodic effect, which is integrated over several CPU cycles. Therefore, the longer the period of the application signal, the less it is impacted by the PLL jitter. Figure 101 shows the PLL jitter integrated on application signals in the range 125 kHz to 2 MHz. At frequencies of less than 125 kHz, the jitter is negligible.
Notes: 1. Measurement conditions: fCPU = 4 MHz, TA = 25C
187/224
ST72361
CLOCK CHARACTERISTICS (Cont'd) 12.6 Auto Wakeup from Halt Oscillator (AWU)
Symbol fAWU tRCSRT Parameter AWU oscillator frequency1) AWU oscillator startup time Conditions Min 50 Typ 100 10 Max 250 Unit kHz s
1. Data based on characterization results, not tested in production.
Figure 102. AWU Oscillator Freq. @ TA 25C
20 0 15 0 10 0 50 Ta=25C
Freq(KH z)
4. 4
5 Vdd
5. 6
188/224
ST72361
12.7 MEMORY CHARACTERISTICS 12.7.1 RAM and Hardware Registers
Symbol VRM Parameter Data retention mode
1)
Conditions HALT mode (or RESET)
Min 1.6
Typ
Max
Unit V
12.7.2 FLASH Memory
DUAL VOLTAGE HDFLASH MEMORY Symbol Parameter fCPU VPP IPP tVPP tRET NRW TPROG TERASE Operating frequency Programming voltage3) VPP current4)5) Internal VPP stabilization time Data retention Write erase cycles Programming or erasing temperature range TA = 85C TA = 105C TA = 125C TA = 25C 40 25 10 100 -40 25 85 Conditions Read mode Write / Erase mode 4.5V VDD 5.5V Read (VPP = 12V) Write / Erase Min2) 0 1 11.4 Typ Max2) 8 8 12.6 200 30 Unit MHz V A mA s years cycles C
104)
Notes: 1. Minimum VDD supply voltage without losing data stored in RAM (in HALT mode or under RESET) or in hardware registers (only in HALT mode). Not tested in production. 2. Data based on characterization results, not tested in production. 3. VPP must be applied only during the programming or erasing operation and not permanently for reliability reasons. 4. Data based on simulation results, not tested in production. 5. In Write / erase mode the IDD supply current consumption is the same as in Run mode (see Section 12.2.2)
189/224
ST72361
12.8 EMC CHARACTERISTICS Susceptibility tests are performed on a sample basis during product characterization. 12.8.1 Functional EMS (Electro Magnetic Susceptibility) Based on a simple running application on the product (toggling two LEDs through I/O ports), the product is stressed by two electro magnetic events until a failure occurs (indicated by the LEDs). ESD: Electro-Static Discharge (positive and negative) is applied on all pins of the device until a functional disturbance occurs. This test conforms with the IEC 1000-4-2 standard. FTB: A Burst of Fast Transient voltage (positive and negative) is applied to VDD and VSS through a 100pF capacitor, until a functional disturbance occurs. This test conforms with the IEC 1000-44 standard. A device reset allows normal operations to be resumed. The test results are given in the table below based on the EMS levels and classes defined in application note AN1709. 12.8.1.1 Designing hardened software to avoid noise problems EMC characterization and optimization are performed at component level with a typical applicaSymbol Parameter
tion environment and simplified MCU software. It should be noted that good EMC performance is highly dependent on the user application and the software in particular. Therefore it is recommended that the user applies EMC software optimization and prequalification tests in relation with the EMC level requested for his application. Software recommendations: The software flowchart must include the management of runaway conditions such as: - Corrupted program counter - Unexpected reset - Critical Data corruption (control registers...) Prequalification trials: Most of the common failures (unexpected reset and program counter corruption) can be reproduced by manually forcing a low state on the RESET pin or the Oscillator pins for 1 second. To complete these trials, ESD stress can be applied directly on the device, over the range of specification values. When unexpected behavior is detected, the software can be hardened to prevent unrecoverable errors occurring (see application note AN1015).
Conditions Level/ Class 3B 2B 3B 2B
VFESD
LQFP64, VDD = 5V, TA = +25C, Voltage limits to be applied on any I/O pin to induce a fOSC = 8 MHz, conforms to IEC 1000-4-2 functional disturbance LQFP44, VDD = 5V, TA = +25C, fOSC = 8 MHz, conforms to IEC 1000-4-2 LQFP64, VDD = 5V, TA = +25C, Fast transient voltage burst limits to be applied fOSC = 8 MHz, conforms to IEC 1000-4-4 through 100pF on VDD and VDD pins to induce a funcLQFP44, VDD = 5V, TA = +25C, tional disturbance fOSC = 8 MHz, conforms to IEC 1000-4-4
VFFTB
190/224
ST72361
EMC CHARACTERISTICS (Cont'd) 12.8.2 Electro Magnetic Interference (EMI) Based on a simple application running on the product (toggling two LEDs through the I/O ports), the product is monitored in terms of emission. This
Symbol Parameter Conditions
emission test is in line with the norm SAE J 1752/ 3 which specifies the board and the loading of each pin.
Monitored Frequency Band 0.1 MHz to 30 MHz 30 MHz to 130 MHz 130 MHz to 1 GHz SAE EMI Level 0.1 MHz to 30 MHz 30 MHz to 130 MHz 130 MHz to 1 GHz SAE EMI Level 0.1 MHz to 30 MHz 30 MHz to 130 MHz 130 MHz to 1 GHz SAE EMI Level Max vs. [fOSC/fCPU] 8/4 MHz 10 12 8 2.5 31 32 11 3.0 10 15 -3 2.0 16/8 MHz 13 19 14 3 32 37 16 3.5 18 25 1 2.5 dBV dBV dBV
Unit
Flash devices: VDD = 5V, TA = +25C, LQFP44 package conforming to SAE J 1752/3 Flash devices: VDD = 5V, TA = +25C, Peak level1) LQFP64 package conforming to SAE J 1752/3 ROM devices: VDD = 5V, TA = +25C, LQFP64 package conforming to SAE J 1752/3 Notes: 1. Not tested in production.
SEMI
191/224
ST72361
EMC CHARACTERISTICS (Cont'd) 12.8.3 Absolute Maximum Ratings (Electrical Sensitivity) Based on three different tests (ESD, LU and DLU) using specific measurement methods, the product is stressed in order to determine its performance in terms of electrical sensitivity (see Table 33 and Table 34 below). For more details, refer to application note AN1181. 12.8.3.1 Electro-Static Discharge (ESD) Electro-Static Discharges (a positive then a negative pulse separated by 1 second) are applied to the pins of each sample according to each pin combination. The sample size depends on the number of supply pins in the device (3 parts*(n+1) supply pin). Two models can be simulated: Human Body Model and Machine Model. This test conforms to the JESD22-A114A/A115A standard.
12.8.3.2 Static and Dynamic Latch-Up LU: Three complementary static tests are required on 10 parts to assess the latch-up performance. A supply overvoltage (applied to each power supply pin) and a current injection (applied to each input, output and configurable I/ O pin) are performed on each sample. This test conforms to the EIA/JESD 78 IC latch-up standard. For more details, refer to application note AN1181. DLU: Electro-Static Discharges (one positive then one negative test) are applied to each pin of three samples when the micro is running to assess the latch-up performance in dynamic mode. Power supplies are set to the typical values, the oscillator is connected as near as possible to the pins of the micro and the component is put in reset mode. This test conforms to the IEC1000-4-2 and SAEJ1752/3 standards. For more details, refer to application note AN1181.
Table 33. Absolute Maximum Ratings
Symbol VESD(MM) Ratings Electro-static discharge voltage (Machine Model) Conditions Maximum value1) 2000 TA = +25C 200 750 on corner pins, 500 on others V Unit VESD(HBM) Electro-static discharge voltage (Human Body Model)
VESD(CDM) Electro-static discharge voltage (Charge Device Model) Notes: 1. Data based on characterization results, not tested in production.
Table 34. Electrical Sensitivities
Symbol LU DLU Parameter Static latch-up class Dynamic latch-up class TA = +25C TA = +85C TA = +125C VDD = 5.5V, fOSC = 4 MHz, TA = +25C Conditions Class1)
A
Notes: 1. Class description: A Class is an STMicroelectronics internal specification. All its limits are higher than the JEDEC specifications, that means when a device belongs to Class A it exceeds the JEDEC standard. B Class strictly covers all the JEDEC criteria (international standard).
192/224
ST72361
12.9 I/O PORT PIN CHARACTERISTICS 12.9.1 General Characteristics Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol VIL VIH Vhys VIL VIH Vhys IINJ(PIN) IINJ(PIN)3) Ilkg IS RPU CIO tf(IO)out tr(IO)out tw(IT)in Parameter Input low level voltage1) CMOS ports 0.7 x VDD 1 0.8 TTL ports Flash devices ROM devices 2 400 0 +4 4 4 25 VSS VIN VDD Floating input mode VIN = VSS VDD = 5V CL = 50pF Between 10% and 90% 1 50 200 90 5 25 250 mA mV V Input high level voltage1) Schmitt trigger voltage hysteresis2) Input low level voltage
1)
Conditions
Min
Typ
Max 0.3 x VDD
Unit
Input high level voltage1) Schmitt trigger voltage hysteresis2) Injected Current on PB3
Injected Current on any other I/O pin VDD = 5V Total injected current (sum of all I/O and control pins)7) Input leakage current4) Static current consumption5) Weak pull-up equivalent resistor6) I/O pin capacitance Output high to low level fall time Output low to high level rise time External interrupt pulse time7)
Input leakage current on robust pins See "10-BIT ADC CHARACTERISTICS" on page 204 1 A k pF ns tCPU
Notes: 1. Data based on characterization results, not tested in production. 2. Hysteresis voltage between Schmitt trigger switching levels. Based on characterization results, not tested. 3. When the current limitation is not possible, the VIN absolute maximum rating must be respected, otherwise refer to IINJ(PIN) specification. A positive injection is induced by VIN > VDD while a negative injection is induced by VIN < VSS. Refer to Section 12.2 on page 179 for more details. 4. Leakage could be higher than max. if negative current is injected on adjacent pins. 5. Configuration not recommended, all unused pins must be kept at a fixed voltage: Using the output mode of the I/O, for example, or an external pull-up or pull-down resistor (see Figure 103). Data based on design simulation and/or technology characteristics, not tested in production. 6. The RPU pull-up equivalent resistor is based on a resistive transistor (corresponding IPU current characteristics described in Figure 104). 7. To generate an external interrupt, a minimum pulse width must be applied on an I/O port pin configured as an external interrupt source.
193/224
ST72361
I/O PORT PIN CHARACTERISTICS (Cont'd) Figure 103. Connecting Unused I/O Pins Figure 105. IPU vs VDD with VIN = VSS
VDD 10k
ST72XXX
100
UNUSED I/O PORT
Ipu (A)
80 60 40 20 0 3.5
Ta=-45C Ta=25C Ta=130C
10k
UNUSED I/O PORT
4
ST72XXX
4.5 Vdd
5
5.5
Figure 104. RPU vs VDD with VIN = VSS
200
150 R pu (Ko)
Ta=-45C Ta=25C Ta=130C
100
50
0 3.5 4 4.5 Vdd 5 5.5
194/224
ST72361
I/O PORT PIN CHARACTERISTICS (Cont'd) 12.9.2 Output Driving Current Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol Parameter Output low level voltage for a standard I/O pin when eight pins are sunk at same time (see Figure 106) VDD=5V Output low level voltage for a high sink I/O pin when four pins are sunk at same time (see Figure 107 and Figure 110) Output high level voltage for an I/O pin when four pins are sourced at same time (see Figure 108 and Figure 111) Conditions IIO=+5mA IIO=+2mA IIO=+20mA, TA85C TA85C IIO=+8mA IIO=-5mA, TA85C VDD-1.4 TA85C VDD-1.6 IIO=-2mA VDD-0.7 Min Max 1.2 0.5 1.3 1.5 0.6 Unit
VOL1)
V
VOH2)
Figure 106. Typical VOL at VDD = 5V (Standard)
0.8 0.7 -45C 0.6 25C Voh(V) 0.5 0.4 0.3 130C
Figure 108. Typical VOH at VDD = 5V
4.9 4.8 4.7 4.6 Voh(V) 4.5 4.4 4.3
-45C 130C 25C
0.2 0.1 2 Iio(mA) 5
4.2 4.1 -2 Iio(mA) -5
Figure 107. Typical VOL at VDD = 5V (High-sink)
0.8 0.7
-45 C
0.6 0.5 Vol (V ) 0.4 0.3 0.2 0.1 0 2
25 C 13 0C
5 Iol (mA)
8
20
Notes: 1. The IIO current sunk must always respect the absolute maximum rating specified in Section 12.2.2 and the sum of IIO (I/O ports and control pins) must not exceed IVSS. 2. The IIO current sourced must always respect the absolute maximum rating specified in Section 12.2.2 and the sum of IIO (I/O ports and control pins) must not exceed IVDD. True open drain I/O pins does not have VOH.
195/224
ST72361
I/O PORT PIN CHARACTERISTICS (Cont'd) Figure 109. Typical VOL vs VDD (Standard I/Os)
1.1 1 0.9 Vol(V) Iio=5mA 0.8 0.7 0.6 0.5 0.4 0.3 3 4 Vdd(V) 5 6 0.15 -45C 0.35 25C Vol(V) Iio=2mA 130C 0.3 25C 130C 0.4 -45C
0.25
0.2
0.1 3 4 Vdd(V) 5 6
Figure 110. Typical VOL vs VDD (High-sink I/Os)
0.4 -45C 0.35 25C Vol(V) Iio=20mA 130C 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.1 3 4 Vdd(V) 5 6 0.3 3 4 Vdd(V) 5 6 -45C 25C 130C
Vol(V) Iio=8mA
0.3
0.25
0.2
0.15
196/224
ST72361
I/O PORT PIN CHARACTERISTICS (Cont'd) Figure 111. Typical VOH vs VDD
6 6 -45C 5 5 Voh(V) Iio=2mA Voh(V) Iio=5mA 4 25C 130C
4
-45C 25C 130C
3
3 2
2 3 4 Vdd(V) 5 6
1 3 4 Vdd(V) 5 6
197/224
ST72361
12.10 CONTROL PIN CHARACTERISTICS 12.10.1 Asynchronous RESET Pin Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol VIL VIH Vhys VOL RON th(RSTL)in tg(RSTL)in Parameter Input low level voltage1) 0.7 x VDD VDD = 5V VDD = 5V
4)
Conditions
Min
Typ
Max 0.3 x VDD
Unit
Input high level voltage1) Schmitt trigger voltage hysteresis2) Output low level voltage3) Weak pull-up equivalent resistor External reset pulse hold time5) Filtered glitch duration6) IIO = +5mA IIO = +2mA
1.5 0.68 0.28 20 2.5 200 40 30 0.95 0.45 80
V
VIN = VSS Internal reset source
k s ns
tw(RSTL)out Generated reset pulse duration
Notes: 1. Data based on characterization results, not tested in production. 2. Hysteresis voltage between Schmitt trigger switching levels. 3. The IIO current sunk must always respect the absolute maximum rating specified in Section 12.2.2 and the sum of IIO (I/O ports and control pins) must not exceed IVSS. 4. To guarantee the reset of the device, a minimum pulse has to be applied to the RESET pin. All short pulses applied on the RESET pin with a duration below th(RSTL)in can be ignored. 5. The reset network (the resistor and two capacitors) protects the device against parasitic resets, especially in noisy environments. 6. Data guaranteed by design, not tested in production.
198/224
ST72361
CONTROL PIN CHARACTERISTICS (Cont'd) Figure 112. RESET Pin Protection When LVD Is Enabled1)2)
VDD
ST72XXX
Recommended
EXTERNAL RESET
0.01F
Optional (note 2.2)
RON
Filter
INTERNAL RESET
1M
PULSE GENERATOR
WATCHDOG LVD RESET
Figure 113. RESET Pin Protection When LVD Is Disabled1)
VDD
VDD ST72XXX
USER EXTERNAL RESET CIRCUIT 0.01F
4.7k
RON
Filter
INTERNAL RESET
PULSE GENERATOR
WATCHDOG
Required
Note 1: 1.1 The reset network protects the device against parasitic resets. 1.2 The output of the external reset circuit must have an open-drain output to drive the ST7 reset pad. Otherwise the device can be damaged when the ST7 generates an internal reset (LVD or watchdog). 1.3 Whatever the reset source is (internal or external), the user must ensure that the level on the RESET pin can go below the VIL max. level specified in Section 12.10.1. Otherwise the reset will not be taken into account internally. 1.4 Because the reset circuit is designed to allow the internal RESET to be output in the RESET pin, the user must ensure that the current sunk on the RESET pin (by an external pull-up for example) is less than the absolute maximum value specified for IINJ(RESET) in Section 12.2.2 on page 179. Note 2: 2.1 When the LVD is enabled, it is mandatory not to connect a pull-up resistor. A 10nF pull-down capacitor is recommended to filter noise on the reset line. 2.2. In case a capacitive power supply is used, it is recommended to connect a1MW pull-down resistor to the RESET pin to discharge any residual voltage induced by this capacitive power supply (this will add 5A to the power consumption of the MCU). 2.3. Tips when using the LVD: - 1. Check that all recommendations related to reset circuit have been applied (see notes above) - 2. Check that the power supply is properly decoupled (100nF + 10F close to the MCU). Refer to AN1709. If this cannot be done, it is recommended to put a 100nF + 1MW pull-down on the RESET pin. - 3. The capacitors connected on the RESET pin and also the power supply are key to avoiding any start-up marginality. In most cases, steps 1 and 2 above are sufficient for a robust solution. Otherwise: Replace 10nF pull-down on the RESET pin with a 5F to 20F capacitor.
199/224
ST72361
CONTROL PIN CHARACTERISTICS (Cont'd) Figure 114. RESET RPU vs VDD
100 Rpu (kOhm ) 80 60 40 20 0 3.5 4 4.5 Vdd 5 5.5 Ta=-45C Ta=130 Ta=25C
12.10.2 ICCSEL/VPP Pin Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol VIL VIH IL Parameter Input low level voltage1) Input high level voltage1) Input leakage current VIN = VSS Conditions Min VSS VDD-0.1 Max 0.2 12.6 1 Unit
V
A
Figure 115. Two Typical Applications with ICCSEL/VPP Pin2)
ICCSEL/VPP VPP 10k
PROGRAMMING TOOL
ST72XXX
ST72XXX
Notes: 1. Data based on design simulation and/or technology characteristics, not tested in production. 2. When ICC mode is not required by the application ICCSEL/VPP pin must be tied to VSS.
200/224
ST72361
12.11 TIMER PERIPHERAL CHARACTERISTICS Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified. 12.11.1 8-Bit PWM-ART Autoreload Timer
Symbol Parameter Conditions Min 1 fCPU = 8 MHz 125 0 fCPU/2 8 VDD = 5V, Res = 8-bits fCPU = 8 MHz 1 0.125 20 128 16 Typ Max Unit tCPU ns MHz bit mV tCPU s
Refer to I/O port characteristics for more details on the input/output alternate function characteristics (output compare, input capture, external clock, PWM output...).
tres(PWM) PWM resolution time fEXT fPWM VOS tCOUNTER ART external clock frequency PWM repetition rate
ResPWM PWM resolution PWM/DAC output step voltage Timer clock period when internal clock is selected
12.11.2 8-Bit Timer
Symbol Parameter Conditions Min 1 2 fCPU = 8 MHz 250 0 fCPU/4 8 fCPU = 8 MHz 2 0.250 8000 1000 Typ Max Unit tCPU ns MHz bit tCPU s
tw(ICAP)in Input capture pulse time tres(PWM) PWM resolution time fPWM PWM repetition rate
ResPWM PWM resolution tCOUNTER Timer clock period
12.11.3 16-Bit Timer
Symbol Parameter Conditions Min 1 2 fCPU = 8 MHz 250 0 fCPU/4 16 fCPU = 8 MHz 2 0.250 8 1 Typ Max Unit tCPU ns MHz bit tCPU s
tw(ICAP)in Input capture pulse time tres(PWM) PWM resolution time fEXT fPWM Timer external clock frequency PWM repetition rate
ResPWM PWM resolution tCOUNTER Timer clock period when internal clock is selected
201/224
ST72361
12.12 COMMUNICATION INTERFACE CHARACTERISTICS 12.12.1 SPI - Serial Peripheral Interface Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol Parameter
Refer to I/O port characteristics for more details on the input/output alternate function characteristics (SS, SCK, MOSI, MISO).
Min 0 Max fCPU / 2 = 4 Unit MHz
Conditions Master, fCPU = 8 MHz Slave, fCPU = 8 MHz
fSCK = 1 / tc(SCK) SPI clock frequency tr(SCK) tf(SCK) tsu(SS)1) th(SS) tw(SCKH)1) tw(SCKL)1) tsu(MI)1) tsu(SI)1) th(MI)
1) 1)
fCPU / 128 = 0.0625 fCPU / 4 = 2
SPI clock rise and fall time SS setup time4) SS hold time SCK high and low time Data input setup time Data input hold time Data output access time Data output disable time Data output valid time Data output hold time Data output valid time Data output hold time Slave Master Slave Master Slave Master Slave Slave Slave (after enable edge) Master (after enable edge)
See I/O port pin description (4 x TCPU) + 50 120 100 90
100 ns 0 120 240 90 0 120 0
th(SI)1) ta(SO)1) tdis(SO)
1)
tv(SO)1) th(SO)1) tv(MO)1) th(MO)
1)
Figure 116. SPI Slave Timing Diagram with CPHA = 03)
SS INPUT tsu(SS) SCK INPUT CPHA = 0 CPOL = 0 CPHA = 0 CPOL = 1 ta(SO) MISO OUTPUT tw(SCKH) tw(SCKL) tv(SO) th(SO) tr(SCK) tf(SCK)
LSB OUT
tc(SCK)
th(SS)
tdis(SO)
See note 2
See note 2
MSB OUT
BIT6 OUT
tsu(SI)
th(SI)
MOSI INPUT
MSB IN
BIT1 IN
LSB IN
Notes: 1. Data based on design simulation and/or characterization results, not tested in production. 2. When no communication is on-going the data output line of the SPI (MOSI in master mode, MISO in slave mode) has its alternate function capability released. In this case, the pin status depends on the I/O port configuration. 3. Measurement points are done at CMOS levels: 0.3 x VDD and 0.7 x VDD. 4. Depends on fCPU. For example, if fCPU = 8 MHz, then TCPU = 1 / fCPU = 125ns and tsu(SS) = 550ns.
202/224
ST72361
COMMUNICATION INTERFACE CHARACTERISTICS (Cont'd) Figure 117. SPI Slave Timing Diagram with CPHA = 11)
SS INPUT tsu(SS) SCK INPUT CPHA = 0 CPOL = 0 CPHA = 0 CPOL = 1 ta(SO) tw(SCKH) tw(SCKL) tv(SO) th(SO) tr(SCK) tf(SCK)
LSB OUT
tc(SCK)
th(SS)
tdis(SO)
MISO OUTPUT
See note 2
Hz
MSB OUT
BIT6 OUT
See note 2
tsu(SI)
th(SI)
MOSI INPUT
MSB IN
BIT1 IN
LSB IN
Figure 118. SPI Master Timing Diagram1)
SS INPUT tc(SCK) CPHA = 0 CPOL = 0 SCK INPUT CPHA = 0 CPOL = 1 CPHA = 1 CPOL = 0 CPHA = 1 CPOL = 1 tw(SCKH) tw(SCKL) tsu(MI) MISO INPUT tv(MO) th(MI) tr(SCK) tf(SCK)
MSB IN
BIT6 IN
LSB IN
th(MO)
MOSI OUTPUT
See note 2
MSB OUT
BIT6 OUT
LSB OUT
See note 2
Notes: 1. Measurement points are done at CMOS levels: 0.3 x VDD and 0.7 x VDD. 2. When no communication is on-going the data output line of the SPI (MOSI in master mode, MISO in slave mode) has its alternate function capability released. In this case, the pin status depends on the I/O port configuration.
203/224
ST72361
COMMUNICATIONS INTERFACE CHARACTERISTICS (Cont'd)
12.13 10-BIT ADC CHARACTERISTICS Subject to general operating conditions for VDD, fCPU, and TA unless otherwise specified.
Symbol fADC VAIN RAIN CAIN fAIN Ilkg CADC tCONV IADC Parameter ADC clock frequency Conversion voltage range2) External input impedance External capacitor on analog input Variation frequency of analog input signal Negative input leakage current on ro- V < V | I | < 400A on IN SS, IN bust analog pins (refer to Table 2 on adjacent robust analog pin page 8) Internal sample and hold capacitor Conversion time Analog part Digital part fADC = 4 MHz Sunk on VDDA2) Sunk on VDD 5 6 3.5 14 3.6 0.2 Conditions Min1) 0.4 VSSA Typ Max1) 4 VDDA see Figure 119 and Figure 120 6 Unit MHz V k pF Hz A pF s 1/fADC mA
Notes: 1. Data based on characterization results, not tested in production. 2. When VDDA and VSSA pins are not available on the pinout, the ADC refers to VDD and VSS.
204/224
ST72361
ADC CHARACTERISTICS (Cont'd) Figure 119. RAIN Max vs fADC with CAIN = 0pF1)2)
45 40
Figure 120. Recommended CAIN/RAIN Values3)
1000
Cain 10 nF
Max. R AIN (Kohm)
35 30 25 20 15 10 5 0 0 10 30
4 MHz
Max. R AIN (Kohm)
2 MHz 1 MHz
100
Cain 22 nF Cain 47 nF
10
1
0.1
70
0.01
0.1
1
10
CPARASITIC (pF)
fAIN(KHz)
Figure 121. Typical Application with ADC
VDD VT 0.6V RAIN VAIN CAIN VT 0.6V IL 1A AINx
ST72XXX
2k(max)
10-Bit A/D Conversion CADC 6pF
Notes: 1. CPARASITIC represents the capacitance of the PCB (dependent on soldering and PCB layout quality) plus the pad capacitance (3pF). A high CPARASITIC value will downgrade conversion accuracy. To remedy this, fADC should be reduced. 2. Any added external serial resistor will downgrade the ADC accuracy (especially for resistance greater than 10k). Data based on characterization results, not tested in production. 3. This graph shows that depending on the input signal variation (fAIN), CAIN can be increased for stabilization time and reduced to allow the use of a larger serial resistor (RAIN). It is valid for all fADC frequencies 4 MHz.
205/224
ST72361
ADC CHARACTERISTICS (Cont'd) 12.13.0.1 Analog Power Supply and Reference Pins Depending on the MCU pin count, the package may feature separate VDDA and VSSA analog power supply pins. These pins supply power to the A/D converter cell and function as the high and low reference voltages for the conversion. In smaller packages VDDA and VSSA pins are not available and the analog supply and reference pads are internally bonded to the VDD and VSS pins. Separation of the digital and analog power pins allow board designers to improve A/D performance. Conversion accuracy can be impacted by voltage drops and noise in the event of heavily loaded or badly decoupled power supply lines (see Section 12.13.0.2 "General PCB Design Guidelines"). 12.13.0.2 General PCB Design Guidelines To obtain best results, some general design and layout rules should be followed when designing the application PCB to shield the noise-sensitive, analog physical interface from noise-generating CMOS logic signals. - Use separate digital and analog planes. The analog ground plane should be connected to the digital ground plane via a single point on the PCB. Figure 122. Power Supply Filtering
ST72XXX 1 to 10F
ST7 DIGITAL NOISE FILTERING
- Filter power to the analog power planes. It is recommended to connect capacitors, with good high frequency characteristics, between the power and ground lines, placing 0.1F and optionally, if needed 10pF capacitors as close as possible to the ST7 power supply pins and a 1 to 10F capacitor close to the power source (see Figure 122). - The analog and digital power supplies should be connected in a star network. Do not use a resistor, as VDDA is used as a reference voltage by the A/D converter and any resistance would cause a voltage drop and a loss of accuracy. - Properly place components and route the signal traces on the PCB to shield the analog inputs. Analog signals paths should run over the analog ground plane and be as short as possible. Isolate analog signals from digital signals that may switch while the analog inputs are being sampled by the A/D converter. Do not toggle digital outputs on the same I/O port as the A/D input being converted. 12.13.0.3 Software Filtering of Spurious Conversion Results For EMC performance reasons, it is recommended to filter A/D conversion outliers using software filtering techniques.
0.1F
VSS
VDD
VDD
POWER SUPPLY SOURCE EXTERNAL NOISE FILTERING
0.1F
VDDA
VSSA
206/224
ST72361
ADC CHARACTERISTICS (Cont'd) ADC Accuracy with fCPU = 8 MHz, fADC = 4 MHz RAIN < 10k, VDD = 5V
Symbol |ET| |EO| |EG| |ED| |EL| Offset error1) Gain Error1) Differential linearity error1)
1)
Parameter Total unadjusted error1)
Conditions
Typ 3.2 1 0.7 1.5 1.2
Max 5 4 2.3 3.6
Unit
LSB
Integral linearity error
Figure 123. ADC Accuracy Characteristics
Digital Result ADCDR 1023 1022 1021 1LSB IDEAL V -V DDA SSA = ----------------------------------------
EG
(1) Example of an actual transfer curve (2) The ideal transfer curve (3) End point correlation line
1024
(2) ET 7 6 5 4 3 2 1 0 1 VSSA 2 3 4 1 LSBIDEAL EO EL ED (3) (1)
ET=Total Unadjusted Error: maximum deviation between the actual and the ideal transfer curves. EO=Offset Error: deviation between the first actual transition and the first ideal one. EG=Gain Error: deviation between the last ideal transition and the last actual one. ED=Differential Linearity Error: maximum deviation between actual steps and the ideal one. EL=Integral Linearity Error: maximum deviation between any actual transition and the end point correlation line.
Vin (LSBIDEAL) 5 6 7 1021 1022 1023 1024 VDDA
Notes: 1. Data based on characterization results, not tested in production. ADC Accuracy vs. Negative Injection Current: Injecting negative current on any of the standard (non-robust) analog input pins should be avoided as this significantly reduces the accuracy of the conversion being performed on another analog input. It is recommended to add a Schottky diode (pin to ground) to standard analog pins which may potentially inject negative current. The effect of negative injection current on robust pins is specified in Section 12.9. Any positive injection current within the limits specified for IINJ(PIN) and IINJ(PIN) in Section 12.9 does not affect the ADC accuracy.
207/224
ST72361
13 PACKAGE CHARACTERISTICS
13.1 PACKAGE MECHANICAL DATA Figure 124. 32-Pin Low Profile Quad Flat Package (7x7)
Dim.
A A2 A1
mm Min 0.05 1.35 0.30 0.09 9.00 7.00 9.00 7.00 0.80 0 0.45 3.5 0.60 1.00 7 0 1.40 0.37 Typ Max 1.60 Min
inches1) Typ Max 0.063 0.006
D D1
A A1 A2 b C D D1 E E1 e
h
0.15 0.002
1.45 0.053 0.055 0.057 0.45 0.012 0.015 0.018 0.20 0.004 0.354 0.276 0.354 0.276 0.031 3.5 0.039 7 0.75 0.018 0.024 0.030 0.008
e E1 E
b
L1 L
c
L L1
Number of Pins N 32 Note 1. Values in inches are converted from mm and rounded to 3 decimal digits.
Figure 125. 44-Pin Low Profile Quad Flat Package (10x10)
D D1 A1 b A A2
Dim. A A1 A2 b C D D1 E E1 e 0 0.45 L L1 0.05 1.35 0.30 0.09 12.00 10.00 12.00 10.00 0.80 3.5 0.60 1.00 7 0 1.40 0.37 mm Min Typ Max 1.60 0.15 0.002 Min inches1) Typ Max 0.063 0.006
1.45 0.053 0.055 0.057 0.45 0.012 0.015 0.018 0.20 0.004 0.000 0.008 0.472 0.394 0.472 0.394 0.031 3.5 0.039 7 0.75 0.018 0.024 0.030
E1 E
e
L1 L h
c
Number of Pins N 44 Note 1. Values in inches are converted from mm and rounded to 3 decimal digits.
208/224
ST72361
Figure 126. 64-Pin Low Profile Quad Flat Package (10 x10)
Dim.
D D1 A1 A A2
mm Min 0.05 1.35 0.17 0.09 12.00 10.00 12.00 10.00 0.50 0 0.45 3.5 0.60 1.00 64 7 0 1.40 0.22 Typ Max 1.60 0.15 0.002 Min
inches Typ Max 0.063 0.006
A A1 A2 b
1.45 0.053 0.055 0.057 0.27 0.007 0.009 0.011 0.20 0.004 0.472 0.394 0.472 0.394 0.020 3.5 0.039 7 0.75 0.018 0.024 0.030 0.008
b
c D D1
E1
E e
E E1 e
c
L L1 N
L1 L
Number of Pins
13.2 THERMAL CHARACTERISTICS
Symbol
Ratings Package thermal resistance (junction to ambient) LQFP64 LQFP44 LQFP32 Power dissipation1) Maximum junction temperature
2)
Value 60 52 70 500 150
Unit
RthJA PD TJmax
C/W
mW C
Notes: 1. The maximum power dissipation is obtained from the formula PD = (TJ - TA) / RthJA. The power dissipation of an application can be defined by the user with the formula: PD = PINT + PPORT where PINT is the chip internal power (IDD x VDD) and PPORT is the port power dissipation depending on the ports used in the application. 2. The maximum chip-junction temperature is based on technology characteristics.
13.3 SOLDERING AND GLUEABILITY INFORMATION In order to meet environmental requirements, ST offers these devices in ECOPACKTM packages. These packages have a lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACKTM specifications are available at www.st.com.
209/224
ST72361
14 DEVICE CONFIGURATION AND ORDERING INFORMATION
Each device is available for production in user programmable versions (FLASH) as well as in factory coded versions (ROM/FASTROM). ST72361 devices are ROM versions. ST72P361 devices are Factory Advanced Service Technique ROM (FASTROM) versions: They are factory-programmed HDFlash devices. ST72F361 FLASH devices are shipped to customers with a default content (FFh), while ROM factory coded parts contain the code supplied by the customer. This implies that FLASH devices have to be configured by the customer using the Option Bytes while the ROM devices are factory-configured. 14.1 FLASH OPTION BYTES The option bytes allows the hardware configuration of the microcontroller to be selected. They have no address in the memory map and can be accessed only in programming mode (for example using a standard ST7 programming tool). The default content of the FLASH is fixed to FFh. To program directly the FLASH devices using ICP, FLASH devices are shipped to customers with a reserved internal clock source enabled. In masked ROM devices, the option bytes are fixed in hardware by the ROM code (see option list). OPTION BYTE 0 OPT7 = WDGHALT Watchdog reset on HALT This option bit determines if a RESET is generated when entering HALT mode while the Watchdog is
STATIC OPTION BYTE 0 7 Reserved PLLOFF WDG HALT SW PKG 1 1 0 1 0 FMP_R 7 AFI_MAP 1 1 0 1 OSCTYPE OSCRANGE 1 1 0 0 1 1 0 1 Reserved 1
active. 0: No Reset generation when entering Halt mode 1: Reset generation when entering Halt mode OPT6 = WDGSW Hardware or software watchdog This option bit selects the watchdog type. 0: Hardware (watchdog always enabled) 1: Software (watchdog to be enabled by software) OPT5 = Reserved, must be kept at default value. OPT4 = LVD Voltage detection This option bit enables the voltage detection block (LVD).
Selected Low Voltage Detector LVD Off LVD On VD 1 0
OPT3 = PLL OFF PLL activation This option bit activates the PLL which allows multiplication by two of the main input clock frequency. The PLL is guaranteed only with an input frequency between 2 and 4 MHz. 0: PLL x2 enabled 1: PLL x2 disabled Caution: The PLL can be enabled only if the "OSC RANGE" (OPT11:10) bits are configured to "MP 2~4 MHz". Otherwise, the device functionality is not guaranteed.
STATIC OPTION BYTE 1 0 RSTC 1
LVD
Default(*)
1
1
1
1
1
1
(*): Option bit values programmed by ST
210/224
ST72361
FLASH OPTION BYTES (Cont'd) OPT2:1 = PKG[1:0] Package selection These option bits select the device package.
PKG Selected Package 1 LQFP 64 LQFP 44 LQFP 32 1 0 0 0 x 1 0
AFI Mapping 0 T16_ICAP2 is mapped on PD1 T16_ICAP2 is mapped on PC1
AFI_MAP(0) 0 1
OPT5:4 = OSCTYPE[1:0] Oscillator Type These option bits select the ST7 main clock source type.
OSCTYPE Clock Source 1 Resonator Oscillator Reserved Reserved internal clock source (used only in ICC mode) External Source 0 0 1 1 0 0 1 0 1
Note: Pads that are not bonded to external pins are in input pull-up configuration when the package selection option bits have been properly programmed. The configuration of these pads must be kept in reset state to avoid added current consumption. OPT0 = FMP_R Flash memory read-out protection Read-out protection, when selected provides a protection against program memory content extraction and against write access to Flash memory. Erasing the option bytes when the FMP_R option is selected causes the whole user memory to be erased first, and the device can be reprogrammed. Refer to Section 4.3.1 and the ST7 Flash Programming Reference Manual for more details. 0: Read-out protection enabled 1: Read-out protection disabled OPTION BYTE 1 OPT7:6 = AFI_MAP[1:0] AFI Mapping These option bits allow the mapping of some of the Alternate Functions to be changed.
AFI Mapping 1 T16_OCMP1 on PD3 T16_OCMP2 on PD5 T16_ICAP1 on PD4 LINSCI2_SCK not available LINSCI2_TDO not available LINSCI2_RDI not available T16_OCMP1 on PB6 T16_OCMP2 on PB7 T16_ICAP1 on PC0 LINSCI2_SCK on PD3 LINSCI2_TDO on PD5 LINSCI2_RDI on PD4 AFI_MAP(1)
OPT3:2 = OSCRANGE[1:0] Oscillator range If the resonator oscillator type is selected, these option bits select the resonator oscillator. This selection corresponds to the frequency range of the resonator used. If external source is selected with the OSCTYPE option, then the OSCRANGE option must be selected with the corresponding range.
OSCRANGE Typ. Freq. Range 1 LP MP MS HS 1~2 MHz 2~4 MHz 4~8 MHz 8~16 MHz 0 0 1 1 0 0 1 0 1
0
OPT1 = Reserved OPT0 = RSTC RESET clock cycle selection This option bit selects the number of CPU cycles inserted during the RESET phase and when exiting HALT mode. For resonator oscillators, it is advised to select 4096 due to the long crystal stabilization time. 0: Reset phase with 4096 CPU cycles 1: Reset phase with 256 CPU cycles
1
211/224
ST72361
DEVICE CONFIGURATION AND ORDER INFORMATION (cont'd) Table 35. FLASH User Programmable Device Types
Part Number ST72F361AR6T6 ST72F361AR7T6 ST72F361AR9T6 ST72F361J6T6 ST72F361J7T6 ST72F361J9T6 ST72F361K6T6 ST72F361K7T6 ST72F361K9T6 ST72F361AR6T3 ST72F361AR7T3 ST72F361AR9T3 ST72F361J6T3 ST72F361J7T3 ST72F361J9T3 ST72F361K6T3 ST72F361K7T3 ST72F361K9T3 Package Memory (Kbytes) 32 48 60 32 48 60 32 48 60 32 48 60 32 48 60 32 48 60 RAM (Kbytes) 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 Temp Range
LQFP64 10x10
LQFP44 10x10
-40 to +85C
LQFP32 7x7
LQFP64 10x10
LQFP44 10x10
-40 to +125C
LQFP32 7x7
14.2 TRANSFER OF CUSTOMER CODE Customer code is made up of the ROM/FASTROM contents and the list of the selected options (if any). The ROM/FASTROM contents are to be sent on diskette, or by electronic means, with the S19 hexadecimal file generated by the development tool. All unused bytes must be set to FFh. The selected options are communicated to STMicroelectronics using the correctly completed OPTION LIST appended.
Refer to application note AN1635 for information on the counter listing returned by ST after code has been transferred. The STMicroelectronics Sales Organization will be pleased to provide detailed information on contractual points.
212/224
ST72361
TRANSFER OF CUSTOMER CODE (cont'd) Figure 127. ROM Commercial Product Code Structure
DEVICE PACKAGE VERSION / XXX TR E
E = leadfree (ECOPACKTM option) Conditioning options: TR = Tape and Reel (left blank if Tray) Code name (defined by STMicroelectronics) 6 = -40 to +85 C 3 = -40 to +125 C T= Low Profile Quad Flat Pack ST72361
Table 36. ROM Factory Coded Device Types
Part Number ST72361AR6T6 ST72361AR7T6 ST72361AR9T6 ST72361J6T6 ST72361J7T6 ST72361J9T6 ST72361K6T6 ST72361K7T6 ST72361K9T6 ST72361AR6T3 ST72361AR7T3 ST72361AR9T3 ST72361J6T3 ST72361J7T3 ST72361J9T3 ST72361K6T3 ST72361K7T3 ST72361K9T3 Package Memory (Kbytes) 32 48 60 32 48 60 32 48 60 32 48 60 32 48 60 32 48 60 RAM (Kbytes) 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 Temp Range
LQFP64 10x10
LQFP44 10x10
-40 to +85C
LQFP32 7x7
LQFP64 10x10
LQFP44 10x10
-40 to +125C
LQFP32 7x7
213/224
ST72361
Figure 128. FASTROM Commercial Product Code Structure
DEVICE PACKAGE VERSION XXX TR E
E = leadfree (ECOPACKTM option) Conditioning options: TR = Tape and Reel (left blank if Tray) Code name (defined by STMicroelectronics) 6 = Standard -40 to +85 C 3 = Standard -40 to +125 C T= Low Profile Quad Flat Pack ST72P361
214/224
ST72361
Figure 129. FASTROM Factory Coded Device Types
Part Number ST72P361AR6T6 ST72P361AR7T6 ST72P361AR9T6 ST72P361J6T6 ST72P361J7T6 ST72P361J9T6 ST72P361K6T6 ST72P361K7T6 ST72P361K9T6 ST72P361AR6T3 ST72P361AR7T3 ST72P361AR9T3 ST72P361J6T3 ST72P361J7T3 ST72P361J9T3 ST72P361K6T3 ST72P361K7T3 ST72P361K9T3 Package Memory (Kbytes) 32 48 60 32 48 60 32 48 60 32 48 60 32 48 60 32 48 60 RAM (Kbytes) 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 1.5 2 2 Temp Range
LQFP64 10x10
LQFP44 10x10
-40 to +85C
LQFP32 7x7
LQFP64 10x10
LQFP44 10x10
-40 to +125C
LQFP32 7x7
215/224
ST72361
TRANSFER OF CUSTOMER CODE (Cont'd)
ST72361 MICROCONTROLLER OPTION LIST (Last update: September 2006)
................................................................................ ................................................................................ ................................................................................ Contact ................................................................................ Phone No ................................................................................ Reference/ROM Code* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . *The ROM/FASTROM code name is assigned by STMicroelectronics. ROM/FASTROM code must be sent in .S19 format. .Hex extension cannot be processed. Device Type/Memory Size/Package (check only one option) Customer Address
ROM:
| | | | | | FASTROM: | | | |
-----------------------| Package -----------------------| LQFP64 10x10: | LQFP44: | LQFP32: | -----------------------| Package -----------------------| LQFP64 10x10: | LQFP44: | LQFP32: |
------------------------- | 60K ------------------------- | [ ] ST72361AR9 | [ ] ST72361J9 | [ ] ST72361K9 | ------------------------- | 60K ------------------------- | [ ] ST72P361AR9 | [ ] ST72P361J9 | [ ] ST72P361K9 |
------------------------- | 48K ------------------------- | [ ] ST72361AR7 | [ ] ST72361J7 | [ ] ST72361K7 | ------------------------- | 48K ------------------------- | [ ] ST72P361AR7 | [ ] ST72P361J7 | [ ] ST72P361K7 |
------------------------ | 32K ------------------------ | [ ] ST72361AR6 | [ ] ST72361J6 | [ ] ST72361K6 | ------------------------ | 32K ------------------------ | [ ] ST72P361AR6 | [ ] ST72P361J6 | [ ] ST72P361K6 |
------------------------ | ------------------------ | | | | ------------------------ | ------------------------ | | | |
Conditioning: [ ] Tray [ ] Tape & Reel Special Marking: [ ] No [ ] Yes "_ _ _ _ _ _ _ _ _ _ " (10 char. max) Authorized characters are letters, digits, '.', '-', '/' and spaces only. Temp. Range. Please refer to datasheet for specific sales conditions: --------------------------------------| Temp. Range --------------------------------------[] | -40C to +85C [] | -40C to +125C Clock Source Selection: Oscillator/External source range: [ ] LP: Low power (1 to 2 MHz) [ ] MP: Medium power (2 to 4 MHz) [ ] MS: Medium speed (4 to 8 MHz) [ ] HS: High speed (8 to 16 MHz) [ ] Disabled [ ] Enabled [ ] Disabled [ ] Enabled [ ] Software Activation [ ] Hardware Activation [ ] Reset [ ] No Reset [ ] Disabled [ ] 256 Cycles [ ] 4096 Cycles [ ] Mapped (AFIMAP[1] = 1) [ ] On PC1 (AFIMAP[0] = 1) [ ] Enabled [ ] Resonator: [ ] External Source
LVD PLL1 Watchdog Selection Watchdog Reset on Halt Read-out Protection Reset Delay LINSCI2 Mapping T16_ICAP2 Mapping
[ ] Not available (AFIMAP[1] = 0) [ ] On PD1 (AFIMAP[0] = 0)
Comments: Supply Operating Range in the application: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes Signature Date
1 If
................................................................................ ................................................................................ ................................................................................
PLL is enabled, medium power (2 to 4 MHz range) has to be selected (MP)
Please download the latest version of this option list from: http://www.st.com
216/224
ST72361
15 DEVELOPMENT TOOLS
Development tools for the ST7 microcontrollers include a complete range of hardware systems and software tools from STMicroelectronics and thirdparty tool suppliers. The range of tools includes solutions to help you evaluate microcontroller peripherals, develop and debug your application, and program your microcontrollers. 15.0.1 Evaluation Tools and Starter Kits ST offers complete, affordable starter kits and full-featured evaluation boards that allow you to evaluate microcontroller features and quickly start developing ST7 applications. Starter kits are complete, affordable hardware/software tool packages that include features and samples to help you quickly start developing your application. ST evaluation boards are open-design, embedded systems, which are developed and documented to serve as references for your application design. They include sample application software to help you demonstrate, learn about and implement your ST7's features. 15.0.2 Development and Debugging Tools Application development for ST7 is supported by fully optimizing C Compilers and the ST7 Assembler-Linker toolchain, which are all seamlessly integrated in the ST7 integrated development environments in order to facilitate the debugging and fine-tuning of your application. The Cosmic C Compiler is available in a free version that outputs up to 16K of code. The range of hardware tools includes cost effective ST7-DVP3 series emulators. These tools are supported by the ST7 Toolset from STMicroelectronics, which includes the STVD7 integrated development environment (IDE) with high-level language debugger, editor, project manager and integrated programming interface. 15.0.3 Programming Tools During the development cycle, the ST7-DVP3 and ST7-EMU3 series emulators and the RLink provide in-circuit programming capability for programming the Flash microcontroller on your application board. ST also provides dedicated a low-cost dedicated in-circuit programmer, the ST7-STICK, as well as ST7 Socket Boards which provide all the sockets required for programming any of the devices in a specific ST7 sub-family on a platform that can be used with any tool with in-circuit programming capability for ST7. For production programming of ST7 devices, ST's third-party tool partners also provide a complete range of gang and automated programming solutions, which are ready to integrate into your production environment. For additional ordering codes for spare parts, accessories and tools available for the ST7 (including from third party manufacturers), refer to the online product selector at www.st.com.
15.0.4 Order Codes for ST72361 Development Tools Table 37. Development Tool Order Codes for the ST72361 Family
MCU ST72361 In-circuit Debugger Starter Kit with Demo Board ST72F36X-SK/RAIS1) Emulator ST7MDT25-DVP32) Programming Tool In-circuit ST7 Socket Board6) Programmer ST7-STICK3)4) ST7SB253) STX-RLINK5)
Notes: 1. In-circuit programming only. In-circuit debugging is not yet supported for HDFlash devices without debug module such as the ST72F36x. 2. Requires optional connection kit. See "How to order and EMU or DVP" for connection kit ordering information in ST product and tool selection guide 3. Add suffix /EU, /UK or /US for the power supply for your region 4. Parellel port connection to PC 5. USB connection to PC 6. Socket boards complement any tool with ICC capabilities (ST7-STICK, InDART, RLINK, DVP3, EMU3, etc.)
217/224
ST72361
16 IMPORTANT NOTES
16.1 ALL DEVICES 16.1.1 RESET Pin Protection with LVD Enabled As mentioned in note 2 below Figure 112 on page 199, when the LVD is enabled, it is recommended not to connect a pull-up resistor or capacitor. A 10nF pull-down capacitor is required to filter noise on the reset line. 16.1.2 Clearing Active Interrupts Outside Interrupt Routine When an active interrupt request occurs at the same time as the related flag or interrupt mask is being cleared, the CC register may be corrupted. Concurrent interrupt context The symptom does not occur when the interrupts are handled normally, that is, when: - The interrupt request is cleared (flag reset or interrupt mask) within its own interrupt routine - The interrupt request is cleared (flag reset or interrupt mask) within any interrupt routine - The interrupt request is cleared (flag reset or interrupt mask) in any part of the code while this interrupt is disabled If these conditions are not met, the symptom can be avoided by implementing the following sequence: Perform SIM and RIM operation before and after resetting an active interrupt request Example: SIM reset flag or interrupt mask RIM Nested interrupt context The symptom does not occur when the interrupts are handled normally, that is, when: - The interrupt request is cleared (flag reset or interrupt mask) within its own interrupt routine - The interrupt request is cleared (flag reset or interrupt mask) within any interrupt routine with higher or identical priority level - The interrupt request is cleared (flag reset or interrupt mask) in any part of the code while this interrupt is disabled If these conditions are not met, the symptom can be avoided by implementing the following sequence: PUSH CC SIM reset flag or interrupt mask POP CC 16.1.3 External Interrupt Missed To avoid any risk of generating a parasitic interrupt, the edge detector is automatically disabled for one clock cycle during an access to either DDR and OR. Any input signal edge during this period will not be detected and will not generate an interrupt. This case can typically occur if the application refreshes the port configuration registers at intervals during runtime. Workaround The workaround is based on software checking the level on the interrupt pin before and after writing to the PxOR or PxDDR registers. If there is a level change (depending on the sensitivity programmed for this pin) the interrupt routine is invoked using the call instruction with three extra PUSH instructions before executing the interrupt routine (this is to make the call compatible with the IRET instruction at the end of the interrupt service routine). But detection of the level change does ensure that edge occurs during the critical 1 cycle duration and the interrupt has been missed. This may lead to occurrence of same interrupt twice (one hardware and another with software call). To avoid this, a semaphore is set to '1' before checking the level change. The semaphore is changed to level '0' inside the interrupt routine. When a level change is detected, the semaphore status is checked and if it is '1' this means that the last interrupt has been missed. In this case, the interrupt routine is invoked with the call instruction. There is another possible case, that is, if writing to PxOR or PxDDR is done with global interrupts disabled (interrupt mask bit set). In this case, the semaphore is changed to '1' when the level change is detected. Detecting a missed interrupt is done after the global interrupts are enabled (interrupt mask bit reset) and by checking the status of the semaphore. If it is '1' this means that the last interrupt was missed and the interrupt routine is invoked with the call instruction. To implement the workaround, the following software sequence is to be followed for writing into the PxOR/PxDDR registers. The example is for Port PF1 with falling edge interrupt sensitivity. The
218/224
ST72361
IMPORTANT NOTES (Cont'd) software sequence is given for both cases (global interrupt disabled/enabled). Case 1: Writing to PxOR or PxDDR with Global Interrupts Enabled: LD A,#01 LD sema,A ; set the semaphore to '1' LD A,PFDR AND A,#02 LD X,A ; store the level before writing to PxOR/PxDDR LD A,#$90 LD PFDDR,A ; Write to PFDDR LD A,#$ff LD PFOR,A ; Write to PFOR LD A,PFDR AND A,#02 LD Y,A ; store the level after writing to PxOR/PxDDR LD A,X ; check for falling edge cp A,#02 jrne OUT TNZ Y jrne OUT LD A,sema ; check the semaphore status if edge is detected CP A,#01 jrne OUT call call_routine; call the interrupt routine OUT:LD A,#00 LD sema,A .call_routine ; entry to call_routine PUSH A PUSH X PUSH CC .ext1_rt ; entry to interrupt routine LD A,#00 LD sema,A IRET Case 2: Writing to PxOR or PxDDR with Global Interrupts Disabled: SIM ; set the interrupt mask LD A,PFDR AND A,#$02
LD X,A ; store the level before writing to PxOR/PxDDR LD A,#$90 LD PFDDR,A; Write into PFDDR LD A,#$ff LD PFOR,A ; Write to PFOR LD A,PFDR AND A,#$02 LD Y,A ; store the level after writing to PxOR/ PxDDR LD A,X ; check for falling edge cp A,#$02 jrne OUT TNZ Y jrne OUT LD A,#$01 LD sema,A ; set the semaphore to '1' if edge is detected RIM ; reset the interrupt mask LD A,sema ; check the semaphore status CP A,#$01 jrne OUT call call_routine; call the interrupt routine RIM OUT: RIM JP while_loop .call_routine ; entry to call_routine PUSH A PUSH X PUSH CC .ext1_rt ; entry to interrupt routine LD A,#$00 LD sema,A IRET 16.1.4 Unexpected Reset Fetch If an interrupt request occurs while a "POP CC" instruction is executed, the interrupt controller does not recognise the source of the interrupt and, by default, passes the RESET vector address to the CPU. Workaround To solve this issue, a "POP CC" instruction must always be preceded by a "SIM" instruction.
219/224
ST72361
IMPORTANT NOTES (Cont'd) 16.1.5 Header Time-out Does Not Prevent Wake-up from Mute Mode Normally, when LINSCI is configured in LIN slave mode, if a header time-out occurs during a LIN header reception (that is, header length > 57 bits), the LIN Header Error bit (LHE) is set, an interrupt occurs to inform the application but the LINSCI should stay in mute mode, waiting for the next header reception. Problem Description The LINSCI sampling period is Tbit / 16. If a LIN Header time-out occurs between the 9th and the 15th sample of the Identifier Field Stop Bit (refer to Figure 130), the LINSCI wakes up from mute mode. Nevertheless, LHE is set and LIN Header Detection Flag (LHDF) is kept cleared. In addition, if LHE is reset by software before this 15th sample (by accessing the SCISR register and Figure 130. Header Reception Event Sequence
reading the SCIDR register in the LINSCI interrupt routine), the LINSCI will generate another LINSCI interrupt (due to the RDRF flag setting). Impact on application Software may execute the interrupt routine twice after header reception. Moreover, in reception mode, as the receiver is no longer in mute mode, an interrupt will be generated on each data byte reception. Workaround The problem can be detected in the LINSCI interrupt routine. In case of timeout error (LHE is set and LHLR is loaded with 00h), the software can check the RWU bit in the SCICR2 register. If RWU is cleared, it can be set by software. Refer to Figure 131 on page 221. Workaround is shown in bold characters.
LIN Synch Break
LIN Synch Field
Identifier Field
THEADER
ID field STOP bit Critical Window Active mode is set (RWU is cleared)
RDRF flag is set
220/224
ST72361
IMPORTANT NOTES (Cont'd) Figure 131.LINSCI Interrupt Routine @interrupt void LINSCI_IT ( void ) /* LINSCI interrupt routine */ { /* clear flags */ SCISR_buffer = SCISR; SCIDR_buffer = SCIDR; if ( SCISR_buffer & LHE )/* header error ? */ { if (!LHLR)/* header time-out? */ { if ( !(SCICR2 & RWU) )/* active mode ? */ { _asm("sim");/* disable interrupts */ SCISR; SCIDR;/* Clear RDRF flag */ SCICR2 |= RWU;/* set mute mode */ SCISR; SCIDR;/* Clear RDRF flag */ SCICR2 |= RWU;/* set mute mode */ _asm("rim");/* enable interrupts */ } } } }
Example using Cosmic compiler syntax
16.2 FLASH/FASTROM DEVICES ONLY 16.2.1 LINSCI Wrong Break Duration SCI mode A single break character is sent by setting and resetting the SBK bit in the SCICR2 register. In some cases, the break character may have a longer duration than expected: - 20 bits instead of 10 bits if M = 0 - 22 bits instead of 11 bits if M = 1 In the same way, as long as the SBK bit is set, break characters are sent to the TDO pin. This may lead to generate one break more than expected. Occurrence The occurrence of the problem is random and proportional to the baud rate. With a transmit frequency of 19200 baud (fCPU = 8 MHz and SCIBRR = 0xC9), the wrong break duration occurrence is around 1%. Workaround
If this wrong duration is not compliant with the communication protocol in the application, software can request that an Idle line be generated before the break character. In this case, the break duration is always correct assuming the application is not doing anything between the idle and the break. This can be ensured by temporarily disabling interrupts. The exact sequence is: - Disable interrupts - Reset and Set TE (IDLE request) - Set and Reset SBK (Break Request) - Re-enable interrupts LIN mode If the LINE bit in the SCICR3 is set and the M bit in the SCICR1 register is reset, the LINSCI is in LIN master mode. A single break character is sent by setting and resetting the SBK bit in the SCICR2 register. In some cases, the break character may have a longer duration than expected: - 24 bits instead of 13 bits
221/224
ST72361
IMPORTANT NOTES (Cont'd) Occurrence The occurrence of the problem is random and proportional to the baud rate. With a transmit frequency of 19200 baud (fCPU = 8 MHz and SCIBRR = 0xC9), the wrong break duration occurrence is around 1%. Analysis The LIN protocol specifies a minimum of 13 bits for the break duration, but there is no maximum value. Nevertheless, the maximum length of the header is specified as (14+10+10+1) x 1.4 = 49 bits. This is composed of: - the synch break field (14 bits) - the synch field (10 bits) - the identifier field (10 bits) Every LIN frame starts with a break character. Adding an idle character increases the length of each header by 10 bits. When the problem occurs, the header length is increased by 11 bits and becomes ((14+11)+10+10+1) = 45 bits. To conclude, the problem is not always critical for LIN communication if the software keeps the time between the sync field and the ID smaller than 4 bits, that is, 208s at 19200 baud.
The workaround is the same as for SCI mode but considering the low probability of occurrence (1%), it may be better to keep the break generation sequence as it is. 16.2.2 16-bit and 8-bit Timer PWM Mode In PWM mode, the first PWM pulse is missed after writing the value FFFCh in the OC1R or OC2R register. 16.3 ROM DEVICES ONLY 16.3.1 16-bit Timer PWM Mode Buffering Feature Change In all devices, the frequency and period of the PWM signal are controlled by comparing the counter with a 16-bit buffer updated by the OCiHR and OCiLR registers. In ROM devices, contrary to the description in Section 10.5.3.5 on page 101, the output compare function is not inhibited after a write instruction to the OCiHR register. Instead the buffer update at the end of the PWM period is inhibited until OCiLR is written. This improved buffer handling is fully compatible with applications written for Flash devices.
222/224
ST72361
17 REVISION HISTORY
Date 04-Oct-2005 Revision 1 Initial revision Changed note in "Device Summary" on page 1 Changed Section 10.6.3.3 on page 112 Changed "FASTROM Factory Coded Device Types" on page 215 Deleted Section 15.1.5 "Clearing active interrupts outside interrupt routine" (text already exists in Section 16.1.2 on page 218) Added Section 16.1.5 on page 220 Replaced TQFP with LQFP packages throughout document Changed Section 12.12.1 on page 202 Changed Section 9.2.1 on page 45 Changed title of Section 9.6 on page 49 from "I/O Port Implementation" to "I/O Port Register Configurations" Corrected name of bit 5 in SPICSR register in Table 22 on page 119 Changed Section 12.5.4 on page 187 Added links to Table 33 and Table 34 in Section 12.8.3 on page 192 Removed EMC protection circuitry in Figure 113 on page 199 (device works correctly without these components) Changed Section 12.12.1 on page 202 Changed notes in Section 13.2 on page 209 Changed AFI mapping for "OPTION BYTE 1" on page 211 Changed title of Figure 124 on page 208 Changed title of Figure 125 on page 208 Changed Figure 127 on page 213 Added Figure 36 on page 213 Replaced "Flash Memory" with "Memory" as column heading in Figure 35 on page 212 and Figure 129 on page 215 Changed Section 15 on page 217 Added Table 37 on page 217 Removed automotive part numbers, see separate ST72361-auto datasheet Added EMI characteristics for LQFP44 in Section 12.8 Updated ADC accuracy characteristics in Section 12.13. Main changes
26-Sep-2006
2
19-Jun-2007
3
223/224
ST72361
Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST's terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein. UNLESS OTHERWISE SET FORTH IN ST'S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY, DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER'S OWN RISK. Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST. ST and the ST logo are trademarks or registered trademarks of ST in various countries. Information in this document supersedes and replaces all information previously supplied. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. (c) 2007 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com
224/224

▲Up To Search▲

Price & Availability of ST72361

	To Download ST72361 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .