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Freescale Semiconductor, Inc.
MC68HC08AB16A/D REV. 2.0
Freescale Semiconductor, Inc...
MC68HC08AB16A
HCMOS Microcontroller Unit
TECHNICAL DATA
For More Information On This Product, Go to: www.freescale.com
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
For More Information On This Product, Go to: www.freescale.com
Freescale Semiconductor, Inc.
Technical Data -- MC68HC08AB16A
List of Sections
Section 1. General Description . . . . . . . . . . . . . . . . . . . .29 Section 2. Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . .41
Freescale Semiconductor, Inc...
Section 3. Random-Access Memory (RAM) . . . . . . . . . .57 Section 4. Read-Only Memory (ROM) . . . . . . . . . . . . . . .59 Section 5. EEPROM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 Section 6. Mask Options (MOR) . . . . . . . . . . . . . . . . . . . .75 Section 7. Central Processor Unit (CPU) . . . . . . . . . . . .81 Section 8. System Integration Module (SIM) . . . . . . . .101 Section 9. Clock Generator Module (CGM) . . . . . . . . . .123 Section 10. Monitor ROM (MON) . . . . . . . . . . . . . . . . . .149 Section 11. Timer Interface Module A (TIMA) . . . . . . . .161 Section 12. Timer Interface Module B (TIMB) . . . . . . . .187 Section 13. Programmable Interrupt Timer (PIT) . . . . .213 Section 14. Analog-to-Digital Converter (ADC) . . . . . .221 Section 15. Serial Communications Interface Module (SCI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .231 Section 16. Serial Peripheral Interface Module (SPI) . .271 Section 17. Input/Output (I/O) Ports . . . . . . . . . . . . . . .303 Section 18. External Interrupt (IRQ) . . . . . . . . . . . . . . .331 Section 19. Keyboard Interrupt Module (KBI). . . . . . . .337
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Freescale Semiconductor, Inc. List of Sections Section 20. Computer Operating Properly (COP) . . . .345 Section 21. Low-Voltage Inhibit (LVI) . . . . . . . . . . . . . .351 Section 22. Break Module (BRK) . . . . . . . . . . . . . . . . . .357 Section 23. Electrical Specifications . . . . . . . . . . . . . . .365 Section 24. Mechanical Specifications . . . . . . . . . . . . .377
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Technical Data
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Technical Data -- MC68HC08AB16A
Table of Contents
Section 1. General Description
1.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
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1.2 1.3 1.4 1.5
1.6 Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 1.6.1 Power Supply Pins (VDD and VSS) . . . . . . . . . . . . . . . . . . . . 34 1.6.2 Oscillator Pins (OSC1 and OSC2) . . . . . . . . . . . . . . . . . . . . 35 1.6.3 External Reset Pin (RST) . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.6.4 External Interrupt Pin (IRQ) . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.6.5 Analog Power Supply Pin (VDDA) . . . . . . . . . . . . . . . . . . . . . 35 1.6.6 Analog Ground Pin (VSSA) . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.6.7 Analog Ground Pin (AVSS/VREFL). . . . . . . . . . . . . . . . . . . . . 35 1.6.8 ADC Voltage Reference Pin (VREFH) . . . . . . . . . . . . . . . . . . 36 1.6.9 Analog Supply Pin (VDDAREF) . . . . . . . . . . . . . . . . . . . . . . . 36 1.6.10 External Filter Capacitor Pin (CGMXFC) . . . . . . . . . . . . . . . 36 1.6.11 Port A Input/Output (I/O) Pins (PTA7-PTA0) . . . . . . . . . . . . 36 1.6.12 Port B I/O Pins (PTB7/ATD7-PTB0/ATD0) . . . . . . . . . . . . . 36 1.6.13 Port C I/O Pins (PTC5-PTC0) . . . . . . . . . . . . . . . . . . . . . . . 36 1.6.14 Port D I/O Pins (PTD7-PTD0) . . . . . . . . . . . . . . . . . . . . . . . 37 1.6.15 Port E I/O Pins (PTE7/SPSCK-PTE0/TxD) . . . . . . . . . . . . . 37 1.6.16 Port F I/O Pins (PTF7-PTF0/TACH2) . . . . . . . . . . . . . . . . . 37 1.6.17 Port G I/O Pins (PTG2/KBD2-PTG0/KBD0) . . . . . . . . . . . . 37 1.6.18 Port H I/O Pins (PTH1/KBD4-PTH0/KBD3). . . . . . . . . . . . . 37 1.7 1.8 1.9
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I/O Pin Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Signal Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Clock Source Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
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Freescale Semiconductor, Inc. Table of Contents Section 2. Memory Map
2.1 2.2 2.3 2.4 2.5 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Unimplemented Memory Locations . . . . . . . . . . . . . . . . . . . . . 41 Reserved Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Input/Output (I/O) Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
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Section 3. Random-Access Memory (RAM)
3.1 3.2 3.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Section 4. Read-Only Memory (ROM)
4.1 4.2 4.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Section 5. EEPROM
5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 EEPROM Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 EEPROM Timebase Requirements . . . . . . . . . . . . . . . . . . . . . 64 EEPROM Security Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 EEPROM Block Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.9 EEPROM Programming and Erasing . . . . . . . . . . . . . . . . . . . . 65 5.9.1 EEPROM Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
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5.9.2
EEPROM Erasing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.10 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 5.10.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 5.10.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 5.11 EEPROM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 5.11.1 EEPROM Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . 69 5.11.2 EEPROM Array Configuration Register . . . . . . . . . . . . . . . . 71 5.11.2.1 EEPROM Non-Volatile Register . . . . . . . . . . . . . . . . . . . 72 5.11.3 EEPROM Timebase Divider Register . . . . . . . . . . . . . . . . . 72 5.11.3.1 EEPROM Timebase Divider Mask Option Register . . . . . 74
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Section 6. Mask Options (MOR)
6.1 6.2 6.3 6.4 6.5 6.6 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Mask Option Register A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Mask Option Register B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 EEPROM Timebase Divider Mask Option Registers . . . . . . . . 79
Section 7. Central Processor Unit (CPU)
7.1 7.2 7.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
7.4 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 7.4.1 Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 7.4.2 Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 7.4.3 Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 7.4.4 Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 7.4.5 Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 7.5 7.6
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Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
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7.6.1 7.6.2 7.7 7.8 7.9 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Section 8. System Integration Module (SIM)
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8.1 8.2
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
8.3 SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . 104 8.3.1 Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 8.3.2 Clock Start-Up from POR or LVI Reset . . . . . . . . . . . . . . . 105 8.3.3 Clocks in Stop and Wait Modes . . . . . . . . . . . . . . . . . . . . . 105 8.4 Reset and System Initialization. . . . . . . . . . . . . . . . . . . . . . . . 105 8.4.1 External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 8.4.2 Active Resets from Internal Sources . . . . . . . . . . . . . . . . . 106 8.4.2.1 Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 8.4.2.2 Computer Operating Properly (COP) Reset . . . . . . . . . 108 8.4.2.3 Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.4.2.4 Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.4.2.5 Low-Voltage Inhibit (LVI) Reset . . . . . . . . . . . . . . . . . . . 109 8.5 SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.5.1 SIM Counter during Power-On Reset. . . . . . . . . . . . . . . . . 110 8.5.2 SIM Counter during Stop Mode Recovery . . . . . . . . . . . . . 110 8.5.3 SIM Counter and Reset States. . . . . . . . . . . . . . . . . . . . . . 110 8.6 Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 8.6.1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 8.6.1.1 Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 8.6.1.2 SWI Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 8.6.2 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 8.6.3 Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 8.6.4 Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . 115 8.7
Technical Data
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
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8.7.1 8.7.2
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
8.8 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 8.8.1 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 119 8.8.2 SIM Reset Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 120 8.8.3 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 121
Section 9. Clock Generator Module (CGM)
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9.1 9.2 9.3
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
9.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 9.4.1 Crystal Oscillator Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 9.4.2 Phase-Locked Loop (PLL) Circuit . . . . . . . . . . . . . . . . . . . 127 9.4.2.1 PLL Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 9.4.2.2 Acquisition and Tracking Modes . . . . . . . . . . . . . . . . . . 128 9.4.2.3 Manual and Automatic PLL Bandwidth Modes . . . . . . . 128 9.4.2.4 Programming the PLL . . . . . . . . . . . . . . . . . . . . . . . . . . 130 9.4.2.5 Special Programming Exceptions . . . . . . . . . . . . . . . . . 131 9.4.3 Base Clock Selector Circuit . . . . . . . . . . . . . . . . . . . . . . . . 132 9.4.4 CGM External Connections . . . . . . . . . . . . . . . . . . . . . . . . 132 9.5 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 9.5.1 Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . 134 9.5.2 Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . 134 9.5.3 External Filter Capacitor Pin (CGMXFC) . . . . . . . . . . . . . . 134 9.5.4 PLL Analog Power Pin (VDDA) . . . . . . . . . . . . . . . . . . . . . . 134 9.5.5 Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . 134 9.5.6 Crystal Output Frequency Signal (CGMXCLK) . . . . . . . . . 135 9.5.7 CGM Base Clock Output (CGMOUT). . . . . . . . . . . . . . . . . 135 9.5.8 CGM CPU Interrupt (CGMINT) . . . . . . . . . . . . . . . . . . . . . 135 9.6 CGM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 9.6.1 PLL Control Register (PCTL) . . . . . . . . . . . . . . . . . . . . . . . 136 9.6.2 PLL Bandwidth Control Register (PBWC) . . . . . . . . . . . . . 138 9.6.3 PLL Programming Register (PPG) . . . . . . . . . . . . . . . . . . . 140
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9.7 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
9.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 9.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 9.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 9.9 CGM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . 143
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9.10 Acquisition/Lock Time Specifications . . . . . . . . . . . . . . . . . . . 143 9.10.1 Acquisition/Lock Time Definitions. . . . . . . . . . . . . . . . . . . . 144 9.10.2 Parametric Influences On Reaction Time. . . . . . . . . . . . . . 145 9.10.3 Choosing a Filter Capacitor . . . . . . . . . . . . . . . . . . . . . . . . 146 9.10.4 Reaction Time Calculation . . . . . . . . . . . . . . . . . . . . . . . . . 147
Section 10. Monitor ROM (MON)
10.1 10.2 10.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
10.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 10.4.1 Entering Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 10.4.2 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 10.4.3 Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 10.4.4 Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 10.4.5 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 10.4.6 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 10.5 10.6 10.7 Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 EEPROM Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Extended Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Section 11. Timer Interface Module A (TIMA)
11.1 11.2 11.3 11.4
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Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
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11.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.5.1 TIMA Counter Prescaler. . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 11.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 11.5.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 167 11.5.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . 168 11.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 169 11.5.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 170 11.5.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 171 11.5.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 11.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
11.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 11.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 11.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 11.8 TIMA During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . 174
11.9 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 11.9.1 TIMA Clock Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 11.9.2 TIMA Channel I/O Pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 11.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 11.10.1 TIMA Status and Control Register . . . . . . . . . . . . . . . . . . . 176 11.10.2 TIMA Counter Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11.10.3 TIMA Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . 179 11.10.4 TIMA Channel Status and Control Registers . . . . . . . . . . . 180 11.10.5 TIMA Channel Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Section 12. Timer Interface Module B (TIMB)
12.1 12.2 12.3 12.4 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
12.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 12.5.1 TIMB Counter Prescaler. . . . . . . . . . . . . . . . . . . . . . . . . . . 189 12.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
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12.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 12.5.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 193 12.5.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . 194 12.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 195 12.5.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 196 12.5.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 197 12.5.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 12.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
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12.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 12.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 12.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 12.8 TIMB During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . 200
12.9 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 12.9.1 TIMB Clock Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 12.9.2 TIMB Channel I/O Pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 12.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 12.10.1 TIMB Status and Control Register . . . . . . . . . . . . . . . . . . . 202 12.10.2 TIMB Counter Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . 204 12.10.3 TIMB Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . 205 12.10.4 TIMB Channel Status and Control Registers . . . . . . . . . . . 206 12.10.5 TIMB Channel Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Section 13. Programmable Interrupt Timer (PIT)
13.1 13.2 13.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
13.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 13.4.1 PIT Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 13.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 13.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 13.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 13.6 PIT During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 216
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13.7 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 13.7.1 PIT Status and Control Register. . . . . . . . . . . . . . . . . . . . . 217 13.7.2 PIT Counter Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 13.7.3 PIT Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . . . 220
Section 14. Analog-to-Digital Converter (ADC)
14.1 14.2 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
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14.3
14.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 14.4.1 ADC Port I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 14.4.2 Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 14.4.3 Conversion Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 14.4.4 Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 14.4.5 Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.5 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
14.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.7 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.7.1 ADC Analog Power Pin (VDDAREF). . . . . . . . . . . . . . . . . . . 226 14.7.2 ADC Analog Ground Pin (AVSS/VREFL) . . . . . . . . . . . . . . . 226 14.7.3 ADC Voltage Reference High Pin (VREFH). . . . . . . . . . . . . 226 14.7.4 ADC Voltage In (VADIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 14.8 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 14.8.1 ADC Status and Control Register (ADSCR). . . . . . . . . . . . 227 14.8.2 ADC Data Register (ADR) . . . . . . . . . . . . . . . . . . . . . . . . . 229 14.8.3 ADC Clock Register (ADCLK) . . . . . . . . . . . . . . . . . . . . . . 229
Section 15. Serial Communications Interface Module (SCI)
15.1 15.2
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Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
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15.3 15.4 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
Freescale Semiconductor, Inc...
15.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 15.5.1 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 15.5.2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 15.5.2.1 Character Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 15.5.2.2 Character Transmission . . . . . . . . . . . . . . . . . . . . . . . . . 239 15.5.2.3 Break Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.5.2.4 Idle Characters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.5.2.5 Inversion of Transmitted Output. . . . . . . . . . . . . . . . . . . 241 15.5.2.6 Transmitter Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . 241 15.5.3 Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 15.5.3.1 Character Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 15.5.3.2 Character Reception . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 15.5.3.3 Data Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 15.5.3.4 Framing Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 15.5.3.5 Baud Rate Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 15.5.3.6 Receiver Wakeup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 15.5.3.7 Receiver Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 15.5.3.8 Error Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 15.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 15.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 15.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 15.7 SCI During Break Module Interrupts. . . . . . . . . . . . . . . . . . . . 252
15.8 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 15.8.1 PTE0/TxD (Transmit Data). . . . . . . . . . . . . . . . . . . . . . . . . 252 15.8.2 PTE1/RxD (Receive Data) . . . . . . . . . . . . . . . . . . . . . . . . . 252 15.9 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 15.9.1 SCI Control Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 15.9.2 SCI Control Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 15.9.3 SCI Control Register 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 15.9.4 SCI Status Register 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 15.9.5 SCI Status Register 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 15.9.6 SCI Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 15.9.7 SCI Baud Rate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
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Section 16. Serial Peripheral Interface Module (SPI)
16.1 16.2 16.3 16.4 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Pin Name Conventions and I/O Register Addresses . . . . . . . 273
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16.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 16.5.1 Master Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 16.5.2 Slave Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 16.6 Transmission Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 16.6.1 Clock Phase and Polarity Controls. . . . . . . . . . . . . . . . . . . 277 16.6.2 Transmission Format When CPHA = 0 . . . . . . . . . . . . . . . 278 16.6.3 Transmission Format When CPHA = 1 . . . . . . . . . . . . . . . 280 16.6.4 Transmission Initiation Latency . . . . . . . . . . . . . . . . . . . . . 281 16.7 Queuing Transmission Data . . . . . . . . . . . . . . . . . . . . . . . . . . 283
16.8 Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 16.8.1 Overflow Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 16.8.2 Mode Fault Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 16.9 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
16.10 Resetting the SPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 16.11 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 16.11.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 16.11.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 16.12 SPI During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 292 16.13 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 16.13.1 MISO (Master In/Slave Out) . . . . . . . . . . . . . . . . . . . . . . . . 293 16.13.2 MOSI (Master Out/Slave In) . . . . . . . . . . . . . . . . . . . . . . . . 293 16.13.3 SPSCK (Serial Clock). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 16.13.4 SS (Slave Select) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 16.13.5 CGND (Clock Ground) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 16.14 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 16.14.1 SPI Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
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16.14.2 SPI Status and Control Register . . . . . . . . . . . . . . . . . . . . 298 16.14.3 SPI Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
Section 17. Input/Output (I/O) Ports
17.1 17.2 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
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17.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308 17.3.1 Port A Data Register (PTA) . . . . . . . . . . . . . . . . . . . . . . . . 308 17.3.2 Data Direction Register A (DDRA) . . . . . . . . . . . . . . . . . . . 308 17.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 17.4.1 Port B Data Register (PTB) . . . . . . . . . . . . . . . . . . . . . . . . 310 17.4.2 Data Direction Register B (DDRB) . . . . . . . . . . . . . . . . . . . 311 17.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 17.5.1 Port C Data Register (PTC) . . . . . . . . . . . . . . . . . . . . . . . . 312 17.5.2 Data Direction Register C (DDRC). . . . . . . . . . . . . . . . . . . 313 17.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 17.6.1 Port D Data Register (PTD) . . . . . . . . . . . . . . . . . . . . . . . . 315 17.6.2 Data Direction Register D (DDRD). . . . . . . . . . . . . . . . . . . 316 17.6.3 Port D Input Pullup Enable Register (PTDPUE). . . . . . . . . 317 17.7 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 17.7.1 Port E Data Register (PTE) . . . . . . . . . . . . . . . . . . . . . . . . 318 17.7.2 Data Direction Register E (DDRE) . . . . . . . . . . . . . . . . . . . 320 17.8 Port F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 17.8.1 Port F Data Register (PTF) . . . . . . . . . . . . . . . . . . . . . . . . 321 17.8.2 Data Direction Register F (DDRF) . . . . . . . . . . . . . . . . . . . 322 17.8.3 Port F Input Pullup Enable Register (PTFPUE) . . . . . . . . . 324 17.9 Port G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 17.9.1 Port G Data Register (PTG) . . . . . . . . . . . . . . . . . . . . . . . . 324 17.9.2 Data Direction Register G (DDRG) . . . . . . . . . . . . . . . . . . 325 17.10 Port H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 17.10.1 Port H Data Register (PTH) . . . . . . . . . . . . . . . . . . . . . . . . 327 17.10.2 Data Direction Register H (DDRH). . . . . . . . . . . . . . . . . . . 327
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Section 18. External Interrupt (IRQ)
18.1 18.2 18.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
18.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 18.4.1 IRQ Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 18.5 IRQ Status and Control Register (ISCR) . . . . . . . . . . . . . . . . 335 IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . 336
Freescale Semiconductor, Inc...
18.6
Section 19. Keyboard Interrupt Module (KBI)
19.1 19.2 19.3 19.4 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
19.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 19.5.1 Keyboard Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 19.5.2 Keyboard Status and Control Register. . . . . . . . . . . . . . . . 341 19.5.3 Keyboard Interrupt Enable Register . . . . . . . . . . . . . . . . . . 343 19.6 19.7 19.8 Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 Keyboard Module During Break Interrupts . . . . . . . . . . . . . . . 344
Section 20. Computer Operating Properly (COP)
20.1 20.2 20.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
20.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.4.1 CGMXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.4.2 STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
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Freescale Semiconductor, Inc. Table of Contents
20.4.3 20.4.4 20.4.5 20.4.6 20.4.7 20.4.8 20.5 20.6 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . 348 COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
Freescale Semiconductor, Inc...
20.7
20.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 20.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 20.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 20.9 COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . 350
Section 21. Low-Voltage Inhibit (LVI)
21.1 21.2 21.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
21.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 21.4.1 Polled LVI Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 21.4.2 Forced Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 21.4.3 False Reset Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 21.5 21.6 LVI Status Register (LVISR) . . . . . . . . . . . . . . . . . . . . . . . . . . 354 LVI Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
21.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 21.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 21.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Section 22. Break Module (BRK)
22.1 22.2
Technical Data
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
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Freescale Semiconductor, Inc.
Table of Contents
22.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
22.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 22.4.1 Flag Protection During Break Interrupts . . . . . . . . . . . . . . . 360 22.4.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 360 22.4.3 PIT, TIMA, and TIMB During Break Interrupts . . . . . . . . . . 360 22.4.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 360 22.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 22.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 22.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 22.6 Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 22.6.1 Break Status and Control Register. . . . . . . . . . . . . . . . . . . 361 22.6.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 362 22.6.3 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 362 22.6.4 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 364
Freescale Semiconductor, Inc...
Section 23. Electrical Specifications
23.1 23.2 23.3 23.4 23.5 23.6 23.7 23.8 23.9 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 366 Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . 367 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 5.0-V DC Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . 368 EEPROM and Memory Characteristics . . . . . . . . . . . . . . . . . 369 5.0-V Control Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 Timer Interface Module Characteristics . . . . . . . . . . . . . . . . . 370
23.10 ADC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371 23.11 SPI Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372 23.12 Clock Generation Module Characteristics . . . . . . . . . . . . . . . 375 23.12.1 CGM Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . 375 23.12.2 CGM Component Information . . . . . . . . . . . . . . . . . . . . . . 375 23.12.3 CGM Acquisition/Lock Time Information . . . . . . . . . . . . . . 376
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Table of Contents For More Information On This Product, Go to: www.freescale.com Technical Data
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Freescale Semiconductor, Inc. Table of Contents Section 24. Mechanical Specifications
24.1 24.2 24.3 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 64-Pin Plastic Quad Flat Pack (QFP) . . . . . . . . . . . . . . . . . . . 378
Freescale Semiconductor, Inc...
Technical Data
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Freescale Semiconductor, Inc.
Technical Data -- MC68HC08AB16A
List of Figures
Figure 1-1 1-2 1-3 2-1 2-2 5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 6-1 6-2 6-3 6-4 7-1 7-2 7-3 7-4 7-5 7-6 8-1 8-2
MC68HC08AB16A -- Rev. 2.0 MOTOROLA
Title
Page
Freescale Semiconductor, Inc...
MC68HC08AB16A Block Diagram . . . . . . . . . . . . . . . . . . . . . . 32 64-Pin QFP Pin Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Power Supply Bypassing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Control, Status, and Data Registers . . . . . . . . . . . . . . . . . . . . . 45 EEPROM I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . 62 EEPROM Control Register (EECR) . . . . . . . . . . . . . . . . . . . . . 69 EEPROM Array Configuration Register (EEACR) . . . . . . . . . . 71 EEPROM Non-Volatile Register (EENVR) . . . . . . . . . . . . . . . . 72 EEPROM Divider Register High (EEDIVH) . . . . . . . . . . . . . . . 73 EEPROM Divider Register Low (EEDIVL) . . . . . . . . . . . . . . . . 73 EEPROM Divider Mask Option Register High (EEDIVHMOR) 74 EEPROM Divider Mask Option Register Low (EEDIVLMOR) . 74 Mask Option Register A (MORA) . . . . . . . . . . . . . . . . . . . . . . . 76 Mask Option Register B (MORB)) . . . . . . . . . . . . . . . . . . . . . . 78 EEPROM Divider Mask Option Register High (EEDIVHMOR) 79 EEPROM Divider Mask Option Register Low (EEDIVLMOR) . 79 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Accumulator (A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Index Register (H:X) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Stack Pointer (SP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Program Counter (PC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Condition Code Register (CCR) . . . . . . . . . . . . . . . . . . . . . . . . 86 SIM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 SIM I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . 104
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Freescale Semiconductor, Inc. List of Figures
Figure 8-3 8-4 8-5 8-6 8-7 8-8 8-9 8-10 8-11 8-12 8-13 8-14 8-15 8-16 8-17 8-18 8-19 9-1 9-2 9-3 9-4 9-5 9-7 9-8 10-1 10-2 10-3 10-4 10-5 10-6 11-1 11-2 11-3 Title Page
Freescale Semiconductor, Inc...
CGM Clock Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 External Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Internal Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Sources of Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 POR Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Interrupt Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Interrupt Recovery Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Interrupt Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Interrupt Recognition Example . . . . . . . . . . . . . . . . . . . . . . . . 113 Wait Mode Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Wait Recovery from Interrupt or Break . . . . . . . . . . . . . . . . . . 117 Wait Recovery from Internal Reset. . . . . . . . . . . . . . . . . . . . . 117 Stop Mode Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Stop Mode Recovery from Interrupt or Break . . . . . . . . . . . . . 118 SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . . . 119 SIM Reset Status Register (SRSR) . . . . . . . . . . . . . . . . . . . . 120 SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . . . 121 CGM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 CGM I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . 126 CGM External Connections . . . . . . . . . . . . . . . . . . . . . . . . . . 133 CGM I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . 136 PLL Control Register (PCTL) . . . . . . . . . . . . . . . . . . . . . . . . . 136 PLL Bandwidth Control Register (PBWC) . . . . . . . . . . . . . . . 138 PLL Programming Register (PPG) . . . . . . . . . . . . . . . . . . . . . 140 Monitor Mode Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 Monitor Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Sample Monitor Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Read Transaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Break Transaction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Monitor Mode Entry Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . 159 TIMA Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 TIMA I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . 165 PWM Period and Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . 169
Technical Data
MC68HC08AB16A -- Rev. 2.0 List of Figures For More Information On This Product, Go to: www.freescale.com MOTOROLA
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Freescale Semiconductor, Inc.
List of Figures
Figure 11-4 11-5 11-6 11-7 11-8 11-9 11-10 11-11 11-12 11-13 11-14 11-15 11-16 11-17 11-18 11-19 11-20 11-21 12-1 12-2 12-3 12-4 12-5 12-6 12-7 12-8 12-9 12-10 12-11 12-12 12-13 12-14 12-15 12-16 12-17
Title
Page
Freescale Semiconductor, Inc...
TIMA Status and Control Register (TASC) . . . . . . . . . . . . . . . 176 TIMA Counter Register High (TACNTH). . . . . . . . . . . . . . . . . 178 TIMA Counter Register Low (TACNTL) . . . . . . . . . . . . . . . . . 179 TIMA Counter Modulo Register High (TAMODH). . . . . . . . . . 179 TIMA Counter Modulo Register Low (TAMODL) . . . . . . . . . . 179 TIMA Channel 0 Status and Control Register (TASC0) . . . . . 180 TIMA Channel 1 Status and Control Register (TASC1) . . . . . 180 TIMA Channel 2 Status and Control Register (TASC2) . . . . . 181 TIMA Channel 3 Status and Control Register (TASC3) . . . . . 181 CHxMAX Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 TIMA Channel 0 Register High (TACH0H) . . . . . . . . . . . . . . . 184 TIMA Channel 0 Register Low (TACH0L). . . . . . . . . . . . . . . . 184 TIMA Channel 1 Register High (TACH1H) . . . . . . . . . . . . . . . 185 TIMA Channel 1 Register Low (TACH1L). . . . . . . . . . . . . . . . 185 TIMA Channel 2 Register High (TACH2H) . . . . . . . . . . . . . . . 185 TIMA Channel 2 Register Low (TACH2L). . . . . . . . . . . . . . . . 185 TIMA Channel 3 Register High (TACH3H) . . . . . . . . . . . . . . . 186 TIMA Channel 3 Register Low (TACH3L). . . . . . . . . . . . . . . . 186 TIMB Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 TIMB I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . 191 PWM Period and Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . 195 TIMB Status and Control Register (TBSC) . . . . . . . . . . . . . . . 202 TIMB Counter Register High (TBCNTH). . . . . . . . . . . . . . . . . 204 TIMB Counter Register Low (TBCNTL) . . . . . . . . . . . . . . . . . 205 TIMB Counter Modulo Register High (TBMODH). . . . . . . . . . 205 TIMB Counter Modulo Register Low (TBMODL) . . . . . . . . . . 205 TIMB Channel 0 Status and Control Register (TBSC0) . . . . . 206 TIMB Channel 1 Status and Control Register (TBSC1) . . . . . 206 TIMB Channel 2 Status and Control Register (TBSC2) . . . . . 207 TIMB Channel 3 Status and Control Register (TBSC3) . . . . . 207 CHxMAX Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 TIMB Channel 0 Register High (TBCH0H) . . . . . . . . . . . . . . . 210 TIMB Channel 0 Register Low (TBCH0L). . . . . . . . . . . . . . . . 210 TIMB Channel 1 Register High (TBCH1H) . . . . . . . . . . . . . . . 211 TIMB Channel 1 Register Low (TBCH1L). . . . . . . . . . . . . . . . 211
MC68HC08AB16A -- Rev. 2.0 MOTOROLA List of Figures For More Information On This Product, Go to: www.freescale.com
Technical Data
23
Freescale Semiconductor, Inc. List of Figures
Figure 12-18 12-19 12-20 12-21 13-1 13-2 13-3 13-4 13-5 13-6 13-7 14-1 14-2 14-3 14-4 14-5 15-1 15-2 15-3 15-4 15-5 15-6 15-7 15-8 15-9 15-10 15-11 15-12 15-13 15-14 15-15 15-16 Title Page
TIMB Channel 2 Register High (TBCH2H) . . . . . . . . . . . . . . . 211 TIMB Channel 2 Register Low (TBCH2L). . . . . . . . . . . . . . . . 211 TIMB Channel 3 Register High (TBCH3H) . . . . . . . . . . . . . . . 212 TIMB Channel 3 Register Low (TBCH3L). . . . . . . . . . . . . . . . 212 PIT Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 PIT I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 PIT Status and Control Register (PSC) . . . . . . . . . . . . . . . . . 217 PIT Counter Register High (PCNTH) . . . . . . . . . . . . . . . . . . . 219 PIT Counter Register Low (PCNTL) . . . . . . . . . . . . . . . . . . . . 220 PIT Counter Modulo Register High (PMODH) . . . . . . . . . . . . 220 PIT Counter Modulo Register Low (PMODL) . . . . . . . . . . . . . 220 ADC Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 ADC Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 ADC Status and Control Register (ADSCR) . . . . . . . . . . . . . . 227 ADC Data Register (ADR) . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 ADC Clock Register (ADCLK) . . . . . . . . . . . . . . . . . . . . . . . . 229 SCI Module Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . 235 SCI I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 SCI Data Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 SCI Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 SCI Receiver Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 243 Receiver Data Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Slow Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 Fast Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 SCI Control Register 1 (SCC1). . . . . . . . . . . . . . . . . . . . . . . . 254 SCI Control Register 2 (SCC2). . . . . . . . . . . . . . . . . . . . . . . . 257 SCI Control Register 3 (SCC3). . . . . . . . . . . . . . . . . . . . . . . . 259 SCI Status Register 1 (SCS1) . . . . . . . . . . . . . . . . . . . . . . . . 261 Flag Clearing Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 SCI Status Register 2 (SCS2) . . . . . . . . . . . . . . . . . . . . . . . . 265 SCI Data Register (SCDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 SCI Baud Rate Register (SCBR) . . . . . . . . . . . . . . . . . . . . . . 267
Freescale Semiconductor, Inc...
Technical Data
MC68HC08AB16A -- Rev. 2.0 List of Figures For More Information On This Product, Go to: www.freescale.com MOTOROLA
24
Freescale Semiconductor, Inc.
List of Figures
Figure 16-1 16-2 16-3 16-4 16-5 16-6 16-7 16-8 16-9 16-10 16-11 16-12 16-13 16-14 16-15 17-1 17-2 17-3 17-4 17-5 17-6 17-7 17-8 17-9 17-10 17-11 17-12 17-13 17-14 17-15 17-16 17-17 17-18 17-19 17-20
Title
Page
Freescale Semiconductor, Inc...
SPI I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 SPI Module Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . 274 Full-Duplex Master-Slave Connections . . . . . . . . . . . . . . . . . 275 Transmission Format (CPHA = 0) . . . . . . . . . . . . . . . . . . . . . 279 CPHA/SS Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Transmission Format (CPHA = 1) . . . . . . . . . . . . . . . . . . . . . 280 Transmission Start Delay (Master) . . . . . . . . . . . . . . . . . . . . . 282 SPRF/SPTE CPU Interrupt Timing . . . . . . . . . . . . . . . . . . . . . 283 Missed Read of Overflow Condition . . . . . . . . . . . . . . . . . . . . 285 Clearing SPRF When OVRF Interrupt Is Not Enabled . . . . . . 286 SPI Interrupt Request Generation . . . . . . . . . . . . . . . . . . . . . 289 CPHA/SS Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 SPI Control Register (SPCR) . . . . . . . . . . . . . . . . . . . . . . . . . 296 SPI Status and Control Register (SPSCR) . . . . . . . . . . . . . . . 298 SPI Data Register (SPDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 I/O Port Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . 304 Port A Data Register (PTA) . . . . . . . . . . . . . . . . . . . . . . . . . . 308 Data Direction Register A (DDRA) . . . . . . . . . . . . . . . . . . . . . 308 Port A I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 Port B Data Register (PTB) . . . . . . . . . . . . . . . . . . . . . . . . . . 310 Data Direction Register B (DDRB) . . . . . . . . . . . . . . . . . . . . . 311 Port B I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 Port C Data Register (PTC) . . . . . . . . . . . . . . . . . . . . . . . . . . 312 Data Direction Register B (DDRB) . . . . . . . . . . . . . . . . . . . . . 313 Port C I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 Port D Data Register (PTD) . . . . . . . . . . . . . . . . . . . . . . . . . . 315 Data Direction Register D (DDRD) . . . . . . . . . . . . . . . . . . . . . 316 Port D I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 Port D Input Pullup Enable Register (PTDPUE) . . . . . . . . . . . 317 Port E Data Register (PTE) . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Data Direction Register E (DDRE) . . . . . . . . . . . . . . . . . . . . . 320 Port E I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 Port F Data Register (PTF). . . . . . . . . . . . . . . . . . . . . . . . . . . 321 Data Direction Register F (DDRF) . . . . . . . . . . . . . . . . . . . . . 322 Port F I/O Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
MC68HC08AB16A -- Rev. 2.0 MOTOROLA List of Figures For More Information On This Product, Go to: www.freescale.com
Technical Data
25
Freescale Semiconductor, Inc. List of Figures
Figure 17-21 17-22 17-23 17-24 17-25 17-26 17-27 Title Page
Port F Input Pullup Enable Register (PTFPUE) . . . . . . . . . . . 324 Port G Data Register (PTG) . . . . . . . . . . . . . . . . . . . . . . . . . . 325 Data Direction Register G (DDRG). . . . . . . . . . . . . . . . . . . . . 325 Port G I/O Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 Port H Data Register (PTH) . . . . . . . . . . . . . . . . . . . . . . . . . . 327 Data Direction Register H (DDRH) . . . . . . . . . . . . . . . . . . . . . 328 Port H I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 IRQ Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 333 IRQ I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . 333 IRQ Status and Control Register (ISCR) . . . . . . . . . . . . . . . . 335 KBI I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 Keyboard Interrupt Block Diagram . . . . . . . . . . . . . . . . . . . . . 339 Keyboard Status and Control Register (KBSCR) . . . . . . . . . . 342 Keyboard Interrupt Enable Register (KBIER) . . . . . . . . . . . . . 343 COP Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 Mask Option Register A (MORA) . . . . . . . . . . . . . . . . . . . . . . 348 COP Control Register (COPCTL) . . . . . . . . . . . . . . . . . . . . . . 349 LVI Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 LVI I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 LVI Status Register (LVISR) . . . . . . . . . . . . . . . . . . . . . . . . . . 354 Break Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 359 Break Module I/O Register Summary . . . . . . . . . . . . . . . . . . . 359 Break Status and Control Register (BRKSCR). . . . . . . . . . . . 361 Break Address Register High (BRKH) . . . . . . . . . . . . . . . . . . 362 Break Address Register Low (BRKL) . . . . . . . . . . . . . . . . . . . 362 SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . . . 363 SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . . . 364 SPI Master Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373 SPI Slave Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 64-Pin Plastic Quad Flat Pack (QFP) . . . . . . . . . . . . . . . . . . . 378
MC68HC08AB16A -- Rev. 2.0
Freescale Semiconductor, Inc...
18-1 18-2 18-3 19-1 19-2 19-3 19-4 20-1 20-2 20-3 21-1 21-2 21-3 22-1 22-2 22-3 22-4 22-5 22-6 22-7 23-1 23-2 24-1
Technical Data
26
List of Figures For More Information On This Product, Go to: www.freescale.com
MOTOROLA
Freescale Semiconductor, Inc.
Technical Data -- MC68HC08AB16A
List of Tables
Table 1-1 1-2 1-3 2-1 5-1 5-2 7-1 7-2 8-1 8-2 8-3 8-4 9-1 10-1 10-2 10-3 10-4 10-5 10-6 10-7 10-8 10-9 11-1 11-2 11-3
MC68HC08AB16A -- Rev. 2.0 MOTOROLA
Title
Page
Freescale Semiconductor, Inc...
I/O Pins Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Signal Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Clock Source Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Vector Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 EEPROM Array Address Blocks. . . . . . . . . . . . . . . . . . . . . . . . 65 EEPROM Program/Erase Mode Select . . . . . . . . . . . . . . . . . . 70 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Signal Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 PIN Bit Set Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Vector Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 VCO Frequency Multiplier (N) Selection. . . . . . . . . . . . . . . . . 141 Monitor Mode Entry Conditions . . . . . . . . . . . . . . . . . . . . . . . 152 Mode Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 READ (Read Memory) Command . . . . . . . . . . . . . . . . . . . . . 155 WRITE (Write Memory) Command. . . . . . . . . . . . . . . . . . . . . 156 IREAD (Indexed Read) Command . . . . . . . . . . . . . . . . . . . . . 156 IWRITE (Indexed Write) Command . . . . . . . . . . . . . . . . . . . . 157 READSP (Read Stack Pointer) Command . . . . . . . . . . . . . . . 157 RUN (Run User Program) Command . . . . . . . . . . . . . . . . . . . 158 Monitor Baud Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . 158 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 Prescaler Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 Mode, Edge, and Level Selection . . . . . . . . . . . . . . . . . . . . . . 183
Technical Data List of Tables For More Information On This Product, Go to: www.freescale.com
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Freescale Semiconductor, Inc. List of Tables
Table 12-1 12-2 12-3 13-1 14-1 14-2 Title Page
Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 Prescaler Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 Mode, Edge, and Level Selection . . . . . . . . . . . . . . . . . . . . . . 209 PIT Prescaler Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 Mux Channel Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 ADC Clock Divide Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 Start Bit Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 Data Bit Recovery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 Stop Bit Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 Character Format Selection . . . . . . . . . . . . . . . . . . . . . . . . . . 256 SCI Baud Rate Prescaling . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 SCI Baud Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268 SCI Baud Rate Selection Examples . . . . . . . . . . . . . . . . . . . . 269 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 SPI Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 SPI Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 SPI Master Baud Rate Selection . . . . . . . . . . . . . . . . . . . . . . 300 Port Control Register Bits Summary. . . . . . . . . . . . . . . . . . . . 306 Port A Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 Port B Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 Port C Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 Port D Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 Port E Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 Port F Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 Port G Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 Port H Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 LVIOUT Bit Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Freescale Semiconductor, Inc...
15-1 15-2 15-3 15-4 15-5 15-6 15-7 15-8 16-1 16-2 16-3 16-4 17-1 17-2 17-3 17-4 17-5 17-6 17-7 17-8 17-9 19-1 21-1
Technical Data
MC68HC08AB16A -- Rev. 2.0 List of Tables For More Information On This Product, Go to: www.freescale.com MOTOROLA
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Freescale Semiconductor, Inc.
Technical Data -- MC68HC08AB16A
Section 1. General Description
1.1 Contents
1.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
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1.3 1.4 1.5
1.6 Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 1.6.1 Power Supply Pins (VDD and VSS) . . . . . . . . . . . . . . . . . . . . 34 1.6.2 Oscillator Pins (OSC1 and OSC2) . . . . . . . . . . . . . . . . . . . . 35 1.6.3 External Reset Pin (RST) . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.6.4 External Interrupt Pin (IRQ) . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.6.5 Analog Power Supply Pin (VDDA) . . . . . . . . . . . . . . . . . . . . . 35 1.6.6 Analog Ground Pin (VSSA) . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.6.7 Analog Ground Pin (AVSS/VREFL). . . . . . . . . . . . . . . . . . . . . 35 1.6.8 ADC Voltage Reference Pin (VREFH) . . . . . . . . . . . . . . . . . . 36 1.6.9 Analog Supply Pin (VDDAREF) . . . . . . . . . . . . . . . . . . . . . . . 36 1.6.10 External Filter Capacitor Pin (CGMXFC) . . . . . . . . . . . . . . . 36 1.6.11 Port A Input/Output (I/O) Pins (PTA7-PTA0) . . . . . . . . . . . . 36 1.6.12 Port B I/O Pins (PTB7/ATD7-PTB0/ATD0) . . . . . . . . . . . . . 36 1.6.13 Port C I/O Pins (PTC5-PTC0) . . . . . . . . . . . . . . . . . . . . . . . 36 1.6.14 Port D I/O Pins (PTD7-PTD0) . . . . . . . . . . . . . . . . . . . . . . . 37 1.6.15 Port E I/O Pins (PTE7/SPSCK-PTE0/TxD) . . . . . . . . . . . . . 37 1.6.16 Port F I/O Pins (PTF7-PTF0/TACH2) . . . . . . . . . . . . . . . . . 37 1.6.17 Port G I/O Pins (PTG2/KBD2-PTG0/KBD0) . . . . . . . . . . . . 37 1.6.18 Port H I/O Pins (PTH1/KBD4-PTH0/KBD3). . . . . . . . . . . . . 37 1.7 1.8 1.9 I/O Pin Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Signal Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Clock Source Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
MC68HC08AB16A -- Rev. 2.0 MOTOROLA General Description For More Information On This Product, Go to: www.freescale.com
Technical Data
29
Freescale Semiconductor, Inc. General Description 1.2 Introduction
The MC68HC08AB16A is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs) with embedded EEPROM for user data storage. All MCUs in the family use the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types.
1.3 Features
Freescale Semiconductor, Inc...
Features of the MC68HC08AB16A include the following: * * * * * * * * * High-performance M68HC08 architecture Fully upward-compatible object code with M6805, M146805, and M68HC05 Families Memory map and pin functions compatible with MC68HC08AB16 8-MHz internal bus frequency 16K-bytes user ROM memory with security1 feature 512 bytes of on-chip EEPROM with security feature 512 byte of on-chip RAM Clock generator module (CGM) Two 16-bit, 4-channel timer interface modules (TIMA and TIMB) with selectable input capture, output compare, and PWM capability on each channel Programmable interrupt timer (PIT) Serial peripheral interface module (SPI) Serial communications interface module (SCI) 8-channel. 8-bit analog-to-digital converter (ADC) Low-power design (fully static with stop and wait modes) Master reset pin and power-on reset
* * * * * *
1. No security feature is absolutely secure. However, Motorola's strategy is to make reading or copying the ROM difficult for unauthorized users.
Technical Data
MC68HC08AB16A -- Rev. 2.0 General Description For More Information On This Product, Go to: www.freescale.com MOTOROLA
30
Freescale Semiconductor, Inc.
General Description MCU Block Diagram
*
51 general-purpose input/output (I/O) pins: - 30 shared-function I/O pins - 5-bit keyboard wakeup port - Selectable pullups on inputs on port D and port F
*
System protection features - Optional computer operating properly (COP) reset - Low-voltage detection with optional reset
Freescale Semiconductor, Inc...
- Illegal opcode detection with optional reset - Illegal address detection with optional reset * 64-pin quad flat pack (QFP)
Features of the CPU08 include the following: * * * * * * * * * * Enhanced HC05 programming model Extensive loop control functions 16 addressing modes (eight more than the HC05) 16-bit Index register and stack pointer Memory-to-memory data transfers Fast 8 x 8 multiply instruction Fast 16/8 divide instruction Binary-coded decimal (BCD) instructions Optimization for controller applications Efficient C language support
1.4 MCU Block Diagram
Figure 1-1 shows the structure of the MC68HC08AB16A.
MC68HC08AB16A -- Rev. 2.0 MOTOROLA General Description For More Information On This Product, Go to: www.freescale.com
Technical Data
31
PORTA
DDRA
CONTROL AND STATUS REGISTERS -- 80 BYTES USER ROM -- 16,384 BYTES USER RAM -- 512 BYTES USER EEPROM -- 512 BYTES MONITOR ROM -- 307 BYTES USER ROM VECTORS -- 48 BYTES CLOCK GENERATOR MODULE OSC1 OSC2 CGMXFC 4.9125-MHz OSCILLATOR
PORTB
DDRB
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PROGRAMMABLE INTERRUPT TIMER MODULE
PORTC
DDRC
PORTD
DDRD
KEYBOARD INTERRUPT MODULE
PHASE-LOCKED LOOP
COMPUTER OPERATING PROPERLY MODULE
PORTE
DDRE
* IRQ VREFH AVSS/VREFL VDDAREF VDD VSS VDDA VSSA
SINGLE EXTERNAL IRQ MODULE 8-BIT ANALOG-TO-DIGITAL CONVERTER MODULE
POWER-ON RESET MODULE PORTG DDRG
PORTF
DDRF
PORTH
DDRH
32
General Description MOTOROLA
Technical Data MC68HC08AB16A -- Rev. 2.0
General Description
INTERNAL BUS M68HC08 CPU CPU REGISTERS ARITHMETIC/LOGIC UNIT (ALU) 4-CHANNEL TIMER INTERFACE MODULE A
PTA7 - PTA0
4-CHANNEL TIMER INTERFACE MODULE B
PTB7/ATD7 - PTB0/ATD0
PTC5 - PTC0 (PTC2/MCLK)
SERIAL COMMUNICATIONS INTERFACE MODULE
SERIAL PERIPHERAL INTERFACE MODULE
PTD7 - PTD0 (PTD6/TACLK) (PTD4/TBCLK) PTE7/SPSCK PTE6/MOSI PTE5/MISO PTE4/SS PTE3/TACH1 PTE2/TACH0 PTE1/RxD PTE0/TxD PTF7 PTF6 PTF5/TBCH1 PTF4/TBCH0 PTF3/TBCH3 PTF2/TBCH2 PTF1/TACH3 PTF0/TACH2
* RST
SYSTEM INTEGRATION MODULE
LOW-VOLTAGE INHIBIT MODULE
PTG2/KBD2 - PTG0/KBD0 **
POWER PTH1/KBD4 - PTH0/KBD3 **
Ports are software configurable with pullup device if input port. Higher current drive port pins * Pin contains integrated pullup device ** Pullup enabled when configured as keyboard interrupt pin
Figure 1-1. MC68HC08AB16A Block Diagram
Freescale Semiconductor, Inc.
General Description Pin Assignments
1.5 Pin Assignments
Figure 1-2 shows the pin assignment for the MC68HC08AB16A.
PTD6/TACLK
PTD4/TBCLK
50
PTC2/MCLK
Freescale Semiconductor, Inc...
64
63
62
61
60
59
58
57
56
55
54
53
52
PTC4 IRQ RST PTF0/TACH2 PTF1/TACH3 PTF2/TBCH2 PTF3/TBCH3 PTF4/TBCH0 NC PTF7 PTF5/TBCH1 PTF6 PTE0/TxD PTE1/RxD PTE2/TACH0 PTE3/TACH1
51
49
PTH1/KBD4
CGMXFC
VREFH
OSC1
OSC2
PTC5
PTC3
PTC1
PTC0
PTD7
PTD5
VDDA
VSSA
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34
PTH0/KBD3 PTD3 PTD2 AVSS/VREFL VDDAREF PTD1 PTD0 PTB7/ATD7 PTB6/ATD6 PTB5/ATD5 PTB4/ATD4 PTB3/ATD3 PTB2/ATD2 PTB1/ATD1 PTB0/ATD0
18
19
20
21
22
23
24
25
26
27
28
29
30
17
31
16
33 32
PTA7
PTE6/MOSI
PTE7/SPSCK
PTE5/MISO
PTG0/KBD0
PTG1/KBD1
PTG2/KBD2
PTE4/SS
PTA0
PTA1
PTA2
PTA3
PTA4
PTA5
Figure 1-2. 64-Pin QFP Pin Assignment
MC68HC08AB16A -- Rev. 2.0 MOTOROLA General Description For More Information On This Product, Go to: www.freescale.com
PTA6
VDD
VSS
Technical Data
33
Freescale Semiconductor, Inc. General Description 1.6 Pin Functions
Description of pin functions are provided here.
1.6.1 Power Supply Pins (VDD and VSS) VDD and VSS are the power supply and ground pins. The MCU operates from a single power supply.
Freescale Semiconductor, Inc...
Fast signal transitions on MCU pins place high, short-duration current demands on the power supply. To prevent noise problems, take special care to provide power supply bypassing at the MCU as Figure 1-3 shows. Place the C1 bypass capacitor as close to the MCU as possible. Use a high-frequency-response ceramic capacitor for C1. C2 is an optional bulk current bypass capacitor for use in applications that require the port pins to source high current levels.
MCU
VDD VSS
C1 0.1 F + C2
VDD
NOTE: Component values shown represent typical applications.
Figure 1-3. Power Supply Bypassing VSS is also the ground for the port output buffers and the ground return for the serial clock in the serial peripheral interface module (SPI). See Section 16. Serial Peripheral Interface Module (SPI). VSS must be grounded for proper MCU operation.
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Freescale Semiconductor, Inc.
General Description Pin Functions
1.6.2 Oscillator Pins (OSC1 and OSC2) The OSC1 and OSC2 pins are the connections for the on-chip oscillator circuit. See Section 9. Clock Generator Module (CGM).
1.6.3 External Reset Pin (RST) A logic 0 on the RST pin forces the MCU to a known start-up state. RST is bidirectional, allowing a reset of the entire system. It is driven low when any internal reset source is asserted. This pin contains an internal pullup resistor. See Section 8. System Integration Module (SIM).
Freescale Semiconductor, Inc...
1.6.4 External Interrupt Pin (IRQ) IRQ is an asynchronous external interrupt pin. This pin contains an internal pullup resistor. See Section 18. External Interrupt (IRQ).
1.6.5 Analog Power Supply Pin (VDDA) VDDA is the power supply pin for the clock generator module (CGM).
1.6.6 Analog Ground Pin (VSSA) The VSSA analog ground pin is used only for the ground connections for the clock generator module (CGM) section of the circuit and should be decoupled as per the VSS digital ground pin. See Section 9. Clock Generator Module (CGM).
1.6.7 Analog Ground Pin (AVSS/VREFL) The AVSS analog ground pin is used only for the ground connections for the analog to digital convertor (ADC) and should be decoupled as per the VSS digital ground pin.
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Technical Data
35
Freescale Semiconductor, Inc. General Description
1.6.8 ADC Voltage Reference Pin (VREFH) VREFH is the power supply for setting the reference voltage VREFH. Connect this pin to a voltage such that 1.5V < VREFH VDDAREF.
1.6.9 Analog Supply Pin (VDDAREF) The VDDAREF analog supply pin is used only for the supply connections for the analog-to-digital convertor (ADC).
Freescale Semiconductor, Inc...
1.6.10 External Filter Capacitor Pin (CGMXFC) CGMXFC is an external filter capacitor connection for the CGM. See Section 9. Clock Generator Module (CGM).
1.6.11 Port A Input/Output (I/O) Pins (PTA7-PTA0) PTA7-PTA0 are general-purpose bidirectional I/O port pins. See Section 17. Input/Output (I/O) Ports.
1.6.12 Port B I/O Pins (PTB7/ATD7-PTB0/ATD0) PTB7-PTB0 are special function, bidirectional port pins. PTB7-PTB0 are shared with the analog to digital convertor (ADC) input pins ATD7-ATD0. See Section 14. Analog-to-Digital Converter (ADC) and Section 17. Input/Output (I/O) Ports.
1.6.13 Port C I/O Pins (PTC5-PTC0) PTC5-PTC0 are general-purpose bidirectional I/O port pins. PTC2 is a special function port pin that is shared with the system clock output pin, MCLK. See Section 17. Input/Output (I/O) Ports.
Technical Data
MC68HC08AB16A -- Rev. 2.0 General Description For More Information On This Product, Go to: www.freescale.com MOTOROLA
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Freescale Semiconductor, Inc.
General Description Pin Functions
1.6.14 Port D I/O Pins (PTD7-PTD0) PTD7-PTD0 are general-purpose bidirectional I/O port pins. PTD6 and PTD4 are special function port pins that are shared with the timer interface modules (TIMA and TIMB). See Section 11. Timer Interface Module A (TIMA) and Section 12. Timer Interface Module B (TIMB).
1.6.15 Port E I/O Pins (PTE7/SPSCK-PTE0/TxD)
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PTE7-PTE0 are special function, bidirectional port pins. PTE7-PTE4 are shared with the serial peripheral interface mode (SPI), PTE3-PTE2 are shared with timer A (TIMA), and PTE1-PTE0 are shared with the serial communications interface (SCI). See Section 15. Serial Communications Interface Module (SCI), Section 16. Serial Peripheral Interface Module (SPI), Section 11. Timer Interface Module A (TIMA), and Section 17. Input/Output (I/O) Ports.
1.6.16 Port F I/O Pins (PTF7-PTF0/TACH2) PTF7-PTF6 are general-purpose bidirectional I/O port pins. PTF5-PTF0 are special function, bidirectional port pins. PTF5-PTF2 are shared with timer B (TIMB), and PTF1-PTF0 are shared with timer A (TIMA). See Section 11. Timer Interface Module A (TIMA), Section 12. Timer Interface Module B (TIMB), and Section 17. Input/Output (I/O) Ports.
1.6.17 Port G I/O Pins (PTG2/KBD2-PTG0/KBD0) PTG2-PTG0 are general-purpose bidirectional I/O pins with keyboard wakeup function. See Section 19. Keyboard Interrupt Module (KBI) and Section 17. Input/Output (I/O) Ports.
1.6.18 Port H I/O Pins (PTH1/KBD4-PTH0/KBD3) PTH1-PTH0 are general-purpose bidirectional I/O pins with Keyboard wakeup function. See Section 19. Keyboard Interrupt Module (KBI) and Section 17. Input/Output (I/O) Ports.
MC68HC08AB16A -- Rev. 2.0 MOTOROLA General Description For More Information On This Product, Go to: www.freescale.com Technical Data
37
Freescale Semiconductor, Inc. General Description 1.7 I/O Pin Summary
Table 1-1. I/O Pins Summary
Pin Name PTA7-PTA0 PTB7/ATD7-PTB0/ATD0 PTC5-PTC3 Function General purpose I/O General purpose I/O / ADC channel General purpose I/O General purpose I/O / System clock General purpose I/O General purpose I/O General purpose I/O / Timer external input clock General purpose I/O General purpose I/O / Timer external input clock General purpose I/O General purpose I/O / SPI clock General purpose I/O / SPI data path General purpose I/O / SPI data path General purpose I/O / SPI slave select General purpose I/O / Timer A channel 1 General purpose I/O / Timer A channel 0 General purpose I/O / SCI receive data General purpose I/O / SCI transmit data General purpose I/O General purpose I/O /Timer B channel 1 Driver Type Dual State Dual State Dual State Dual State Dual State Dual State Dual State Dual State Dual State Dual State Dual State (open drain) Dual State (open drain) Dual State (open drain) Dual State Dual State Dual State Dual State Dual State Dual State Dual State Hysteresis No No No No No No No No No No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Reset State Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z)
Freescale Semiconductor, Inc...
PTC2/MCLK PTC1-PTC0 PTD7 PTD6/TACLK PTD5 PTD4/TBCLK PTD3-PTD0 PTE7/SPSCK PTE6/MOSI PTE5/MISO PTE4/SS PTE3/TACH1 PTE2/TACH0 PTE1/RxD PTE0/TxD PTF7-PTF6 PTF5/TBCH1
Technical Data
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Freescale Semiconductor, Inc.
General Description I/O Pin Summary
Table 1-1. I/O Pins Summary
Pin Name PTF4/TBCH0 PTF3/TBCH3 PTF2/TBCH2 PTF1/TACH3 Function General purpose I/O / Timer B channel 0 General purpose I/O / Timer B channel 3 General purpose I/O / Timer B channel 2 General purpose I/O /Timer A channel 3 General purpose I/O / Timer A channel 2 General purpose I/O with key wakeup feature General purpose I/O with key wakeup feature Logical chip power supply Logical chip ground Analog power supply (CGM) Analog ground (CGM) ADC reference voltage ADC ground and reference voltage ADC power supply External clock in External clock out PLL loop filter cap External interrupt request Reset Driver Type Dual State Dual State Dual State Dual State Dual State Dual State Dual State NA NA NA NA NA NA NA NA NA NA NA NA Hysteresis Yes Yes Yes Yes Yes Yes Yes NA NA NA NA NA NA NA NA NA NA NA NA Reset State Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) Input (Hi-Z) NA NA NA NA NA NA NA Input (Hi-Z) Output NA Input (pullup) Input (pullup)
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PTF0/TACH2 PTG2/KBD2-PTG0/KBD0 PTH1/KBD4-PTH0/KBD3 VDD VSS VDDA VSSA VREFH AVSS/VREFL VDDAREF OSC1 OSC2 CGMXFC IRQ RST
Details of the clock connections to each of the modules on the MC68HC08AB16A are shown in Table 1-2. A short description of each clock source is also given in Table 1-3.
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Technical Data
39
Freescale Semiconductor, Inc. General Description 1.8 Signal Name Conventions
Table 1-2. Signal Name Conventions
Signal name CGMXCLK CGMOUT Bus clock Description Buffered version of OSC1 from clock generator module (CGM) PLL-based or OSC1-based clock output from CGM module) CGMOUT divided by two SPI serial clock (see 16.13.3 SPSCK (Serial Clock)) External clock input for TIMA (see 11.9.1 TIMA Clock Pin) External clock input for TIMB (see 12.9.1 TIMB Clock Pin)
Freescale Semiconductor, Inc...
SPSCK TACLK TBCLK
1.9 Clock Source Summary
Table 1-3. Clock Source Summary
Module ADC COP CPU EEPROM ROM RAM SPI SCI TIMA TIMB PIT KBI Clock Source CGMXCLK or bus clock CGMXCLK Bus clock CGMXCLK or bus clock Bus clock Bus clock SPSCK CGMXCLK Bus clock or PTD6/TACLK Bus clock or PTD4/TBCLK Bus clock Bus clock
Technical Data
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Freescale Semiconductor, Inc.
Technical Data -- MC68HC08AB16A
Section 2. Memory Map
2.1 Contents
2.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Unimplemented Memory Locations . . . . . . . . . . . . . . . . . . . . . 41 Reserved Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Input/Output (I/O) Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
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2.3 2.4 2.5
2.2 Introduction
The CPU08 can address 64K-bytes of memory space. The memory map, shown in Figure 2-1, includes: * * * * * 16,384 bytes of user ROM memory 512 bytes of EEPROM 512 bytes of random-access memory (RAM) 48 bytes of user-defined vectors 307 bytes of monitor ROM
2.3 Unimplemented Memory Locations
Accessing an unimplemented location can cause an illegal address reset if illegal address resets are enabled. In the memory map (Figure 2-1) and in register figures in this document, unimplemented locations are shaded.
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41
Freescale Semiconductor, Inc. Memory Map 2.4 Reserved Memory Locations
Accessing a reserved location can have unpredictable effects on MCU operation. In the Figure 2-1 and in register figures in this document, reserved locations are marked with the word Reserved or with the letter R.
2.5 Input/Output (I/O) Section
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Most of the control, status, and data registers are in the zero page $0000-$004F. Additional I/O registers have the following addresses: * * * * * * * * * * * * * * * $FE00; SIM break status register, SBSR $FE01; SIM reset status register, SRSR $FE03; SIM break flag control register, SBFCR $FE0C; break address register high, BRKH $FE0D; break address register low, BRKL $FE0E; break status and control register, BRKSCR $FE0F; LVI status register, LVISR $FE10; EEPROM divider mask option register high, EEDIVHMOR $FE11; EEPROM divider mask option register low, EEDIVLMOR $FE1A; EEPROM timebase divider register high, EEDIVH $FE1B; EEPROM timebase divider register low, EEDIVL $FE1C; EEPROM non-volatile register, EENVR $FE1D; EEPROM control register, EECR $FE1F; EEPROM array configuration register, EEACR $FFFF; COP control register, COPCTL
Data registers are shown in Figure 2-2, Table 2-1 is a list of vector locations.
Technical Data
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Freescale Semiconductor, Inc.
Memory Map Input/Output (I/O) Section
$0000 $004F $0050 $024F $0250 Unimplemented 688 Bytes RAM 512 Bytes I/O Registers 80 Bytes
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$04FF $0500 $057F $0580 $07FF $0800 $09FF $0A00 $BDFF $BE00 $FDFF $FE00 $FE01 $FE02 $FE03 $FE04 $FE07 $FE08 SIM Break Status Register (SBSR) SIM Reset Status Register (SRSR) Reserved SIM Break Flag Control Register (SBFCR) Reserved 4 Bytes Unimplemented ROM 16,384 Bytes Unimplemented 46,080 Bytes EEPROM 512 Bytes Unimplemented 640 Bytes Reserved 128 Bytes
Figure 2-1. Memory Map
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Memory Map For More Information On This Product, Go to: www.freescale.com
Technical Data
43
Freescale Semiconductor, Inc. Memory Map
$FE09 $FE0B $FE0C $FE0D $FE0E $FE0F $FE10 $FE11
Reserved 3 Bytes Break Address Register High (BRKH) Break Address Register Low (BRKL) Break Status and Control Register (BRKSCR) LVI Status Register (LVISR) EEPROM Divider Mask Option Register High (EEDIVHMOR) EEPROM Divider Mask Option Register Low (EEDIVLMOR) Reserved 8 Bytes EEPROM Timebase Divider Register High (EEDIVH) EEPROM Timebase Divider Register Low (EEDIVL) EEPROM Non-volatile Register (EENVR) EEPROM Control Register (EECR) Reserved EEPROM Array Configuration Register (EEACR) Monitor ROM 307 Bytes
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$FE12 $FE19 $FE1A $FE1B $FE1C $FE1D $FE1E $FE1F $FE20 $FF52 $FF53 $FF7D $FF7E $FF7F $FFBF $FFC0 ROM 16 Bytes $FFCF $FFD0 $FFFF
Unimplemented 43 Bytes Unimplemented Unimplemented 65 Bytes
Reserved ROM 16 Bytes Reserved for Compatibility with HC08AB16
ROM Vectors 48 Bytes
Figure 2-1. Memory Map (Continued)
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Memory Map Input/Output (I/O) Section
Addr.
Register Name Read: Port A Data Register Write: (PTA) Reset: Read: Port B Data Register Write: (PTB) Reset: Read: Port C Data Register Write: (PTC) Reset: Read: Port D Data Register Write: (PTD) Reset:
Bit 7 PTA7
6 PTA6
5 PTA5
4 PTA4
3 PTA3
2 PTA2
1 PTA1
Bit 0 PTA0
$0000
Unaffected by reset PTB7 PTB6 PTB5 PTB4 PTB3 PTB2 PTB1 PTB0
$0001
Unaffected by reset 0 0 PTC5 PTC4 PTC3 PTC2 PTC1 PTC0
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$0002
Unaffected by reset PTD7 PTD6 PTD5 PTD4 PTD3 PTD2 PTD1 PTD0
$0003
Unaffected by reset DDRA6 0 DDRB6 0 0 DDRA5 0 DDRB5 0 DDRC5 0 DDRD5 0 PTE5 DDRA4 0 DDRB4 0 DDRC4 0 DDRD4 0 PTE4 DDRA3 0 DDRB3 0 DDRC3 0 DDRD3 0 PTE3 DDRA2 0 DDRB2 0 DDRC2 0 DDRD2 0 PTE2 DDRA1 0 DDRB1 0 DDRC1 0 DDRD1 0 PTE1 DDRA0 0 DDRB0 0 DDRC0 0 DDRD0 0 PTE0
Read: DDRA7 Data Direction Register A $0004 Write: (DDRA) Reset: 0 Read: DDRB7 Data Direction Register B $0005 Write: (DDRB) Reset: 0 Read: MCLKEN Data Direction Register C $0006 Write: (DDRC) Reset: 0 Read: DDRD7 Data Direction Register D $0007 Write: (DDRD) Reset: 0 Read: Port E Data Register Write: (PTE) Reset: Read: Port F Data Register Write: (PTF) Reset: PTE7
0 DDRD6 0 PTE6
$0008
Unaffected by reset PTF7 PTF6 PTF5 PTF4 PTF3 PTF2 PTF1 PTF0
$0009
Unaffected by reset = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 1 of 11)
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Freescale Semiconductor, Inc. Memory Map
Addr.
Register Name Read: Port G Data Register Write: (PTG) Reset: Read: Port H Data Register Write: (PTH) Reset:
Bit 7 0
6 0
5 0
4 0
3 0
2 PTG2
1 PTG1
Bit 0 PTG0
$000A
Unaffected by reset 0 0 0 0 0 0 PTH1 PTH0
$000B
Unaffected by reset DDRE6 0 DDRF6 0 0 DDRE5 0 DDRF5 0 0 DDRE4 0 DDRF4 0 0 DDRE3 0 DDRF3 0 0 DDRE2 0 DDRF2 0 DDRG2 0 0 DDRE1 0 DDRF1 0 DDRG1 0 DDRH1 0 SPE 0 SPR1 0 R1 T1 DDRE0 0 DDRF0 0 DDRG0 0 DDRH0 0
SPTIE
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Read: DDRE7 Data Direction Register E $000C Write: (DDRE) Reset: 0 Read: DDRF7 Data Direction Register F $000D Write: (DDRF) Reset: 0 Read: Data Direction Register G $000E Write: (DDRG) Reset: Read: Data Direction Register H $000F Write: (DDRH) Reset: Read: SPI Control Register Write: (SPCR) Reset: Read: SPI Status and Control Register Write: (SPSCR) Reset: Read: SPI Data Register Write: (SPDR) Reset: 0
0 0
0 0
0 0
0 0
0 0
0 SPRIE 0 SPRF
0 R 0 ERRIE 0 R6 T6
0 SPMSTR 1 OVRF
0 CPOL 0 MODF
0 CPHA 1 SPTE
0 SPWOM 0 MODFEN 0 R2 T2
$0010
0 SPR0 0 R0 T0
$0011
0 R7 T7
0 R5 T5
0 R4 T4
1 R3 T3
$0012
Unaffected by reset ENSCI 0 TXINV 0 M 0 WAKE 0 R ILTY 0 = Reserved PEN 0 PTY 0
$0013
Read: LOOPS SCI Control Register 1 Write: (SCC1) Reset: 0
= Unimplemented
Figure 2-2. Control, Status, and Data Registers (Sheet 2 of 11)
Technical Data
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Freescale Semiconductor, Inc.
Memory Map Input/Output (I/O) Section
Addr.
Register Name Read: SCI Control Register 2 Write: (SCC2) Reset:
Bit 7 SCTIE 0
6 TCIE 0
5 SCRIE 0 R 0 SCRF
4 ILIE 0 R 0 IDLE
3 TE 0 ORIE 0 OR
2 RE 0 NEIE 0 NF
1 RWU 0 FEIE 0 FE
Bit 0 SBK 0 PEIE 0 PE
$0014
$0015
Read: R8 T8 SCI Control Register 3 Write: (SCC3) Reset: Unaffected Unaffected Read: SCI Status Register 1 Write: (SCS1) Reset: Read: SCI Status Register 2 Write: (SCS2) Reset: Read: SCI Data Register Write: (SCDR) Reset: Read: SCI Baud Rate Register Write: (SCBR) Reset: Read: IRQ Status and Control Register Write: (ISCR) Reset: Keyboard Status and Read: Control Register Write: (KBSCR) Reset: Read: PLL Control Register Write: (PCTL) Reset: Read: PLL Bandwidth Control Register Write: (PBWC) Reset: SCTE TC
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$0016
1 0
1 0
0 0
0 0
0 0
0 0
0 BKF
0 RPF
$0017
0 R7 T7
0 R6 T6
0 R5 T5
0 R4 T4
0 R3 T3
0 R2 T2
0 R1 T1
0 R0 T0
$0018
Unaffected by reset 0 0 SCP1 0 0 SCP0 0 0 R 0 IRQF SCR2 0 0 ACK 0 0 0 0 0 0 0 0 0 KEYF 0 0 ACKK 0 PLLIE 0 AUTO 0 0 PLLF 0 PLLON 1 ACQ 0 0 BCS 0 XLD 0 0 1 0 1 SCR1 0 IMASK 0 IMASKK 0 1 SCR0 0 MODE 0 MODEK 0 1
$0019
0 0
0 0
$001A
$001B
$001C
0 LOCK
1 0
1 0
1 0
1 0
$001D
0
0 R
0 = Reserved
0
0
= Unimplemented
Figure 2-2. Control, Status, and Data Registers (Sheet 3 of 11)
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Technical Data
47
Freescale Semiconductor, Inc. Memory Map
Addr.
Register Name Read: PLL Programming Register Write: (PPG) Reset:
Bit 7 MUL7 0
6 MUL6 1 SEC
5 MUL5 1
4 MUL4 0
3 VRS7 0 SSREC
2 VRS6 1 COPRS
1 VRS5 1 STOP
Bit 0 VRS4 0 COPD
$001E
$001F
Read: LVISTOP Mask Option Register A Write: (MORA) Reset:
LVIRSTD LVIPWRD
Unaffected by reset; mask option
Hard-wired register, specified during ROM code submission.
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$0020
Read: Timer A Status and Control Register Write: (TASC) Reset:
TOF 0 0 0
TOIE 0 0
TSTOP 1 0
0 TRST 0 KBIE4 0 12
0
PS2 0 KBIE2 0 10
PS1 0 KBIE1 0 9
PS0 0 KBIE0 0 Bit 8
0 KBIE3 0 11
Read: Keyboard Interrupt Enable $0021 Register Write: (KBIER) Reset: Read: Timer A Counter Register High Write: (TACNTH) Reset: Read: Timer A Counter Register Low Write: (TACNTL) Reset: Read: Timer A Counter Modulo Register High Write: (TAMODH) Reset: Read: Timer A Counter Modulo Register Low Write: (TAMODL) Reset:
0 Bit 15
0 14
0 13
$0022
0 Bit 7
0 6
0 5
0 4
0 3
0 2
0 1
0 Bit 0
$0023
0 Bit 15 1 Bit 7 1 CH0F 0 0 Bit 15
0 14 1 6 1 CH0IE 0 14
0 13 1 5 1 MS0B 0 13
0 12 1 4 1 MS0A 0 12
0 11 1 3 1 ELS0B 0 11
0 10 1 2 1 ELS0A 0 10
0 9 1 1 1 TOV0 0 9
0 Bit 8 1 Bit 0 1 CH0MAX 0 Bit 8
$0024
$0025
Read: Timer A Channel 0 Status $0026 and Control Register Write: (TASC0) Reset: Read: Timer A Channel 0 Register High Write: (TACH0H) Reset:
$0027
Indeterminate after reset = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 4 of 11)
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Freescale Semiconductor, Inc.
Memory Map Input/Output (I/O) Section
Addr.
Register Name Read: Timer A Channel 0 Register Low Write: (TACH0L) Reset:
Bit 7 Bit 7
6 6
5 5
4 4
3 3
2 2
1 1
Bit 0 Bit 0
$0028
Indeterminate after reset CH1F 0 0 Bit 15 CH1IE 0 14 0 MS1A 0 12 ELS1B 0 11 ELS1A 0 10 TOV1 0 9 CH1MAX 0 Bit 8
Read: Timer A Channel 1 Status $0029 and Control Register Write: (TASC1) Reset: Read: Timer A Channel 1 Register High Write: (TACH1H) Reset: Read: Timer A Channel 1 Register Low Write: (TACH1L) Reset:
0 13
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$002A
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$002B
Indeterminate after reset CH2F 0 0 Bit 15 CH2IE 0 14 MS2B 0 13 MS2A 0 12 ELS2B 0 11 ELS2A 0 10 TOV2 0 9 CH2MAX 0 Bit 8
Read: Timer A Channel 2 Status $002C and Control Register Write: (TASC2) Reset: Read: Timer A Channel 2 Register High Write: (TACH2H) Reset: Read: Timer A Channel 2 Register Low Write: (TACH2L) Reset:
$002D
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$002E
Indeterminate after reset CH3F 0 0 Bit 15 CH3IE 0 14 0 MS3A 0 12 ELS3B 0 11 ELS3A 0 10 TOV3 0 9 CH3MAX 0 Bit 8
Read: Timer A Channel 3 Status $002F and Control Register Write: (TASC3) Reset: Read: Timer A Channel 3 Register High Write: (TACH3H) Reset: Read: Timer A Channel 3 Register Low Write: (TACH3L) Reset:
0 13
$0030
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$0031
Indeterminate after reset = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 5 of 11)
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Technical Data
49
Freescale Semiconductor, Inc. Memory Map
Addr.
Register Name
Bit 7 CH2F 0 0 Bit 15
6 CH2IE 0 14
5 MS2B 0 13
4 MS2A 0 12
3 ELS2B 0 11
2 ELS2A 0 10
1 TOV2 0 9
Bit 0 CH2MAX 0 Bit 8
Read: Timer B Channel 2 Status $0032 and Control Register Write: (TBSC2) Reset: Read: Timer B Channel 2 Register High Write: (TBCH2H) Reset: Read: Timer B Channel 2 Register Low Write: (TBCH2L) Reset:
$0033
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
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$0034
Indeterminate after reset CH3F 0 0 Bit 15 CH3IE 0 14 0 MS3A 0 12 ELS3B 0 11 ELS3A 0 10 TOV3 0 9 CH3MAX 0 Bit 8
Read: Timer B Channel 3 Status $0035 and Control Register Write: (TBSC3) Reset: Read: Timer B Channel 3 Register High Write: (TACH3H) Reset: Read: Timer B Channel 3 Register Low Write: (TBCH3L) Reset: Read: Analog-to-Digital Status and Control Register Write: (ADSCR) Reset: Read: Analog-to-Digital Data Register Write: (ADR) Reset: Read: Analog-to-Digital Clock Register Write: (ADCLK) Reset: Read: $003B Reserved Write: Reset:
0 13
$0036
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$0037
Indeterminate after reset COCO 0 AD7 AIEN 0 AD6 ADCO 0 AD5 ADCH4 1 AD4 ADCH3 1 AD3 ADCH2 1 AD2 ADCH1 1 AD1 ADCH0 1 AD0
$0038
$0039
0 ADIV2 0 R
0 ADIV1 0 R
0 ADIV0 0 R
0 ADICLK 0 R
0 0
0 0
0 0
0 0
$003A
0 R
0 R
0 R
0 R
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 6 of 11)
Technical Data
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Memory Map Input/Output (I/O) Section
Addr.
Register Name Read:
Bit 7 R
6 R
5 R
4 R
3 R
2 R
1 R
Bit 0 R
$003C
Reserved Write: Reset:
Read: Port D Input Pullup Enable PTDPUE7 PTDPUE6 PTDPUE5 PTDPUE4 PTDPUE3 PTDPUE2 PTDPUE1 PTDPUE0 $003D Register Write: (PTDPUE) Reset: 0 0 0 0 0 0 0 0 Read: Port F Input Pullup Enable PTFPUE7 PTFPUE6 PTFPUE5 PTFPUE4 PTFPUE3 PTFPUE2 PTFPUE1 PTFPUE0 $003E Register Write: (PTFPUE) Reset: 0 0 0 0 0 0 0 0 Read: Mask Option Register B Write: (MORB) Reset: R
EEDIVCLK
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EESEC
EEMONSEC
R
R
R
R
$003F
Unaffected by reset; mask option
Hard-wired register, specified during ROM code submission. Read: Timer B Status and Control Register Write: (TBSC) Reset: Read: Timer B Counter Register High Write: (TBCNTH) Reset: Read: Timer B Counter Register Low Write: (TBCNTL) Reset: Read: Timer B Counter Modulo Register High Write: (TBMODH) Reset: Read: Timer B Counter Modulo Register Low Write: (TBMODL) Reset: TOF 0 0 Bit 15 TOIE 0 14 TSTOP 1 13 0 TRST 0 12 0 11 0 PS2 0 10 PS1 0 9 PS0 0 Bit 8
$0040
$0041
0 Bit 7
0 6
0 5
0 4
0 3
0 2
0 1
0 Bit 0
$0042
0 Bit 15 1 Bit 7 1 CH0F 0 0
0 14 1 6 1 CH0IE 0
0 13 1 5 1 MS0B 0
0 12 1 4 1 MS0A 0
0 11 1 3 1 ELS0B 0 R
0 10 1 2 1 ELS0A 0 = Reserved
0 9 1 1 1 TOV0 0
0 Bit 8 1 Bit 0 1 CH0MAX 0
$0043
$0044
Read: Timer B Channel 0 Status $0045 and Control Register Write: (TBSC0) Reset:
= Unimplemented
Figure 2-2. Control, Status, and Data Registers (Sheet 7 of 11)
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Freescale Semiconductor, Inc. Memory Map
Addr.
Register Name Read: Timer B Channel 0 Register High Write: (TBCH0H) Reset: Read: Timer B Channel 0 Register Low Write: (TBCH0L) Reset:
Bit 7 Bit 15
6 14
5 13
4 12
3 11
2 10
1 9
Bit 0 Bit 8
$0046
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$0047
Indeterminate after reset CH1F 0 0 Bit 15 CH1IE 0 14 0 MS1A 0 12 ELS1B 0 11 ELS1A 0 10 TOV1 0 9 CH1MAX 0 Bit 8
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Read: Timer B Channel 1 Status $0048 and Control Register Write: (TBSC1) Reset: Read: Timer B Channel 1 Register High Write: (TBCH1H) Reset: Read: Timer B Channel 1 Register Low Write: (TBCH1L) Reset: Read: PIT Status and Control Register Write: (PSC) Reset:
0 13
$0049
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$004A
Indeterminate after reset POF 0 0 Bit 15 POIE 0 14 PSTOP 1 13 0 PRST 0 12 0 11 0 PPS2 0 10 PPS1 0 9 PPS0 0 Bit 8
$004B
Read: PIT Counter Register High $004C Write: (PCNTH) Reset: Read: PIT Counter Register Low $004D Write: (PCNTL) Reset: Read: PIT Counter Modulo Register High Write: (PMODH) Reset: Read: PIT Counter Modulo Register Low Write: (PMODL) Reset:
0 Bit 7
0 6
0 5
0 4
0 3
0 2
0 1
0 Bit 0
0 Bit 15 1 Bit 7 1
0 14 1 6 1
0 13 1 5 1
0 12 1 4 1
0 11 1 3 1
0 10 1 2 1
0 9 1 1 1
0 Bit 8 1 Bit 0 1
$004E
$004F
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 8 of 11)
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Memory Map Input/Output (I/O) Section
Addr.
Register Name
Bit 7 R 0
6 R 0
5 R 0
4 R 0
3 R 0
2 R 0
1 SBSW Note 0
Bit 0 R 0
Read: SIM Break Status Register $FE00 Write: (SBSR) Reset: Note: Writing a logic 0 clears SBSW. Read: SIM Reset Status Register $FE01 Write: (SRSR) POR:
POR
PIN
COP
ILOP
ILAD
0
LVI
0
1 R 0 BCFE 0 R
0 R 0 R
0 R 0 R
0 R 0 R
0 R 0 R
0 R 0 R
0 R 0 R
0 R 0 R
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Read: $FE02 Reserved Write: Reset: Read: SIM Break Flag Control Register Write: (SBFCR) Reset: Read: $FE04 Reserved Write: Reset: Read: $FE05 Reserved Write: Reset: Read: $FE06 Reserved Write: Reset: Read: $FE07 Reserved Write: Reset: Read: $FE08 Unimplemented Write: Reset: Read: $FE09 Reserved Write: Reset:
$FE03
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 9 of 11)
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Freescale Semiconductor, Inc. Memory Map
Addr.
Register Name Read:
Bit 7 R
6 R
5 R
4 R
3 R
2 R
1 R
Bit 0 R
$FE0A
Reserved Write: Reset: Read:
$FE0B
Reserved Write: Reset: Read: Break Address Register High Write: (BRKH) Reset: Read: Break Address Register Low Write: (BRKL) Reset:
R
R
R
R
R
R
R
R
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$FE0C
Bit 15 0 Bit 7 0 BRKE 0
14 0 6 0 BRKA 0 0
13 0 5 0 0
12 0 4 0 0
11 0 3 0 0
10 0 2 0 0
9 0 1 0 0
Bit 8 0 Bit 0 0 0
$FE0D
Read: Break Status and Control $FE0E Register Write: (BRKSCR) Reset:
0 0
0 0
0 0
0 0
0 0
0 0
Read: LVIOUT Low-Voltage Inhibit Status $FE0F Register Write: (LVISR) Reset: 0 Read: EEDIV Mask Option Register High Write: (EEDIVHMOR) Reset:
EEDIVSECD
0 R
0 R
0 R
0 R
0 EEDIV10
0 EEDIV9
0 EEDIV8
$FE10
Unaffected by reset; mask option EEDIV6 EEDIV5 EEDIV4 EEDIV3 EEDIV2 EEDIV1 EEDIV0
$FE11
Read: EEDIV7 EEDIV Mask Option Register Low Write: (EEDIVLMOR) Reset:
Unaffected by reset; mask option
Hard-wired register, specified during ROM code submission. Read: EE Divider Register High $FE1A Write: (EEDIVH) Reset:
EEDIVSECD
R
R
R
R
EEDIV10
EEDIV9
EEDIV8
Contents of EEDIVHMOR ($FE10) EEDIV6 EEDIV5 EEDIV4 EEDIV3 EEDIV2 EEDIV1 EEDIV0
$FE1B
Read: EEDIV7 EE Divider Register Low Write: (EEDIVL) Reset:
Contents of EEDIVLMOR ($FE11) = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 10 of 11)
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Memory Map Input/Output (I/O) Section
Addr.
Register Name Read: EEPROM Non-volatile Register Write: (EENVR)* Reset:
Bit 7 CON3
6 CON2
5 CON1
4 EEPRTCT
3 EEBP3
2 EEBP2
1 EEBP1
Bit 0 EEBP0
$FE1C
Unaffected by reset; $FF when blank; factory programmed $10
* Non-volatile EEPROM register; write by programming. Read: EEDUM EEPROM Control Register $FE1D Write: (EECR) Reset: 0 0 EEOFF 0 R EERAS1 0 R EERAS0 0 R EELAT 0 R AUTO 0 R EEPGM 0 R
0 R
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Read: $FE1E Reserved Write: Reset: Read: EEPROM Array Configuration Register Write: (EEACR) Reset:
R
CON3
CON2
CON1
EEPRTCT
EEBP3
EEBP2
EEBP1
EEBP0
$FE1F
Contents of EENVR ($FE1C)
Read: $FF7E Unimplemented Write: Reset:
$FFFF
Read: COP Control Register Write: (COPCTL) Reset:
Low byte of reset vector Writing clears COP counter (any value) Unaffected by reset = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 11 of 11)
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Freescale Semiconductor, Inc. Memory Map
Table 2-1. Vector Addresses
Vector Priority Lowest Address
$FFD0 $FFD1 $FFD2 $FFD3 $FFD4 $FFD5 $FFD6 $FFD7 $FFD8 $FFD9 $FFDA $FFDB $FFDC $FFDD $FFDE $FFDF $FFE0 $FFE1 $FFE2 $FFE3 $FFE4 $FFE5 $FFE6 $FFE7 $FFE8 $FFE9 $FFEA $FFEB $FFEC $FFED $FFEE $FFEF $FFF0 $FFF1 $FFF2 $FFF3 $FFF4 $FFF5 $FFF6 $FFF7 $FFF8 $FFF9 $FFFA $FFFB $FFFC $FFFD $FFFE $FFFF
Vector
ADC Conversion Complete Vector (High) ADC Conversion Complete Vector (Low) Keyboard Vector (High) Keyboard Vector (Low) SCI Transmit Vector (High) SCI Transmit Vector (Low) SCI Receive Vector (High) SCI Receive Vector (Low) SCI Error Vector (High) SCI Error Vector (Low) Reserved Reserved Reserved Reserved Timer B Channel 3 Vector (High) Timer B Channel 3 Vector (Low) Timer B Channel 2 Vector (High) Timer B Channel 2 Vector (Low) SPI Transmit Vector (High) SPI Transmit Vector (Low) SPI Receive Vector (High) SPI Receive Vector (Low) Timer B Overflow Vector (High) Timer B Overflow Vector (Low) Timer B Channel 1 Vector (High) Timer B Channel 1 Vector (Low) Timer B Channel 0 Vector (High) Timer B Channel 0 Vector (Low) Timer A Overflow Vector (High) Timer A Overflow Vector (Low) Timer A Channel 3 Vector (High) Timer A Channel 3 Vector (Low) Timer A Channel 2 Vector (High) Timer A Channel 2 Vector (Low) Timer A Channel 1 Vector (High) Timer A Channel 1 Vector (Low) Timer A Channel 0 Vector (High) Timer A Channel 0 Vector (Low) Programmable Interrupt Timer Vector (High) Programmable Interrupt Timer Vector (Low) PLL Vector (High) PLL Vector (Low) IRQ Vector (High) IRQ Vector (Low) SWI Vector (High) SWI Vector (Low) Reset Vector (High) Reset Vector (Low)
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Highest
Technical Data
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Technical Data -- MC68HC08AB16A
Section 3. Random-Access Memory (RAM)
3.1 Contents
3.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
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3.3
3.2 Introduction
This section describes the 512 bytes of RAM (random-access memory).
3.3 Functional Description
Addresses $0050 through $024F are RAM locations. The location of the stack RAM is programmable. The 16-bit stack pointer allows the stack to be anywhere in the 64K-byte memory space.
NOTE:
For correct operation, the stack pointer must point only to RAM locations.
Within page zero are 176 bytes of RAM. Because the location of the stack RAM is programmable, all page zero RAM locations can be used for I/O control and user data or code. When the stack pointer is moved from its reset location at $00FF out of page zero, direct addressing mode instructions can efficiently access all page zero RAM locations. Page zero RAM, therefore, provides ideal locations for frequently accessed global variables. Before processing an interrupt, the CPU uses five bytes of the stack to save the contents of the CPU registers.
NOTE:
For M6805 compatibility, the H register is not stacked.
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Freescale Semiconductor, Inc. Random-Access Memory (RAM)
During a subroutine call, the CPU uses two bytes of the stack to store the return address. The stack pointer decrements during pushes and increments during pulls.
NOTE:
Be careful when using nested subroutines. The CPU may overwrite data in the RAM during a subroutine or during the interrupt stacking operation.
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Technical Data
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Technical Data -- MC68HC08AB16A
Section 4. Read-Only Memory (ROM)
4.1 Contents
4.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
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4.3
4.2 Introduction
This section describes the 16,384 bytes of read-only memory (ROM) and 48 bytes of user vectors.
4.3 Functional Description
These addresses are user ROM locations: $BE00-$FDFF; user memory, 16,384 bytes. $FFD0-$FFFF (These locations are reserved for user-defined interrupt and reset vectors.)
NOTE:
A mask option sets the security feature which prevents viewing of the ROM contents.1 See Section 6. Mask Options (MOR).
1. No security feature is absolutely secure. However, Motorola's strategy is to make reading or copying the ROM contents difficult for unauthorized users.
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Technical Data
59
Freescale Semiconductor, Inc. Read-Only Memory (ROM)
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Technical Data
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Technical Data -- MC68HC08AB16A
Section 5. EEPROM
5.1 Contents
5.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 EEPROM Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 EEPROM Timebase Requirements . . . . . . . . . . . . . . . . . . . . . 64 EEPROM Security Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 EEPROM Block Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
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5.3 5.4 5.5 5.6 5.7 5.8
5.9 EEPROM Programming and Erasing . . . . . . . . . . . . . . . . . . . . 65 5.9.1 EEPROM Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 5.9.2 EEPROM Erasing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 5.10 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 5.10.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 5.10.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 5.11 EEPROM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 5.11.1 EEPROM Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . 69 5.11.2 EEPROM Array Configuration Register . . . . . . . . . . . . . . . . 71 5.11.2.1 EEPROM Non-Volatile Register . . . . . . . . . . . . . . . . . . . 72 5.11.3 EEPROM Timebase Divider Register . . . . . . . . . . . . . . . . . 72 5.11.3.1 EEPROM Timebase Divider Mask Option Register . . . . . 74
5.2 Introduction
This section describes the 512 bytes electrically erasable programmable read-only-memory (EEPROM).
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Freescale Semiconductor, Inc. EEPROM 5.3 Features
Features of the EEPROM include the following: * * * * * 512 bytes non-volatile memory Byte, block or bulk erasable operations Non-volatile EEPROM configuration and block protection options On-chip charge pump for programming/erasing Security option
Bit 7
EEDIVSECD
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Addr.
Register Name Read: EEDIV Mask Option Register High Write: (EEDIVHMOR) Reset:
6 R
5 R
4 R
3 R
2 EEDIV10
1 EEDIV9
Bit 0 EEDIV8
$FE10
Unaffected by reset; mask option EEDIV6 EEDIV5 EEDIV4 EEDIV3 EEDIV2 EEDIV1 EEDIV0
$FE11
Read: EEDIV7 EEDIV Mask Option Register Low Write: (EEDIVLMOR) Reset:
EEDIVSECD
Unaffected by reset; mask option R R R R EEDIV10 EEDIV9 EEDIV8
Read: EE Divider Register High $FE1A Write: (EEDIVH) Reset:
Contents of EEDIVHMOR ($FE10) EEDIV6 EEDIV5 EEDIV4 EEDIV3 EEDIV2 EEDIV1 EEDIV0
$FE1B
Read: EEDIV7 EE Divider Register Low Write: (EEDIVL) Reset: Read: EEPROM Non-volatile Register Write: (EENVR)* Reset: CON3
Contents of EEDIVLMOR ($FE11) CON2 CON1 EEPRTCT EEBP3 EEBP2 EEBP1 EEBP0
$FE1C
Unaffected by reset; $FF when blank; factory programmed $10 0 EEOFF 0 CON1 EERAS1 0 EEPRTCT EERAS0 0 EEBP3 EELAT 0 EEBP2 AUTO 0 EEBP1 EEPGM 0 EEBP0
Read: EEDUM EEPROM Control Register $FE1D Write: (EECR) Reset: 0 Read: EEPROM Array Configuration Register Write: (EEACR) Reset: CON3
0 CON2
$FE1F
Contents of EENVR ($FE1C)
Hard-wired register, specified during ROM code submission. * Non-volatile EEPROM register; write by programming. = Unimplemented R = Reserved
Figure 5-1. EEPROM I/O Register Summary
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EEPROM Functional Description
5.4 Functional Description
The 512 bytes of EEPROM is located at $0800-$09FF, and can be programmed or erased without an additional external high voltage supply. The program and erase operations are enabled through the use of an internal charge pump. For each byte of EEPROM, the write/erase endurance is 10,000 cycles.
5.5 EEPROM Configuration
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The 8-bit EEPROM non-volatile register (EENVR) and the 16-bit EEPROM timebase divider mask option register (EEDIVMOR) contain the default settings for the following EEPROM configurations: * * * Security option Block protection EEPROM timebase reference
EENVR is a non-volatile EEPROM register. It is programmed and erased in the same way as an EEPROM byte. EEDIVMOR is a mask option register, specified at the same time as the ROM code. The contents of these registers are loaded into their respective volatile registers during a MCU reset. The values in these read/write, volatile registers define the EEPROM configurations. For EENVR, the corresponding volatile register is the EEPROM array configuration register (EEACR). For the EEDIVMOR (two 8-bit registers: EEDIVHMOR and EEDIVLMOR), the corresponding volatile register is the EEPROM timebase divider register (EEDIV: EEDIVH and EEDIVL)
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Technical Data
63
Freescale Semiconductor, Inc. EEPROM 5.6 EEPROM Timebase Requirements
A 35s timebase is required by the EEPROM control circuit for program and erase of EEPROM content. This timebase is derived from dividing the CGMXCLK or bus clock (selected by EEDIVCLK bit in MORB register) using a timebase divider circuit, controlled by the 16-bit EEPROM timebase divider register (EEDIVH and EEDIVL). As the CGMXCLK or bus clock is user selected, the EEPROM timebase divider register must be configured with the appropriate value to obtain the 35s. The timebase divider is calculated using the following formula: EEDIV = INT [Reference frequency (Hz) x 35 x 10 -6 + 0.5] This value is written to the EEPROM timebase divider register (EEDIVH and EEDIVL) or predefined into the EEPROM timebase divider mask option register (EEDIVHMOR and EEDIVLMOR) prior to any EEPROM program or erase operations (see 5.5 EEPROM Configuration and 5.11.3.1 EEPROM Timebase Divider Mask Option Register).
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5.7 EEPROM Security Options
The EEPROM has a special security option, enabled by programming the EEPRTCT bit to 0 in the EEPROM non-volatile register (EENVR). Once security is enabled, the following limitations apply to the EEPROM: * * * The 16-byte EEPROM locations from $08F0 to $08FF are protected from erase and program operations. The block erase and bulk erase modes are disabled. Byte erase can be used for all EEPROM locations except $08F0 to $08FF. The EENVR is protected from further erase or program operations.
5.8 EEPROM Block Protection
The 512 bytes of EEPROM is divided into four 128-byte blocks. Each of these blocks can be protected from erase/program operations by setting the EEBPx bit in the EENVR. Table 5-1 shows the address ranges for the blocks.
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EEPROM EEPROM Programming and Erasing
Table 5-1. EEPROM Array Address Blocks
Block Number (EEBPx) EEBP0 EEBP1 EEBP2 EEBP3 Address Range $0800-$087F $0880-$08FF $0900-$097F $0980-$09FF
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These bits are effective after a reset or a read to EENVR register. The block protect configuration can be modified by erasing/programming the corresponding bits in the EENVR register and then reading the EENVR register.
5.9 EEPROM Programming and Erasing
The unprogrammed or erased state of an EEPROM bit is a logic 1. The factory default for the EEPROM array is $FF for all bytes. The programming operation changes an EEPROM bit from logic 1 to logic 0 (programming cannot change a bit from logic 0 to a logic 1). In a single programming operation, the minimum EEPROM programming size is zero bits; the maximum is eight bits (one byte). The erase operation changes an EEPROM bit from logic 0 to logic 1. In a single erase operation, the minimum EEPROM erase size is one byte; the maximum is the entire EEPROM array. For each EEPROM byte, the write/erase endurance is 10,000 cycles. One write/erase cycle is defined as: a maximum of eight programming operations on the same byte followed by an erase operation of the that byte. Therefore, it is possible to program a byte, bit by bit to logic 0 before requiring an erase on that byte.
NOTE:
Although programming a bit (from 0 or 1) with a logic 1 does not change the state of that bit, it is still regarded as a programming operation. That is, if the same byte is programmed eight times (with any value), that byte must be erased before it can be successfully programmed again.
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Freescale Semiconductor, Inc. EEPROM
5.9.1 EEPROM Programming The unprogrammed or erased state of an EEPROM bit is a logic 1. Programming changes the state to a logic 0. Only EEPROM bytes in the non-protected blocks and the EENVR register can be programmed. Use the following procedure to program a byte of EEPROM: 1. Clear EERAS1 and EERAS0, and set EELAT in the EECR.(A) 2. Write the desired data to the desired EEPROM address.(B) 3. Set the EEPGM bit.(C) Go to step 7 if AUTO is set. 4. Wait for a time, tEEPGM, to program the byte. 5. Clear EEPGM bit. 6. Wait for a time, tEEFPV, for the programming voltage to fall. Go to step 8. 7. Poll the EEPGM bit until it is cleared by the internal timer.(D) 8. Clear EELAT bit.(E)
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NOTE:
A. EERAS1 and EERAS0 must be cleared for programming. Setting the EELAT bit configures the address and data buses to latch data for programming the array. Only data with a valid EEPROM address will be latched. If EELAT is set, other writes to the EECR will be allowed after a valid EEPROM write. B. If more than one valid EEPROM writes occur, the last address and data will be latched, overriding the previous address and data. Once written data to the desired address, do not read EEPROM locations other than the written location. (Reading an EEPROM location returns the latched data, and causes the read address to be latched.) C. The EEPGM bit cannot be set if the EELAT bit is cleared or a nonvalid EEPROM address is latched. This is to ensure proper programming sequence. Once EEPGM is set, do not read any EEPROM locations, otherwise the current program cycle will be unsuccessful. When EEPGM is set, the on-board programming sequence will be activated.
Technical Data
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EEPROM EEPROM Programming and Erasing
D. The delay time for the EEPGM bit to be cleared in AUTO mode is less than tEEPGM. However, on other MCUs, this delay time may be different. For forward compatibility, software should not make any dependency on this delay time. E. Any attempt to clear both EEPGM and EELAT bits with a single instruction will only clear EEPGM. This is to allow time for removal of high voltage from the EEPROM array.
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5.9.2 EEPROM Erasing The programmed state of an EEPROM bit is logic 0. Erasing changes the state to a logic 1. Only EEPROM bytes in the non-protected blocks and EENVR register can be erased. Use the following procedure to erase a byte, block, or the entire EEPROM: 1. Configure EERAS1 and EERAS0 for byte, block, or bulk erase; set EELAT in EECR.(A) 2. Byte erase: write any data to the desired address.(B) Block erase: write any data to an address within the desired block.(B) Bulk erase: write any data to an address within the array.(B) 3. Set the EEPGM bit.(C) Go to step 7 if AUTO is set. 4. Wait for a time: tEBYTE for byte erase; tEBLOCK for block erase; tEBULK for bulk erase. 5. Clear EEPGM bit. 6. Wait for a time, tEEFPV, for the erasing voltage to fall. Go to step 8. 7. Poll the EEPGM bit until it is cleared by the internal timer.(D) 8. Clear EELAT bits.(E)
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Freescale Semiconductor, Inc. EEPROM
NOTE:
A. Setting the EELAT bit configures the address and data buses to latch data for erasing the array. Only valid EEPROM addresses will be latched. If EELAT is set, other writes to the EECR will be allowed after a valid EEPROM write. B. If more than one valid EEPROM writes occur, the last address and data will be latched, overriding the previous address and data. Once written data to the desired address, do not read EEPROM locations other than the written location. (Reading an EEPROM location returns the latched data, and causes the read address to be latched.) EENVR is not affected by block or bulk erase. C. The EEPGM bit cannot be set if the EELAT bit is cleared or a nonvalid EEPROM address is latched. This is to ensure proper programming sequence. Once EEPGM is set, do not read any EEPROM locations, otherwise the current erase cycle will be unsuccessful. When EEPGM is set, the erase mode cannot be changed, and the on-board erasing sequence will be activated. D. The delay time for the EEPGM bit to be cleared in AUTO mode is less than tEBYTE / tEBLOCK / tEBULK. However, on other MCUs, this delay time may be different. For forward compatibility, software should not make any dependency on this delay time. E. Any attempt to clear both EEPGM and EELAT bits with a single instruction will only clear EEPGM. This is to allow time for removal of high voltage from the EEPROM array.
Freescale Semiconductor, Inc...
5.10 Low Power Modes
The WAIT and STOP instructions can put the MCU in low power consumption standby modes.
5.10.1 Wait Mode The WAIT instruction does not affect the EEPROM. It is possible to start the program or erase sequence on the EEPROM and put the MCU in wait mode.
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EEPROM EEPROM Registers
5.10.2 Stop Mode The STOP instruction reduces the EEPROM power consumption to a minimum. The STOP instruction should not be executed while the programming and erasing sequence is in progress. If stop mode is entered while EELAT and EEPGM is set, the programming sequence will be stopped and the programming voltage to the EEPROM array removed. The programming sequence will be restarted after leaving stop mode; access to the EEPROM is only possible after the programming sequence has completed. If stop mode is entered while EELAT and EEPGM is cleared, the programming sequence will be terminated abruptly. In either case, the data integrity of the EEPROM is not guaranteed.
Freescale Semiconductor, Inc...
5.11 EEPROM Registers
Four I/O registers and three non-volatile registers control program, erase, and options of the EEPROM array. 5.11.1 EEPROM Control Register This read/write register controls programming/erasing of the EEPROM array.
Address: $FE1D Bit 7 Read: EEDUM Write: Reset: 0 0 0 0 0 0 0 0 6 0 EEOFF EERAS1 EERAS0 EELAT AUTO EEPGM 5 4 3 2 1 Bit 0
Figure 5-2. EEPROM Control Register (EECR) EEDUM -- Dummy Bit This read/write bit has no function.
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EEOFF -- EEPROM Power-Off This read/write bit disables the EEPROM module for lower power consumption. Any attempts to access the array will give unpredictable results. Reset clears this bit. 1 = Disable EEPROM array 0 = Enable EEPROM array EERAS[1:0] -- Erase/Program Mode Select Bits These read/write bits set the erase modes. Reset clears these bits.
Freescale Semiconductor, Inc...
Table 5-2. EEPROM Program/Erase Mode Select
EEBPx 0 0 0 0 1
X = don't care
EERAS1 0 0 1 1 X
EERAS0 0 1 0 1 X
Mode Byte Program Byte Erase Block Erase Bulk Erase No Erase/Program
EELAT -- EEPROM Latch Control This read/write bit latches the address and data buses for programming the EEPROM array. EELAT can not be cleared if EEPGM is still set. Reset clears this bit. 1 = Buses configured for EEPROM program or erase operation 0 = Buses configured for normal operation AUTO -- Automatic termination of program/erase cycle When AUTO is set, EEPGM is cleared automatically after the program/erase cycle is terminated by the internal timer. (See note D for 5.9.1 EEPROM Programming and 5.9.2 EEPROM Erasing.) 0 = Automatic clear of EEPGM is disabled 1 = Automatic clear of EEPGM is enabled
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EEPROM EEPROM Registers
EEPGM -- EEPROM Program/Erase Enable This read/write bit enables the internal charge pump and applies the programming/erasing voltage to the EEPROM array if the EELAT bit is set and a write to a valid EEPROM location has occurred. Reset clears the EEPGM bit. 1 = EEPROM programming/erasing power switched on 0 = EEPROM programming/erasing power switched off
NOTE:
Freescale Semiconductor, Inc...
Writing 0s to both the EELAT and EEPGM bits with a single instruction will only clear EEPGM. This is to allow time for the removal of high voltage.
5.11.2 EEPROM Array Configuration Register The EEPROM array configuration register configures EEPROM security and EEPROM block protection. This read-only register is loaded with the contents of the EEPROM nonvolatile register (EENVR) after a reset.
Address: $FE1F Bit 7 Read: Write: Reset: Contents of EENVR ($FE1C) CON3 6 CON2 5 CON1 4
EEPRTCT
3 EEBP3
2 EEBP2
1 EEBP1
Bit 0 EEBP0
Figure 5-3. EEPROM Array Configuration Register (EEACR) CON[3:1] -- Unused EEPRTCT -- EEPROM Protection Bit The EEPRTCT bit is used to enable the security feature in the EEPROM (see 5.7 EEPROM Security Options). This bit has no effect unless the EESEC bit is set in the mask option register B ($003F) (see 6.5 Mask Option Register B). 1 = EEPROM security disabled 0 = EEPROM security enabled
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EEBP[3:0] -- EEPROM Block Protection Bits These bits prevent blocks of EEPROM array from being programmed or erased. 1 = EEPROM array block is protected 0 = EEPROM array block is unprotected
Block Number (EEBPx) EEBP0 Address Range $0800-$087F $0880-$08FF $0900-$097F $0980-$09FF
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EEBP1 EEBP2 EEBP3
5.11.2.1 EEPROM Non-Volatile Register
The contents of this register is loaded into the EEPROM array configuration register (EEACR) after a reset. This register is erased and programmed in the same way as an EEPROM byte.
Address: $FE1C Bit 7 Read: CON3 Write: Reset: Unaffected by reset; $FF when blank; factory programmed $10 CON2 CON1
EEPRTCT
6
5
4
3 EEBP3
2 EEBP2
1 EEBP1
Bit 0 EEBP0
Note: Non-volatile EEPROM register; write by programming.
Figure 5-4. EEPROM Non-Volatile Register (EENVR)
NOTE:
The EENVR is factory programmed with $10.
5.11.3 EEPROM Timebase Divider Register The 16-bit EEPROM timebase divider register consists of two 8-bit registers: EEDIVH and EEDIVL. The 11-bit value in this register is used to configure the timebase divider circuit to obtain the 35s timebase for EEPROM control.
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EEPROM EEPROM Registers
These two read/write registers are respectively loaded with the contents of the EEPROM timebase divider mask option registers (EEDIVHMOR and EEDIVLMOR) after a reset.
Address: $FE1A Bit 7 Read:
EEDIVSECD
6 R
5 R
4 R
3 R
2 EEDIV10
1 EEDIV9
Bit 0 EEDIV8
Write: Reset: Contents of EEDIVHMOR ($FE10)
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Figure 5-5. EEPROM Divider Register High (EEDIVH)
Address: $FE1B Bit 7 Read: EEDIV7 Write: Reset: Contents of EEDIVLMOR ($FE11) EEDIV6 EEDIV5 EEDIV4 EEDIV3 EEDIV2 EEDIV1 EEDIV0 6 5 4 3 2 1 Bit 0
Figure 5-6. EEPROM Divider Register Low (EEDIVL) EEDIVSECD -- EEPROM Divider Security Disable This bit enables/disables the security feature of the EEDIV registers. When EEDIV security feature is enabled, the state of the registers EEDIVH and EEDIVL are locked (including this EEDIVSECD bit). 1 = EEDIV security feature disabled 0 = EEDIV security feature enabled EEDIV[10:0] -- EEPROM Timebase Prescaler These prescaler bits store the value of EEDIV which is used as the divisor to derive a timebase of 35s from the selected reference clock source (CGMXCLK or bus clock, see 6.5 Mask Option Register B) for the EEPROM related internal timer and circuits. EEDIV[10:0] bits are readable at any time. They are writable when EELAT=0 and EEDIVSECD=1. The EEDIV value is calculated by the following formula: EEDIV = INT [Reference frequency (Hz) x 35 x 10 -6 + 0.5]
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Freescale Semiconductor, Inc. EEPROM
Where the result inside the bracket is rounded down to the nearest integer value. For example, if the reference frequency is 4.9152MHz, the EEDIV value is 172.
NOTE:
Programming/erasing the EEPROM with an improper EEDIV value may result in data lost and reduce endurance of the EEPROM device.
5.11.3.1 EEPROM Timebase Divider Mask Option Register
Freescale Semiconductor, Inc...
The 16-bit EEPROM timebase divider mask option register consists of two 8-bit read-only registers: EEDIVHMOR and EEDIVLMOR. The contents of these two registers are respectively loaded into the EEPROM timebase divider registers, EEDIVH and EEDIVL, after a reset. These two registers are hard-wired connections specified at the same time as the ROM code.
Address: $FE10 Bit 7 Read: Write: Reset: Unaffected by reset; mask option
EEDIVSECD
6 R
5 R
4 R
3 R
2 EEDIV10
1 EEDIV9
Bit 0 EEDIV8
Figure 5-7. EEPROM Divider Mask Option Register High (EEDIVHMOR)
Address: $FE11 Bit 7 Read: Write: Reset: Unaffected by reset; mask option EEDIV7 6 EEDIV6 5 EEDIV5 4 EEDIV4 3 EEDIV3 2 EEDIV2 1 EEDIV1 Bit 0 EEDIV0
Figure 5-8. EEPROM Divider Mask Option Register Low (EEDIVLMOR)
Technical Data
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Technical Data -- MC68HC08AB16A
Section 6. Mask Options (MOR)
6.1 Contents
6.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Mask Option Register A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Mask Option Register B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 EEPROM Timebase Divider Mask Option Registers . . . . . . . . 79
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6.3 6.4 6.5 6.6
6.2 Introduction
This section describes the mask options and the mask option registers, MORA, MORB, EEDIVHMOR, and EEDIVLMOR. Mask options are hard-wired connections specified at the same time as the ROM code, which allows the user to customize the MCU. These options enable or disable the following functions: * * * * * * * * * *
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Low-voltage inhibit (LVI) in stop mode ROM security LVI reset LVI module power Stop mode recovery time (32 CGMXCLK cycles or 4096 CGMXCLK cycles) COP timeout period (218 - 24 or 213 - 24 CGMXCLK cycles) STOP instruction Computer operating properly module (COP) EEPROM reference clock source (CPU bus clock or CGMXCLK) EEPROM security
Technical Data
75
Freescale Semiconductor, Inc. Mask Options (MOR) 6.3 Functional Description
The two mask option registers (MORA and MORB) and two EEPROM timebase divider mask option registers (EEDIVHMOR and EEDIVLMOR) are read-only registers, and are used in the initialization of various options. These registers are hard-wired connections specified at the same time as the ROM code. The MORA and MORB registers are located at $001F and $003F respectively. The EEDIVHMOR and EEDIVLMOR are located at $FE10 and $FE11 respectively.
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6.4 Mask Option Register A
Address: $001F Bit 7 Read: LVISTOP Write: Reset: Unaffected by reset 6 SEC 5 4 3 SSREC 2 COPRS 1 STOP Bit 0 COPD
LVIRSTD LVIPWRD
Figure 6-1. Mask Option Register A (MORA) LVISTOP -- LVI Enable in Stop Mode Bit When the LVIPWRD bit is clear, setting the LVISTOP bit enables the LVI to operate in stop mode. Reset clears LVISTOP. (See Section 21. Low-Voltage Inhibit (LVI).) 1 = LVI enabled during stop mode 0 = LVI disabled during stop mode SEC -- ROM Security Bit When the SEC bit is set, ROM security is enabled, ROM content cannot be dumped if security bypass fails on entering monitor mode. (See 10.5 Security.) 1 = ROM security enabled 0 = ROM security disabled LVIRSTD -- LVI Reset Disable Bit LVIRSTD disables the reset signal from the LVI module. (See Section 21. Low-Voltage Inhibit (LVI).) 1 = LVI module resets disabled 0 = LVI module resets enabled
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Mask Options (MOR) Mask Option Register A
LVIPWRD -- LVI Power Disable Bit LVIPWRD disables the LVI module. (See Section 21. Low-Voltage Inhibit (LVI).) 1 = LVI module power disabled 0 = LVI module power enabled SSREC -- Short Stop Recovery Bit SSREC enables the CPU to exit stop mode with a delay of 32 CGMXCLK cycles instead of a 4096 CGMXCLK cycle delay. 1 = STOP mode recovery after 32 CGMXCLK cycles 0 = STOP mode recovery after 4096 CGMXCLK cycles
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NOTE:
If using an external crystal oscillator, do not set the SSREC bit.
COPRS -- COP Rate Select Bit COPRS selects the COP timeout period. Reset clears COPRS. (See Section 20. Computer Operating Properly (COP).) 1 = COP timeout period is 218 - 24 CGMXCLK cycles 0 = COP timeout period is 213 - 24 CGMXCLK cycles STOP -- STOP Instruction Enable Bit STOP enables the STOP instruction. 1 = STOP instruction enabled 0 = STOP instruction treated as illegal opcode COPD -- COP Disable Bit COPD disables the COP module. (See Section 20. Computer Operating Properly (COP).) 1 = COP module disabled 0 = COP module enabled Extra care should be exercised when selecting the mask options for ROM code submission. Ensure that the selected mask options match exactly the setting in the CONFIG register of the emulation part. The enable/disable logic is not necessarily identical in all parts of the AB, AS, and AZ families. If in doubt, check with your local field applications representative.
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Technical Data
77
Freescale Semiconductor, Inc. Mask Options (MOR) 6.5 Mask Option Register B
Address: $003F Bit 7 Read: Write: Reset: R = Reserved Unaffected by reset R 6
EEDIVCLK
5 EESEC
4
EEMONSEC
3 R
2 R
1 R
Bit 0 R
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Figure 6-2. Mask Option Register B (MORB)) EEDIVCLK -- EEPROM Timebase Divider Clock Select Bit EEDIVCLK selects the reference clock source for the EEPROM timebase divider. (See Section 5. EEPROM.) 1 = CPU bus clock drives the EEPROM timebase divider 0 = CGMXCLK drives the EEPROM timebase divider EESEC -- EEPROM Security Enable Bit When EESEC is set, the EEPROM protection bit, EEPRTCT, in the EEPROM non-volatile register ($FE1C) can be used for EEPROM protection. (See 5.7 EEPROM Security Options.) 1 = EEPROM security depends on EEPRTCT bit 0 = EEPROM security disabled EEMONSEC -- EEPROM Security in Monitor Mode Bit When EEMONSEC is set, the entire EEPROM array cannot be accessed in monitor mode, unless a valid security code is entered. 1 = EEPROM security enabled in monitor mode 0 = EEPROM security disabled in monitor mode Extra care should be exercised when selecting the mask options for ROM code submission. Ensure that the selected mask options match exactly the setting in the CONFIG register of the emulation part. The enable/disable logic is not necessarily identical in all parts of the AB, AS, and AZ families. If in doubt, check with your local field applications representative.
Technical Data
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Mask Options (MOR) EEPROM Timebase Divider Mask Option Registers
6.6 EEPROM Timebase Divider Mask Option Registers
The EEPROM timebase divider mask option registers define the reset states for the EEPROM timebase divider registers. See Section 5. EEPROM for bit descriptions.
Address: $FE10 Bit 7 Read:
EEDIVSECD
6 R
5 R
4 R
3 R
2 EEDIV10
1 EEDIV9
Bit 0 EEDIV8
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Write: Reset: Unaffected by reset
Figure 6-3. EEPROM Divider Mask Option Register High (EEDIVHMOR)
Address: $FE11 Bit 7 Read: Write: Reset: Unaffected by reset EEDIV7 6 EEDIV6 5 EEDIV5 4 EEDIV4 3 EEDIV3 2 EEDIV2 1 EEDIV1 Bit 0 EEDIV0
Figure 6-4. EEPROM Divider Mask Option Register Low (EEDIVLMOR)
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Technical Data
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Freescale Semiconductor, Inc. Mask Options (MOR)
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Technical Data
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Technical Data -- MC68HC08AB16A
Section 7. Central Processor Unit (CPU)
7.1 Contents
7.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
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7.3
7.4 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 7.4.1 Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 7.4.2 Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 7.4.3 Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 7.4.4 Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 7.4.5 Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 7.5 Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
7.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 7.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 7.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 7.7 7.8 7.9 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
7.2 Introduction
The M68HC08 CPU (central processor unit) is an enhanced and fully object-code-compatible version of the M68HC05 CPU. The CPU08 Reference Manual (Motorola document order number CPU08RM/AD) contains a description of the CPU instruction set, addressing modes, and architecture.
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* * * * * * Object code fully upward-compatible with M68HC05 Family 16-bit stack pointer with stack manipulation instructions 16-bit index register with x-register manipulation instructions 8-MHz CPU internal bus frequency 64K-byte program/data memory space 16 addressing modes Memory-to-memory data moves without using accumulator Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divide instructions Enhanced binary-coded decimal (BCD) data handling Modular architecture with expandable internal bus definition for extension of addressing range beyond 64K-bytes Low-power stop and wait modes
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* * * * *
7.4 CPU Registers
Figure 7-1 shows the five CPU registers. CPU registers are not part of the memory map.
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Central Processor Unit (CPU) CPU Registers
7 15 H 15 15 X
0 ACCUMULATOR (A) 0 INDEX REGISTER (H:X) 0 STACK POINTER (SP) 0 PROGRAM COUNTER (PC)
7 0 V11HINZC
CONDITION CODE REGISTER (CCR)
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CARRY/BORROW FLAG ZERO FLAG NEGATIVE FLAG INTERRUPT MASK HALF-CARRY FLAG TWO'S COMPLEMENT OVERFLOW FLAG
Figure 7-1. CPU Registers
7.4.1 Accumulator The accumulator is a general-purpose 8-bit register. The CPU uses the accumulator to hold operands and the results of arithmetic/logic operations.
Bit 7
Read: Write: Reset: Unaffected by reset
6
5
4
3
2
1
Bit 0
Figure 7-2. Accumulator (A)
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Freescale Semiconductor, Inc. Central Processor Unit (CPU)
7.4.2 Index Register The 16-bit index register allows indexed addressing of a 64K-byte memory space. H is the upper byte of the index register, and X is the lower byte. H:X is the concatenated 16-bit index register. In the indexed addressing modes, the CPU uses the contents of the index register to determine the conditional address of the operand. The index register can serve also as a temporary data storage location.
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Bit 15
Read: Write: Reset: 0
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Bit 0
0
0
0
0
0
0
0
X
X
X
X
X
X
X
X
X = Indeterminate
Figure 7-3. Index Register (H:X)
7.4.3 Stack Pointer The stack pointer is a 16-bit register that contains the address of the next location on the stack. During a reset, the stack pointer is preset to $00FF. The reset stack pointer (RSP) instruction sets the least significant byte to $FF and does not affect the most significant byte. The stack pointer decrements as data is pushed onto the stack and increments as data is pulled from the stack. In the stack pointer 8-bit offset and 16-bit offset addressing modes, the stack pointer can function as an index register to access data on the stack. The CPU uses the contents of the stack pointer to determine the conditional address of the operand.
Technical Data
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Central Processor Unit (CPU) CPU Registers
Bit 15
Read: Write: Reset: 0
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Bit 0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Figure 7-4. Stack Pointer (SP)
NOTE:
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The location of the stack is arbitrary and may be relocated anywhere in RAM. Moving the SP out of page 0 ($0000 to $00FF) frees direct address (page 0) space. For correct operation, the stack pointer must point only to RAM locations.
7.4.4 Program Counter The program counter is a 16-bit register that contains the address of the next instruction or operand to be fetched. Normally, the program counter automatically increments to the next sequential memory location every time an instruction or operand is fetched. Jump, branch, and interrupt operations load the program counter with an address other than that of the next sequential location. During reset, the program counter is loaded with the reset vector address located at $FFFE and $FFFF. The vector address is the address of the first instruction to be executed after exiting the reset state.
Bit 15
Read: Write: Reset: Loaded with Vector from $FFFE and $FFFF
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Bit 0
Figure 7-5. Program Counter (PC)
7.4.5 Condition Code Register The 8-bit condition code register contains the interrupt mask and five flags that indicate the results of the instruction just executed. Bits 6 and
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Freescale Semiconductor, Inc. Central Processor Unit (CPU)
5 are set permanently to logic 1. The following paragraphs describe the functions of the condition code register.
Bit 7
Read: V Write: Reset: X X = Indeterminate 1 1 X 1 X X X 1 1 H I N Z C
6
5
4
3
2
1
Bit 0
Figure 7-6. Condition Code Register (CCR)
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V -- Overflow Flag The CPU sets the overflow flag when a two's complement overflow occurs. The signed branch instructions BGT, BGE, BLE, and BLT use the overflow flag. 1 = Overflow 0 = No overflow H -- Half-Carry Flag The CPU sets the half-carry flag when a carry occurs between accumulator bits 3 and 4 during an add-without-carry (ADD) or addwith-carry (ADC) operation. The half-carry flag is required for binarycoded decimal (BCD) arithmetic operations. The DAA instruction uses the states of the H and C flags to determine the appropriate correction factor. 1 = Carry between bits 3 and 4 0 = No carry between bits 3 and 4
Technical Data
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Central Processor Unit (CPU) CPU Registers
I -- Interrupt Mask When the interrupt mask is set, all maskable CPU interrupts are disabled. CPU interrupts are enabled when the interrupt mask is cleared. When a CPU interrupt occurs, the interrupt mask is set automatically after the CPU registers are saved on the stack, but before the interrupt vector is fetched. 1 = Interrupts disabled 0 = Interrupts enabled
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NOTE:
To maintain M6805 Family compatibility, the upper byte of the index register (H) is not stacked automatically. If the interrupt service routine modifies H, then the user must stack and unstack H using the PSHH and PULH instructions.
After the I bit is cleared, the highest-priority interrupt request is serviced first. A return-from-interrupt (RTI) instruction pulls the CPU registers from the stack and restores the interrupt mask from the stack. After any reset, the interrupt mask is set and can be cleared only by the clear interrupt mask software instruction (CLI). N -- Negative flag The CPU sets the negative flag when an arithmetic operation, logic operation, or data manipulation produces a negative result, setting bit 7 of the result. 1 = Negative result 0 = Non-negative result Z -- Zero flag The CPU sets the zero flag when an arithmetic operation, logic operation, or data manipulation produces a result of $00. 1 = Zero result 0 = Non-zero result
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com
Technical Data
87
Freescale Semiconductor, Inc. Central Processor Unit (CPU)
C -- Carry/Borrow Flag The CPU sets the carry/borrow flag when an addition operation produces a carry out of bit 7 of the accumulator or when a subtraction operation requires a borrow. Some instructions -- such as bit test and branch, shift, and rotate -- also clear or set the carry/borrow flag. 1 = Carry out of bit 7 0 = No carry out of bit 7
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7.5 Arithmetic/Logic Unit (ALU)
The ALU performs the arithmetic and logic operations defined by the instruction set. Refer to the CPU08 Reference Manual (Motorola document order number CPU08RM/AD) for a description of the instructions and addressing modes and more detail about the architecture of the CPU.
7.6 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption standby modes.
7.6.1 Wait Mode The WAIT instruction: * Clears the interrupt mask (I bit) in the condition code register, enabling interrupts. After exit from wait mode by interrupt, the I bit remains clear. After exit by reset, the I bit is set. Disables the CPU clock
*
Technical Data
MC68HC08AB16A -- Rev. 2.0 Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com MOTOROLA
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Freescale Semiconductor, Inc.
Central Processor Unit (CPU) CPU During Break Interrupts
7.6.2 Stop Mode The STOP instruction: * Clears the interrupt mask (I bit) in the condition code register, enabling external interrupts. After exit from stop mode by external interrupt, the I bit remains clear. After exit by reset, the I bit is set. Disables the CPU clock
*
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After exiting stop mode, the CPU clock begins running after the oscillator stabilization delay.
7.7 CPU During Break Interrupts
If a break module is present on the MCU, the CPU starts a break interrupt by: * * Loading the instruction register with the SWI instruction Loading the program counter with $FFFC:$FFFD or with $FEFC:$FEFD in monitor mode
The break interrupt begins after completion of the CPU instruction in progress. If the break address register match occurs on the last cycle of a CPU instruction, the break interrupt begins immediately. A return-from-interrupt instruction (RTI) in the break routine ends the break interrupt and returns the MCU to normal operation if the break interrupt has been deasserted.
7.8 Instruction Set Summary
7.9 Opcode Map
See Table 7-2.
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com
Technical Data
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Freescale Semiconductor, Inc. Central Processor Unit (CPU)
Table 7-1. Instruction Set Summary
Cycles 2 3 4 4 3 2 4 5 2 3 4 4 3 2 4 5 2 2 2 3 4 4 3 2 4 5 4 1 1 4 3 5 4 1 1 4 3 5 3 4 4 4 4 4 4 4 4 Source Form ADC #opr ADC opr ADC opr ADC opr,X ADC opr,X ADC ,X ADC opr,SP ADC opr,SP Operand ii dd hh ll ee ff ff ff ee ff ii dd hh ll ee ff ff ff ee ff ii ii ii dd hh ll ee ff ff ff ee ff dd ff ff dd ff ff rr dd dd dd dd dd dd dd dd Address Mode Opcode A9 B9 C9 D9 E9 F9 9EE9 9ED9 AB BB CB DB EB FB 9EEB 9EDB A7 AF A4 B4 C4 D4 E4 F4 9EE4 9ED4 38 48 58 68 78 9E68 37 47 57 67 77 9E67 24 11 13 15 17 19 1B 1D 1F Effect on CCR VHINZC
Operation
Description
Add with Carry
A (A) + (M) + (C)
IMM DIR EXT IX2 - IX1 IX SP1 SP2 IMM DIR EXT IX2 - IX1 IX SP1 SP2 - - - - - - IMM - - - - - - IMM IMM DIR EXT IX2 0--- IX1 IX SP1 SP2 DIR INH INH -- IX1 IX SP1 DIR INH INH -- IX1 IX SP1 - - - - - - REL DIR (b0) DIR (b1) DIR (b2) DIR (b3) ------ DIR (b4) DIR (b5) DIR (b6) DIR (b7)
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ADD #opr ADD opr ADD opr ADD opr,X ADD opr,X ADD ,X ADD opr,SP ADD opr,SP AIS #opr AIX #opr AND #opr AND opr AND opr AND opr,X AND opr,X AND ,X AND opr,SP AND opr,SP ASL opr ASLA ASLX ASL opr,X ASL ,X ASL opr,SP ASR opr ASRA ASRX ASR opr,X ASR opr,X ASR opr,SP BCC rel
Add without Carry
A (A) + (M)
Add Immediate Value (Signed) to SP Add Immediate Value (Signed) to H:X
SP (SP) + (16 M) H:X (H:X) + (16 M)
Logical AND
A (A) & (M)
Arithmetic Shift Left (Same as LSL)
C b7 b0
0
Arithmetic Shift Right
b7 b0
C
Branch if Carry Bit Clear
PC (PC) + 2 + rel ? (C) = 0
BCLR n, opr
Clear Bit n in M
Mn 0
Technical Data
MC68HC08AB16A -- Rev. 2.0 Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com MOTOROLA
90
Freescale Semiconductor, Inc.
Central Processor Unit (CPU) Opcode Map
Table 7-1. Instruction Set Summary (Continued)
Cycles 3 3 3 3 3 3 3 3 3 3 2 3 4 4 3 2 4 5 3 3 3 3 3 3 3 3 3 3 Source Form BCS rel BEQ rel BGE opr Operand rr rr rr rr rr rr rr rr rr rr ii dd hh ll ee ff ff ff ee ff rr rr rr rr rr rr rr rr rr rr Address Mode Opcode 25 27 90 92 28 29 22 24 2F 2E A5 B5 C5 D5 E5 F5 9EE5 9ED5 93 25 23 91 2C 2B 2D 26 2A 20 Effect on CCR VHINZC Branch if Carry Bit Set (Same as BLO) Branch if Equal Branch if Greater Than or Equal To (Signed Operands) Branch if Greater Than (Signed Operands) Branch if Half Carry Bit Clear Branch if Half Carry Bit Set Branch if Higher Branch if Higher or Same (Same as BCC) Branch if IRQ Pin High Branch if IRQ Pin Low PC (PC) + 2 + rel ? (C) = 1 PC (PC) + 2 + rel ? (Z) = 1 PC (PC) + 2 + rel ? (N V) = 0
Operation
Description
- - - - - - REL - - - - - - REL - - - - - - REL
BGT opr
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PC (PC) + 2 + rel ? (Z) | (N V) = - - - - - - REL 0 PC (PC) + 2 + rel ? (H) = 0 PC (PC) + 2 + rel ? (H) = 1 PC (PC) + 2 + rel ? (C) | (Z) = 0 PC (PC) + 2 + rel ? (C) = 0 PC (PC) + 2 + rel ? IRQ = 1 PC (PC) + 2 + rel ? IRQ = 0 - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL IMM DIR EXT IX2 0--- IX1 IX SP1 SP2
BHCC rel BHCS rel BHI rel BHS rel BIH rel BIL rel BIT #opr BIT opr BIT opr BIT opr,X BIT opr,X BIT ,X BIT opr,SP BIT opr,SP BLE opr BLO rel BLS rel BLT opr BMC rel BMI rel BMS rel BNE rel BPL rel BRA rel
Bit Test
(A) & (M)
Branch if Less Than or Equal To (Signed Operands) Branch if Lower (Same as BCS) Branch if Lower or Same Branch if Less Than (Signed Operands) Branch if Interrupt Mask Clear Branch if Minus Branch if Interrupt Mask Set Branch if Not Equal Branch if Plus Branch Always
PC (PC) + 2 + rel ? (Z) | (N V) = - - - - - - REL 1 PC (PC) + 2 + rel ? (C) = 1 PC (PC) + 2 + rel ? (C) | (Z) = 1 PC (PC) + 2 + rel ? (N V) =1 PC (PC) + 2 + rel ? (I) = 0 PC (PC) + 2 + rel ? (N) = 1 PC (PC) + 2 + rel ? (I) = 1 PC (PC) + 2 + rel ? (Z) = 0 PC (PC) + 2 + rel ? (N) = 0 PC (PC) + 2 + rel - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL - - - - - - REL
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com
Technical Data
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Freescale Semiconductor, Inc. Central Processor Unit (CPU)
Table 7-1. Instruction Set Summary (Continued)
Cycles 5 5 5 5 5 5 5 5 3 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 5 4 4 5 4 6 1 2 dd 3 1 1 1 3 2 4 Source Form Operand dd rr dd rr dd rr dd rr dd rr dd rr dd rr dd rr rr dd rr dd rr dd rr dd rr dd rr dd rr dd rr dd rr dd dd dd dd dd dd dd dd rr dd rr ii rr ii rr ff rr rr ff rr ff ff Address Mode Opcode 01 03 05 07 09 0B 0D 0F 21 00 02 04 06 08 0A 0C 0E 10 12 14 16 18 1A 1C 1E AD 31 41 51 61 71 9E61 98 9A 3F 4F 5F 8C 6F 7F 9E6F Effect on CCR VHINZC
Operation
Description
BRCLR n,opr,rel Branch if Bit n in M Clear
PC (PC) + 3 + rel ? (Mn) = 0
DIR (b0) DIR (b1) DIR (b2) DIR (b3) ----- DIR (b4) DIR (b5) DIR (b6) DIR (b7) - - - - - - REL DIR (b0) DIR (b1) DIR (b2) DIR (b3) ----- DIR (b4) DIR (b5) DIR (b6) DIR (b7) DIR (b0) DIR (b1) DIR (b2) DIR (b3) ------ DIR (b4) DIR (b5) DIR (b6) DIR (b7)
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BRN rel
Branch Never
PC (PC) + 2
BRSET n,opr,rel Branch if Bit n in M Set
PC (PC) + 3 + rel ? (Mn) = 1
BSET n,opr
Set Bit n in M
Mn 1
BSR rel
Branch to Subroutine
PC (PC) + 2; push (PCL) SP (SP) - 1; push (PCH) SP (SP) - 1 PC (PC) + rel
- - - - - - REL
CBEQ opr,rel CBEQA #opr,rel CBEQX #opr,rel Compare and Branch if Equal CBEQ opr,X+,rel CBEQ X+,rel CBEQ opr,SP,rel CLC CLI CLR opr CLRA CLRX CLRH CLR opr,X CLR ,X CLR opr,SP Clear Carry Bit Clear Interrupt Mask
PC (PC) + 3 + rel ? (A) - (M) = $00 DIR PC (PC) + 3 + rel ? (A) - (M) = $00 IMM PC (PC) + 3 + rel ? (X) - (M) = $00 IMM ------ PC (PC) + 3 + rel ? (A) - (M) = $00 IX1+ PC (PC) + 2 + rel ? (A) - (M) = $00 IX+ PC (PC) + 4 + rel ? (A) - (M) = $00 SP1 C0 I0 M $00 A $00 X $00 H $00 M $00 M $00 M $00 - - - - - 0 INH - - 0 - - - INH DIR INH INH 0 - - 0 1 - INH IX1 IX SP1
Clear
Technical Data
MC68HC08AB16A -- Rev. 2.0 Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com MOTOROLA
92
Freescale Semiconductor, Inc.
Central Processor Unit (CPU) Opcode Map
Table 7-1. Instruction Set Summary (Continued)
Cycles 2 3 4 4 3 2 4 5 4 1 1 4 3 5 3 4 2 3 4 4 3 2 4 5 2 5 3 3 5 4 6 4 1 1 4 3 5 7 Source Form CMP #opr CMP opr CMP opr CMP opr,X CMP opr,X CMP ,X CMP opr,SP CMP opr,SP Operand ii dd hh ll ee ff ff ff ee ff dd ff ff ii ii+1 dd ii dd hh ll ee ff ff ff ee ff dd rr rr rr ff rr rr ff rr dd ff ff Address Mode Opcode A1 B1 C1 D1 E1 F1 9EE1 9ED1 33 43 53 63 73 9E63 65 75 A3 B3 C3 D3 E3 F3 9EE3 9ED3 72 3B 4B 5B 6B 7B 9E6B 3A 4A 5A 6A 7A 9E6A 52 Effect on CCR VHINZC
Operation
Description
Compare A with M
(A) - (M)
IMM DIR EXT IX2 -- IX1 IX SP1 SP2 DIR INH INH 0--1 IX1 IX SP1 -- IMM DIR
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COM opr COMA COMX COM opr,X COM ,X COM opr,SP CPHX #opr CPHX opr CPX #opr CPX opr CPX opr CPX ,X CPX opr,X CPX opr,X CPX opr,SP CPX opr,SP DAA
Complement (One's Complement)
M (M) = $FF - (M) A (A) = $FF - (M) X (X) = $FF - (M) M (M) = $FF - (M) M (M) = $FF - (M) M (M) = $FF - (M) (H:X) - (M:M + 1)
Compare H:X with M
Compare X with M
(X) - (M)
IMM DIR EXT IX2 -- IX1 IX SP1 SP2 U - - INH
Decimal Adjust A
(A)10
DBNZ opr,rel DBNZA rel DBNZX rel Decrement and Branch if Not Zero DBNZ opr,X,rel DBNZ X,rel DBNZ opr,SP,rel DEC opr DECA DECX DEC opr,X DEC ,X DEC opr,SP DIV
A (A) - 1 or M (M) - 1 or X (X) - 1 DIR PC (PC) + 3 + rel ? (result) 0 INH PC (PC) + 2 + rel ? (result) 0 - - - - - - INH PC (PC) + 2 + rel ? (result) 0 IX1 PC (PC) + 3 + rel ? (result) 0 IX PC (PC) + 2 + rel ? (result) 0 SP1 PC (PC) + 4 + rel ? (result) 0 M (M) - 1 A (A) - 1 X (X) - 1 M (M) - 1 M (M) - 1 M (M) - 1 A (H:A)/(X) H Remainder DIR INH INH --- IX1 IX SP1 - - - - INH
Decrement
Divide
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com
Technical Data
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Freescale Semiconductor, Inc. Central Processor Unit (CPU)
Table 7-1. Instruction Set Summary (Continued)
Cycles 2 3 4 4 3 2 4 5 4 1 1 4 3 5 2 3 4 3 2 4 5 6 5 4 2 3 4 4 3 2 4 5 3 4 2 3 4 4 3 2 4 5 4 1 1 4 3 5 Source Form EOR #opr EOR opr EOR opr EOR opr,X EOR opr,X EOR ,X EOR opr,SP EOR opr,SP Operand ii dd hh ll ee ff ff ff ee ff dd ff ff dd hh ll ee ff ff dd hh ll ee ff ff ii dd hh ll ee ff ff ff ee ff ii jj dd ii dd hh ll ee ff ff ff ee ff dd ff ff Address Mode Opcode A8 B8 C8 D8 E8 F8 9EE8 9ED8 3C 4C 5C 6C 7C 9E6C BC CC DC EC FC BD CD DD ED FD A6 B6 C6 D6 E6 F6 9EE6 9ED6 45 55 AE BE CE DE EE FE 9EEE 9EDE 38 48 58 68 78 9E68 Effect on CCR VHINZC
Operation
Description
Exclusive OR M with A
A (A M)
IMM DIR EXT IX2 0--- IX1 IX SP1 SP2 DIR INH INH --- IX1 IX SP1 DIR EXT - - - - - - IX2 IX1 IX DIR EXT - - - - - - IX2 IX1 IX IMM DIR EXT IX2 0--- IX1 IX SP1 SP2 0--- IMM DIR
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INC opr INCA INCX INC opr,X INC ,X INC opr,SP JMP opr JMP opr JMP opr,X JMP opr,X JMP ,X JSR opr JSR opr JSR opr,X JSR opr,X JSR ,X LDA #opr LDA opr LDA opr LDA opr,X LDA opr,X LDA ,X LDA opr,SP LDA opr,SP LDHX #opr LDHX opr LDX #opr LDX opr LDX opr LDX opr,X LDX opr,X LDX ,X LDX opr,SP LDX opr,SP LSL opr LSLA LSLX LSL opr,X LSL ,X LSL opr,SP
Increment
M (M) + 1 A (A) + 1 X (X) + 1 M (M) + 1 M (M) + 1 M (M) + 1
Jump
PC Jump Address
Jump to Subroutine
PC (PC) + n (n = 1, 2, or 3) Push (PCL); SP (SP) - 1 Push (PCH); SP (SP) - 1 PC Unconditional Address
Load A from M
A (M)
Load H:X from M
H:X (M:M + 1)
Load X from M
X (M)
IMM DIR EXT IX2 0--- IX1 IX SP1 SP2 DIR INH INH -- IX1 IX SP1
Logical Shift Left (Same as ASL)
C b7 b0
0
Technical Data
MC68HC08AB16A -- Rev. 2.0 Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com MOTOROLA
94
Freescale Semiconductor, Inc.
Central Processor Unit (CPU) Opcode Map
Table 7-1. Instruction Set Summary (Continued)
Cycles 4 1 1 4 3 5 5 4 4 4 5 dd 4 1 1 4 3 5 1 3 ii dd hh ll ee ff ff ff ee ff 2 3 4 4 3 2 4 5 2 2 2 2 2 2 dd 4 1 1 4 3 5 Source Form LSR opr LSRA LSRX LSR opr,X LSR ,X LSR opr,SP MOV opr,opr MOV opr,X+ MOV #opr,opr MOV X+,opr MUL NEG opr NEGA NEGX NEG opr,X NEG ,X NEG opr,SP NOP NSA ORA #opr ORA opr ORA opr ORA opr,X ORA opr,X ORA ,X ORA opr,SP ORA opr,SP PSHA PSHH PSHX PULA PULH PULX ROL opr ROLA ROLX ROL opr,X ROL ,X ROL opr,SP Operand dd ff ff dd dd dd ii dd dd ff ff ff ff Address Mode Opcode 34 44 54 64 74 9E64 4E 5E 6E 7E 42 30 40 50 60 70 9E60 9D 62 AA BA CA DA EA FA 9EEA 9EDA 87 8B 89 86 8A 88 39 49 59 69 79 9E69 Effect on CCR VHINZC
Operation
Description
Logical Shift Right
0 b7 b0
C
DIR INH INH --0 IX1 IX SP1 DD DIX+ 0--- IMD IX+D - 0 - - - 0 INH DIR INH INH -- IX1 IX SP1 - - - - - - INH - - - - - - INH IMM DIR EXT IX2 0--- IX1 IX SP1 SP2 - - - - - - INH - - - - - - INH - - - - - - INH - - - - - - INH - - - - - - INH - - - - - - INH DIR INH INH -- IX1 IX SP1
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(M)Destination (M)Source Move H:X (H:X) + 1 (IX+D, DIX+) Unsigned multiply X:A (X) x (A) M -(M) = $00 - (M) A -(A) = $00 - (A) X -(X) = $00 - (X) M -(M) = $00 - (M) M -(M) = $00 - (M) None A (A[3:0]:A[7:4])
Negate (Two's Complement)
No Operation Nibble Swap A
Inclusive OR A and M
A (A) | (M)
Push A onto Stack Push H onto Stack Push X onto Stack Pull A from Stack Pull H from Stack Pull X from Stack
Push (A); SP (SP) - 1 Push (H); SP (SP) - 1 Push (X); SP (SP) - 1 SP (SP + 1); Pull (A) SP (SP + 1); Pull (H) SP (SP + 1); Pull (X)
Rotate Left through Carry
C b7 b0
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com
Technical Data
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Freescale Semiconductor, Inc. Central Processor Unit (CPU)
Table 7-1. Instruction Set Summary (Continued)
Cycles 4 1 1 4 3 5 1 7 4 ii dd hh ll ee ff ff ff ee ff 2 3 4 4 3 2 4 5 1 2 dd hh ll ee ff ff ff ee ff dd 3 4 4 3 2 4 5 4 1 dd hh ll ee ff ff ff ee ff 3 4 4 3 2 4 5 Source Form ROR opr RORA RORX ROR opr,X ROR ,X ROR opr,SP RSP Operand dd ff ff Address Mode Opcode 36 46 56 66 76 9E66 9C 80 81 A2 B2 C2 D2 E2 F2 9EE2 9ED2 99 9B B7 C7 D7 E7 F7 9EE7 9ED7 35 8E BF CF DF EF FF 9EEF 9EDF Effect on CCR VHINZC
Operation
Description
Rotate Right through Carry
b7 b0
C
DIR INH INH -- IX1 IX SP1 - - - - - - INH
Reset Stack Pointer
SP $FF SP (SP) + 1; Pull (CCR) SP (SP) + 1; Pull (A) SP (SP) + 1; Pull (X) SP (SP) + 1; Pull (PCH) SP (SP) + 1; Pull (PCL) SP SP + 1; Pull (PCH) SP SP + 1; Pull (PCL)
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RTI
Return from Interrupt
INH
RTS SBC #opr SBC opr SBC opr SBC opr,X SBC opr,X SBC ,X SBC opr,SP SBC opr,SP SEC SEI STA opr STA opr STA opr,X STA opr,X STA ,X STA opr,SP STA opr,SP STHX opr STOP STX opr STX opr STX opr,X STX opr,X STX ,X STX opr,SP STX opr,SP
Return from Subroutine
- - - - - - INH IMM DIR EXT IX2 -- IX1 IX SP1 SP2 - - - - - 1 INH - - 1 - - - INH DIR EXT IX2 0 - - - IX1 IX SP1 SP2 0 - - - DIR - - 0 - - - INH DIR EXT IX2 0 - - - IX1 IX SP1 SP2
Subtract with Carry
A (A) - (M) - (C)
Set Carry Bit Set Interrupt Mask
C1 I1
Store A in M
M (A)
Store H:X in M Enable IRQ Pin; Stop Oscillator
(M:M + 1) (H:X) I 0; Stop Oscillator
Store X in M
M (X)
Technical Data
MC68HC08AB16A -- Rev. 2.0 Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com MOTOROLA
96
Freescale Semiconductor, Inc.
Central Processor Unit (CPU) Opcode Map
Table 7-1. Instruction Set Summary (Continued)
Cycles 2 3 4 4 3 2 4 5 9 2 1 1 dd 3 1 1 3 2 4 2 1 2 Source Form SUB #opr SUB opr SUB opr SUB opr,X SUB opr,X SUB ,X SUB opr,SP SUB opr,SP Operand ii dd hh ll ee ff ff ff ee ff ff ff Address Mode Opcode A0 B0 C0 D0 E0 F0 9EE0 9ED0 83 84 97 85 3D 4D 5D 6D 7D 9E6D 95 9F 94 Effect on CCR VHINZC
Operation
Description
Subtract
A (A) - (M)
IMM DIR EXT IX2 -- IX1 IX SP1 SP2
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SWI
Software Interrupt
PC (PC) + 1; Push (PCL) SP (SP) - 1; Push (PCH) SP (SP) - 1; Push (X) SP (SP) - 1; Push (A) SP (SP) - 1; Push (CCR) SP (SP) - 1; I 1 PCH Interrupt Vector High Byte PCL Interrupt Vector Low Byte CCR (A) X (A) A (CCR)
- - 1 - - - INH
TAP TAX TPA TST opr TSTA TSTX TST opr,X TST ,X TST opr,SP TSX TXA TXS
Transfer A to CCR Transfer A to X Transfer CCR to A
INH - - - - - - INH - - - - - - INH DIR INH INH 0--- IX1 IX SP1 - - - - - - INH - - - - - - INH - - - - - - INH
Test for Negative or Zero
(A) - $00 or (X) - $00 or (M) - $00
Transfer SP to H:X Transfer X to A Transfer H:X to SP
H:X (SP) + 1 A (X) (SP) (H:X) - 1
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com
Technical Data
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Table 7-1. Instruction Set Summary (Continued)
Cycles Source Form A C CCR dd dd rr DD DIR DIX+ ee ff EXT ff H H hh ll I ii IMD IMM INH IX IX+ IX+D IX1 IX1+ IX2 M N Operand Address Mode Opcode Effect on CCR VHINZC Accumulator Carry/borrow bit Condition code register Direct address of operand Direct address of operand and relative offset of branch instruction Direct to direct addressing mode Direct addressing mode Direct to indexed with post increment addressing mode High and low bytes of offset in indexed, 16-bit offset addressing Extended addressing mode Offset byte in indexed, 8-bit offset addressing Half-carry bit Index register high byte High and low bytes of operand address in extended addressing Interrupt mask Immediate operand byte Immediate source to direct destination addressing mode Immediate addressing mode Inherent addressing mode Indexed, no offset addressing mode Indexed, no offset, post increment addressing mode Indexed with post increment to direct addressing mode Indexed, 8-bit offset addressing mode Indexed, 8-bit offset, post increment addressing mode Indexed, 16-bit offset addressing mode Memory location Negative bit
Operation
Description
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n opr PC PCH PCL REL rel rr SP1 SP2 SP U V X Z & |
() -( ) # ? : --
Any bit Operand (one or two bytes) Program counter Program counter high byte Program counter low byte Relative addressing mode Relative program counter offset byte Relative program counter offset byte Stack pointer, 8-bit offset addressing mode Stack pointer 16-bit offset addressing mode Stack pointer Undefined Overflow bit Index register low byte Zero bit Logical AND Logical OR Logical EXCLUSIVE OR Contents of Negation (two's complement) Immediate value Sign extend Loaded with If Concatenated with Set or cleared Not affected
Technical Data
MC68HC08AB16A -- Rev. 2.0 Central Processor Unit (CPU) For More Information On This Product, Go to: www.freescale.com MOTOROLA
98
Freescale Semiconductor, Inc...
MOTOROLA Central Processor Unit (CPU)
MC68HC08AB16A -- Rev. 2.0 Technical Data
Table 7-2. Opcode Map
Bit Manipulation DIR DIR
MSB LSB
Branch REL 2 3 BRA 2 REL 3 BRN 2 REL 3 BHI 2 REL 3 BLS 2 REL 3 BCC 2 REL 3 BCS 2 REL 3 BNE 2 REL 3 BEQ 2 REL 3 BHCC 2 REL 3 BHCS 2 REL 3 BPL 2 REL 3 BMI 2 REL 3 BMC 2 REL 3 BMS 2 REL 3 BIL 2 REL 3 BIH 2 REL
DIR 3
INH 4
Read-Modify-Write INH IX1 5 1 NEGX 1 INH 4 CBEQX 3 IMM 7 DIV 1 INH 1 COMX 1 INH 1 LSRX 1 INH 4 LDHX 2 DIR 1 RORX 1 INH 1 ASRX 1 INH 1 LSLX 1 INH 1 ROLX 1 INH 1 DECX 1 INH 3 DBNZX 2 INH 1 INCX 1 INH 1 TSTX 1 INH 4 MOV 2 DIX+ 1 CLRX 1 INH 6 4 NEG 2 IX1 5 CBEQ 3 IX1+ 3 NSA 1 INH 4 COM 2 IX1 4 LSR 2 IX1 3 CPHX 3 IMM 4 ROR 2 IX1 4 ASR 2 IX1 4 LSL 2 IX1 4 ROL 2 IX1 4 DEC 2 IX1 5 DBNZ 3 IX1 4 INC 2 IX1 3 TST 2 IX1 4 MOV 3 IMD 3 CLR 2 IX1
SP1 9E6
IX 7
Control INH INH 8 9
IMM A 2 SUB 2 IMM 2 CMP 2 IMM 2 SBC 2 IMM 2 CPX 2 IMM 2 AND 2 IMM 2 BIT 2 IMM 2 LDA 2 IMM 2 AIS 2 IMM 2 EOR 2 IMM 2 ADC 2 IMM 2 ORA 2 IMM 2 ADD 2 IMM
DIR B
EXT C 4 SUB 3 EXT 4 CMP 3 EXT 4 SBC 3 EXT 4 CPX 3 EXT 4 AND 3 EXT 4 BIT 3 EXT 4 LDA 3 EXT 4 STA 3 EXT 4 EOR 3 EXT 4 ADC 3 EXT 4 ORA 3 EXT 4 ADD 3 EXT 3 JMP 3 EXT 5 JSR 3 EXT 4 LDX 3 EXT 4 STX 3 EXT
Register/Memory IX2 SP2 D 4 SUB 3 IX2 4 CMP 3 IX2 4 SBC 3 IX2 4 CPX 3 IX2 4 AND 3 IX2 4 BIT 3 IX2 4 LDA 3 IX2 4 STA 3 IX2 4 EOR 3 IX2 4 ADC 3 IX2 4 ORA 3 IX2 4 ADD 3 IX2 4 JMP 3 IX2 6 JSR 3 IX2 4 LDX 3 IX2 4 STX 3 IX2 9ED 5 SUB 4 SP2 5 CMP 4 SP2 5 SBC 4 SP2 5 CPX 4 SP2 5 AND 4 SP2 5 BIT 4 SP2 5 LDA 4 SP2 5 STA 4 SP2 5 EOR 4 SP2 5 ADC 4 SP2 5 ORA 4 SP2 5 ADD 4 SP2
IX1 E
SP1 9EE 4 SUB 3 SP1 4 CMP 3 SP1 4 SBC 3 SP1 4 CPX 3 SP1 4 AND 3 SP1 4 BIT 3 SP1 4 LDA 3 SP1 4 STA 3 SP1 4 EOR 3 SP1 4 ADC 3 SP1 4 ORA 3 SP1 4 ADD 3 SP1
IX F
0 5 BRSET0 3 DIR 5 BRCLR0 3 DIR 5 BRSET1 3 DIR 5 BRCLR1 3 DIR 5 BRSET2 3 DIR 5 BRCLR2 3 DIR 5 BRSET3 3 DIR 5 BRCLR3 3 DIR 5 BRSET4 3 DIR 5 BRCLR4 3 DIR 5 BRSET5 3 DIR 5 BRCLR5 3 DIR 5 BRSET6 3 DIR 5 BRCLR6 3 DIR 5 BRSET7 3 DIR 5 BRCLR7 3 DIR
1 4 BSET0 2 DIR 4 BCLR0 2 DIR 4 BSET1 2 DIR 4 BCLR1 2 DIR 4 BSET2 2 DIR 4 BCLR2 2 DIR 4 BSET3 2 DIR 4 BCLR3 2 DIR 4 BSET4 2 DIR 4 BCLR4 2 DIR 4 BSET5 2 DIR 4 BCLR5 2 DIR 4 BSET6 2 DIR 4 BCLR6 2 DIR 4 BSET7 2 DIR 4 BCLR7 2 DIR
0 1
2
3 4
5
6
7 8
9
A
B
C
D E F
4 1 NEG NEGA 2 DIR 1 INH 5 4 CBEQ CBEQA 3 DIR 3 IMM 5 MUL 1 INH 4 1 COM COMA 2 DIR 1 INH 4 1 LSR LSRA 2 DIR 1 INH 4 3 STHX LDHX 2 DIR 3 IMM 4 1 ROR RORA 2 DIR 1 INH 4 1 ASR ASRA 2 DIR 1 INH 4 1 LSL LSLA 2 DIR 1 INH 4 1 ROL ROLA 2 DIR 1 INH 4 1 DEC DECA 2 DIR 1 INH 5 3 DBNZ DBNZA 3 DIR 2 INH 4 1 INC INCA 2 DIR 1 INH 3 1 TST TSTA 2 DIR 1 INH 5 MOV 3 DD 3 1 CLR CLRA 2 DIR 1 INH
5 3 NEG NEG 3 SP1 1 IX 6 4 CBEQ CBEQ 4 SP1 2 IX+ 2 DAA 1 INH 5 3 COM COM 3 SP1 1 IX 5 3 LSR LSR 3 SP1 1 IX 4 CPHX 2 DIR 5 3 ROR ROR 3 SP1 1 IX 5 3 ASR ASR 3 SP1 1 IX 5 3 LSL LSL 3 SP1 1 IX 5 3 ROL ROL 3 SP1 1 IX 5 3 DEC DEC 3 SP1 1 IX 6 4 DBNZ DBNZ 4 SP1 2 IX 5 3 INC INC 3 SP1 1 IX 4 2 TST TST 3 SP1 1 IX 4 MOV 2 IX+D 4 2 CLR CLR 3 SP1 1 IX
7 3 RTI BGE 1 INH 2 REL 4 3 RTS BLT 1 INH 2 REL 3 BGT 2 REL 9 3 SWI BLE 1 INH 2 REL 2 2 TAP TXS 1 INH 1 INH 1 2 TPA TSX 1 INH 1 INH 2 PULA 1 INH 2 1 PSHA TAX 1 INH 1 INH 2 1 PULX CLC 1 INH 1 INH 2 1 PSHX SEC 1 INH 1 INH 2 2 PULH CLI 1 INH 1 INH 2 2 PSHH SEI 1 INH 1 INH 1 1 CLRH RSP 1 INH 1 INH 1 NOP 1 INH 1 STOP * 1 INH 1 1 WAIT TXA 1 INH 1 INH
3 SUB 2 DIR 3 CMP 2 DIR 3 SBC 2 DIR 3 CPX 2 DIR 3 AND 2 DIR 3 BIT 2 DIR 3 LDA 2 DIR 3 STA 2 DIR 3 EOR 2 DIR 3 ADC 2 DIR 3 ORA 2 DIR 3 ADD 2 DIR 2 JMP 2 DIR 4 4 BSR JSR 2 REL 2 DIR 2 3 LDX LDX 2 IMM 2 DIR 2 3 AIX STX 2 IMM 2 DIR
MSB LSB
3 SUB 2 IX1 3 CMP 2 IX1 3 SBC 2 IX1 3 CPX 2 IX1 3 AND 2 IX1 3 BIT 2 IX1 3 LDA 2 IX1 3 STA 2 IX1 3 EOR 2 IX1 3 ADC 2 IX1 3 ORA 2 IX1 3 ADD 2 IX1 3 JMP 2 IX1 5 JSR 2 IX1 5 3 LDX LDX 4 SP2 2 IX1 5 3 STX STX 4 SP2 2 IX1
2 SUB 1 IX 2 CMP 1 IX 2 SBC 1 IX 2 CPX 1 IX 2 AND 1 IX 2 BIT 1 IX 2 LDA 1 IX 2 STA 1 IX 2 EOR 1 IX 2 ADC 1 IX 2 ORA 1 IX 2 ADD 1 IX 2 JMP 1 IX 4 JSR 1 IX 4 2 LDX LDX 3 SP1 1 IX 4 2 STX STX 3 SP1 1 IX
Central Processor Unit (CPU) Opcode Map
Inherent REL Relative Immediate IX Indexed, No Offset Direct IX1 Indexed, 8-Bit Offset Extended IX2 Indexed, 16-Bit Offset Direct-Direct IMD Immediate-Direct Indexed-Direct DIX+ Direct-Indexed *Pre-byte for stack pointer indexed instructions
INH IMM DIR EXT DD IX+D
SP1 Stack Pointer, 8-Bit Offset SP2 Stack Pointer, 16-Bit Offset IX+ Indexed, No Offset with Post Increment IX1+ Indexed, 1-Byte Offset with Post Increment
0
High Byte of Opcode in Hexadecimal
Low Byte of Opcode in Hexadecimal
0
5 Cycles BRSET0 Opcode Mnemonic 3 DIR Number of Bytes / Addressing Mode
99
Freescale Semiconductor, Inc. Central Processor Unit (CPU)
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Technical Data -- MC68HC08AB16A
Section 8. System Integration Module (SIM)
8.1 Contents
8.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
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8.3 SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . 104 8.3.1 Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 8.3.2 Clock Start-Up from POR or LVI Reset . . . . . . . . . . . . . . . 105 8.3.3 Clocks in Stop and Wait Modes . . . . . . . . . . . . . . . . . . . . . 105 8.4 Reset and System Initialization. . . . . . . . . . . . . . . . . . . . . . . . 105 8.4.1 External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 8.4.2 Active Resets from Internal Sources . . . . . . . . . . . . . . . . . 106 8.4.2.1 Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 8.4.2.2 Computer Operating Properly (COP) Reset . . . . . . . . . 108 8.4.2.3 Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.4.2.4 Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.4.2.5 Low-Voltage Inhibit (LVI) Reset . . . . . . . . . . . . . . . . . . . 109 8.5 SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.5.1 SIM Counter during Power-On Reset. . . . . . . . . . . . . . . . . 110 8.5.2 SIM Counter during Stop Mode Recovery . . . . . . . . . . . . . 110 8.5.3 SIM Counter and Reset States. . . . . . . . . . . . . . . . . . . . . . 110 8.6 Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 8.6.1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 8.6.1.1 Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 8.6.1.2 SWI Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 8.6.2 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 8.6.3 Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 8.6.4 Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . 115 8.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 8.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 8.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
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8.8 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 8.8.1 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 119 8.8.2 SIM Reset Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 120 8.8.3 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 121
8.2 Introduction
This section describes the system integration module (SIM), which supports up to 24 external and/or internal interrupts. Together with the CPU, the SIM controls all MCU activities. A block diagram of the SIM is shown in Figure 8-1. Figure 8-2 is a summary of the SIM I/O registers. The SIM is a system state controller that coordinates CPU and exception timing. The SIM is responsible for: * Bus clock generation and control for CPU and peripherals: - Stop/wait/reset/break entry and recovery - Internal clock control * * Master reset control, including power-on reset (POR) and COP timeout Interrupt control: - Acknowledge timing - Arbitration control timing - Vector address generation * * CPU enable/disable timing Modular architecture expandable to 128 interrupt sources
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Table 8-1 shows the internal signal names used in this section.
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System Integration Module (SIM) Introduction
MODULE STOP MODULE WAIT STOP/WAIT CONTROL CPU STOP (FROM CPU) CPU WAIT (FROM CPU) SIMOSCEN (TO CGM) SIM COUNTER COP CLOCK
CGMXCLK (FROM CGM) CGMOUT (FROM CGM)
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/2
CLOCK CONTROL
CLOCK GENERATORS
INTERNAL CLOCKS
RESET PIN LOGIC
POR CONTROL RESET PIN CONTROL SIM RESET STATUS REGISTER MASTER RESET CONTROL
LVI (FROM LVI MODULE) ILLEGAL OPCODE (FROM CPU) ILLEGAL ADDRESS (FROM ADDRESS MAP DECODERS) COP (FROM COP MODULE)
RESET
INTERRUPT CONTROL AND PRIORITY DECODE
INTERRUPT SOURCES CPU INTERFACE
Figure 8-1. SIM Block Diagram Table 8-1. Signal Name Conventions
Signal Name CGMXCLK CGMVCLK CGMOUT IAB IDB PORRST IRST R/W PLL output PLL-based or OSC1-based clock output from CGM module (Bus clock = CGMOUT divided by two) Internal address bus Internal data bus Signal from the power-on reset module to the SIM Internal reset signal Read/write signal Technical Data System Integration Module (SIM) For More Information On This Product, Go to: www.freescale.com Description Buffered version of OSC1 from clock generator module (CGM)
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Addr.
Register Name
Bit 7 R 0
6 R 0
5 R 0
4 R 0
3 R 0
2 R 0
1 SBSW Note 0
Bit 0 R 0
Read: SIM Break Status Register $FE00 Write: (SBSR) Reset: Note: Writing a logic 0 clears SBSW. Read: SIM Reset Status Register $FE01 Write: (SRSR) POR:
POR
PIN
COP
ILOP
ILAD
0
LVI
0
1 BCFE 0
0 R
0 R
0 R
0 R
0 R
0 R
0 R
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$FE03
Read: SIM Break Flag Control Register Write: (SBFCR) Reset:
= Unimplemented
R
= Reserved
Figure 8-2. SIM I/O Register Summary
8.3 SIM Bus Clock Control and Generation
The bus clock generator provides system clock signals for the CPU and peripherals on the MCU. The system clocks are generated from an incoming clock, CGMOUT, as shown in Figure 8-3. This clock can come from either an external oscillator or from the on-chip PLL. See Section 9. Clock Generator Module (CGM).
OSC1 CLOCK SELECT CIRCUIT
CGMXCLK
SIM COUNTER
CGMVCLK
/2
A B S*
CGMOUT
/2
BUS CLOCK GENERATORS
*When S = 1,
CGMOUT = B PLL BCS PTC3 MONITOR MODE USER MODE
SIM
CGM
Figure 8-3. CGM Clock Signals
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System Integration Module (SIM) Reset and System Initialization
8.3.1 Bus Timing In user mode, the internal bus frequency is either the crystal oscillator output (CGMXCLK) divided by four or the PLL output (CGMVCLK) divided by four. See Section 9. Clock Generator Module (CGM). 8.3.2 Clock Start-Up from POR or LVI Reset When the power-on reset module or the low-voltage inhibit module generates a reset, the clocks to the CPU and peripherals are inactive and held in an inactive phase until after the 4096 CGMXCLK cycle POR timeout has been completed. The RST pin is driven low by the SIM during this entire period. The IBUS clocks start upon completion of the timeout. 8.3.3 Clocks in Stop and Wait Modes Upon exit from stop mode (by an interrupt, break, or reset), the SIM allows CGMXCLK to clock the SIM counter. The CPU and peripheral clocks do not become active until after the stop delay timeout. This timeout is selectable as 4096 or 32 CGMXCLK cycles. (See 8.7.2 Stop Mode.) In wait mode, the CPU clocks are inactive. The SIM also produces two sets of clocks for other modules. Refer to the wait mode subsection of each module to see if the module is active or inactive in wait mode. Some modules can be programmed to be active in wait mode.
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8.4 Reset and System Initialization
The MCU has the following reset sources: * * * * * *
MC68HC08AB16A -- Rev. 2.0 MOTOROLA System Integration Module (SIM) For More Information On This Product, Go to: www.freescale.com
Power-on reset module (POR) External reset pin (RST) Computer operating properly module (COP) Low-voltage inhibit module (LVI) Illegal opcode Illegal address
Technical Data
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All of these resets produce the vector $FFFE-FFFF ($FEFE-FEFF in monitor mode) and assert the internal reset signal (IRST). IRST causes all registers to be returned to their default values and all modules to be returned to their reset states. An internal reset clears the SIM counter (see 8.5 SIM Counter), but an external reset does not. Each of the resets sets a corresponding bit in the SIM reset status register (SRSR). (See 8.8 SIM Registers.) 8.4.1 External Pin Reset
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Pulling the asynchronous RST pin low halts all processing. The PIN bit of the SIM reset status register (SRSR) is set as long as RST is held low for a minimum of 67 CGMXCLK cycles, assuming that neither the POR nor the LVI was the source of the reset. See Table 8-2 for details. Figure 8-4 shows the relative timing. Table 8-2. PIN Bit Set Timing
Reset Type POR/LVI All others
CGMOUT
Number of Cycles Required to Set PIN 4163 (4096 + 64 + 3) 67 (64 + 3)
RST
IAB
PC
VECT H VECT L
Figure 8-4. External Reset Timing 8.4.2 Active Resets from Internal Sources All internal reset sources actively pull the RST pin low for 32 CGMXCLK cycles to allow for resetting of external peripherals. The internal reset signal IRST continues to be asserted for an additional 32 cycles. See Figure 8-5. An internal reset can be caused by an illegal address, illegal opcode, COP timeout, LVI, or POR. See Figure 8-6. Note that for LVI or POR resets, the SIM cycles through 4096 CGMXCLK cycles, during which the SIM forces the RST pin low. The internal reset signal then follows the sequence from the falling edge of RST as shown in Figure 8-5.
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System Integration Module (SIM) Reset and System Initialization
IRST
RST
RST PULLED LOW BY MCU 32 CYCLES 32 CYCLES
CGMXCLK
IAB
VECTOR HIGH
Figure 8-5. Internal Reset Timing
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The COP reset is asynchronous to the bus clock.
ILLEGAL ADDRESS RST ILLEGAL OPCODE RST COPRST LVI POR
INTERNAL RESET
Figure 8-6. Sources of Internal Reset The active reset feature allows the part to issue a reset to peripherals and other chips within a system built around the MCU.
8.4.2.1 Power-On Reset
When power is first applied to the MCU, the power-on reset module (POR) generates a pulse to indicate that power-on has occurred. The external reset pin (RST) is held low while the SIM counter counts out 4096 CGMXCLK cycles. 64 CGMXCLK cycles later, the CPU and memories are released from reset to allow the reset vector sequence to occur. At power-on, the following events occur: * * * * A POR pulse is generated The internal reset signal is asserted The SIM enables CGMOUT Internal clocks to the CPU and modules are held inactive for 4096 CGMXCLK cycles to allow the oscillator to stabilize
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* * The RST pin is driven low during the oscillator stabilization time The POR bit of the SIM reset status register (SRSR) is set and all other bits in the register are cleared
OSC1
PORRST 4096 CYCLES 32 CYCLES 32 CYCLES
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CGMXCLK
CGMOUT
RST
IAB
$FFFE
$FFFF
Figure 8-7. POR Recovery
8.4.2.2 Computer Operating Properly (COP) Reset
An input to the SIM is reserved for the COP reset signal. The overflow of the COP counter causes an internal reset and sets the COP bit in the SIM reset status register (SRSR). The SIM actively pulls down the RST pin for all internal reset sources. To prevent a COP module timeout, a value (any value) should be written to location $FFFF. Writing to location $FFFF clears the COP counter and bits 12 through 4 of the SIM counter. The SIM counter output, which occurs at least every 213 - 24 CGMXCLK cycles, drives the COP counter. The COP should be serviced as soon as possible out of reset to guarantee the maximum amount of time before the first timeout. The COP module is disabled if the RST pin or the IRQ pin is held at VTST while the MCU is in monitor mode. The COP module can be disabled only through combinational logic conditioned with the high voltage signal on the RST or the IRQ pin. This prevents the COP from becoming disabled as a result of external noise. During a break state, VTST on the RST pin disables the COP module.
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System Integration Module (SIM) SIM Counter
8.4.2.3 Illegal Opcode Reset
The SIM decodes signals from the CPU to detect illegal instructions. An illegal instruction sets the ILOP bit in the SIM reset status register (SRSR) and causes a reset. If the STOP enable bit, STOP, in the mask option register A (MORA) is logic 0, the SIM treats the STOP instruction as an illegal opcode and causes an illegal opcode reset. The SIM actively pulls down the RST pin for all internal reset sources.
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8.4.2.4 Illegal Address Reset
An opcode fetch from an unmapped address generates an illegal address reset. The SIM verifies that the CPU is fetching an opcode prior to asserting the ILAD bit in the SIM reset status register (SRSR) and resetting the MCU. A data fetch from an unmapped address does not generate a reset. The SIM actively pulls down the RST pin for all internal reset sources.
8.4.2.5 Low-Voltage Inhibit (LVI) Reset
The low-voltage inhibit module (LVI) asserts its output to the SIM when the VDD voltage falls to the trip voltage, VLVII. The LVI bit in the SIM reset status register (SRSR) is set, and the external reset pin (RST) is held low while the SIM counter counts out 4096 CGMXCLK cycles. 64 CGMXCLK cycles later, the CPU is released from reset to allow the reset vector sequence to occur. The SIM actively pulls down the RST pin for all internal reset sources.
8.5 SIM Counter
The SIM counter is used by the power-on reset module (POR) and in stop mode recovery to allow the oscillator time to stabilize before enabling the internal bus (IBUS) clocks. The SIM counter also serves as a prescaler for the computer operating properly (COP) module. The SIM counter overflow supplies the clock for the COP module. The SIM counter is 13 bits long and is clocked by the falling edge of CGMXCLK.
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8.5.1 SIM Counter during Power-On Reset The power-on reset (POR) module detects power applied to the MCU. At power-on, the POR circuit asserts the signal PORRST. Once the SIM is initialized, it enables the clock generation module (CGM) to drive the bus clock state machine.
8.5.2 SIM Counter during Stop Mode Recovery
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The SIM counter is also used for stop mode recovery. The STOP instruction clears the SIM counter. After an interrupt, break, or reset, the SIM senses the state of the short STOP recovery bit, SSREC, in the mask option register A (MORA). If the SSREC bit is a logic 1, then the stop recovery is reduced from the normal delay of 4096 CGMXCLK cycles down to 32 CGMXCLK cycles. This is ideal for applications using canned oscillators that do not require long start-up times from stop mode. External crystal applications should use the full stop recovery time, that is, with SSREC cleared.
8.5.3 SIM Counter and Reset States External reset has no effect on the SIM counter. (See 8.7.2 Stop Mode for details.) The SIM counter is free-running after all reset states. (See 8.4.2 Active Resets from Internal Sources for counter control and internal reset recovery sequences.)
8.6 Exception Control
Normal, sequential program execution can be changed in three different ways: * Interrupts - Maskable hardware CPU interrupts - Non-maskable software interrupt instruction (SWI) * *
Technical Data
Reset Break interrupts
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System Integration Module (SIM) Exception Control
8.6.1 Interrupts At the beginning of an interrupt, the CPU saves the CPU register contents onto the stack and sets the interrupt mask (I-bit) to prevent additional interrupts. At the end of an interrupt, the RTI instruction recovers the CPU register contents from the stack so that normal processing can resume. Figure 8-8 shows interrupt entry timing, and Figure 8-9 shows interrupt recovery timing.
MODULE INTERRUPT I-BIT
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IAB
DUMMY
SP
SP - 1
SP - 2
SP - 3
SP - 4
VECT H
VECT L
START ADDR
IDB
DUMMY
PC - 1[7:0] PC - 1[15:8]
X
A
CCR
V DATA H
V DATA L
OPCODE
R/W
Figure 8-8. Interrupt Entry Timing
MODULE INTERRUPT I-BIT
IAB
SP - 4
SP - 3
SP - 2
SP - 1
SP
PC
PC + 1
IDB
CCR
A
X
PC - 1[7:0] PC - 1[15:8] OPCODE
OPERAND
R/W
Figure 8-9. Interrupt Recovery Timing Interrupts are latched, and arbitration is performed in the SIM at the start of interrupt processing. The arbitration result is a constant that the CPU uses to determine which vector to fetch. Once an interrupt is latched by the SIM, no other interrupt may take precedence, regardless of priority, until the latched interrupt is serviced (or the I-bit is cleared). (See Figure 8-10.)
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FROM RESET
BREAK I BIT SET? INTERRUPT? NO YES
YES
I-BIT SET? NO
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IRQ INTERRUPT? NO
YES
AS MANY INTERRUPTS AS EXIST ON CHIP
STACK CPU REGISTERS SET I-BIT LOAD PC WITH INTERRUPT VECTOR
FETCH NEXT INSTRUCTION
SWI INSTRUCTION? NO RTI INSTRUCTION? NO
YES
YES
UNSTACK CPU REGISTERS
EXECUTE INSTRUCTION
Figure 8-10. Interrupt Processing
8.6.1.1 Hardware Interrupts
Processing of a hardware interrupt begins after completion of the current instruction. When the instruction is complete, the SIM checks all pending hardware interrupts. If interrupts are not masked (I-bit clear in the condition code register), and if the corresponding interrupt enable bit is set, the SIM proceeds with interrupt processing; otherwise, the next instruction is fetched and executed.
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System Integration Module (SIM) Exception Control
If more than one interrupt is pending at the end of an instruction execution, the highest priority interrupt is serviced first. Figure 8-11 demonstrates what happens when two interrupts are pending. If an interrupt is pending upon exit from the original interrupt service routine, the pending interrupt is serviced before the LDA instruction is executed.
CLI LDA #$FF BACKGROUND ROUTINE
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INT1
PSHH INT1 INTERRUPT SERVICE ROUTINE PULH RTI
INT2
PSHH INT2 INTERRUPT SERVICE ROUTINE PULH RTI
Figure 8-11. Interrupt Recognition Example The LDA opcode is prefetched by both the INT1 and INT2 RTI instructions. However, in the case of the INT1 RTI prefetch, this is a redundant operation.
NOTE:
To maintain compatibility with the M6805 Family, the H register is not pushed on the stack during interrupt entry. If the interrupt service routine modifies the H register or uses the indexed addressing mode, software should save the H register and then restore it prior to exiting the routine.
8.6.1.2 SWI Instruction
The SWI instruction is a non-maskable instruction that causes an interrupt regardless of the state of the interrupt mask (I-bit) in the condition code register.
NOTE:
A software interrupt pushes PC onto the stack. A software interrupt does not push PC - 1, as a hardware interrupt does.
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Table 8-3. Vector Addresses
Vector Priority Lowest Address
$FFD0 $FFD1 $FFD2 $FFD3 $FFD4 $FFD5 $FFD6 $FFD7 $FFD8 $FFD9 $FFDA $FFDB $FFDC $FFDD $FFDE $FFDF $FFE0 $FFE1 $FFE2 $FFE3 $FFE4 $FFE5 $FFE6 $FFE7 $FFE8 $FFE9 $FFEA $FFEB $FFEC $FFED $FFEE $FFEF $FFF0 $FFF1 $FFF2 $FFF3 $FFF4 $FFF5 $FFF6 $FFF7 $FFF8 $FFF9 $FFFA $FFFB $FFFC $FFFD $FFFE $FFFF
Vector
ADC Conversion Complete Vector (High) ADC Conversion Complete Vector (Low) Keyboard Vector (High) Keyboard Vector (Low) SCI Transmit Vector (High) SCI Transmit Vector (Low) SCI Receive Vector (High) SCI Receive Vector (Low) SCI Error Vector (High) SCI Error Vector (Low) Reserved Reserved Reserved Reserved Timer B Channel 3 Vector (High) Timer B Channel 3 Vector (Low) Timer B Channel 2 Vector (High) Timer B Channel 2 Vector (Low) SPI Transmit Vector (High) SPI Transmit Vector (Low) SPI Receive Vector (High) SPI Receive Vector (Low) Timer B Overflow Vector (High) Timer B Overflow Vector (Low) Timer B Channel 1 Vector (High) Timer B Channel 1 Vector (Low) Timer B Channel 0 Vector (High) Timer B Channel 0 Vector (Low) Timer A Overflow Vector (High) Timer A Overflow Vector (Low) Timer A Channel 3 Vector (High) Timer A Channel 3 Vector (Low) Timer A Channel 2 Vector (High) Timer A Channel 2 Vector (Low) Timer A Channel 1 Vector (High) Timer A Channel 1 Vector (Low) Timer A Channel 0 Vector (High) Timer A Channel 0 Vector (Low) Programmable Interrupt Timer Vector (High) Programmable Interrupt Timer Vector (Low) PLL Vector (High) PLL Vector (Low) IRQ Vector (High) IRQ Vector (Low) SWI Vector (High) SWI Vector (Low) Reset Vector (High) Reset Vector (Low)
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Highest
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System Integration Module (SIM) Exception Control
8.6.2 Reset All reset sources always have equal and highest priority and cannot be arbitrated.
8.6.3 Break Interrupts The break module can stop normal program flow at a softwareprogrammable break point by asserting its break interrupt output. See Section 22. Break Module (BRK). The SIM puts the CPU into the break state by forcing it to the SWI vector location. Refer to the break interrupt subsection of each module to see how each module is affected by the break state.
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8.6.4 Status Flag Protection in Break Mode The SIM controls whether status flags contained in other modules can be cleared during break mode. The user can select whether flags are protected from being cleared by properly initializing the break clear flag enable bit (BCFE) in the SIM break flag control register (SBFCR). Protecting flags in break mode ensures that set flags will not be cleared while in break mode. This protection allows registers to be freely read and written during break mode without losing status flag information. Setting the BCFE bit enables the clearing mechanisms. Once cleared in break mode, a flag remains cleared even when break mode is exited. Status flags with a two-step clearing mechanism -- for example, a read of one register followed by the read or write of another -- are protected, even when the first step is accomplished prior to entering break mode. Upon leaving break mode, execution of the second step will clear the flag as normal.
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Executing the STOP or WAIT instruction puts the MCU in a low-powerconsumption mode for standby situations. The SIM holds the CPU in a non-clocked state. The operation of each of these modes is described below. Both STOP and WAIT clear the interrupt mask (I) in the condition code register, allowing interrupts to occur.
8.7.1 Wait Mode
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In wait mode, the CPU clocks are inactive while the peripheral clocks continue to run. Figure 8-12 shows the timing for wait mode entry. A module that is active during wait mode can wake up the CPU with an interrupt if the interrupt is enabled. Stacking for the interrupt begins one cycle after the WAIT instruction during which the interrupt occurred. In wait mode, the CPU clocks are inactive. Refer to the wait mode subsection of each module to see if the module is active or inactive in wait mode. Some modules can be programmed to be active in wait mode. wait mode can also be exited by a reset or break. A break interrupt during wait mode sets the SIM break STOP/WAIT bit, SBSW, in the SIM break status register (SBSR). If the COP disable bit, COPD, in the mask option register A (MORA) is 0, then the computer operating properly (COP) module is enabled and remains active in wait mode.
IAB
WAIT ADDR
WAIT ADDR + 1
SAME
SAME
IDB
PREVIOUS DATA
NEXT OPCODE
SAME
SAME
R/W
NOTE: Previous data can be operand data or the WAIT opcode, depending on the last instruction.
Figure 8-12. Wait Mode Entry Timing Figure 8-13 and Figure 8-14 show the timing for wait recovery.
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System Integration Module (SIM) Low-Power Modes
IAB
$6E0B
$6E0C
$00FF
$00FE
$00FD
$00FC
IDB
$A6
$A6
$A6
$01
$0B
$6E
EXITSTOPWAIT
NOTE: EXITSTOPWAIT = RST pin OR CPU interrupt OR break interrupt
Figure 8-13. Wait Recovery from Interrupt or Break
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32 Cycles IAB $6E0B
32 Cycles RST VCT H RST VCT L
IDB
$A6
$A6
$A6
RST
CGMXCLK
Figure 8-14. Wait Recovery from Internal Reset
8.7.2 Stop Mode In stop mode, the SIM counter is reset and the system clocks are disabled. An interrupt request from a module can cause an exit from stop mode. Stacking for interrupts begins after the selected stop recovery time has elapsed. Reset or break also causes an exit from stop mode. The SIM disables the clock generator module outputs (CGMOUT and CGMXCLK) in stop mode, stopping the CPU and peripherals. Stop recovery time is selectable using the SSREC bit in the mask option register A (MORA). If SSREC is set, stop recovery is reduced from the normal delay of 4096 CGMXCLK cycles down to 32. This is ideal for applications using canned oscillators that do not require long start-up times from stop mode.
NOTE:
External crystal applications should use the full stop recovery time by clearing the SSREC bit.
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A break interrupt during stop mode sets the SIM break STOP/WAIT bit (SBSW) in the SIM break status register (SBSR). The SIM counter is held in reset from the execution of the STOP instruction until the beginning of stop recovery. It is then used to time the recovery period. Figure 8-15 shows stop mode entry timing.
CPUSTOP
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IAB
STOP ADDR
STOP ADDR + 1
SAME
SAME
IDB
PREVIOUS DATA
NEXT OPCODE
SAME
SAME
R/W
NOTE: Previous data can be operand data or the STOP opcode, depending on the last instruction.
Figure 8-15. Stop Mode Entry Timing
STOP RECOVERY PERIOD CGMXCLK
INT/BREAK
IAB
STOP +1
STOP + 2
STOP + 2
SP
SP - 1
SP - 2
SP - 3
Figure 8-16. Stop Mode Recovery from Interrupt or Break
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System Integration Module (SIM) SIM Registers
8.8 SIM Registers
The SIM has three memory mapped registers. Table 8-4 shows the mapping of these registers. Table 8-4. SIM Registers
Address $FE00 Register SBSR SRSR SBFCR Access Mode User User User
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$FE01 $FE03
8.8.1 SIM Break Status Register The SIM break status register (SBSR) contains a flag to indicate that a break caused an exit from stop or wait mode.
Address: $FE00 Bit 7 Read: R Write: Reset: 0 R 0 = Reserved 0 0 0 0 R R R R R 6 5 4 3 2 1 SBSW Note(1) 0 R 0 Bit 0
Note: 1. Writing a logic 0 clears SBSW.
Figure 8-17. SIM Break Status Register (SBSR) SBSW -- SIM Break STOP/WAIT This status bit is useful in applications requiring a return to stop or wait mode after exiting from a break interrupt. SBSW can be cleared by writing a logic 0 to it. Reset clears SBSW. 1 = Stop or wait mode was exited by break interrupt 0 = Stop or wait mode was not exited by break interrupt SBSW can be read within the break state SWI routine. The user can modify the return address on the stack by subtracting one from it. The following code is an example of this.
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; This code works if the H register has been pushed onto the stack in the break ; service routine software. This code should be executed at the end of the ; break service routine software. HIBYTE LOBYTE ; EQU EQU 5 6
If not SBSW, do RTI BRCLR TST SBSW,SBSR, RETURN ; See if STOP or WAIT mode was exited by ; break. LOBYTE,SP DOLO HIBYTE,SP LOBYTE,SP ; If RETURNLO is not 0, ; then just decrement low byte. ; Else deal with high byte, too. ; Point to STOP/WAIT opcode. ; Restore H register.
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BNE DEC DOLO RETURN DEC PULH RTI
8.8.2 SIM Reset Status Register This register contains six flags that show the source of the last reset. The SIM reset status register can be cleared by reading it. A power-on reset sets the POR bit and clears all other bits in the register.
Address: $FE01 Bit 7 Read: Write: Reset: 1 0 0 0 0 0 0 0 POR 6 PIN 5 COP 4 ILOP 3 ILAD 2 0 1 LVI Bit 0 0
= Unimplemented
Figure 8-18. SIM Reset Status Register (SRSR) POR -- Power-On Reset Bit 1 = Last reset caused by POR circuit 0 = Read of SRSR
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System Integration Module (SIM) SIM Registers
PIN -- External Reset Bit 1 = Last reset caused by external reset pin (RST) 0 = POR or read of SRSR COP -- Computer Operating Properly Reset Bit 1 = Last reset caused by COP counter 0 = POR or read of SRSR ILOP -- Illegal Opcode Reset Bit 1 = Last reset caused by an illegal opcode 0 = POR or read of SRSR ILAD -- Illegal Address Reset Bit (opcode fetches only) 1 = Last reset caused by an opcode fetch from an illegal address 0 = POR or read of SRSR LVI -- Low-Voltage Inhibit Reset Bit 1 = Last reset was caused by the LVI circuit 0 = POR or read of SRSR 8.8.3 SIM Break Flag Control Register The SIM break control register contains a bit that enables software to clear status bits while the MCU is in a break state.
Address: $FE03 Bit 7 Read: BCFE Write: Reset: 0 R = Reserved R R R R R R R 6 5 4 3 2 1 Bit 0
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Figure 8-19. SIM Break Flag Control Register (SBFCR) BCFE -- Break Clear Flag Enable Bit This read/write bit enables software to clear status bits by accessing status registers while the MCU is in a break state. To clear status bits during the break state, the BCFE bit must be set. 1 = Status bits clearable during break 0 = Status bits not clearable during break
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Technical Data -- MC68HC08AB16A
Section 9. Clock Generator Module (CGM)
9.1 Contents
9.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
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9.3
9.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 9.4.1 Crystal Oscillator Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 9.4.2 Phase-Locked Loop (PLL) Circuit . . . . . . . . . . . . . . . . . . . 127 9.4.2.1 PLL Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 9.4.2.2 Acquisition and Tracking Modes . . . . . . . . . . . . . . . . . . 128 9.4.2.3 Manual and Automatic PLL Bandwidth Modes . . . . . . . 128 9.4.2.4 Programming the PLL . . . . . . . . . . . . . . . . . . . . . . . . . . 130 9.4.2.5 Special Programming Exceptions . . . . . . . . . . . . . . . . . 131 9.4.3 Base Clock Selector Circuit . . . . . . . . . . . . . . . . . . . . . . . . 132 9.4.4 CGM External Connections . . . . . . . . . . . . . . . . . . . . . . . . 132 9.5 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 9.5.1 Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . 134 9.5.2 Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . 134 9.5.3 External Filter Capacitor Pin (CGMXFC) . . . . . . . . . . . . . . 134 9.5.4 PLL Analog Power Pin (VDDA) . . . . . . . . . . . . . . . . . . . . . . 134 9.5.5 Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . 134 9.5.6 Crystal Output Frequency Signal (CGMXCLK) . . . . . . . . . 135 9.5.7 CGM Base Clock Output (CGMOUT). . . . . . . . . . . . . . . . . 135 9.5.8 CGM CPU Interrupt (CGMINT) . . . . . . . . . . . . . . . . . . . . . 135 9.6 CGM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 9.6.1 PLL Control Register (PCTL) . . . . . . . . . . . . . . . . . . . . . . . 136 9.6.2 PLL Bandwidth Control Register (PBWC) . . . . . . . . . . . . . 138 9.6.3 PLL Programming Register (PPG) . . . . . . . . . . . . . . . . . . . 140 9.7 9.8
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Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
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9.8.1 9.8.2 9.9 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 CGM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . 143
9.10 Acquisition/Lock Time Specifications . . . . . . . . . . . . . . . . . . . 143 9.10.1 Acquisition/Lock Time Definitions. . . . . . . . . . . . . . . . . . . . 144 9.10.2 Parametric Influences On Reaction Time. . . . . . . . . . . . . . 145 9.10.3 Choosing a Filter Capacitor . . . . . . . . . . . . . . . . . . . . . . . . 146 9.10.4 Reaction Time Calculation . . . . . . . . . . . . . . . . . . . . . . . . . 147
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9.2 Introduction
This section describes the clock generator module (CGM). The CGM generates the crystal clock signal, CGMXCLK, which operates at the frequency of the crystal. The CGM also generates the base clock signal, CGMOUT, from which the system integration module (SIM) derives the system clocks. CGMOUT is based on either the crystal clock divided by two or the phase-locked loop (PLL) clock, CGMVCLK, divided by two. The PLL is a frequency generator designed for use with 1MHz to 8MHz crystals or ceramic resonators. The PLL can generate an 8MHz bus frequency without using a higher frequency crystal.
9.3 Features
Features of the CGM include the following: * * * * * Phase-locked loop with output frequency in integer multiples of the crystal reference Programmable hardware voltage-controlled oscillator (VCO) for low-jitter operation Automatic bandwidth control mode for low-jitter operation Automatic frequency lock detector CPU interrupt on entry or exit from locked condition
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Clock Generator Module (CGM) Functional Description
9.4 Functional Description
The CGM consists of three major sub-modules: * * * Crystal oscillator circuit which generates the constant crystal frequency clock, CGMXCLK. Phase-locked loop (PLL) which generates the programmable VCO frequency clock CGMVCLK. Base clock selector circuit; this software-controlled circuit selects either CGMXCLK divided by two or the VCO clock CGMVCLK divided by two, as the base clock CGMOUT. The SIM derives the system clocks from CGMOUT.
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Figure 9-1 shows the structure of the CGM.
OSC2 CRYSTAL OSCILLATOR CGMXCLK CLOCK SELECT CIRCUIT TO SIM, SCI CGMOUT TO SIM
OSC1
/2
A B S*
SIMOSCEN CGMRDV CGMRCLK BCS
*When S = 1, CGMOUT = B
VDDA
CGMXFC
VSS VRS[7:4]
USER MODE PTC3 MONITOR MODE
PHASE DETECTOR
LOOP FILTER
VOLTAGE CONTROLLED OSCILLATOR PLL ANALOG
LOCK DETECTOR
BANDWIDTH CONTROL
INTERRUPT CONTROL
CGMINT
LOCK
AUTO
ACQ
PLLIE
PLLF
MUL[7:4]
CGMVDV
FREQUENCY DIVIDER
CGMVCLK
Figure 9-1. CGM Block Diagram
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Addr.
Register Name Read: PLL Control Register Write: (PCTL) Reset: Read: PLL Bandwidth Control Register Write: (PBWC) Reset: Read: PLL Programming Register Write: (PPG) Reset:
Bit 7 PLLIE 0 AUTO 0 MUL7 0
6 PLLF
5 PLLON
4 BCS 0 XLD 0 MUL4 0
3 1
2 1
1 1
Bit 0 1
$001C
0 LOCK
1 ACQ
1 0
1 0
1 0
1 0
$001D
0 MUL6 1
0 MUL5 1
0 VRS7 0
0 VRS6 1
0 VRS5 1
0 VRS4 0
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$001E
= Unimplemented
Figure 9-2. CGM I/O Register Summary 9.4.1 Crystal Oscillator Circuit The crystal oscillator circuit consists of an inverting amplifier and an external crystal. The OSC1 pin is the input to the amplifier and the OSC2 pin is the output. The SIMOSCEN signal from the system integration module (SIM) enables the crystal oscillator circuit. The CGMXCLK signal is the output of the crystal oscillator circuit and runs at a rate equal to the crystal frequency. CGMXCLK is then buffered to produce CGMRCLK, the PLL reference clock. CGMXCLK can be used by other modules which require precise timing for operation. The duty cycle of CGMXCLK is not guaranteed to be 50% and depends on external factors, including the crystal and related external components. An externally generated clock can also feed the OSC1 pin of the crystal oscillator circuit. For this configuration, the external clock should be connected to the OSC1 pin and the OSC2 pin allowed to float.
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Clock Generator Module (CGM) Functional Description
9.4.2 Phase-Locked Loop (PLL) Circuit The PLL is a frequency generator that can operate in either acquisition mode or tracking mode, depending on the accuracy of the output frequency. The PLL can change between acquisition and tracking modes either automatically or manually.
9.4.2.1 PLL Circuits
The PLL consists of the following circuits:
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* * * * *
Voltage-controlled oscillator (VCO) Modulo VCO frequency divider Phase detector Loop filter Lock detector
The operating range of the VCO is programmable for a wide range of frequencies and for maximum immunity to external noise, including supply and CGMXFC noise. The VCO frequency is bound to a range from roughly one-half to twice the center-of-range frequency, fVRS. Modulating the voltage on the CGMXFC pin changes the frequency within this range. By design, fVRS is equal to the nominal center-of-range frequency, fNOM, (4.9152MHz) times a linear factor L, or (L)fNOM. CGMRCLK is the PLL reference clock, a buffered version of CGMXCLK. CGMRCLK runs at a frequency fRCLK, and is fed to the PLL through a buffer. The buffer output is the final reference clock, CGMRDV, running at a frequency fRDV = fRCLK. The VCO's output clock, CGMVCLK, running at a frequency fVCLK, is fed back through a programmable modulo divider. The modulo divider reduces the VCO clock by a factor N. The divider's output is the VCO feedback clock, CGMVDV, running at a frequency fVDV = fVCLK/N. (See 9.4.2.4 Programming the PLL for more information). The phase detector then compares the VCO feedback clock, CGMVDV, with the final reference clock, CGMRDV. A correction pulse is generated based on the phase difference between the two signals. The loop filter
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then slightly alters the DC voltage on the external capacitor connected to CGMXFC based on the width and direction of the correction pulse. The filter can make fast or slow corrections depending on its mode, described in 9.4.2.2 Acquisition and Tracking Modes. The value of the external capacitor and the reference frequency determines the speed of the corrections and the stability of the PLL. The lock detector compares the frequencies of the VCO feedback clock, CGMVDV, and the final reference clock, CGMRDV. Therefore, the speed of the lock detector is directly proportional to the final reference frequency fRDV. The circuit determines the mode of the PLL and the lock condition based on this comparison.
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9.4.2.2 Acquisition and Tracking Modes
The PLL filter is manually or automatically configurable into one of two operating modes: * Acquisition mode -- in acquisition mode, the filter can make large frequency corrections to the VCO. This mode is used at PLL startup or when the PLL has suffered a severe noise hit and the resulting VCO frequency is much different from the desired frequency. When in acquisition mode, the ACQ bit is clear in the PLL bandwidth control register. See 9.6.2 PLL Bandwidth Control Register (PBWC). Tracking mode -- in tracking mode, the filter makes only small corrections to the frequency of the VCO. PLL jitter is much lower in tracking mode, but the response to noise is also slower. The PLL enters tracking mode when the VCO frequency is nearly correct, such as when the PLL is selected as the base clock source. See 9.4.3 Base Clock Selector Circuit. The PLL is automatically in tracking mode when not in acquisition mode or when the ACQ bit is set.
*
9.4.2.3 Manual and Automatic PLL Bandwidth Modes
The PLL can change the bandwidth or operational mode of the loop filter manually or automatically.
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Clock Generator Module (CGM) Functional Description
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In automatic bandwidth control mode (AUTO = 1), the lock detector automatically switches between acquisition and tracking modes. Automatic bandwidth control mode is used also to determine when the VCO clock, CGMVCLK, is safe to use as the source for the base clock, CGMOUT. See 9.6.2 PLL Bandwidth Control Register (PBWC). If PLL interrupts are enabled, the software can wait for a PLL interrupt request and then check the LOCK bit. If interrupts are disabled, software can poll the LOCK bit continuously (during PLL start-up, usually) or at periodic intervals. In either case, when the LOCK bit is set, the VCO clock is safe to use as the source for the base clock. See 9.4.3 Base Clock Selector Circuit. If the VCO is selected as the source for the base clock and the LOCK bit is clear, the PLL has suffered a severe noise hit and the software must take appropriate action, depending on the application. (See 9.7 Interrupts for information and precautions on using interrupts). The following conditions apply when the PLL is in automatic bandwidth control mode: * The ACQ bit (see 9.6.2 PLL Bandwidth Control Register (PBWC)) is a read-only indicator of the mode of the filter. (See 9.4.2.2 Acquisition and Tracking Modes) The ACQ bit is set when the VCO frequency is within a certain tolerance TRK and is cleared when the VCO frequency is out of a certain tolerance UNT. (See 9.10 Acquisition/Lock Time Specifications) The LOCK bit is a read-only indicator of the locked state of the PLL. The LOCK bit is set when the VCO frequency is within a certain tolerance LOCK and is cleared when the VCO frequency is out of a certain tolerance UNL. (See 9.10 Acquisition/Lock Time Specifications) CPU interrupts can occur if enabled (PLLIE = 1) when the PLL's lock condition changes, toggling the LOCK bit. (See 9.6.1 PLL Control Register (PCTL))
*
* *
*
The PLL also may operate in manual mode (AUTO = 0). Manual mode is used by systems that do not require an indicator of the lock condition for proper operation. Such systems typically operate well below fBUSMAX
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and require fast start-up. The following conditions apply when in manual mode: * ACQ is a writable control bit that controls the mode of the filter. Before turning on the PLL in manual mode, the ACQ bit must be clear. Before entering tracking mode (ACQ = 1), software must wait a given time, tACQ (see 9.10 Acquisition/Lock Time Specifications), after turning on the PLL by setting PLLON in the PLL control register (PCTL). Software must wait a given time, tAL, after entering tracking mode before selecting the PLL as the clock source to CGMOUT (BCS = 1). The LOCK bit is disabled. CPU interrupts from the CGM are disabled.
*
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*
* *
9.4.2.4 Programming the PLL
The following procedure shows how to program the PLL.
NOTE:
The round function in the following equations means that the real number should be rounded to the nearest integer number.
1. Choose the desired bus frequency, fBUSDES. 2. Calculate the desired VCO frequency (four times the desired bus frequency). f VCLKDES = 4 x f BUSDES 3. Choose a practical PLL reference frequency, fRCLK. 4. Select a VCO frequency multiplier, N. f VCLKDES N = round --------------------- f RCLK -
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Clock Generator Module (CGM) Functional Description
5. Calculate and verify the adequacy of the VCO and bus frequencies fVCLK and fBUS. f VCLK = N x f RCLK f BUS = ( f VCLK ) 4 6. Select a VCO linear range multiplier, L. f VCLK L = round ------------ f NOM where fNOM = 4.9152MHz 7. Calculate and verify the adequacy of the VCO programmed center-of-range frequency fVRS. fVRS = (L)fNOM 8. Verify the choice of N and L by comparing fVCLK to fVRS and fVCLKDES. For proper operation, fVCLK must be within the application's tolerance of fVCLKDES, and fVRS must be as close as possible to fVCLK.
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NOTE:
Exceeding the recommended maximum bus frequency or VCO frequency can cause the MCU to "crash".
9. Program the PLL registers accordingly: a. In the upper 4 bits of the PLL programming register (PPG), program the binary equivalent of N. b. In the lower 4 bits of the PLL programming register (PPG), program the binary equivalent of L.
9.4.2.5 Special Programming Exceptions
The programming method described in 9.4.2.4 Programming the PLL does not account for two possible exceptions -- a value of zero for N or L is meaningless when used in the equations given. To account for these exceptions:
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* * A zero value for N is interpreted exactly the same as a value of one. A zero value for L disables the PLL and prevents its selection as the source for the base clock. (See 9.4.3 Base Clock Selector Circuit)
9.4.3 Base Clock Selector Circuit This circuit is used to select either the crystal clock, CGMXCLK, or the VCO clock, CGMVCLK, as the source of the base clock, CGMOUT. The two input clocks go through a transition control circuit that waits up to three CGMXCLK cycles and three CGMVCLK cycles to change from one clock source to the other. During this time, CGMOUT is held in stasis. The output of the transition control circuit is then divided by two to correct the duty cycle. Therefore, the bus clock frequency, which is one-half of the base clock frequency, is one-fourth the frequency of the selected clock (CGMXCLK or CGMVCLK). The BCS bit in the PLL control register (PCTL) selects which clock drives CGMOUT. The VCO clock cannot be selected as the base clock source if the PLL is not turned on. The PLL cannot be turned off if the VCO clock is selected. The PLL cannot be turned on or off simultaneously with the selection or deselection of the VCO clock. The VCO clock also cannot be selected as the base clock source if the factor L is programmed to a zero. This value would set up a condition inconsistent with the operation of the PLL, so that the PLL would be disabled and the crystal clock would be forced as the source of the base clock. 9.4.4 CGM External Connections In its typical configuration, the CGM requires seven external components. Five of these are for the crystal oscillator and two are for the PLL. The crystal oscillator is normally connected in a Pierce oscillator configuration, as shown in Figure 9-3. This figure shows only the logical representation of the internal components and may not represent actual circuitry. The oscillator configuration uses five components:
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Clock Generator Module (CGM) Functional Description
* * * * *
Crystal, X1 Fixed capacitor, C1 Tuning capacitor, C2 (can also be a fixed capacitor) Feedback resistor, RB Series resistor, RS (optional)
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The series resistor (RS) is included in the diagram to follow strict Pierce oscillator guidelines and may not be required for all ranges of operation, especially with high frequency crystals. Refer to the crystal manufacturer's data for more information. Figure 9-3 also shows the external components for the PLL: * * Bypass capacitor, CBYP Filter capacitor, CF
Care should be taken with routing in order to minimize signal cross talk and noise. (See 9.10 Acquisition/Lock Time Specifications for routing information and more information on the filter capacitor's value and its effects on PLL performance).
SIMOSCEN
CGMXCLK
OSC1 RB
OSC2
VSSA
CGMXFC CF
VDDA VDD CBYP
RS* X1
C1
C2
*RS can be zero (shorted) when used with higher-frequency crystals. Refer to manufacturer's data.
Figure 9-3. CGM External Connections
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The following paragraphs describe the CGM I/O signals.
9.5.1 Crystal Amplifier Input Pin (OSC1) The OSC1 pin is an input to the crystal oscillator amplifier.
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9.5.2 Crystal Amplifier Output Pin (OSC2) The OSC2 pin is the output of the crystal oscillator inverting amplifier.
9.5.3 External Filter Capacitor Pin (CGMXFC) The CGMXFC pin is required by the loop filter to filter out phase corrections. A small external capacitor is connected to this pin.
NOTE:
To prevent noise problems, CF should be placed as close to the CGMXFC pin as possible, with minimum routing distances and no routing of other signals across the CF connection.
9.5.4 PLL Analog Power Pin (VDDA) VDDA is a power pin used by the analog portions of the PLL. The pin should be connected to the same voltage potential as the VDD pin.
NOTE:
Route VDDA carefully for maximum noise immunity and place bypass capacitors as close as possible to the package.
9.5.5 Oscillator Enable Signal (SIMOSCEN) The SIMOSCEN signal comes from the system integration module (SIM) and enables the oscillator and PLL.
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Clock Generator Module (CGM) CGM Registers
9.5.6 Crystal Output Frequency Signal (CGMXCLK) CGMXCLK is the crystal oscillator output signal. It runs at the full speed of the crystal (fXCLK) and is generated directly from the crystal oscillator circuit. Figure 9-3 shows only the logical relation of CGMXCLK to OSC1 and OSC2 and may not represent the actual circuitry. The duty cycle of CGMXCLK is unknown and may depend on the crystal and other external factors. Also, the frequency and amplitude of CGMXCLK can be unstable at start-up.
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9.5.7 CGM Base Clock Output (CGMOUT) CGMOUT is the clock output of the CGM. This signal goes to the SIM, which generates the MCU clocks. CGMOUT is a 50% duty cycle clock running at twice the bus frequency. CGMOUT is software programmable to be either the oscillator output (CGMXCLK) divided by two or the VCO clock (CGMVCLK) divided by two.
9.5.8 CGM CPU Interrupt (CGMINT) CGMINT is the interrupt signal generated by the PLL lock detector.
9.6 CGM Registers
The following registers control and monitor operation of the CGM: * * * PLL control register (PCTL). (See 9.6.1 PLL Control Register (PCTL)) PLL bandwidth control register (PBWC). (See 9.6.2 PLL Bandwidth Control Register (PBWC)) PLL programming register (PPG). (See 9.6.3 PLL Programming Register (PPG))
Figure 9-4 is a summary of the CGM registers.
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Addr.
Register Name Read: PLL Control Register Write: (PCTL) Reset: Read: PLL Bandwidth Control Register Write: (PBWC) Reset: Read: PLL Programming Register Write: (PPG) Reset:
Bit 7 PLLIE 0 AUTO 0 MUL7 0
6 PLLF
5 PLLON
4 BCS 0 XLD 0 MUL4 0
3 1
2 1
1 1
Bit 0 1
$001C
0 LOCK
1 ACQ
1 0
1 0
1 0
1 0
$001D
0 MUL6 1
0 MUL5 1
0 VRS7 0
0 VRS6 1
0 VRS5 1
0 VRS4 0
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$001E
= Unimplemented
NOTES: 1. When AUTO = 0, PLLIE is forced to logic zero and is read-only. 2. When AUTO = 0, PLLF and LOCK read as logic zero. 3. When AUTO = 1, ACQ is read-only. 4. When PLLON = 0 or VRS[7:4] = $0, BCS is forced to logic zero and is read-only. 5. When PLLON = 1, the PLL programming register is read-only. 6. When BCS = 1, PLLON is forced set and is read-only.
Figure 9-4. CGM I/O Register Summary 9.6.1 PLL Control Register (PCTL) The PLL control register contains the interrupt enable and flag bits, the on/off switch, and the base clock selector bit.
Address: $001C Bit 7 Read: PLLIE Write: Reset: 0 0 1 0 1 1 1 1 6 PLLF PLLON BCS 5 4 3 1 2 1 1 1 Bit 0 1
= Unimplemented
Figure 9-5. PLL Control Register (PCTL)
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Clock Generator Module (CGM) CGM Registers
PLLIE -- PLL Interrupt Enable Bit This read/write bit enables the PLL to generate an interrupt request when the LOCK bit toggles, setting the PLL flag, PLLF. When the AUTO bit in the PLL bandwidth control register (PBWC) is clear, PLLIE cannot be written and reads as 0. Reset clears the PLLIE bit. 1 = PLL interrupts enabled 0 = PLL interrupts disabled PLLF -- PLL Interrupt Flag Bit
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This read-only bit is set whenever the LOCK bit toggles. PLLF generates an interrupt request if the PLLIE bit is set also. PLLF always reads as 0 when the AUTO bit in the PLL bandwidth control register (PBWC) is clear. The PLLF bit should be cleared by reading the PLL control register. Reset clears the PLLF bit. 1 = Change in lock condition 0 = No change in lock condition
NOTE:
The PLLF bit should not be inadvertently cleared. Any read or readmodify-write operation on the PLL control register clears the PLLF bit.
PLLON -- PLL On Bit This read/write bit activates the PLL and enables the VCO clock, CGMVCLK. PLLON cannot be cleared if the VCO clock is driving the base clock, CGMOUT (BCS = 1). See 9.4.3 Base Clock Selector Circuit. Reset sets this bit so that the loop can stabilize as the MCU is powering up. 1 = PLL on 0 = PLL off BCS -- Base Clock Select Bit This read/write bit selects either the crystal oscillator output, CGMXCLK, or the VCO clock, CGMVCLK, as the source of the CGM output, CGMOUT. CGMOUT frequency is one-half the frequency of the selected clock. BCS cannot be set while the PLLON bit is clear. After toggling BCS, it may take up to three CGMXCLK and three CGMVCLK cycles to complete the transition from one source clock
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to the other. During the transition, CGMOUT is held in stasis. See 9.4.3 Base Clock Selector Circuit. Reset and the STOP instruction clear the BCS bit. 1 = CGMOUT driven by CGMVCLK/2 0 = CGMOUT driven by CGMXCLK/2
NOTE:
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PLLON and BCS have built-in protection that prevents the base clock selector circuit from selecting the VCO clock as the source of the base clock if the PLL is off. Therefore, PLLON cannot be cleared when BCS is set, and BCS cannot be set when PLLON is clear. If the PLL is off (PLLON = 0), selecting CGMVCLK requires two writes to the PLL control register. See 9.4.3 Base Clock Selector Circuit.
Bits [3:0] -- Unimplemented bits These bits provide no function and always read as 1.
9.6.2 PLL Bandwidth Control Register (PBWC) The PLL bandwidth control register does the following: * * * * Selects automatic or manual (software-controlled) bandwidth control mode Indicates when the PLL is locked In automatic bandwidth control mode, indicates when the PLL is in acquisition or tracking mode In manual operation, forces the PLL into acquisition or tracking mode.
$001D Bit 7 Read: AUTO Write: Reset: 0 0 0 0 0 0 0 0 6 LOCK ACQ XLD 5 4 3 0 2 0 1 0 Bit 0 0
Address:
= Unimplemented
Figure 9-7. PLL Bandwidth Control Register (PBWC)
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Clock Generator Module (CGM) CGM Registers
AUTO -- Automatic Bandwidth Control Bit This read/write bit selects automatic or manual bandwidth control. When initializing the PLL for manual operation (AUTO = 0), the ACQ bit should be cleared before turning the PLL on. Reset clears the AUTO bit. 1 = Automatic bandwidth control 0 = Manual bandwidth control LOCK -- Lock Indicator Bit
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When the AUTO bit is set, LOCK is a read-only bit that becomes set when the VCO clock CGMVCLK, is locked (running at the programmed frequency). When the AUTO bit is clear, LOCK reads as 0 and has no meaning. Reset clears the LOCK bit. 1 = VCO frequency correct or locked 0 = VCO frequency incorrect or unlocked ACQ -- Acquisition Mode Bit When the AUTO bit is set, ACQ is a read-only bit that indicates whether the PLL is in acquisition mode or tracking mode. When the AUTO bit is clear, ACQ is a read/write bit that controls whether the PLL is in acquisition or tracking mode. In automatic bandwidth control mode (AUTO = 1), the last-written value from manual operation is stored in a temporary location and is recovered when manual operation resumes. Reset clears this bit, enabling acquisition mode. 1 = Tracking mode 0 = Acquisition mode XLD -- Crystal Loss Detect Bit When the VCO output, CGMVCLK, is driving CGMOUT, this read/write bit indicates whether the crystal reference frequency is active or not. To check the status of the crystal reference, the following procedure should be followed: 1. Write a 1 to XLD. 2. Wait 4 x N cycles. (N is the VCO frequency multiplier.) 3. Read XLD. 1 = Crystal reference is not active 0 = Crystal reference is active
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The crystal loss detect function works only when the BCS bit is set, selecting CGMVCLK to drive CGMOUT. When BCS is clear, XLD always reads as 0. Bits [3:0] -- Reserved for test These bits enable test functions not available in user mode. To ensure software portability from development systems to user applications, software should write zeros to Bits [3:0] whenever writing to PBWC.
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9.6.3 PLL Programming Register (PPG) The PLL programming register contains the programming information for the modulo feedback divider and the programming information for the hardware configuration of the VCO.
Address: $001E Bit 7 Read: MUL7 Write: Reset: 0 1 1 0 0 1 1 0 MUL6 MUL5 MUL4 VRS7 VRS6 VRS5 VRS4 6 5 4 3 2 1 Bit 0
Figure 9-8. PLL Programming Register (PPG) MUL[7:4] -- Multiplier Select Bits These read/write bits control the modulo feedback divider that selects the VCO frequency multiplier, N. (See 9.4.2.1 PLL Circuits and 9.4.2.4 Programming the PLL). A value of $0 in the multiplier select bits configures the modulo feedback divider the same as a value of $1. Reset initializes these bits to $6 to give a default multiply value of 6.
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Clock Generator Module (CGM) CGM Registers
Table 9-1. VCO Frequency Multiplier (N) Selection
MUL7:MUL6:MUL5:MUL4 0000 0001 0010 0011 VCO Frequency Multiplier (N) 1 1 2 3
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1101 1110 1111
13 14 15
NOTE:
The multiplier select bits have built-in protection that prevents them from being written when the PLL is on (PLLON = 1).
VRS[7:4] -- VCO Range Select Bits These read/write bits control the hardware center-of-range linear multiplier L, which controls the hardware center-of-range frequency fVRS. (See 9.4.2.1 PLL Circuits, 9.4.2.4 Programming the PLL, and 9.6.1 PLL Control Register (PCTL)). VRS[7:4] cannot be written when the PLLON bit in the PLL control register (PCTL) is set. (See 9.4.2.5 Special Programming Exceptions). A value of $0 in the VCO range select bits disables the PLL and clears the BCS bit in the PCTL. (See 9.4.3 Base Clock Selector Circuit and 9.4.2.5 Special Programming Exceptions for more information). Reset initializes the bits to $6 to give a default range multiply value of 6.
NOTE:
The VCO range select bits have built-in protection that prevents them from being written when the PLL is on (PLLON = 1) and prevents selection of the VCO clock as the source of the base clock (BCS = 1) if the VCO range select bits are all clear. The VCO range select bits must be programmed correctly. Incorrect programming may result in failure of the PLL to achieve lock.
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When the AUTO bit is set in the PLL bandwidth control register (PBWC), the PLL can generate a CPU interrupt request every time the LOCK bit changes state. The PLLIE bit in the PLL control register (PCTL) enables CPU interrupts from the PLL. PLLF, the interrupt flag in the PCTL, becomes set whether interrupts are enabled or not. When the AUTO bit is clear, CPU interrupts from the PLL are disabled and PLLF reads as 0.
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Software should read the LOCK bit after a PLL interrupt request to see if the request was due to an entry into lock or an exit from lock. When the PLL enters lock, the VCO clock CGMVCLK, divided by two can be selected as the CGMOUT source by setting BCS in the PCTL. When the PLL exits lock, the VCO clock frequency is corrupt, and appropriate precautions should be taken. If the application is not frequencysensitive, interrupts should be disabled to prevent PLL interrupt service routines from impeding software performance or from exceeding stack limitations.
NOTE:
Software can select CGMVCLK/2 as the CGMOUT source even if the PLL is not locked (LOCK = 0). Therefore, software should make sure the PLL is locked before setting the BCS bit.
9.8 Low-Power Modes
The WAIT and STOP instructions put the MCU in low-powerconsumption standby modes.
9.8.1 Wait Mode The WAIT instruction does not affect the CGM. Before entering WAIT mode, software can disengage and turn off the PLL by clearing the BCS and PLLON bits in the PLL control register (PCTL). Less powersensitive applications can disengage the PLL without turning it off. Applications that require the PLL to wake the MCU from WAIT mode also can deselect the PLL output without turning off the PLL.
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Clock Generator Module (CGM) CGM During Break Interrupts
9.8.2 Stop Mode When the STOP instruction executes, the SIM drives the SIMOSCEN signal low, disabling the CGM and holding low all CGM outputs (CGMXCLK, CGMOUT, and CGMINT). If the STOP instruction is executed with the VCO clock, CGMVCLK, divided by two driving CGMOUT, the PLL automatically clears the BCS bit in the PLL control register (PCTL), thereby selecting the crystal clock, CGMXCLK, divided by two as the source of CGMOUT. When the MCU recovers from STOP, the crystal clock divided by two drives CGMOUT and BCS remains clear.
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9.9 CGM During Break Interrupts
The system integration module (SIM) controls whether status bits in other modules can be cleared during the break state. The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear status bits during the break state. See Section 8. System Integration Module (SIM). To allow software to clear status bits during a break interrupt, a 1 should be written to the BCFE bit. If a status bit is cleared during the break state, it remains cleared when the MCU exits the break state. To protect the PLLF bit during the break state, write a 0 to the BCFE bit. With BCFE at 0 (its default state), software can read and write the PLL control register during the break state without affecting the PLLF bit.
9.10 Acquisition/Lock Time Specifications
The acquisition and lock times of the PLL are, in many applications, the most critical PLL design parameters. Proper design and use of the PLL ensures the highest stability and lowest acquisition/lock times.
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9.10.1 Acquisition/Lock Time Definitions Typical control systems refer to the acquisition time or lock time as the reaction time of the system, within specified tolerances, to a step input. In a PLL, the step input occurs when the PLL is turned on or when it suffers a noise hit. The tolerance is usually specified as a percentage of the step input or when the output settles to the desired value plus or minus a percentage of the frequency change. Therefore, the reaction time is constant in this definition, regardless of the size of the step input. For example, consider a system with a 5% acquisition time tolerance. If a command instructs the system to change from 0Hz to 1MHz, the acquisition time is the time taken for the frequency to reach 1MHz 50kHz. 50kHz = 5% of the 1MHz step input. If the system is operating at 1MHz and suffers a -100kHz noise hit, the acquisition time is the time taken to return from 900kHz to 1MHz 5kHz. 5kHz = 5% of the 100kHz step input. Other systems refer to acquisition and lock times as the time the system takes to reduce the error between the actual output and the desired output to within specified tolerances. Therefore, the acquisition or lock time varies according to the original error in the output. Minor errors may not even be registered. Typical PLL applications prefer to use this definition because the system requires the output frequency to be within a certain tolerance of the desired frequency regardless of the size of the initial error. The discrepancy in these definitions makes it difficult to specify an acquisition or lock time for a typical PLL. Therefore, the definitions for acquisition and lock times for this module are as follows: * Acquisition time, tACQ, is the time the PLL takes to reduce the error between the actual output frequency and the desired output frequency to less than the tracking mode entry tolerance TRK. Acquisition time is based on an initial frequency error, (fDES - fORIG)/fDES, of not more than 100%. In automatic bandwidth control mode (see 9.4.2.3 Manual and Automatic PLL Bandwidth Modes), acquisition time expires when the ACQ bit becomes set in the PLL bandwidth control register (PBWC).
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Clock Generator Module (CGM) Acquisition/Lock Time Specifications
*
Lock time, tLOCK, is the time the PLL takes to reduce the error between the actual output frequency and the desired output frequency to less than the lock mode entry tolerance LOCK. Lock time is based on an initial frequency error, (fDES - fORIG)/fDES, of not more than 100%. In automatic bandwidth control mode, lock time expires when the LOCK bit becomes set in the PLL bandwidth control register (PBWC). See 9.4.2.3 Manual and Automatic PLL Bandwidth Modes.
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Obviously, the acquisition and lock times can vary according to how large the frequency error is and may be shorter or longer in many cases.
9.10.2 Parametric Influences On Reaction Time Acquisition and lock times are designed to be as short as possible while still providing the highest possible stability. These reaction times are not constant, however. Many factors directly and indirectly affect the acquisition time. The most critical parameter which affects the reaction times of the PLL is the reference frequency, fRDV. This frequency is the input to the phase detector and controls how often the PLL makes corrections. For stability, the corrections must be small compared to the desired frequency, so several corrections are required to reduce the frequency error. Therefore, the slower the reference the longer it takes to make these corrections. This parameter is also under user control via the choice of crystal frequency fXCLK. Another critical parameter is the external filter capacitor. The PLL modifies the voltage on the VCO by adding or subtracting charge from this capacitor. Therefore, the rate at which the voltage changes for a given frequency error (thus change in charge) is proportional to the capacitor size. The size of the capacitor also is related to the stability of the PLL. If the capacitor is too small, the PLL cannot make small enough adjustments to the voltage and the system cannot lock. If the capacitor is too large, the PLL may not be able to adjust the voltage in a reasonable time. See 9.10.3 Choosing a Filter Capacitor.
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Also important is the operating voltage potential applied to VDDA. The power supply potential alters the characteristics of the PLL. A fixed value is best. Variable supplies, such as batteries, are acceptable if they vary within a known range at very slow speeds. Noise on the power supply is not acceptable, because it causes small frequency errors which continually change the acquisition time of the PLL. Temperature and processing also can affect acquisition time because the electrical characteristics of the PLL change. The part operates as specified as long as these influences stay within the specified limits. External factors, however, can cause drastic changes in the operation of the PLL. These factors include noise injected into the PLL through the filter capacitor, filter capacitor leakage, stray impedances on the circuit board, and even humidity or circuit board contamination.
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9.10.3 Choosing a Filter Capacitor As described in 9.10.2 Parametric Influences On Reaction Time, the external filter capacitor CF is critical to the stability and reaction time of the PLL. The PLL is also dependent on reference frequency and supply voltage. The value of the capacitor must, therefore, be chosen with supply potential and reference frequency in mind. For proper operation, the external filter capacitor must be chosen according to the following equation: V DDA C F = C FACT ------------ f RDV- For the value of VDDA, the voltage potential at which the MCU is operating should be used. If the power supply is variable, choose a value near the middle of the range of possible supply values. This equation does not always yield a commonly available capacitor size, so round to the nearest available size. If the value is between two different sizes, choose the higher value for better stability. Choosing the lower size may seem attractive for acquisition time improvement,
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Clock Generator Module (CGM) Acquisition/Lock Time Specifications
but the PLL may become unstable. Also, always choose a capacitor with a tight tolerance (20% or better) and low dissipation.
9.10.4 Reaction Time Calculation The actual acquisition and lock times can be calculated using the equations below. These equations yield nominal values under the following conditions:
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* * * *
Correct selection of filter capacitor, CF, (see 9.10.3 Choosing a Filter Capacitor) Room temperature operation Negligible external leakage on CGMXFC Negligible noise
The K factor in the equations is derived from internal PLL parameters. KACQ is the K factor when the PLL is configured in acquisition mode, and KTRK is the K factor when the PLL is configured in tracking mode. See 9.4.2.2 Acquisition and Tracking Modes.
V DDA 8 t ACQ = ------------ ------------ f RDV- K ACQ
V DDA 4 t AL = ------------ ------------ - f RDV K TRK
t LOCK = t ACQ + t AL Note the inverse proportionality between the lock time and the reference frequency. In automatic bandwidth control mode the acquisition and lock times are quantized into units based on the reference frequency. See 9.4.2.3
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Manual and Automatic PLL Bandwidth Modes. A certain number of clock cycles, nACQ, is required to ascertain whether the PLL is within the tracking mode entry tolerance TRK, before exiting acquisition mode. Also, a certain number of clock cycles, nTRK, is required to ascertain whether the PLL is within the lock mode entry tolerance LOCK. Therefore, the acquisition time tACQ, is an integer multiple of nACQ/fRDV, and the acquisition to lock time tAL, is an integer multiple of nTRK/fRDV. Also, since the average frequency over the entire measurement period must be within the specified tolerance, the total time usually is longer than tLOCK as calculated above. In manual mode, it is usually necessary to wait considerably longer than tLOCK before selecting the PLL clock (see 9.4.3 Base Clock Selector Circuit), because the factors described in 9.10.2 Parametric Influences On Reaction Time may slow the lock time considerably.
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Technical Data -- MC68HC08AB16A
Section 10. Monitor ROM (MON)
10.1 Contents
10.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
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10.3
10.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 10.4.1 Entering Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 10.4.2 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 10.4.3 Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 10.4.4 Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 10.4.5 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 10.4.6 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 10.5 10.6 10.7 Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 EEPROM Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Extended Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
10.2 Introduction
This section describes the monitor ROM (MON). The monitor ROM allows complete testing of the MCU through a single-wire interface with a host computer.
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Features of the monitor ROM include the following: * * * Normal user-mode pin functionality One pin dedicated to serial communication between monitor ROM and host computer Standard mark/space non-return-to-zero (NRZ) communication with host computer 4800 baud to 28.8 k-baud communication with host computer Execution of code in RAM or ROM
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* *
10.4 Functional Description
The monitor ROM receives and executes commands from a host computer. Figure 10-1 shows a example circuit used to enter monitor mode and communicate with a host computer via a standard RS-232 interface. While simple monitor commands can access any memory address, the MCU has a ROM security feature to prevent external viewing of the ROM contents. Proper procedures must be followed to verify ROM content. Access to the ROM is denied to unauthorized users of customer specified software. In monitor mode, the MCU can execute host-computer code in RAM while all MCU pins except PTA0 retain normal operating mode functions. All communication between the host computer and the MCU is through the PTA0 pin. A level-shifting and multiplexing interface is required between PTA0 and the host computer. PTA0 is used in a wired-OR configuration and requires a pullup resistor.
Technical Data
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Monitor ROM (MON) Functional Description
VDD MC68HC08AB16A 10 k RST 0.1 F
VTST 10 IRQ
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VDDA VDDA
VCGMXFC 1 10 F + 3 4 10 F + 18 17 + 10 F VDD 20 pF X1 4.9152 MHz 10 M OSC2 20 pF DB-25 2 3 7 0.1 F VDD 1 2 6 4 MC74HC125 14 3 5 VDD 10 k A (See NOTES) B VDD 10 k PTC0 PTC1 PTA0 PTC3 VDD 10 k 5 6 16 15 VDD VDD VSS OSC1 MC145407 20 + 10 F 0.1 F
2
19
7 NOTES: Position A -- Bus clock = CGMXCLK / 4 or CGMVCLK / 4 Position B -- Bus clock = CGMXCLK / 2
Figure 10-1. Monitor Mode Circuit
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10.4.1 Entering Monitor Mode Table 10-1 shows the pin conditions for entering monitor mode. Table 10-1. Monitor Mode Entry Conditions
PTC0 Pin PTC1 Pin PTA0 Pin PTC3 Pin Bus Frequency (CGMOUT / 2) CGMXCLK / 4 or CGMVCLK / 4 CGMXCLK / 2
IRQ Pin
CGMOUT
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VTST
(1)
1
0
1
1
CGMXCLK / 2 or CGMVCLK / 2 CGMXCLK
VTST
1
0
1
0
Notes: 1. For VTST, see Section 23. Electrical Specifications.
Enter monitor mode by either * * Executing a software interrupt instruction (SWI) or Applying a logic 0 and then a logic 1 to the RST pin.
The MCU sends a break signal (10 consecutive logic 0s) to the host computer, indicating that it is ready to receive a command. The break signal also provides a timing reference to allow the host to determine the necessary baud rate. Monitor mode uses alternate vectors for reset, SWI, and break interrupt. The alternate vectors are in the $FE page instead of the $FF page and allow code execution from the internal monitor firmware instead of user code. The COP module is disabled in monitor mode as long as VTST (see Section 23. Electrical Specifications) is applied to either the IRQ pin or the RST pin. (See Section 8. System Integration Module (SIM) for more information on modes of operation.)
NOTE:
Holding the PTC3 pin low when entering monitor mode causes a bypass of a divide-by-two stage at the oscillator. The CGMOUT frequency is equal to the CGMXCLK frequency, and the OSC1 input directly generates internal bus clocks. In this case, the OSC1 signal must have a 50% duty cycle at maximum bus frequency.
Technical Data
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Monitor ROM (MON) Functional Description
Table 10-2 is a summary of the differences between user mode and monitor mode. Table 10-2. Mode Differences
Functions Modes COP User Enabled Disabled(1) Reset Vector High $FFFE $FEFE Reset Vector Low $FFFF $FEFF Break Vector High $FFFC $FEFC Break Vector Low $FFFD $FEFD SWI Vector High $FFFC $FEFC SWI Vector Low $FFFD $FEFD
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Monitor
Notes: 1. If the high voltage (VTST) is removed from the IRQ pin while in monitor mode, the SIM asserts its COP enable output. The COP can be enabled or disabled by the COPD bit in the configuration register 1 (CONFIG1). (See 23.6 5.0-V DC Electrical Characteristics.)
10.4.2 Data Format Communication with the monitor ROM is in standard non-return-to-zero (NRZ) mark/space data format. (See Figure 10-2 and Figure 10-3.) The data transmit and receive rate can be anywhere from 4800 baud to 28.8 k-baud. Transmit and receive baud rates must be identical.
NEXT START BIT
START BIT
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
STOP BIT
Figure 10-2. Monitor Data Format
NEXT START BIT
$A5
START BIT START BIT
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
STOP BIT STOP BIT
BREAK
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
Figure 10-3. Sample Monitor Waveforms
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10.4.3 Echoing As shown in Figure 10-4, the monitor ROM immediately echoes each received byte back to the PTA0 pin for error checking. Any result of a command appears after the echo of the last byte of the command.
SENT TO MONITOR
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READ
READ
ADDR. HIGH ADDR. HIGH ADDR. LOW
ADDR. LOW
DATA
ECHO
RESULT
Figure 10-4. Read Transaction
10.4.4 Break Signal A start bit followed by nine low bits is a break signal. (See Figure 10-5.) When the monitor receives a break signal, it drives the PTA0 pin high for the duration of two bits before echoing the break signal.
MISSING STOP BIT TWO-STOP-BIT DELAY BEFORE ZERO ECHO
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
Figure 10-5. Break Transaction
Technical Data
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Monitor ROM (MON) Functional Description
10.4.5 Commands The monitor ROM uses these commands: * * * * * READ, read memory WRITE, write memory IREAD, indexed read IWRITE, indexed write READSP, read stack pointer RUN, run user program
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*
A sequence of IREAD or IWRITE commands can access a block of memory sequentially over the full 64k-byte memory map.
Table 10-3. READ (Read Memory) Command
Description Operand Data Returned Opcode Read byte from memory Specifies 2-byte address in high byte:low byte order Returns contents of specified address $4A Command Sequence
SENT TO MONITOR
READ
READ
ADDRESS HIGH
ADDRESS HIGH
ADDRESS LOW
ADDRESS LOW
DATA
ECHO
RETURN
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Table 10-4. WRITE (Write Memory) Command
Description Operand Data Returned Opcode Write byte to memory Specifics 2-byte address in high byte:low byte order; low byte followed by data byte None $49 Command Sequence
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SENT TO MONITOR
WRITE
WRITE
ADDRESS HIGH
ADDRESS HIGH
ADDRESS LOW
ADDRESS LOW
DATA
DATA
ECHO
Table 10-5. IREAD (Indexed Read) Command
Description Operand Data Returned Opcode Read next 2 bytes in memory from last address accessed Specifies 2-byte address in high byte:low byte order Returns contents of next two addresses $1A Command Sequence
SENT TO MONITOR
IREAD
IREAD
DATA
DATA
ECHO
RETURN
Technical Data
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Monitor ROM (MON) Functional Description
Table 10-6. IWRITE (Indexed Write) Command
Description Operand Data Returned Opcode Write to last address accessed + 1 Specifies single data byte None $19 Command Sequence
SENT TO MONITOR
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IWRITE
IWRITE
DATA
DATA
ECHO
Table 10-7. READSP (Read Stack Pointer) Command
Description Operand Data Returned Opcode Reads stack pointer None Returns stack pointer in high byte:low byte order $0C Command Sequence
SENT TO MONITOR
READSP
READSP
SP HIGH
SP LOW
ECHO
RETURN
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Table 10-8. RUN (Run User Program) Command
Description Operand Data Returned Opcode Executes RTI instruction None None $28 Command Sequence
SENT TO MONITOR
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RUN
RUN
ECHO
10.4.6 Baud Rate With a 4.9152-MHz crystal and the PTC3 pin at logic 1 during reset, data is transferred between the monitor and host at 4800 baud. If the PTC3 pin is at logic 0 during reset, the monitor baud rate is 9600. When the CGM output, CGMOUT, is driven by the PLL, the baud rate is determined by the MUL[7:4] bits in the PLL programming register (PPG). (See Section 9. Clock Generator Module (CGM).) Table 10-9. Monitor Baud Rate Selection
Monitor Baud Rate 4.9152 MHz 4.194 MHz VCO Frequency Multiplier (N) 1 4800 4096 2 9600 8192 3 14,400 12,288 4 19,200 16,384 5 24,000 20,480 6 28,800 24,576
Technical Data
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Monitor ROM (MON) Security
10.5 Security
A security feature discourages unauthorized reading of ROM locations while in monitor mode. The host can bypass the security feature at monitor mode entry by sending eight security bytes that match the bytes at locations $FFF6-$FFFD. Locations $FFF6-$FFFD contain userdefined data.
NOTE:
Do not leave locations $FFF6-$FFFD blank. For security reasons, program locations $FFF6-$FFFD even if they are not used for vectors.
During monitor mode entry, the MCU waits after the power-on reset for the host to send the eight security bytes on pin PTA0. If the received bytes match those at locations $FFF6-$FFFD, the host bypasses the security feature and can read all ROM locations and execute code from ROM. Security remains bypassed until a power-on reset occurs. If the reset was not a power-on reset, security remains bypassed and security code entry is not required. (See Figure 10-6.)
VDD 4096 + 32 CGMXCLK CYCLES RST 256 BUS CYCLES (MINIMUM) COMMAND 1 BYTE 2 ECHO BYTE 8 ECHO 2 4 1 COMMAND ECHO BREAK
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BYTE 1
BYTE 2
FROM HOST
PTA0 1 BYTE 1 ECHO FROM MCU 4 1
NOTES: 1 = Echo delay, 2 bit times 2 = Data return delay, 2 bit times 4 = Wait 1 bit time before sending next byte.
Figure 10-6. Monitor Mode Entry Timing
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BYTE 8
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Freescale Semiconductor, Inc. Monitor ROM (MON)
Upon power-on reset, if the received bytes of the security code do not match the data at locations $FFF6-$FFFD, the host fails to bypass the security feature. The MCU remains in monitor mode, but reading a ROM location returns an invalid value and trying to execute code from ROM causes an illegal address reset. After receiving the eight security bytes from the host, the MCU transmits a break character, signifying that it is ready to receive a command. To determine whether the security code entered is correct, check to see if bit 6 of RAM address $50 is set. If it is, then the correct security code has been entered and ROM can be accessed.
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NOTE:
The MCU does not transmit a break character until after the host sends the eight security bits.
If the host fails the security bypass as described in 10.5 Security, the MCU remains in monitor mode, but reading a ROM location returns an invalid value and trying to execute code from ROM causes an illegal address reset. The MCU monitor commands are still valid and user software can execute from RAM; accessing I/Os and EEPROM (see 10.6 EEPROM Security).
10.6 EEPROM Security
When the EEPROM security feature is set (EEMONSEC=1 in mask option register B), user software cannot access the EEPROM locations in monitor mode if security bypass had failed.
10.7 Extended Security
To further disable monitor mode functions, an extended security command keyword can be set at ROM locations $FFC0-$FFC7. The keyword is eight bytes long with a 7-byte ASCII string and 1-byte $00 delimiter. The keyword for the MC68HC08AB16A MCU is "PSWDOPT" + $00. Entry to monitor mode with extended security command keyword programmed, the MCU stops communicating with the host after transmitting a break character if the host fails the security bypass as described in 10.5 Security.
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Technical Data -- MC68HC08AB16A
Section 11. Timer Interface Module A (TIMA)
11.1 Contents
11.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
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11.3 11.4
11.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.5.1 TIMA Counter Prescaler. . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 11.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 11.5.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 167 11.5.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . 168 11.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 169 11.5.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 170 11.5.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 171 11.5.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 11.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
11.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 11.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 11.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 11.8 TIMA During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . 174
11.9 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 11.9.1 TIMA Clock Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 11.9.2 TIMA Channel I/O Pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 11.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 11.10.1 TIMA Status and Control Register . . . . . . . . . . . . . . . . . . . 176 11.10.2 TIMA Counter Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11.10.3 TIMA Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . 179 11.10.4 TIMA Channel Status and Control Registers . . . . . . . . . . . 180 11.10.5 TIMA Channel Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 184
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Freescale Semiconductor, Inc. Timer Interface Module A (TIMA) 11.2 Introduction
This section describes the timer interface module A (TIMA). The TIMA is a four-channel timer that provides a timing reference with input capture, output compare, and pulse-width-modulation functions. Figure 11-1 is a block diagram of the TIMA.
11.3 Features
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Features of the TIMA include the following: * Four input capture/output compare channels: - Rising-edge, falling-edge, or any-edge input capture trigger - Set, clear, or toggle output compare action * * Buffered and unbuffered pulse-width-modulation (PWM) signal generation Programmable TIMA clock input: - Seven-frequency internal bus clock prescaler selection - External TIMA clock input (4MHz maximum frequency) * * * * Free-running or modulo up-count operation Toggle any channel pin on overflow TIMA counter stop and reset bits Modular architecture expandable to eight channels
Technical Data
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Timer Interface Module A (TIMA) Pin Name Conventions
11.4 Pin Name Conventions
The TIMA share five I/O pins with port D, E, and F I/O pins. The full name of the TIMA I/O pin is listed in Table 11-1. The generic pin name appear in the text that follows. Table 11-1. Pin Name Conventions
TIMA Generic Pin Names: TACLK Full TIMA Pin Names: PTD6/TACLK PTE2/TACH0 PTE3/TACH1 PTF0/TACH2 PTF1/TACH3
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TACH0 TACH1 TACH2 TACH3
11.5 Functional Description
Figure 11-1 shows the structure of the TIMA. The central component of the TIMA is the 16-bit TIMA counter that can operate as a free-running counter or a modulo up-counter. The TIMA counter provides the timing reference for the input capture and output compare functions. The TIMA counter modulo registers, TAMODH:TAMODL, control the modulo value of the TIMA counter. Software can read the TIMA counter value at any time without affecting the counting sequence. The four TIMA channels are programmable independently as input capture or output compare channels.
11.5.1 TIMA Counter Prescaler The TIMA clock source can be one of the seven prescaler outputs or the TIMA clock pin, PTD6/TACLK. The prescaler generates seven clock rates from the internal bus clock. The prescaler select bits, PS[2:0], in the TIMA status and control register select the TIMA clock source.
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PTD6/TACLK INTERNAL BUS CLOCK TSTOP TRST 16-BIT COUNTER 16-BIT COMPARATOR PRESCALER SELECT PRESCALER
PS2
PS1
PS0
TOF TOIE
INTERRUPT LOGIC
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TAMODH:TAMODL TOV0 CHANNEL 0 16-BIT COMPARATOR TACH0H:TACH0L 16-BIT LATCH MS0A MS0B TOV1 INTERNAL BUS CHANNEL 1 16-BIT COMPARATOR TACH1H:TACH1L 16-BIT LATCH MS1A CH1IE TOV2 CHANNEL 2 16-BIT COMPARATOR TACH2H:TACH2L 16-BIT LATCH MS2A MS2B TOV3 CHANNEL 3 16-BIT COMPARATOR TACH3H:TACH3L 16-BIT LATCH MS3A CH3IE CH3F INTERRUPT LOGIC ELS3B ELS3A CH3MAX PTF1 LOGIC PTF1/TACH3 CH2IE CH2F INTERRUPT LOGIC ELS2B ELS2A CH2MAX PTF0 LOGIC PTF0/TACH2 CH1F INTERRUPT LOGIC ELS1B ELS1A CH1MAX PTE3 LOGIC PTE3/TACH1 CH0IE CH0F INTERRUPT LOGIC ELS0B ELS0A CH0MAX PTE2 LOGIC PTE2/TACH0
Figure 11-1. TIMA Block Diagram
Technical Data
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Timer Interface Module A (TIMA) Functional Description
Addr.
Register Name Read: Timer A Status and Control Register Write: (TASC) Reset: Read: Timer A Counter Register High Write: (TACNTH) Reset: Read: Timer A Counter Register Low Write: (TACNTL) Reset: Read: Timer A Counter Modulo Register High Write: (TAMODH) Reset: Read: Timer A Counter Modulo Register Low Write: (TAMODL) Reset:
Bit 7 TOF 0 0 Bit 15
6 TOIE 0 14
5 TSTOP 1 13
4 0 TRST 0 12
3 0
2 PS2 0 10
1 PS1 0 9
Bit 0 PS0 0 Bit 8
$0020
0 11
$0022
0 Bit 7
0 6
0 5
0 4
0 3
0 2
0 1
0 Bit 0
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$0023
0 Bit 15 1 Bit 7 1 CH0F 0 0 Bit 15
0 14 1 6 1 CH0IE 0 14
0 13 1 5 1 MS0B 0 13
0 12 1 4 1 MS0A 0 12
0 11 1 3 1 ELS0B 0 11
0 10 1 2 1 ELS0A 0 10
0 9 1 1 1 TOV0 0 9
0 Bit 8 1 Bit 0 1 CH0MAX 0 Bit 8
$0024
$0025
Read: Timer A Channel 0 Status $0026 and Control Register Write: (TASC0) Reset: Read: Timer A Channel 0 Register High Write: (TACH0H) Reset: Read: Timer A Channel 0 Register Low Write: (TACH0L) Reset:
$0027
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$0028
Indeterminate after reset CH1F 0 0 Bit 15 CH1IE 0 14 0 MS1A 0 12 ELS1B 0 11 ELS1A 0 10 TOV1 0 9 CH1MAX 0 Bit 8
Read: Timer A Channel 1 Status $0029 and Control Register Write: (TASC1) Reset: Read: Timer A Channel 1 Register High Write: (TACH1H) Reset:
0 13
$002A
Indeterminate after reset = Unimplemented
Figure 11-2. TIMA I/O Register Summary (Sheet 1 of 2)
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Addr.
Register Name Read: Timer A Channel 1 Register Low Write: (TACH1L) Reset:
Bit 7 Bit 7
6 6
5 5
4 4
3 3
2 2
1 1
Bit 0 Bit 0
$002B
Indeterminate after reset CH2F 0 0 Bit 15 CH2IE 0 14 MS2B 0 13 MS2A 0 12 ELS2B 0 11 ELS2A 0 10 TOV2 0 9 CH2MAX 0 Bit 8
Read: Timer A Channel 2 Status $002C and Control Register Write: (TASC2) Reset: Read: Timer A Channel 2 Register High Write: (TACH2H) Reset: Read: Timer A Channel 2 Register Low Write: (TACH2L) Reset:
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$002D
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$002E
Indeterminate after reset CH3F 0 0 Bit 15 CH3IE 0 14 0 MS3A 0 12 ELS3B 0 11 ELS3A 0 10 TOV3 0 9 CH3MAX 0 Bit 8
Read: Timer A Channel 3 Status $002F and Control Register Write: (TASC3) Reset: Read: Timer A Channel 3 Register High Write: (TACH3H) Reset: Read: Timer A Channel 3 Register Low Write: (TACH3L) Reset:
0 13
$0030
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$0031
Indeterminate after reset = Unimplemented
Figure 11-2. TIMA I/O Register Summary (Sheet 2 of 2) 11.5.2 Input Capture With the input capture function, the TIMA can capture the time at which an external event occurs. When an active edge occurs on the pin of an input capture channel, the TIMA latches the contents of the TIMA counter into the TIMA channel registers, TACHxH:TACHxL. The polarity of the active edge is programmable. Input captures can generate TIMA CPU interrupt requests.
Technical Data
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Timer Interface Module A (TIMA) Functional Description
11.5.3 Output Compare With the output compare function, the TIMA can generate a periodic pulse with a programmable polarity, duration, and frequency. When the counter reaches the value in the registers of an output compare channel, the TIMA can set, clear, or toggle the channel pin. Output compares can generate TIMA CPU interrupt requests.
11.5.3.1 Unbuffered Output Compare
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Any output compare channel can generate unbuffered output compare pulses as described in 11.5.3 Output Compare. The pulses are unbuffered because changing the output compare value requires writing the new value over the old value currently in the TIMA channel registers. An unsynchronized write to the TIMA channel registers to change an output compare value could cause incorrect operation for up to two counter overflow periods. For example, writing a new value before the counter reaches the old value but after the counter reaches the new value prevents any compare during that counter overflow period. Also, using a TIMA overflow interrupt routine to write a new, smaller output compare value may cause the compare to be missed. The TIMA may pass the new value before it is written. Use the following methods to synchronize unbuffered changes in the output compare value on channel x: * When changing to a smaller value, enable channel x output compare interrupts and write the new value in the output compare interrupt routine. The output compare interrupt occurs at the end of the current output compare pulse. The interrupt routine has until the end of the counter overflow period to write the new value. When changing to a larger output compare value, enable channel x TIMA overflow interrupts and write the new value in the TIMA overflow interrupt routine. The TIMA overflow interrupt occurs at the end of the current counter overflow period. Writing a larger value in an output compare interrupt routine (at the end of the current pulse) could cause two output compares to occur in the same counter overflow period.
*
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11.5.3.2 Buffered Output Compare
Channels 0 and 1 can be linked to form a buffered output compare channel whose output appears on the PTE2/TACH0 pin. The TIMA channel registers of the linked pair alternately control the output. Setting the MS0B bit in TIMA channel 0 status and control register (TASC0) links channel 0 and channel 1. The output compare value in the TIMA channel 0 registers initially controls the output on the PTE2/TACH0 pin. Writing to the TIMA channel 1 registers enables the TIMA channel 1 registers to synchronously control the output after the TIMA overflows. At each subsequent overflow, the TIMA channel registers (0 or 1) that control the output are the ones written to last. TASC0 controls and monitors the buffered output compare function, and TIMA channel 1 status and control register (TASC1) is unused. While the MS0B bit is set, the channel 1 pin, PTE3/TACH1, is available as a general-purpose I/O pin. Channels 2 and 3 can be linked to form a buffered output compare channel whose output appears on the PTF0/TACH2 pin. The TIMA channel registers of the linked pair alternately control the output. Setting the MS2B bit in TIMA channel 2 status and control register (TASC2) links channel 2 and channel 3. The output compare value in the TIMA channel 2 registers initially controls the output on the PTF0/TACH2 pin. Writing to the TIMA channel 3 registers enables the TIMA channel 3 registers to synchronously control the output after the TIMA overflows. At each subsequent overflow, the TIMA channel registers (2 or 3) that control the output are the ones written to last. TASC2 controls and monitors the buffered output compare function, and TIMA channel 3 status and control register (TASC3) is unused. While the MS2B bit is set, the channel 3 pin, PTF1/TACH3, is available as a general-purpose I/O pin.
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NOTE:
In buffered output compare operation, do not write new output compare values to the currently active channel registers. Writing to the active channel registers is the same as generating unbuffered output compares.
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Timer Interface Module A (TIMA) Functional Description
11.5.4 Pulse Width Modulation (PWM) By using the toggle-on-overflow feature with an output compare channel, the TIMA can generate a PWM signal. The value in the TIMA counter modulo registers determines the period of the PWM signal. The channel pin toggles when the counter reaches the value in the TIMA counter modulo registers. The time between overflows is the period of the PWM signal. As Figure 11-3 shows, the output compare value in the TIMA channel registers determines the pulse width of the PWM signal. The time between overflow and output compare is the pulse width. Program the TIMA to clear the channel pin on output compare if the state of the PWM pulse is logic one. Program the TIMA to set the pin if the state of the PWM pulse is logic zero.
OVERFLOW OVERFLOW OVERFLOW
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PERIOD
PULSE WIDTH TACHx
OUTPUT COMPARE
OUTPUT COMPARE
OUTPUT COMPARE
Figure 11-3PWM Period and Pulse Width The value in the TIMA counter modulo registers and the selected prescaler output determines the frequency of the PWM output. The frequency of an 8-bit PWM signal is variable in 256 increments. Writing $00FF (255) to the TIMA counter modulo registers produces a PWM period of 256 times the internal bus clock period if the prescaler select value is $000. See 11.10.1 TIMA Status and Control Register. The value in the TIMA channel registers determines the pulse width of the PWM output. The pulse width of an 8-bit PWM signal is variable in 256 increments. Writing $0080 (128) to the TIMA channel registers produces a duty cycle of 128/256 or 50%.
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11.5.4.1 Unbuffered PWM Signal Generation
Any output compare channel can generate unbuffered PWM pulses as described in 11.5.4 Pulse Width Modulation (PWM). The pulses are unbuffered because changing the pulse width requires writing the new pulse width value over the old value currently in the TIMA channel registers. An unsynchronized write to the TIMA channel registers to change a pulse width value could cause incorrect operation for up to two PWM periods. For example, writing a new value before the counter reaches the old value but after the counter reaches the new value prevents any compare during that PWM period. Also, using a TIMA overflow interrupt routine to write a new, smaller pulse width value may cause the compare to be missed. The TIMA may pass the new value before it is written. Use the following methods to synchronize unbuffered changes in the PWM pulse width on channel x: * When changing to a shorter pulse width, enable channel x output compare interrupts and write the new value in the output compare interrupt routine. The output compare interrupt occurs at the end of the current pulse. The interrupt routine has until the end of the PWM period to write the new value. When changing to a longer pulse width, enable channel x TIMA overflow interrupts and write the new value in the TIMA overflow interrupt routine. The TIMA overflow interrupt occurs at the end of the current PWM period. Writing a larger value in an output compare interrupt routine (at the end of the current pulse) could cause two output compares to occur in the same PWM period.
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*
NOTE:
In PWM signal generation, do not program the PWM channel to toggle on output compare. Toggling on output compare prevents reliable 0% duty cycle generation and removes the ability of the channel to selfcorrect in the event of software error or noise. Toggling on output compare also can cause incorrect PWM signal generation when changing the PWM pulse width to a new, much larger value.
Technical Data
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Timer Interface Module A (TIMA) Functional Description
11.5.4.2 Buffered PWM Signal Generation
Channels 0 and 1 can be linked to form a buffered PWM channel whose output appears on the PTE2/TACH0 pin. The TIMA channel registers of the linked pair alternately control the pulse width of the output. Setting the MS0B bit in TIMA channel 0 status and control register (TASC0) links channel 0 and channel 1. The TIMA channel 0 registers initially control the pulse width on the PTE2/TACH0 pin. Writing to the TIMA channel 1 registers enables the TIMA channel 1 registers to synchronously control the pulse width at the beginning of the next PWM period. At each subsequent overflow, the TIMA channel registers (0 or 1) that control the pulse width are the ones written to last. TASC0 controls and monitors the buffered PWM function, and TIMA channel 1 status and control register (TASC1) is unused. While the MS0B bit is set, the channel 1 pin, PTE3/TACH1, is available as a general-purpose I/O pin. Channels 2 and 3 can be linked to form a buffered PWM channel whose output appears on the PTF0/TACH2 pin. The TIMA channel registers of the linked pair alternately control the pulse width of the output. Setting the MS2B bit in TIMA channel 2 status and control register (TASC2) links channel 2 and channel 3. The TIMA channel 2 registers initially control the pulse width on the PTF0/TACH2 pin. Writing to the TIMA channel 3 registers enables the TIMA channel 3 registers to synchronously control the pulse width at the beginning of the next PWM period. At each subsequent overflow, the TIMA channel registers (2 or 3) that control the pulse width are the ones written to last. TASC2 controls and monitors the buffered PWM function, and TIMA channel 3 status and control register (TASC3) is unused. While the MS2B bit is set, the channel 3 pin, PTF1/TACH3, is available as a general-purpose I/O pin.
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NOTE:
In buffered PWM signal generation, do not write new pulse width values to the currently active channel registers. Writing to the active channel registers is the same as generating unbuffered PWM signals.
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11.5.4.3 PWM Initialization
To ensure correct operation when generating unbuffered or buffered PWM signals, use the following initialization procedure: 1. In the TIMA status and control register (TASC): a. Stop the TIMA counter by setting the TIMA stop bit, TSTOP. b. Reset the TIMA counter by setting the TIMA reset bit, TRST.
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2. In the TIMA counter modulo registers (TAMODH:TAMODL), write the value for the required PWM period. 3. In the TIMA channel x registers (TACHxH:TACHxL), write the value for the required pulse width. 4. In TIMA channel x status and control register (TASCx): a. Write 0:1 (for unbuffered output compare or PWM signals) or 1:0 (for buffered output compare or PWM signals) to the mode select bits, MSxB:MSxA. See Table 11-3. a. Write 1 to the toggle-on-overflow bit, TOVx. b. Write 1:0 (to clear output on compare) or 1:1 (to set output on compare) to the edge/level select bits, ELSxB:ELSxA. The output action on compare must force the output to the complement of the pulse width level. See Table 11-3.
NOTE:
In PWM signal generation, do not program the PWM channel to toggle on output compare. Toggling on output compare prevents reliable 0% duty cycle generation and removes the ability of the channel to selfcorrect in the event of software error or noise. Toggling on output compare can also cause incorrect PWM signal generation when changing the PWM pulse width to a new, much larger value.
5. In the TIMA status control register (TASC), clear the TIMA stop bit, TSTOP. Setting MS0B links channels 0 and 1 and configures them for buffered PWM operation. The TIMA channel 0 registers (TACH0H:TACH0L) initially control the buffered PWM output. TIMA channel 0 status and control register 0 (TASC0) controls and monitors the PWM signal from the linked channels. MS0B takes priority over MS0A.
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Timer Interface Module A (TIMA) Interrupts
Setting MS2B links channels 2 and 3 and configures them for buffered PWM operation. The TIMA channel 2 registers (TACH2H:TACH2L) initially control the PWM output. TIMA channel 2 status and control register (TASC2) controls and monitors the PWM signal from the linked channels. MS2B takes priority over MS2A. Clearing the toggle-on-overflow bit, TOVx, inhibits output toggles on TIMA overflows. Subsequent output compares try to force the output to a state it is already in and have no effect. The result is a 0% duty cycle output.
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Setting the channel x maximum duty cycle bit (CHxMAX) and clearing the TOVx bit generates a 100% duty cycle output. See 11.10.4 TIMA Channel Status and Control Registers.
11.6 Interrupts
The following TIMA sources can generate interrupt requests: * TIMA overflow flag (TOF) -- The TOF bit is set when the TIMA counter value rolls over to $0000 after matching the value in the TIMA counter modulo registers. The TIMA overflow interrupt enable bit, TOIE, enables TIMA overflow CPU interrupt requests. TOF and TOIE are in the TIMA status and control register. TIMA channel flags (CH3F-CH0F) -- The CHxF bit is set when an input capture or output compare occurs on channel x. Channel x TIM CPU interrupt requests are controlled by the channel x interrupt enable bit, CHxIE. Channel x TIM CPU interrupt requests are enabled when CHxIE= 1. CHxF and CHxIE are in the TIMA channel x status and control register.
*
11.7 Low-Power Modes
The WAIT and STOP instructions puts the MCU in low-powerconsumption standby modes.
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11.7.1 Wait Mode The TIMA remains active after the execution of a WAIT instruction. In wait mode the TIMA registers are not accessible by the CPU. Any enabled CPU interrupt request from the TIMA can bring the MCU out of wait mode. If TIMA functions are not required during wait mode, reduce power consumption by stopping the TIMA before executing the WAIT instruction.
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11.7.2 Stop Mode The TIMA is inactive after the execution of a STOP instruction. The STOP instruction does not affect register conditions or the state of the TIMA counter. TIMA operation resumes when the MCU exit stop mode after an external interrupt.
11.8 TIMA During Break Interrupts
A break interrupt stops the TIMA counter. The system integration module (SIM) controls whether status bits in other modules can be cleared during the break state. The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear status bits during the break state. See 8.8.3 SIM Break Flag Control Register. To allow software to clear status bits during a break interrupt, write a logic one to the BCFE bit. If a status bit is cleared during the break state, it remains cleared when the MCU exits the break state. To protect status bits during the break state, write a logic zero to the BCFE bit. With BCFE at logic zero (its default state), software can read and write I/O registers during the break state without affecting status bits. Some status bits have a two-step read/write clearing procedure. If software does the first step on such a bit before the break, the bit cannot change during the break state as long as BCFE is at logic zero. After the break, doing the second step clears the status bit.
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Timer Interface Module A (TIMA) I/O Signals
11.9 I/O Signals
Ports E and F each share two pins with the TIMA and port D shares one. PTD6/TACLK is an external clock input to the TIMA prescaler. The four TIMA channel I/O pins are PTE2/TACH0, PTE3/TACH1, PTF0/TACH2, and PTF1/TACH3.
11.9.1 TIMA Clock Pin
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PTD6/TACLK is an external clock input that can be the clock source for the TIMA counter instead of the prescaled internal bus clock. Select the PTD6/TACLK input by writing logic 1s to the three prescaler select bits, PS[2:0]. See 11.10.1 TIMA Status and Control Register. The minimum TACLK pulse width, TACLKLMIN or TACLKHMIN, is: 1 ------------------------------------ + t SU bus frequency The maximum TACLK frequency is: bus frequency / 2 PTD6/TACLK is available as a general-purpose I/O pin when not used as the TIMA clock input. When the PTD6/TACLK pin is the TIMA clock input, it is an input regardless of the state of the DDRD6 bit in data direction register D.
11.9.2 TIMA Channel I/O Pins Each channel I/O pin is programmable independently as an input capture pin or an output compare pin. PTF0/TACH2 and PTE3/TACH1 can be configured as buffered output compare or buffered PWM pins.
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The following I/O registers control and monitor operation of the TIMA: * * * * TIMA status and control register (TASC) TIMA counter registers (TACNTH:TACNTL) TIMA counter modulo registers (TAMODH:TAMODL) TIMA channel status and control registers (TASC0, TASC1, TASC2, and TASC3) TIMA channel registers (TACH0H:TACH0L, TACH1H:TACH1L, TACH2H:TACH2L, and TACH3H:TACH3L)
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*
11.10.1 TIMA Status and Control Register The TIMA status and control register does the following: * * * * *
Address:
Enables TIMA overflow interrupts Flags TIMA overflows Stops the TIMA counter Resets the TIMA counter Prescales the TIMA counter clock
$0020 Bit 7 6 TOIE 5 TSTOP TRST 0 1 0 0 0 0 0 4 0 3 0 PS2 PS1 PS0 2 1 Bit 0
Read: Write: Reset:
TOF 0 0
= Unimplemented
Figure 11-4. TIMA Status and Control Register (TASC)
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Timer Interface Module A (TIMA) I/O Registers
TOF -- TIMA Overflow Flag Bit This read/write flag is set when the TIMA counter resets to $0000 after reaching the modulo value programmed in the TIMA counter modulo registers. Clear TOF by reading the TIMA status and control register when TOF is set and then writing a logic zero to TOF. If another TIMA overflow occurs before the clearing sequence is complete, then writing logic zero to TOF has no effect. Therefore, a TOF interrupt request cannot be lost due to inadvertent clearing of TOF. Reset clears the TOF bit. Writing a logic one to TOF has no effect. 1 = TIMA counter has reached modulo value 0 = TIMA counter has not reached modulo value TOIE -- TIMA Overflow Interrupt Enable Bit This read/write bit enables TIMA overflow interrupts when the TOF bit becomes set. Reset clears the TOIE bit. 1 = TIMA overflow interrupts enabled 0 = TIMA overflow interrupts disabled TSTOP -- TIMA Stop Bit This read/write bit stops the TIMA counter. Counting resumes when TSTOP is cleared. Reset sets the TSTOP bit, stopping the TIMA counter until software clears the TSTOP bit. 1 = TIMA counter stopped 0 = TIMA counter active
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NOTE:
Do not set the TSTOP bit before entering wait mode if the TIMA is required to exit wait mode.
TRST -- TIMA Reset Bit Setting this write-only bit resets the TIMA counter and the TIMA prescaler. Setting TRST has no effect on any other registers. Counting resumes from $0000. TRST is cleared automatically after the TIMA counter is reset and always reads as logic zero. Reset clears the TRST bit. 1 = Prescaler and TIMA counter cleared 0 = No effect
NOTE:
Setting the TSTOP and TRST bits simultaneously stops the TIMA counter at a value of $0000.
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PS[2:0] -- Prescaler Select Bits These read/write bits select either the PTD6/TACLK pin or one of the seven prescaler outputs as the input to the TIMA counter as Table 11-2 shows. Reset clears the PS[2:0] bits. Table 11-2. Prescaler Selection
PS2 0 0 PS1 0 0 1 1 0 0 1 1 PS0 0 1 0 1 0 1 0 1 TIM Clock Source Internal Bus Clock /1 Internal Bus Clock / 2 Internal Bus Clock / 4 Internal Bus Clock / 8 Internal Bus Clock / 16 Internal Bus Clock / 32 Internal Bus Clock / 64 PTD6/TACLK
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0 0 1 1 1 1
11.10.2 TIMA Counter Registers The two read-only TIMA counter registers contain the high and low bytes of the value in the TIMA counter. Reading the high byte (TACNTH) latches the contents of the low byte (TACNTL) into a buffer. Subsequent reads of TACNTH do not affect the latched TACNTL value until TACNTL is read. Reset clears the TIMA counter registers. Setting the TIMA reset bit (TRST) also clears the TIMA counter registers.
NOTE:
If you read TACNTH during a break interrupt, be sure to unlatch TACNTL by reading TACNTL before exiting the break interrupt. Otherwise, TACNTL retains the value latched during the break.
Address: $0022 Bit 7 Read: Write: Reset: 0 0 0 0 0 0 0 0 Bit 15 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
= Unimplemented
Figure 11-5. TIMA Counter Register High (TACNTH)
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Timer Interface Module A (TIMA) I/O Registers
Address:
$0023 Bit 7 6 6 5 5 4 4 3 3 2 2 1 1 Bit 0 Bit 0
Read: Write: Reset:
Bit 7
0
0
0
0
0
0
0
0
= Unimplemented
Figure 11-6. TIMA Counter Register Low (TACNTL)
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11.10.3 TIMA Counter Modulo Registers The read/write TIMA modulo registers contain the modulo value for the TIMA counter. When the TIMA counter reaches the modulo value, the overflow flag (TOF) becomes set, and the TIMA counter resumes counting from $0000 at the next clock. Writing to the high byte (TAMODH) inhibits the TOF bit and overflow interrupts until the low byte (TAMODL) is written. Reset sets the TIMA counter modulo registers.
Address: $0024 Bit 7 Read: Bit 15 Write: Reset: 1 1 1 1 1 1 1 1 14 13 12 11 10 9 Bit 8 6 5 4 3 2 1 Bit 0
Figure 11-7. TIMA Counter Modulo Register High (TAMODH)
Address: $0025 Bit 7 Read: Bit 7 Write: Reset: 1 1 1 1 1 1 1 1 6 5 4 3 2 1 Bit 0 6 5 4 3 2 1 Bit 0
Figure 11-8. TIMA Counter Modulo Register Low (TAMODL)
NOTE:
Reset the TIMA counter before writing to the TIMA counter modulo registers.
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11.10.4 TIMA Channel Status and Control Registers Each of the TIMA channel status and control registers does the following: * * * * Flags input captures and output compares Enables input capture and output compare interrupts Selects input capture, output compare, or PWM operation Selects high, low, or toggling output on output compare Selects rising edge, falling edge, or any edge as the active input capture trigger Selects output toggling on TIMA overflow Selects 100% PWM duty cycle Selects buffered or unbuffered output compare/PWM operation
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* * * *
Address:
$0026 Bit 7 6 CH0IE 5 MS0B 0 4 MS0A 0 3 ELS0B 0 2 ELS0A 0 1 TOV0 0 Bit 0 CH0MAX 0
Read: Write: Reset:
CH0F 0 0 0
Figure 11-9. TIMA Channel 0 Status and Control Register (TASC0)
Address: $0029 Bit 7 Read: Write: Reset: CH1F CH1IE 0 0 0 0 0 0 0 0 0 6 5 0 MS1A ELS1B ELS1A TOV1 CH1MAX 4 3 2 1 Bit 0
Figure 11-10. TIMA Channel 1 Status and Control Register (TASC1)
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Timer Interface Module A (TIMA) I/O Registers
Address:
$002C Bit 7 6 CH2IE 5 MS2B 0 4 MS2A 0 3 ELS2B 0 2 ELS2A 0 1 TOV2 0 Bit 0 CH2MAX 0
Read: Write: Reset:
CH2F 0 0 0
Figure 11-11. TIMA Channel 2 Status and Control Register (TASC2)
Address: $002F Bit 7 Read: Write: Reset: CH3F CH3IE 0 0 0 0 0 0 0 0 0 6 5 0 MS3A ELS3B ELS3A TOV3 CH3MAX 4 3 2 1 Bit 0
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Figure 11-12. TIMA Channel 3 Status and Control Register (TASC3) CHxF -- Channel x Flag Bit When channel x is an input capture channel, this read/write bit is set when an active edge occurs on the channel x pin. When channel x is an output compare channel, CHxF is set when the value in the TIMA counter registers matches the value in the TIMA channel x registers. When TIM CPU interrupt requests are enabled (CHxIE = 1), clear CHxF by reading TIMA channel x status and control register with CHxF set and then writing a logic zero to CHxF. If another interrupt request occurs before the clearing sequence is complete, then writing logic zero to CHxF has no effect. Therefore, an interrupt request cannot be lost due to inadvertent clearing of CHxF. Reset clears the CHxF bit. Writing a logic one to CHxF has no effect. 1 = Input capture or output compare on channel x 0 = No input capture or output compare on channel x CHxIE -- Channel x Interrupt Enable Bit This read/write bit enables TIMA CPU interrupts on channel x. Reset clears the CHxIE bit. 1 = Channel x CPU interrupt requests enabled 0 = Channel x CPU interrupt requests disabled
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MSxB -- Mode Select Bit B This read/write bit selects buffered output compare/PWM operation. MSxB exists only in the TIMA channel 0 and TIMA channel 2 status and control registers. Setting MS0B disables the channel 1 status and control register and reverts TCH1B to general-purpose I/O. Setting MS2B disables the channel 3 status and control register and reverts TCH3B to general-purpose I/O.
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Reset clears the MSxB bit. 1 = Buffered output compare/PWM operation enabled 0 = Buffered output compare/PWM operation disabled MSxA -- Mode Select Bit A When ELSxB:A 00, this read/write bit selects either input capture operation or unbuffered output compare/PWM operation. See Table 11-3. 1 = Unbuffered output compare/PWM operation 0 = Input capture operation When ELSxB:A = 00, this read/write bit selects the initial output level of the TBCHx pin. See Table 11-3. Reset clears the MSxA bit. 1 = Initial output level low 0 = Initial output level high
NOTE:
Before changing a channel function by writing to the MSxB or MSxA bit, set the TSTOP and TRST bits in the TIMA status and control register (TASC).
ELSxB and ELSxA -- Edge/Level Select Bits When channel x is an input capture channel, these read/write bits control the active edge-sensing logic on channel x. When channel x is an output compare channel, ELSxB and ELSxA control the channel x output behavior when an output compare occurs. When ELSxB and ELSxA are both clear, channel x is not connected to the port I/O, and pin TACHx is available as a general-purpose I/O pin. Table 11-3 shows how ELSxB and ELSxA work. Reset clears the ELSxB and ELSxA bits.
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Timer Interface Module A (TIMA) I/O Registers
Table 11-3. Mode, Edge, and Level Selection
MSxB
X X 0 0 0
MSxA
0 1 0 0 0 1 1 1 X X X
ELSxB
0 0 0 1 1 0 1 1 0 1 1
ELSxA
0
Mode
Output Preset
Configuration
Pin under Port Control; Initial Output Level High Pin under Port Control; Initial Output Level Low Capture on Rising Edge Only
0 1 0 1 1 0 1 1 0 1 Output Compare or PWM Input Capture
Capture on Falling Edge Only Capture on Rising or Falling Edge Toggle Output on Compare Clear Output on Compare Set Output on Compare
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0 0 0 1 1 1
Toggle Output on Compare Buffered Output Clear Output on Compare Compare or Buffered Set Output on Compare PWM
NOTE:
Before enabling a TIMA channel register for input capture operation, make sure that the TACHx pin is stable for at least two bus clocks.
TOVx -- Toggle-On-Overflow Bit When channel x is an output compare channel, this read/write bit controls the behavior of the channel x output when the TIMA counter overflows. When channel x is an input capture channel, TOVx has no effect. Reset clears the TOVx bit. 1 = Channel x pin toggles on TIMA counter overflow. 0 = Channel x pin does not toggle on TIMA counter overflow.
NOTE:
When TOVx is set, a TIMA counter overflow takes precedence over a channel x output compare if both occur at the same time.
CHxMAX -- Channel x Maximum Duty Cycle Bit When the TOVx bit is at logic zero, setting the CHxMAX bit forces the duty cycle of buffered and unbuffered PWM signals to 100%. As Figure 11-13 shows, the CHxMAX bit takes effect in the cycle after it is set or cleared. The output stays at the 100% duty cycle level until the cycle after CHxMAX is cleared.
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OVERFLOW PERIOD OVERFLOW OVERFLOW OVERFLOW OVERFLOW
TACHx
OUTPUT COMPARE CHxMAX
OUTPUT COMPARE
OUTPUT COMPARE
OUTPUT COMPARE
Figure 11-13. CHxMAX Latency
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11.10.5 TIMA Channel Registers These read/write registers contain the captured TIMA counter value of the input capture function or the output compare value of the output compare function. The state of the TIMA channel registers after reset is unknown. In input capture mode (MSxB:MSxA = 0:0), reading the high byte of the TIMA channel x registers (TACHxH) inhibits input captures until the low byte (TACHxL) is read. In output compare mode (MSxB:MSxA 0:0), writing to the high byte of the TIMA channel x registers (TACHxH) inhibits output compares until the low byte (TACHxL) is written.
Address: $0027 Bit 7 Read: Bit 15 Write: Reset: Indeterminate after reset 14 13 12 11 10 9 Bit 8 6 5 4 3 2 1 Bit 0
Figure 11-14. TIMA Channel 0 Register High (TACH0H)
Address: $0028 Bit 7 Read: Bit 7 Write: Reset: Indeterminate after reset 6 5 4 3 2 1 Bit 0 6 5 4 3 2 1 Bit 0
Figure 11-15. TIMA Channel 0 Register Low (TACH0L)
Technical Data MC68HC08AB16A -- Rev. 2.0 Timer Interface Module A (TIMA) For More Information On This Product, Go to: www.freescale.com MOTOROLA
184
Freescale Semiconductor, Inc.
Timer Interface Module A (TIMA) I/O Registers
Address:
$002A Bit 7 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
Read: Bit 15 Write: Reset: Indeterminate after reset
Figure 11-16. TIMA Channel 1 Register High (TACH1H)
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Address:
$002B Bit 7 6 6 5 5 4 4 3 3 2 2 1 1 Bit 0 Bit 0
Read: Bit 7 Write: Reset: Indeterminate after reset
Figure 11-17. TIMA Channel 1 Register Low (TACH1L)
Address:
$002D Bit 7 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
Read: Bit 15 Write: Reset: Indeterminate after reset
Figure 11-18. TIMA Channel 2 Register High (TACH2H)
Address: $002E Bit 7 Read: Bit 7 Write: Reset: Indeterminate after reset 6 5 4 3 2 1 Bit 0 6 5 4 3 2 1 Bit 0
Figure 11-19. TIMA Channel 2 Register Low (TACH2L)
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Address:
$0030 Bit 7 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
Read: Bit 15 Write: Reset: Indeterminate after reset
Figure 11-20. TIMA Channel 3 Register High (TACH3H)
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Address:
$0031 Bit 7 6 6 5 5 4 4 3 3 2 2 1 1 Bit 0 Bit 0
Read: Bit 7 Write: Reset: Indeterminate after reset
Figure 11-21. TIMA Channel 3 Register Low (TACH3L)
Technical Data
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Technical Data -- MC68HC08AB16A
Section 12. Timer Interface Module B (TIMB)
12.1 Contents
12.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
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12.3 12.4
12.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 12.5.1 TIMB Counter Prescaler. . . . . . . . . . . . . . . . . . . . . . . . . . . 189 12.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 12.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 12.5.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 193 12.5.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . 194 12.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 195 12.5.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 196 12.5.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 197 12.5.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 12.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
12.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 12.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 12.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 12.8 TIMB During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . 200
12.9 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 12.9.1 TIMB Clock Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 12.9.2 TIMB Channel I/O Pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 12.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 12.10.1 TIMB Status and Control Register . . . . . . . . . . . . . . . . . . . 202 12.10.2 TIMB Counter Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . 204 12.10.3 TIMB Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . 205 12.10.4 TIMB Channel Status and Control Registers . . . . . . . . . . . 206 12.10.5 TIMB Channel Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 210
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Timer Interface Module B (TIMB) For More Information On This Product, Go to: www.freescale.com Technical Data
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Freescale Semiconductor, Inc. Timer Interface Module B (TIMB) 12.2 Introduction
This section describes the timer interface module A (TIMB). The TIMB is a four-channel timer that provides a timing reference with input capture, output compare, and pulse-width-modulation functions. Figure 12-1 is a block diagram of the TIMB.
12.3 Features
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Features of the TIMB include the following: * Four input capture/output compare channels: - Rising-edge, falling-edge, or any-edge input capture trigger - Set, clear, or toggle output compare action * * Buffered and unbuffered pulse-width-modulation (PWM) signal generation Programmable TIMB clock input: - Seven-frequency internal bus clock prescaler selection - External TIMB clock input (4MHz maximum frequency) * * * * Free-running or modulo up-count operation Toggle any channel pin on overflow TIMB counter stop and reset bits Modular architecture expandable to eight channels
Technical Data
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Timer Interface Module B (TIMB) Pin Name Conventions
12.4 Pin Name Conventions
The TIMB share five I/O pins with port D and F I/O pins. The full name of the TIMB I/O pin is listed in Table 12-1. The generic pin name appear in the text that follows. Table 12-1. Pin Name Conventions
TIMB Generic Pin Names: TBCLK Full TIMB Pin Names: PTD4/TBCLK PTF4/TBCH0 PTF5/TBCH1 PTF2/TBCH2 PTF3/TBCH3
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TBCH0 TBCH1 TBCH2 TBCH3
12.5 Functional Description
Figure 12-1 shows the structure of the TIMB. The central component of the TIMB is the 16-bit TIMB counter that can operate as a free-running counter or a modulo up-counter. The TIMB counter provides the timing reference for the input capture and output compare functions. The TIMB counter modulo registers, TBMODH:TBMODL, control the modulo value of the TIMB counter. Software can read the TIMB counter value at any time without affecting the counting sequence. The four TIMB channels are programmable independently as input capture or output compare channels.
12.5.1 TIMB Counter Prescaler The TIMB clock source can be one of the seven prescaler outputs or the TIMB clock pin, PTD4/TBCLK. The prescaler generates seven clock rates from the internal bus clock. The prescaler select bits, PS[2:0], in the TIMB status and control register select the TIMB clock source.
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PTD4/TBCLK INTERNAL BUS CLOCK TSTOP TRST 16-BIT COUNTER 16-BIT COMPARATOR PRESCALER SELECT PRESCALER
PS2
PS1
PS0
TOF TOIE
INTERRUPT LOGIC
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TBMODH:TBMODL TOV0 CHANNEL 0 16-BIT COMPARATOR TBCH0H:TBCH0L 16-BIT LATCH MS0A MS0B TOV1 INTERNAL BUS CHANNEL 1 16-BIT COMPARATOR TBCH1H:TBCH1L 16-BIT LATCH MS1A CH1IE TOV2 CHANNEL 2 16-BIT COMPARATOR TBCH2H:TBCH2L 16-BIT LATCH MS2A MS2B TOV3 CHANNEL 3 16-BIT COMPARATOR TBCH3H:TBCH3L 16-BIT LATCH MS3A CH3IE CH3F INTERRUPT LOGIC ELS3B ELS3A CH3MAX PTF3 LOGIC PTF3/TBCH3 CH2IE CH2F INTERRUPT LOGIC ELS2B ELS2A CH2MAX PTF2 LOGIC PTF2/TBCH2T CH1F INTERRUPT LOGIC ELS1B ELS1A CH1MAX PTF5 LOGIC PTF5/TBCH1 CH0IE CH0F INTERRUPT LOGIC ELS0B ELS0A CH0MAX PTF4 LOGIC PTF4/TBCH0
Figure 12-1. TIMB Block Diagram
Technical Data
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Timer Interface Module B (TIMB) Functional Description
Addr.
Register Name Read: Timer B Status and Control Register Write: (TBSC) Reset: Read: Timer B Counter Register High Write: (TBCNTH) Reset: Read: Timer B Counter Register Low Write: (TBCNTL) Reset: Read: Timer B Counter Modulo Register High Write: (TBMODH) Reset: Read: Timer B Counter Modulo Register Low Write: (TBMODL) Reset:
Bit 7 TOF 0 0 Bit 15
6 TOIE 0 14
5 TSTOP 1 13
4 0 TRST 0 12
3 0
2 PS2 0 10
1 PS1 0 9
Bit 0 PS0 0 Bit 8
$0040
0 11
$0041
0 Bit 7
0 6
0 5
0 4
0 3
0 2
0 1
0 Bit 0
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$0042
0 Bit 15 1 Bit 7 1 CH0F 0 0 Bit 15
0 14 1 6 1 CH0IE 0 14
0 13 1 5 1 MS0B 0 13
0 12 1 4 1 MS0A 0 12
0 11 1 3 1 ELS0B 0 11
0 10 1 2 1 ELS0A 0 10
0 9 1 1 1 TOV0 0 9
0 Bit 8 1 Bit 0 1 CH0MAX 0 Bit 8
$0043
$0044
Read: Timer B Channel 0 Status $0045 and Control Register Write: (TBSC0) Reset: Read: Timer B Channel 0 Register High Write: (TBCH0H) Reset: Read: Timer B Channel 0 Register Low Write: (TBCH0L) Reset:
$0046
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$0047
Indeterminate after reset CH1F 0 0 Bit 15 CH1IE 0 14 0 MS1A 0 12 ELS1B 0 11 ELS1A 0 10 TOV1 0 9 CH1MAX 0 Bit 8
Read: Timer B Channel 1 Status $0048 and Control Register Write: (TBSC1) Reset: Read: Timer B Channel 1 Register High Write: (TBCH1H) Reset:
0 13
$0049
Indeterminate after reset = Unimplemented
Figure 12-2. TIMB I/O Register Summary (Sheet 1 of 2)
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Freescale Semiconductor, Inc. Timer Interface Module B (TIMB)
Addr.
Register Name Read: Timer B Channel 1 Register Low Write: (TBCH1L) Reset:
Bit 7 Bit 7
6 6
5 5
4 4
3 3
2 2
1 1
Bit 0 Bit 0
$004A
Indeterminate after reset CH2F 0 0 Bit 15 CH2IE 0 14 MS2B 0 13 MS2A 0 12 ELS2B 0 11 ELS2A 0 10 TOV2 0 9 CH2MAX 0 Bit 8
Read: Timer B Channel 2 Status $0032 and Control Register Write: (TBSC2) Reset: Read: Timer B Channel 2 Register High Write: (TBCH2H) Reset: Read: Timer B Channel 2 Register Low Write: (TBCH2L) Reset:
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$0033
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$0034
Indeterminate after reset CH3F 0 0 Bit 15 CH3IE 0 14 0 MS3A 0 12 ELS3B 0 11 ELS3A 0 10 TOV3 0 9 CH3MAX 0 Bit 8
Read: Timer B Channel 3 Status $0035 and Control Register Write: (TBSC3) Reset: Read: Timer B Channel 3 Register High Write: (TBCH3H) Reset: Read: Timer B Channel 3 Register Low Write: (TBCH3L) Reset:
0 13
$0036
Indeterminate after reset Bit 7 6 5 4 3 2 1 Bit 0
$0037
Indeterminate after reset = Unimplemented
Figure 12-2. TIMB I/O Register Summary (Sheet 2 of 2) 12.5.2 Input Capture With the input capture function, the TIMB can capture the time at which an external event occurs. When an active edge occurs on the pin of an input capture channel, the TIMB latches the contents of the TIMB counter into the TIMB channel registers, TBCHxH:TBCHxL. The polarity of the active edge is programmable. Input captures can generate TIMB CPU interrupt requests.
Technical Data
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Freescale Semiconductor, Inc.
Timer Interface Module B (TIMB) Functional Description
12.5.3 Output Compare With the output compare function, the TIMB can generate a periodic pulse with a programmable polarity, duration, and frequency. When the counter reaches the value in the registers of an output compare channel, the TIMB can set, clear, or toggle the channel pin. Output compares can generate TIMB CPU interrupt requests.
12.5.3.1 Unbuffered Output Compare
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Any output compare channel can generate unbuffered output compare pulses as described in 12.5.3 Output Compare. The pulses are unbuffered because changing the output compare value requires writing the new value over the old value currently in the TIMB channel registers. An unsynchronized write to the TIMB channel registers to change an output compare value could cause incorrect operation for up to two counter overflow periods. For example, writing a new value before the counter reaches the old value but after the counter reaches the new value prevents any compare during that counter overflow period. Also, using a TIMB overflow interrupt routine to write a new, smaller output compare value may cause the compare to be missed. The TIMB may pass the new value before it is written. Use the following methods to synchronize unbuffered changes in the output compare value on channel x: * When changing to a smaller value, enable channel x output compare interrupts and write the new value in the output compare interrupt routine. The output compare interrupt occurs at the end of the current output compare pulse. The interrupt routine has until the end of the counter overflow period to write the new value. When changing to a larger output compare value, enable channel x TIMB overflow interrupts and write the new value in the TIMB overflow interrupt routine. The TIMB overflow interrupt occurs at the end of the current counter overflow period. Writing a larger value in an output compare interrupt routine (at the end of the current pulse) could cause two output compares to occur in the same counter overflow period.
*
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12.5.3.2 Buffered Output Compare
Channels 0 and 1 can be linked to form a buffered output compare channel whose output appears on the PTF4/TBCH0 pin. The TIMB channel registers of the linked pair alternately control the output. Setting the MS0B bit in TIMB channel 0 status and control register (TBSC0) links channel 0 and channel 1. The output compare value in the TIMB channel 0 registers initially controls the output on the PTF4/TBCH0 pin. Writing to the TIMB channel 1 registers enables the TIMB channel 1 registers to synchronously control the output after the TIMB overflows. At each subsequent overflow, the TIMB channel registers (0 or 1) that control the output are the ones written to last. TBSC0 controls and monitors the buffered output compare function, and TIMB channel 1 status and control register (TBSC1) is unused. While the MS0B bit is set, the channel 1 pin, PTF5/TBCH1, is available as a general-purpose I/O pin. Channels 2 and 3 can be linked to form a buffered output compare channel whose output appears on the PTF2/TBCH2 pin. The TIMB channel registers of the linked pair alternately control the output. Setting the MS2B bit in TIMB channel 2 status and control register (TBSC2) links channel 2 and channel 3. The output compare value in the TIMB channel 2 registers initially controls the output on the PTF2/TBCH2 pin. Writing to the TIMB channel 3 registers enables the TIMB channel 3 registers to synchronously control the output after the TIMB overflows. At each subsequent overflow, the TIMB channel registers (2 or 3) that control the output are the ones written to last. TBSC2 controls and monitors the buffered output compare function, and TIMB channel 3 status and control register (TBSC3) is unused. While the MS2B bit is set, the channel 3 pin, PTF3/TBCH3, is available as a general-purpose I/O pin.
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NOTE:
In buffered output compare operation, do not write new output compare values to the currently active channel registers. Writing to the active channel registers is the same as generating unbuffered output compares.
Technical Data
MC68HC08AB16A -- Rev. 2.0 Timer Interface Module B (TIMB) For More Information On This Product, Go to: www.freescale.com MOTOROLA
194
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Timer Interface Module B (TIMB) Functional Description
12.5.4 Pulse Width Modulation (PWM) By using the toggle-on-overflow feature with an output compare channel, the TIMB can generate a PWM signal. The value in the TIMB counter modulo registers determines the period of the PWM signal. The channel pin toggles when the counter reaches the value in the TIMB counter modulo registers. The time between overflows is the period of the PWM signal. As Figure 12-3 shows, the output compare value in the TIMB channel registers determines the pulse width of the PWM signal. The time between overflow and output compare is the pulse width. Program the TIMB to clear the channel pin on output compare if the state of the PWM pulse is logic one. Program the TIMB to set the pin if the state of the PWM pulse is logic zero.
OVERFLOW OVERFLOW OVERFLOW
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PERIOD
PULSE WIDTH TBCHx
OUTPUT COMPARE
OUTPUT COMPARE
OUTPUT COMPARE
Figure 12-3PWM Period and Pulse Width The value in the TIMB counter modulo registers and the selected prescaler output determines the frequency of the PWM output. The frequency of an 8-bit PWM signal is variable in 256 increments. Writing $00FF (255) to the TIMB counter modulo registers produces a PWM period of 256 times the internal bus clock period if the prescaler select value is $000. See 12.10.1 TIMB Status and Control Register. The value in the TIMB channel registers determines the pulse width of the PWM output. The pulse width of an 8-bit PWM signal is variable in 256 increments. Writing $0080 (128) to the TIMB channel registers produces a duty cycle of 128/256 or 50%.
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12.5.4.1 Unbuffered PWM Signal Generation
Any output compare channel can generate unbuffered PWM pulses as described in 12.5.4 Pulse Width Modulation (PWM). The pulses are unbuffered because changing the pulse width requires writing the new pulse width value over the old value currently in the TIMB channel registers. An unsynchronized write to the TIMB channel registers to change a pulse width value could cause incorrect operation for up to two PWM periods. For example, writing a new value before the counter reaches the old value but after the counter reaches the new value prevents any compare during that PWM period. Also, using a TIMB overflow interrupt routine to write a new, smaller pulse width value may cause the compare to be missed. The TIMB may pass the new value before it is written. Use the following methods to synchronize unbuffered changes in the PWM pulse width on channel x: * When changing to a shorter pulse width, enable channel x output compare interrupts and write the new value in the output compare interrupt routine. The output compare interrupt occurs at the end of the current pulse. The interrupt routine has until the end of the PWM period to write the new value. When changing to a longer pulse width, enable channel x TIMB overflow interrupts and write the new value in the TIMB overflow interrupt routine. The TIMB overflow interrupt occurs at the end of the current PWM period. Writing a larger value in an output compare interrupt routine (at the end of the current pulse) could cause two output compares to occur in the same PWM period.
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*
NOTE:
In PWM signal generation, do not program the PWM channel to toggle on output compare. Toggling on output compare prevents reliable 0% duty cycle generation and removes the ability of the channel to selfcorrect in the event of software error or noise. Toggling on output compare also can cause incorrect PWM signal generation when changing the PWM pulse width to a new, much larger value.
Technical Data
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196
Freescale Semiconductor, Inc.
Timer Interface Module B (TIMB) Functional Description
12.5.4.2 Buffered PWM Signal Generation
Channels 0 and 1 can be linked to form a buffered PWM channel whose output appears on the PTF4/TBCH0 pin. The TIMB channel registers of the linked pair alternately control the pulse width of the output. Setting the MS0B bit in TIMB channel 0 status and control register (TBSC0) links channel 0 and channel 1. The TIMB channel 0 registers initially control the pulse width on the PTF4/TBCH0 pin. Writing to the TIMB channel 1 registers enables the TIMB channel 1 registers to synchronously control the pulse width at the beginning of the next PWM period. At each subsequent overflow, the TIMB channel registers (0 or 1) that control the pulse width are the ones written to last. TBSC0 controls and monitors the buffered PWM function, and TIMB channel 1 status and control register (TBSC1) is unused. While the MS0B bit is set, the channel 1 pin, PTF5/TBCH1, is available as a general-purpose I/O pin. Channels 2 and 3 can be linked to form a buffered PWM channel whose output appears on the PTF2/TBCH2 pin. The TIMB channel registers of the linked pair alternately control the pulse width of the output. Setting the MS2B bit in TIMB channel 2 status and control register (TBSC2) links channel 2 and channel 3. The TIMB channel 2 registers initially control the pulse width on the PTF2/TBCH2 pin. Writing to the TIMB channel 3 registers enables the TIMB channel 3 registers to synchronously control the pulse width at the beginning of the next PWM period. At each subsequent overflow, the TIMB channel registers (2 or 3) that control the pulse width are the ones written to last. TBSC2 controls and monitors the buffered PWM function, and TIMB channel 3 status and control register (TBSC3) is unused. While the MS2B bit is set, the channel 3 pin, PTF3/TBCH3, is available as a general-purpose I/O pin.
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NOTE:
In buffered PWM signal generation, do not write new pulse width values to the currently active channel registers. Writing to the active channel registers is the same as generating unbuffered PWM signals.
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Freescale Semiconductor, Inc. Timer Interface Module B (TIMB)
12.5.4.3 PWM Initialization
To ensure correct operation when generating unbuffered or buffered PWM signals, use the following initialization procedure: 1. In the TIMB status and control register (TBSC): a. Stop the TIMB counter by setting the TIMB stop bit, TSTOP. b. Reset the TIMB counter by setting the TIMB reset bit, TRST.
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2. In the TIMB counter modulo registers (TBMODH:TBMODL), write the value for the required PWM period. 3. In the TIMB channel x registers (TBCHxH:TBCHxL), write the value for the required pulse width. 4. In TIMB channel x status and control register (TBSCx): a. Write 0:1 (for unbuffered output compare or PWM signals) or 1:0 (for buffered output compare or PWM signals) to the mode select bits, MSxB:MSxA. See Table 12-3. a. Write 1 to the toggle-on-overflow bit, TOVx. b. Write 1:0 (to clear output on compare) or 1:1 (to set output on compare) to the edge/level select bits, ELSxB:ELSxA. The output action on compare must force the output to the complement of the pulse width level. See Table 12-3.
NOTE:
In PWM signal generation, do not program the PWM channel to toggle on output compare. Toggling on output compare prevents reliable 0% duty cycle generation and removes the ability of the channel to selfcorrect in the event of software error or noise. Toggling on output compare can also cause incorrect PWM signal generation when changing the PWM pulse width to a new, much larger value.
5. In the TIMB status control register (TBSC), clear the TIMB stop bit, TSTOP. Setting MS0B links channels 0 and 1 and configures them for buffered PWM operation. The TIMB channel 0 registers (TBCH0H:TBCH0L) initially control the buffered PWM output. TIMB channel 0 status and control register (TBSC0) controls and monitors the PWM signal from the linked channels. MS0B takes priority over MS0A.
Technical Data
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Timer Interface Module B (TIMB) Interrupts
Setting MS2B links channels 2 and 3 and configures them for buffered PWM operation. The TIMB channel 2 registers (TBCH2H:TBCH2L) initially control the PWM output. TIMB channel 2 status and control register (TBSC2) controls and monitors the PWM signal from the linked channels. MS2B takes priority over MS2A. Clearing the toggle-on-overflow bit, TOVx, inhibits output toggles on TIMB overflows. Subsequent output compares try to force the output to a state it is already in and have no effect. The result is a 0% duty cycle output.
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Setting the channel x maximum duty cycle bit (CHxMAX) and clearing the TOVx bit generates a 100% duty cycle output. See 12.10.4 TIMB Channel Status and Control Registers.
12.6 Interrupts
The following TIMB sources can generate interrupt requests: * TIMB overflow flag (TOF) -- The TOF bit is set when the TIMB counter value rolls over to $0000 after matching the value in the TIMB counter modulo registers. The TIMB overflow interrupt enable bit, TOIE, enables TIMB overflow CPU interrupt requests. TOF and TOIE are in the TIMB status and control register. TIMB channel flags (CH3F-CH0F) -- The CHxF bit is set when an input capture or output compare occurs on channel x. Channel x TIM CPU interrupt requests are controlled by the channel x interrupt enable bit, CHxIE. Channel x TIM CPU interrupt requests are enabled when CHxIE= 1. CHxF and CHxIE are in the TIMB channel x status and control register.
*
12.7 Low-Power Modes
The WAIT and STOP instructions puts the MCU in low-powerconsumption standby modes.
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Freescale Semiconductor, Inc. Timer Interface Module B (TIMB)
12.7.1 Wait Mode The TIMB remains active after the execution of a WAIT instruction. In wait mode the TIMB registers are not accessible by the CPU. Any enabled CPU interrupt request from the TIMB can bring the MCU out of wait mode. If TIMB functions are not required during wait mode, reduce power consumption by stopping the TIMB before executing the WAIT instruction.
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12.7.2 Stop Mode The TIMB is inactive after the execution of a STOP instruction. The STOP instruction does not affect register conditions or the state of the TIMB counter. TIMB operation resumes when the MCU exit stop mode after an external interrupt.
12.8 TIMB During Break Interrupts
A break interrupt stops the TIMB counter. The system integration module (SIM) controls whether status bits in other modules can be cleared during the break state. The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear status bits during the break state. See 8.8.3 SIM Break Flag Control Register. To allow software to clear status bits during a break interrupt, write a logic one to the BCFE bit. If a status bit is cleared during the break state, it remains cleared when the MCU exits the break state. To protect status bits during the break state, write a logic zero to the BCFE bit. With BCFE at logic zero (its default state), software can read and write I/O registers during the break state without affecting status bits. Some status bits have a two-step read/write clearing procedure. If software does the first step on such a bit before the break, the bit cannot change during the break state as long as BCFE is at logic zero. After the break, doing the second step clears the status bit.
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Timer Interface Module B (TIMB) I/O Signals
12.9 I/O Signals
Port F shares four pins with the TIMB and port D shares one. PTD4/TBCLK is an external clock input to the TIMB prescaler. The four TIMB channel I/O pins are PTF4/TBCH0, PTF5/TBCH1, PTF2/TBCH2, and PTF3/TBCH3.
12.9.1 TIMB Clock Pin
Freescale Semiconductor, Inc...
PTD4/TBCLK is an external clock input that can be the clock source for the TIMB counter instead of the prescaled internal bus clock. Select the PTD4/TBCLK input by writing logic 1s to the three prescaler select bits, PS[2:0]. See 12.10.1 TIMB Status and Control Register. The minimum TBCLK pulse width, TBCLKLMIN or TBCLKHMIN, is: 1 ------------------------------------ + t SU bus frequency The maximum TBCLK frequency is: bus frequency / 2 PTD4/TBCLK is available as a general-purpose I/O pin when not used as the TIMB clock input. When the PTD4/TBCLK pin is the TIMB clock input, it is an input regardless of the state of the DDRD6 bit in data direction register D.
12.9.2 TIMB Channel I/O Pins Each channel I/O pin is programmable independently as an input capture pin or an output compare pin. PTF2/TBCH2 and PTF5/TBCH1 can be configured as buffered output compare or buffered PWM pins.
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The following I/O registers control and monitor operation of the TIMB: * * * * TIMB status and control register (TBSC) TIMB counter registers (TBCNTH:TBCNTL) TIMB counter modulo registers (TBMODH:TBMODL) TIMB channel status and control registers (TBSC0, TBSC1, TBSC2, and TBSC3) TIMB channel registers (TBCH0H:TBCH0L, TBCH1H:TBCH1L, TBCH2H:TBCH2L, and TBCH3H:TBCH3L)
Freescale Semiconductor, Inc...
*
12.10.1 TIMB Status and Control Register The TIMB status and control register does the following: * * * * *
Address:
Enables TIMB overflow interrupts Flags TIMB overflows Stops the TIMB counter Resets the TIMB counter Prescales the TIMB counter clock
$0040 Bit 7 6 TOIE 5 TSTOP TRST 0 1 0 0 0 0 0 4 0 3 0 PS2 PS1 PS0 2 1 Bit 0
Read: Write: Reset:
TOF 0 0
= Unimplemented
Figure 12-4. TIMB Status and Control Register (TBSC)
Technical Data
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Timer Interface Module B (TIMB) I/O Registers
TOF -- TIMB Overflow Flag Bit This read/write flag is set when the TIMB counter resets to $0000 after reaching the modulo value programmed in the TIMB counter modulo registers. Clear TOF by reading the TIMB status and control register when TOF is set and then writing a logic zero to TOF. If another TIMB overflow occurs before the clearing sequence is complete, then writing logic zero to TOF has no effect. Therefore, a TOF interrupt request cannot be lost due to inadvertent clearing of TOF. Reset clears the TOF bit. Writing a logic one to TOF has no effect. 1 = TIMB counter has reached modulo value 0 = TIMB counter has not reached modulo value TOIE -- TIMB Overflow Interrupt Enable Bit This read/write bit enables TIMB overflow interrupts when the TOF bit becomes set. Reset clears the TOIE bit. 1 = TIMB overflow interrupts enabled 0 = TIMB overflow interrupts disabled TSTOP -- TIMB Stop Bit This read/write bit stops the TIMB counter. Counting resumes when TSTOP is cleared. Reset sets the TSTOP bit, stopping the TIMB counter until software clears the TSTOP bit. 1 = TIMB counter stopped 0 = TIMB counter active
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NOTE:
Do not set the TSTOP bit before entering wait mode if the TIMB is required to exit wait mode.
TRST -- TIMB Reset Bit Setting this write-only bit resets the TIMB counter and the TIMB prescaler. Setting TRST has no effect on any other registers. Counting resumes from $0000. TRST is cleared automatically after the TIMB counter is reset and always reads as logic zero. Reset clears the TRST bit. 1 = Prescaler and TIMB counter cleared 0 = No effect
NOTE:
Setting the TSTOP and TRST bits simultaneously stops the TIMB counter at a value of $0000.
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203
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PS[2:0] -- Prescaler Select Bits These read/write bits select either the PTD4/TBCLK pin or one of the seven prescaler outputs as the input to the TIMB counter as Table 12-2 shows. Reset clears the PS[2:0] bits. Table 12-2. Prescaler Selection
PS2 0 0 PS1 0 0 1 1 0 0 1 1 PS0 0 1 0 1 0 1 0 1 TIM Clock Source Internal Bus Clock /1 Internal Bus Clock / 2 Internal Bus Clock / 4 Internal Bus Clock / 8 Internal Bus Clock / 16 Internal Bus Clock / 32 Internal Bus Clock / 64 PTD4/TBCLK
Freescale Semiconductor, Inc...
0 0 1 1 1 1
12.10.2 TIMB Counter Registers The two read-only TIMB counter registers contain the high and low bytes of the value in the TIMB counter. Reading the high byte (TBCNTH) latches the contents of the low byte (TBCNTL) into a buffer. Subsequent reads of TBCNTH do not affect the latched TBCNTL value until TBCNTL is read. Reset clears the TIMB counter registers. Setting the TIMB reset bit (TRST) also clears the TIMB counter registers.
NOTE:
If you read TBCNTH during a break interrupt, be sure to unlatch TBCNTL by reading TBCNTL before exiting the break interrupt. Otherwise, TBCNTL retains the value latched during the break.
Address: $0041 Bit 7 Read: Write: Reset: 0 0 0 0 0 0 0 0 Bit 15 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
= Unimplemented
Figure 12-5. TIMB Counter Register High (TBCNTH)
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Timer Interface Module B (TIMB) I/O Registers
Address:
$0042 Bit 7 6 6 5 5 4 4 3 3 2 2 1 1 Bit 0 Bit 0
Read: Write: Reset:
Bit 7
0
0
0
0
0
0
0
0
= Unimplemented
Figure 12-6. TIMB Counter Register Low (TBCNTL)
Freescale Semiconductor, Inc...
12.10.3 TIMB Counter Modulo Registers The read/write TIMB modulo registers contain the modulo value for the TIMB counter. When the TIMB counter reaches the modulo value, the overflow flag (TOF) becomes set, and the TIMB counter resumes counting from $0000 at the next clock. Writing to the high byte (TBMODH) inhibits the TOF bit and overflow interrupts until the low byte (TBMODL) is written. Reset sets the TIMB counter modulo registers.
Address: $0043 Bit 7 Read: Bit 15 Write: Reset: 1 1 1 1 1 1 1 1 14 13 12 11 10 9 Bit 8 6 5 4 3 2 1 Bit 0
Figure 12-7. TIMB Counter Modulo Register High (TBMODH)
Address: $0044 Bit 7 Read: Bit 7 Write: Reset: 1 1 1 1 1 1 1 1 6 5 4 3 2 1 Bit 0 6 5 4 3 2 1 Bit 0
Figure 12-8. TIMB Counter Modulo Register Low (TBMODL)
NOTE:
Reset the TIMB counter before writing to the TIMB counter modulo registers.
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205
Freescale Semiconductor, Inc. Timer Interface Module B (TIMB)
12.10.4 TIMB Channel Status and Control Registers Each of the TIMB channel status and control registers does the following: * * * * Flags input captures and output compares Enables input capture and output compare interrupts Selects input capture, output compare, or PWM operation Selects high, low, or toggling output on output compare Selects rising edge, falling edge, or any edge as the active input capture trigger Selects output toggling on TIMB overflow Selects 100% PWM duty cycle Selects buffered or unbuffered output compare/PWM operation
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* * * *
Address:
$0045 Bit 7 6 CH0IE 5 MS0B 0 4 MS0A 0 3 ELS0B 0 2 ELS0A 0 1 TOV0 0 Bit 0 CH0MAX 0
Read: Write: Reset:
CH0F 0 0 0
Figure 12-9. TIMB Channel 0 Status and Control Register (TBSC0)
Address: $0048 Bit 7 Read: Write: Reset: CH1F CH1IE 0 0 0 0 0 0 0 0 0 6 5 0 MS1A ELS1B ELS1A TOV1 CH1MAX 4 3 2 1 Bit 0
Figure 12-10. TIMB Channel 1 Status and Control Register (TBSC1)
Technical Data
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Timer Interface Module B (TIMB) I/O Registers
Address:
$0032 Bit 7 6 CH2IE 5 MS2B 0 4 MS2A 0 3 ELS2B 0 2 ELS2A 0 1 TOV2 0 Bit 0 CH2MAX 0
Read: Write: Reset:
CH2F 0 0 0
Figure 12-11. TIMB Channel 2 Status and Control Register (TBSC2)
Address: $0035 Bit 7 Read: Write: Reset: CH3F CH3IE 0 0 0 0 0 0 0 0 0 6 5 0 MS3A ELS3B ELS3A TOV3 CH3MAX 4 3 2 1 Bit 0
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Figure 12-12. TIMB Channel 3 Status and Control Register (TBSC3) CHxF -- Channel x Flag Bit When channel x is an input capture channel, this read/write bit is set when an active edge occurs on the channel x pin. When channel x is an output compare channel, CHxF is set when the value in the TIMB counter registers matches the value in the TIMB channel x registers. When TIM CPU interrupt requests are enabled (CHxIE = 1), clear CHxF by reading TIMB channel x status and control register with CHxF set and then writing a logic zero to CHxF. If another interrupt request occurs before the clearing sequence is complete, then writing logic zero to CHxF has no effect. Therefore, an interrupt request cannot be lost due to inadvertent clearing of CHxF. Reset clears the CHxF bit. Writing a logic one to CHxF has no effect. 1 = Input capture or output compare on channel x 0 = No input capture or output compare on channel x CHxIE -- Channel x Interrupt Enable Bit This read/write bit enables TIMB CPU interrupts on channel x. Reset clears the CHxIE bit. 1 = Channel x CPU interrupt requests enabled 0 = Channel x CPU interrupt requests disabled
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Freescale Semiconductor, Inc. Timer Interface Module B (TIMB)
MSxB -- Mode Select Bit B This read/write bit selects buffered output compare/PWM operation. MSxB exists only in the TIMB channel 0 and TIMB channel 2 status and control registers. Setting MS0B disables the channel 1 status and control register and reverts TCH1B to general-purpose I/O. Setting MS2B disables the channel 3 status and control register and reverts TCH3B to general-purpose I/O.
Freescale Semiconductor, Inc...
Reset clears the MSxB bit. 1 = Buffered output compare/PWM operation enabled 0 = Buffered output compare/PWM operation disabled MSxA -- Mode Select Bit A When ELSxB:A 00, this read/write bit selects either input capture operation or unbuffered output compare/PWM operation. See Table 12-3. 1 = Unbuffered output compare/PWM operation 0 = Input capture operation When ELSxB:A = 00, this read/write bit selects the initial output level of the TBCHx pin. See Table 12-3. Reset clears the MSxA bit. 1 = Initial output level low 0 = Initial output level high
NOTE:
Before changing a channel function by writing to the MSxB or MSxA bit, set the TSTOP and TRST bits in the TIMB status and control register (TBSC).
ELSxB and ELSxA -- Edge/Level Select Bits When channel x is an input capture channel, these read/write bits control the active edge-sensing logic on channel x. When channel x is an output compare channel, ELSxB and ELSxA control the channel x output behavior when an output compare occurs. When ELSxB and ELSxA are both clear, channel x is not connected to the port I/O, and pin TBCHx is available as a general-purpose I/O pin. Table 12-3 shows how ELSxB and ELSxA work. Reset clears the ELSxB and ELSxA bits.
Technical Data
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Timer Interface Module B (TIMB) I/O Registers
Table 12-3. Mode, Edge, and Level Selection
MSxB
X X 0 0 0
MSxA
0 1 0 0 0 1 1 1 X X X
ELSxB
0 0 0 1 1 0 1 1 0 1 1
ELSxA
0
Mode
Output Preset
Configuration
Pin under Port Control; Initial Output Level High Pin under Port Control; Initial Output Level Low Capture on Rising Edge Only
0 1 0 1 1 0 1 1 0 1 Output Compare or PWM Input Capture
Capture on Falling Edge Only Capture on Rising or Falling Edge Toggle Output on Compare Clear Output on Compare Set Output on Compare
Freescale Semiconductor, Inc...
0 0 0 1 1 1
Toggle Output on Compare Buffered Output Clear Output on Compare Compare or Buffered Set Output on Compare PWM
NOTE:
Before enabling a TIMB channel register for input capture operation, make sure that the TBCHx pin is stable for at least two bus clocks.
TOVx -- Toggle-On-Overflow Bit When channel x is an output compare channel, this read/write bit controls the behavior of the channel x output when the TIMB counter overflows. When channel x is an input capture channel, TOVx has no effect. Reset clears the TOVx bit. 1 = Channel x pin toggles on TIMB counter overflow. 0 = Channel x pin does not toggle on TIMB counter overflow.
NOTE:
When TOVx is set, a TIMB counter overflow takes precedence over a channel x output compare if both occur at the same time.
CHxMAX -- Channel x Maximum Duty Cycle Bit When the TOVx bit is at logic zero, setting the CHxMAX bit forces the duty cycle of buffered and unbuffered PWM signals to 100%. As Figure 12-13 shows, the CHxMAX bit takes effect in the cycle after it is set or cleared. The output stays at the 100% duty cycle level until the cycle after CHxMAX is cleared.
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Freescale Semiconductor, Inc. Timer Interface Module B (TIMB)
OVERFLOW PERIOD OVERFLOW OVERFLOW OVERFLOW OVERFLOW
TBCHx
OUTPUT COMPARE CHxMAX
OUTPUT COMPARE
OUTPUT COMPARE
OUTPUT COMPARE
Figure 12-13. CHxMAX Latency
Freescale Semiconductor, Inc...
12.10.5 TIMB Channel Registers These read/write registers contain the captured TIMB counter value of the input capture function or the output compare value of the output compare function. The state of the TIMB channel registers after reset is unknown. In input capture mode (MSxB:MSxA = 0:0), reading the high byte of the TIMB channel x registers (TBCHxH) inhibits input captures until the low byte (TBCHxL) is read. In output compare mode (MSxB:MSxA 0:0), writing to the high byte of the TIMB channel x registers (TBCHxH) inhibits output compares until the low byte (TBCHxL) is written.
Address: $0046 Bit 7 Read: Bit 15 Write: Reset: Indeterminate after reset 14 13 12 11 10 9 Bit 8 6 5 4 3 2 1 Bit 0
Figure 12-14. TIMB Channel 0 Register High (TBCH0H)
Address: $0047 Bit 7 Read: Bit 7 Write: Reset: Indeterminate after reset 6 5 4 3 2 1 Bit 0 6 5 4 3 2 1 Bit 0
Figure 12-15. TIMB Channel 0 Register Low (TBCH0L)
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Timer Interface Module B (TIMB) I/O Registers
Address:
$0049 Bit 7 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
Read: Bit 15 Write: Reset: Indeterminate after reset
Figure 12-16. TIMB Channel 1 Register High (TBCH1H)
Freescale Semiconductor, Inc...
Address:
$004A Bit 7 6 6 5 5 4 4 3 3 2 2 1 1 Bit 0 Bit 0
Read: Bit 7 Write: Reset: Indeterminate after reset
Figure 12-17. TIMB Channel 1 Register Low (TBCH1L)
Address:
$0033 Bit 7 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
Read: Bit 15 Write: Reset: Indeterminate after reset
Figure 12-18. TIMB Channel 2 Register High (TBCH2H)
Address: $0034 Bit 7 Read: Bit 7 Write: Reset: Indeterminate after reset 6 5 4 3 2 1 Bit 0 6 5 4 3 2 1 Bit 0
Figure 12-19. TIMB Channel 2 Register Low (TBCH2L)
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Freescale Semiconductor, Inc. Timer Interface Module B (TIMB)
Address:
$0036 Bit 7 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
Read: Bit 15 Write: Reset: Indeterminate after reset
Figure 12-20. TIMB Channel 3 Register High (TBCH3H)
Freescale Semiconductor, Inc...
Address:
$0037 Bit 7 6 6 5 5 4 4 3 3 2 2 1 1 Bit 0 Bit 0
Read: Bit 7 Write: Reset: Indeterminate after reset
Figure 12-21. TIMB Channel 3 Register Low (TBCH3L)
Technical Data
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Technical Data -- MC68HC08AB16A
Section 13. Programmable Interrupt Timer (PIT)
13.1 Contents
13.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Freescale Semiconductor, Inc...
13.3
13.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 13.4.1 PIT Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 13.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 13.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 13.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 13.6 PIT During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 216
13.7 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 13.7.1 PIT Status and Control Register. . . . . . . . . . . . . . . . . . . . . 217 13.7.2 PIT Counter Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 13.7.3 PIT Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . . . 220
13.2 Introduction
This section describes the programmable interrupt timer (PIT), which is a timer whose counter is clocked internally via software programmable options. Figure 13-1 is a block diagram of the PIT.
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Freescale Semiconductor, Inc. Programmable Interrupt Timer (PIT) 13.3 Features
Features of the PIT include the following: * * * Programmable PIT clock input Free-running or modulo up-count operation PIT counter stop and reset bits
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13.4 Functional Description
Figure 13-1 shows the structure of the PIT. The central component of the PIT is the 16-bit PIT counter that can operate as a free-running counter or a modulo up-counter. The counter provides the timing reference for the interrupt. The PIT counter modulo registers, PMODH:PMODL, control the modulo value of the counter. Software can read the counter value at any time without affecting the counting sequence.
INTERNAL BUS CLOCK PSTOP PRST
PRESCALER SELECT PRESCALER
PPS2
PPS1
PPS0
16-BIT COUNTER 16-BIT COMPARATOR PMODH:PMODL
POF POIE
INTERRUPT LOGIC
Figure 13-1. PIT Block Diagram
Technical Data
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Programmable Interrupt Timer (PIT) Functional Description
Addr.
Register Name Read: PIT Status and Control Register Write: (PSC) Reset:
Bit 7 POF 0 0 Bit 15
6 POIE 0 14
5 PSTOP 1 13
4 0 PRST 0 12
3 0
2 PPS2 0 10
1 PPS1 0 9
Bit 0 PPS0 0 Bit 8
$004B
0 11
Read: PIT Counter Register High $004C Write: (PCNTH) Reset: Read: PIT Counter Register Low $004D Write: (PCNTL) Reset: Read: PIT Counter Modulo Register High Write: (PMODH) Reset: Read: PIT Counter Modulo Register Low Write: (PMODL) Reset:
0 Bit 7
0 6
0 5
0 4
0 3
0 2
0 1
0 Bit 0
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0 Bit 15 1 Bit 7 1
0 14 1 6 1
0 13 1 5 1
0 12 1 4 1
0 11 1 3 1
0 10 1 2 1
0 9 1 1 1
0 Bit 8 1 Bit 0 1
$004E
$004F
= Unimplemented
Figure 13-2. PIT I/O Register Summary 13.4.1 PIT Counter Prescaler The clock source can be one of the seven prescaler outputs. The prescaler generates seven clock rates from the internal bus clock. The prescaler select bits, PPS[2:0] in the status and control register select the PIT clock source. The value in the PIT counter modulo registers and the selected prescaler output determines the frequency of the Periodic Interrupt. The PIT overflow flag (POF) is set when the PIT counter value rolls over to $0000 after matching the value in the PIT counter modulo registers. The PIT interrupt enable bit, POIE, enables PIT overflow CPU interrupt requests. POF and POIE are in the PIT status and control register.
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Freescale Semiconductor, Inc. Programmable Interrupt Timer (PIT) 13.5 Low-Power Modes
The WAIT and STOP instructions put the MCU in low-powerconsumption standby modes.
13.5.1 Wait Mode The PIT remains active after the execution of a WAIT instruction. In wait mode the PIT registers are not accessible by the CPU. Any enabled CPU interrupt request from the PIT can bring the MCU out of wait mode. If PIT functions are not required during wait mode, reduce power consumption by stopping the PIT before executing the WAIT instruction.
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13.5.2 Stop Mode The PIT is inactive after the execution of a STOP instruction. The STOP instruction does not affect register conditions or the state of the PIT counter. PIT operation resumes when the MCU exits stop mode after an external interrupt.
13.6 PIT During Break Interrupts
A break interrupt stops the PIT counter. The system integration module (SIM) controls whether status bits in other modules can be cleared during the break state. The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear status bits during the break state. See 8.8.3 SIM Break Flag Control Register. To allow software to clear status bits during a break interrupt, write a logic one to the BCFE bit. If a status bit is cleared during the break state, it remains cleared when the MCU exits the break state. To protect status bits during the break state, write a logic zero to the BCFE bit. With BCFE at logic zero (its default state), software can read and write I/O registers during the break state without affecting status
Technical Data
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Programmable Interrupt Timer (PIT) I/O Registers
bits. Some status bits have a two-step read/write clearing procedure. If software does the first step on such a bit before the break, the bit cannot change during the break state as long as BCFE is at logic zero. After the break, doing the second step clears the status bit.
13.7 I/O Registers
The following I/O registers control and monitor operation of the PIT:
Freescale Semiconductor, Inc...
* * *
PIT status and control register (PSC) PIT counter registers (PCNTH:PCNTL) PIT counter modulo registers (PMODH:PMODL)
13.7.1 PIT Status and Control Register The PIT status and control register does the following: * * * * *
Address:
Enables PIT interrupt Flags PIT overflows Stops the PIT counter Resets the PIT counter Prescales the PIT counter clock
$004B Bit 7 6 POIE 5 PSTOP PRST 0 1 0 0 0 0 0 4 0 3 0 PPS2 PPS1 PPS0 2 1 Bit 0
Read: Write: Reset:
POF 0 0
= Unimplemented
Figure 13-3. PIT Status and Control Register (PSC)
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POF -- PIT Overflow Flag Bit This read/write flag is set when the PIT counter resets to $0000 after reaching the modulo value programmed in the PIT counter modulo registers. Clear POF by reading the PIT status and control register when POF is set and then writing a logic zero to POF. If another PIT overflow occurs before the clearing sequence is complete, then writing logic zero to POF has no effect. Therefore, a POF interrupt request cannot be lost due to inadvertent clearing of POF. Reset clears the POF bit. Writing a logic one to POF has no effect. 1 = PIT counter has reached modulo value 0 = PIT counter has not reached modulo value POIE -- PIT Overflow Interrupt Enable Bit This read/write bit enables PIT overflow interrupts when the POF bit becomes set. Reset clears the POIE bit. 1 = PIT overflow interrupts enabled 0 = PIT overflow interrupts disabled PSTOP -- PIT Stop Bit This read/write bit stops the PIT counter. Counting resumes when PSTOP is cleared. Reset sets the PSTOP bit, stopping the PIT counter until software clears the PSTOP bit. 1 = PIT counter stopped 0 = PIT counter active
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NOTE:
Do not set the PSTOP bit before entering wait mode if the PIT is required to exit wait mode.
PRST -- PIT Reset Bit Setting this write-only bit resets the PIT counter and the PIT prescaler. Setting PRST has no effect on any other registers. Counting resumes from $0000. PRST is cleared automatically after the PIT counter is reset and always reads as logic zero. Reset clears the PRST bit. 1 = Prescaler and PIT counter cleared 0 = No effect
NOTE:
Setting the PSTOP and PRST bits simultaneously stops the PIT counter at a value of $0000.
Technical Data
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Programmable Interrupt Timer (PIT) I/O Registers
PPS[2:0] -- PIT Prescaler Select Bits These read/write bits select one of the seven prescaler outputs as the input to the PIT counter as Table 13-1 shows. Reset clears the PPS[2:0] bits. Table 13-1. PIT Prescaler Selection
PPS2 0 0 PPS1 0 0 1 1 0 0 1 1 PPS0 0 1 0 1 0 1 0 1 PIT Clock Source Internal Bus Clock /1 Internal Bus Clock / 2 Internal Bus Clock / 4 Internal Bus Clock / 8 Internal Bus Clock / 16 Internal Bus Clock / 32 Internal Bus Clock / 64 Internal Bus Clock / 64
Freescale Semiconductor, Inc...
0 0 1 1 1 1
13.7.2 PIT Counter Registers The two read-only PIT counter registers contain the high and low bytes of the value in the PIT counter. Reading the high byte (PCNTH) latches the contents of the low byte (PCNTL) into a buffer. Subsequent reads of PCNTH do not affect the latched PCNTL value until PCNTL is read. Reset clears the PIT counter registers. Setting the PIT reset bit (PRST) also clears the PIT counter registers.
NOTE:
If you read PCNTH during a break interrupt, be sure to unlatch PCNTL by reading PCNTL before exiting the break interrupt. Otherwise, PCNTL retains the value latched during the break.
Address: $004C Bit 7 Read: Write: Reset: 0 0 0 0 0 0 0 0 Bit 15 6 14 5 13 4 12 3 11 2 10 1 9 Bit 0 Bit 8
= Unimplemented
Figure 13-4. PIT Counter Register High (PCNTH)
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Freescale Semiconductor, Inc. Programmable Interrupt Timer (PIT)
Address:
$004D Bit 7 6 6 5 5 4 4 3 3 2 2 1 1 Bit 0 Bit 0
Read: Write: Reset:
Bit 7
0
0
0
0
0
0
0
0
= Unimplemented
Figure 13-5. PIT Counter Register Low (PCNTL)
Freescale Semiconductor, Inc...
13.7.3 PIT Counter Modulo Registers The read/write PIT modulo registers contain the modulo value for the PIT counter. When the PIT counter reaches the modulo value, the overflow flag (POF) becomes set, and the PIT counter resumes counting from $0000 at the next clock. Writing to the high byte (PMODH) inhibits the POF bit and overflow interrupts until the low byte (PMODL) is written. Reset sets the PIT counter modulo registers.
Address: $004E Bit 7 Read: Bit 15 Write: Reset: 1 1 1 1 1 1 1 1 14 13 12 11 10 9 Bit 8 6 5 4 3 2 1 Bit 0
Figure 13-6. PIT Counter Modulo Register High (PMODH)
Address: $004F Bit 7 Read: Bit 7 Write: Reset: 1 1 1 1 1 1 1 1 6 5 4 3 2 1 Bit 0 6 5 4 3 2 1 Bit 0
Figure 13-7. PIT Counter Modulo Register Low (PMODL)
NOTE:
Reset the PIT counter before writing to the PIT counter modulo registers.
Technical Data
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Technical Data -- MC68HC08AB16A
Section 14. Analog-to-Digital Converter (ADC)
14.1 Contents
14.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
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14.3
14.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 14.4.1 ADC Port I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 14.4.2 Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 14.4.3 Conversion Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 14.4.4 Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 14.4.5 Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.5 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
14.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.7 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 14.7.1 ADC Analog Power Pin (VDDAREF). . . . . . . . . . . . . . . . . . . 226 14.7.2 ADC Analog Ground Pin (AVSS/VREFL) . . . . . . . . . . . . . . . 226 14.7.3 ADC Voltage Reference High Pin (VREFH). . . . . . . . . . . . . 226 14.7.4 ADC Voltage In (VADIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 14.8 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 14.8.1 ADC Status and Control Register (ADSCR). . . . . . . . . . . . 227 14.8.2 ADC Data Register (ADR) . . . . . . . . . . . . . . . . . . . . . . . . . 229 14.8.3 ADC Clock Register (ADCLK) . . . . . . . . . . . . . . . . . . . . . . 229
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This section describes the 8-bit analog-to-digital converter (ADC).
14.3 Features
Features of the ADC module include: * Eight channels with multiplexed input Linear successive approximation with monotonicity 8-bit resolution Single or continuous conversion Conversion complete flag or conversion complete interrupt Selectable ADC clock
Bit 7 Read: COCO Write: Reset: Read: $0039 ADC Data Register (ADR) Write: Reset: Read: $003A ADC Clock Register (ADCLK) ADIV2 Write: Reset: 0 0 0 0 0 0 0 0 ADIV1 ADIV0 ADICLK 0 0 0 0 0 0 0 0 0 0 0 0 0 AD7 0 AD6 0 AD5 1 AD4 1 AD3 1 AD2 1 AD1 1 AD0 AIEN ADCO ADCH4 ADCH3 ADCH2 ADCH1 ADCH0 6 5 4 3 2 1 Bit 0
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* * * * *
Addr. Register Name
$0038 ADC Status and Control Register (ADSCR)
= Unimplemented
Figure 14-1. ADC Register Summary
Technical Data
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Analog-to-Digital Converter (ADC) Functional Description
14.4 Functional Description
The ADC provides eight pins for sampling external sources at pins PTB7/ATD7-PTB0/ATD0. An analog multiplexer allows the single ADC converter to select one of eight ADC channels as ADC voltage in (VADIN). VADIN is converted by the successive approximation register-based analog-to-digital converter. When the conversion is completed, ADC places the result in the ADC data register and sets a flag or generates an interrupt. (See Figure 14-2.)
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INTERNAL DATA BUS READ DDRBx WRITE DDRBx RESET WRITE PTBx DDRBx PTBx PTBx ADC CHANNEL x DISABLE
READ PTBx
DISABLE ADC DATA REGISTER ADC I/P CHANNELS ADC VOLTAGE IN (VADIN) ADC
CONVERSION INTERRUPT COMPLETE LOGIC
CHANNEL SELECT
ADCH[4:0]
AIEN
COCO CGMXCLK BUS CLOCK
ADC CLOCK CLOCK GENERATOR
ADIV[2:0]
ADICLK
Figure 14-2. ADC Block Diagram
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14.4.1 ADC Port I/O Pins PTB7/ATD7-PTB0/ATD0 are general-purpose I/O (input/output) pins that share with the ADC channels. The channel select bits define which ADC channel/port pin will be used as the input signal. The ADC overrides the port I/O logic by forcing that pin as input to the ADC. The remaining ADC channels/port pins are controlled by the port I/O logic and can be used as general-purpose I/O. Writes to the port register or DDR will not have any affect on the port pin that is selected by the ADC. Read of a port pin in use by the ADC will return a logic 0.
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14.4.2 Voltage Conversion When the input voltage to the ADC equals VREFH, the ADC converts the signal to $FF (full scale). If the input voltage equals VREFL, the ADC converts it to $00. Input voltages between VREFH and VREFL are a straight-line linear conversion. 14.4.3 Conversion Time Conversion starts after a write to the ADSCR. One conversion will take between 16 and 17 ADC clock cycles. The ADIVx and ADICLK bits should be set to provide a 1-MHz ADC clock frequency. Conversion time = 16 to 17 ADC cycles ADC frequency Number of bus cycles = conversion time x bus frequency 14.4.4 Conversion In continuous conversion mode, the ADC data register will be filled with new data after each conversion. Data from the previous conversion will be overwritten whether that data has been read or not. Conversions will continue until the ADCO bit is cleared. The COCO bit is set after the first conversion and will stay set until the next write of the ADC status and control register or the next read of the ADC data register. In single conversion mode, conversion begins with a write to the ADSCR. Only one conversion occurs between writes to the ADSCR.
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Analog-to-Digital Converter (ADC) Interrupts
14.4.5 Accuracy and Precision The conversion process is monotonic and has no missing codes.
14.5 Interrupts
When the AIEN bit is set, the ADC module is capable of generating CPU interrupts after each ADC conversion. A CPU interrupt is generated if the COCO bit is at logic 0. The COCO bit is not used as a conversion complete flag when interrupts are enabled.
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14.6 Low-Power Modes
The WAIT and STOP instruction can put the MCU in low powerconsumption standby modes.
14.6.1 Wait Mode The ADC continues normal operation during wait mode. Any enabled CPU interrupt request from the ADC can bring the MCU out of wait mode. If the ADC is not required to bring the MCU out of wait mode, power down the ADC by setting ADCH[4:0] bits in the ADC status and control register before executing the WAIT instruction.
14.6.2 Stop Mode The ADC module is inactive after the execution of a STOP instruction. Any pending conversion is aborted. ADC conversions resume when the MCU exits stop mode after an external interrupt. Allow one conversion cycle to stabilize the analog circuitry.
14.7 I/O Signals
The ADC module has eight pins shared with port B, PTB7/ATD7-PTB0/ATD0.
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14.7.1 ADC Analog Power Pin (VDDAREF) The ADC analog portion uses VDDAREF as its power pin. Connect the VDDAREF pin to the same voltage potential as VDD. External filtering may be necessary to ensure clean VDDAREF for good results.
NOTE:
For maximum noise immunity, route VDDAREF carefully and place bypass capacitors as close as possible to the package.
Freescale Semiconductor, Inc...
14.7.2 ADC Analog Ground Pin (AVSS/VREFL) The ADC analog portion uses AVSS/VREFL as its ground pin. Connect the AVSS/VREFL pin to the same voltage potential as VSS.
NOTE:
Route AVSS/VREFL cleanly to avoid any offset errors.
14.7.3 ADC Voltage Reference High Pin (VREFH) VREFH is the reference voltage for the ADC.
14.7.4 ADC Voltage In (VADIN) VADIN is the input voltage signal from one of the eight ADC channels to the ADC module.
14.8 I/O Registers
These I/O registers control and monitor ADC operation: * * * ADC status and control register (ADSCR) ADC data register (ADR) ADC clock register (ADCLK)
Technical Data
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Analog-to-Digital Converter (ADC) I/O Registers
14.8.1 ADC Status and Control Register (ADSCR) Function of the ADC status and control register is described here.
Address: $0038 Bit 7 Read: COCO Write: Reset: 0 0 0 1 1 1 1 1 AIEN ADCO ADCH4 ADCH3 ADCH2 ADCH1 ADCH0 6 5 4 3 2 1 Bit 0
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Figure 14-3. ADC Status and Control Register (ADSCR) COCO -- Conversions Complete When the AIEN bit is a logic 0, the COCO is a read-only bit which is set each time a conversion is completed except in the continuous conversion mode where it is set after the first conversion. This bit is cleared whenever the ADSCR is written or whenever the ADR is read. If the AIEN bit is a logic 1, the COCO becomes a read/write bit, which should be cleared to logic 0 for CPU to service the ADC interrupt request. Reset clears the COCO bit. 1 = Conversion completed (AIEN=0) 0 = Conversion not completed (AIEN=0)/CPU interrupt (AIEN=1) AIEN -- ADC Interrupt Enable Bit When this bit is set, an interrupt is generated at the end of an ADC conversion. The interrupt signal is cleared when the data register is read or the status/control register is written.Reset clears the AIEN bit. 1 = ADC interrupt enabled 0 = ADC interrupt disabled ADCO -- ADC Continuous Conversion Bit When set, the ADC will convert samples continuously and update the ADR register at the end of each conversion. Only one conversion is completed between writes to the ADSCR when this bit is cleared. Reset clears the ADCO bit. 1 = Continuous ADC conversion 0 = One ADC conversion
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ADCH[4:0] -- ADC Channel Select Bits ADCH[4:0] form a 5-bit field which is used to select one of the eight ADC channels, ATD7-ATD0. The channels are detailed in Table 14-1. Care should be taken when using a port pin as both an analog and digital input simultaneously to prevent switching noise from corrupting the analog signal. The ADC subsystem is turned off when the channel select bits are all set to 1. This feature allows for reduced power consumption for the MCU when the ADC is not being used.
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NOTE:
Recovery from the disabled state requires one conversion cycle to stabilize.
The voltage levels supplied from internal reference nodes, as specified in Table 14-1, are used to verify the operation of the ADC converter both in production test and for user applications. Table 14-1. Mux Channel Select
ADCH4 0 0 0 0 0 0 0 0 0 1 1 1 1 ADCH3 0 0 0 0 0 0 0 0 1 1 1 1 1 ADCH2 0 0 0 0 1 1 1 1 0 1 1 1 1 ADCH1 0 0 1 1 0 0 1 1 0 0 0 1 1 ADCH0 0 1 0 1 0 1 0 1 0 0 1 0 1 VREFH VREFL ADC power off Reserved Input Select PTB0/ATD0 PTB1/ATD1 PTB2/ATD2 PTB3/ATD3 PTB4/ATD4 PTB5/ATD5 PTB6/ATD6 PTB7/ATD7
NOTE: If any unused channels are selected, the resulting ADC conversion will be unknown or reserved.
Technical Data
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Analog-to-Digital Converter (ADC) I/O Registers
14.8.2 ADC Data Register (ADR) One 8-bit result register, ADC data register (ADR), is provided. This register is updated each time an ADC conversion completes.
Address: $0039 Bit 7 Read: Write: AD7 6 AD6 5 AD5 4 AD4 3 AD3 2 AD2 1 AD1 Bit 0 AD0
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Reset:
0
0
0
0
0
0
0
0
= Unimplemented
Figure 14-4. ADC Data Register (ADR)
14.8.3 ADC Clock Register (ADCLK) The ADC clock register (ADCLK) selects the clock frequency for the ADC.
Address: $003A Bit 7 Read: ADIV2 Write: Reset: 0 0 0 0 0 0 0 0 ADIV1 ADIV0 ADICLK 6 5 4 3 0 2 0 1 0 Bit 0 0
= Unimplemented
Figure 14-5. ADC Clock Register (ADCLK) ADIV[2:0] -- ADC Clock Prescaler Bits ADIV[2:0] form a 3-bit field which selects the divide ratio used by the ADC to generate the internal ADC clock. Table 14-2 shows the available clock configurations. The ADC clock should be set to approximately 1 MHz.
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Table 14-2. ADC Clock Divide Ratio
ADIV2 0 0 0 0 1 ADIV1 0 0 1 1 X ADIV0 0 1 0 1 X ADC Clock Rate ADC input clock / 1 ADC input clock / 2 ADC input clock / 4 ADC input clock / 8 ADC input clock / 16
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X = don't care
ADICLK -- ADC Input Clock Select Bit ADICLK selects either the bus clock or CGMXCLK as the input clock source to generate the internal ADC clock. Reset selects CGMXCLK as the ADC clock source. If the external clock (CGMXCLK) is equal to or greater than 1 MHz, CGMXCLK can be used as the clock source for the ADC. If CGMXCLK is less than 1 MHz, use the PLL-generated bus clock as the clock source. As long as the internal ADC clock is at approximately 1 MHz, correct operation can be guaranteed. 1 = Internal bus clock 0 = External clock (CGMXCLK) ADC input clock frequency ----------------------------------------------------------------------- = 1MHz ADIV[2:0]
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Technical Data -- MC68HC08AB16A
Section 15. Serial Communications Interface Module (SCI)
15.1 Contents
15.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
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15.3 15.4
15.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 15.5.1 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 15.5.2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 15.5.2.1 Character Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 15.5.2.2 Character Transmission . . . . . . . . . . . . . . . . . . . . . . . . . 239 15.5.2.3 Break Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.5.2.4 Idle Characters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.5.2.5 Inversion of Transmitted Output. . . . . . . . . . . . . . . . . . . 241 15.5.2.6 Transmitter Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . 241 15.5.3 Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 15.5.3.1 Character Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 15.5.3.2 Character Reception . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 15.5.3.3 Data Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 15.5.3.4 Framing Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 15.5.3.5 Baud Rate Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 15.5.3.6 Receiver Wakeup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 15.5.3.7 Receiver Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 15.5.3.8 Error Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 15.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 15.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 15.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 15.7 SCI During Break Module Interrupts. . . . . . . . . . . . . . . . . . . . 252
15.8 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 15.8.1 PTE0/TxD (Transmit Data). . . . . . . . . . . . . . . . . . . . . . . . . 252
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15.8.2 PTE1/RxD (Receive Data) . . . . . . . . . . . . . . . . . . . . . . . . . 252
15.9 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 15.9.1 SCI Control Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 15.9.2 SCI Control Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 15.9.3 SCI Control Register 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 15.9.4 SCI Status Register 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 15.9.5 SCI Status Register 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 15.9.6 SCI Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 15.9.7 SCI Baud Rate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
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15.2 Introduction
This section describes the serial communications interface (SCI) module, which allows high-speed asynchronous communications with peripheral devices and other MCUs.
NOTE:
References to DMA (direct-memory access) and associated functions are only valid if the MCU has a DMA module. This MCU does not have the DMA function. Any DMA-related register bits should be left in their reset state for normal MCU operation.
15.3 Features
Features of the SCI module include the following: * * * * * * * Full-duplex operation Standard mark/space non-return-to-zero (NRZ) format 32 programmable baud rates Programmable 8-bit or 9-bit character length Separately enabled transmitter and receiver Separate receiver and transmitter CPU interrupt requests Programmable transmitter output polarity
Technical Data
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Serial Communications Interface Module (SCI) Features
*
Two receiver wakeup methods: - Idle line wakeup - Address mark wakeup
*
Interrupt-driven operation with eight interrupt flags: - Transmitter empty - Transmission complete - Receiver full
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- Idle receiver input - Receiver overrun - Noise error - Framing error - Parity error * * * Receiver framing error detection Hardware parity checking 1/16 bit-time noise detection
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Freescale Semiconductor, Inc. Serial Communications Interface 15.4 Pin Name Conventions
The generic names of the SCI I/O pins are: * * RxD (receive data) TxD (transmit data)
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SCI I/O (input/output) lines are implemented by sharing parallel I/O port pins. The full name of an SCI input or output reflects the name of the shared port pin. Table 15-1 shows the full names and the generic names of the SCI I/O pins. The generic pin names appear in the text of this section. Table 15-1. Pin Name Conventions
Generic Pin Names: Full Pin Names: RxD PTE1/RxD TxD PTE0/TxD
15.5 Functional Description
Figure 15-1 shows the structure of the SCI module. The SCI allows fullduplex, asynchronous, NRZ serial communication among the MCU and remote devices, including other MCUs. The transmitter and receiver of the SCI operate independently, although they use the same baud rate generator. During normal operation, the CPU monitors the status of the SCI, writes the data to be transmitted, and processes received data.
Technical Data
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Serial Communications Interface Module (SCI) Functional Description
INTERNAL BUS
SCI DATA REGISTER TRANSMITTER INTERRUPT CONTROL DMA INTERRUPT CONTROL RECEIVER INTERRUPT CONTROL RECEIVE SHIFT REGISTER ERROR INTERRUPT CONTROL
SCI DATA REGISTER TRANSMIT SHIFT REGISTER
PTE1/RxD
PTE0/TxD
TXINV SCTIE TCIE
R8 T8
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SCRIE ILIE TE RE RWU SBK SCTE TC SCRF IDLE OR NF FE PE LOOPS LOOPS WAKEUP CONTROL RECEIVE CONTROL FLAG CONTROL M WAKE ILTY CGMXCLK /4 PRESCALER BAUD DIVIDER PEN PTY DATA SELECTION CONTROL ENSCI
R R
ORIE NEIE FEIE PEIE
TRANSMIT CONTROL
ENSCI
BKF RPF
/ 16
Figure 15-1. SCI Module Block Diagram
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Addr.
Register Name Read:
Bit 7
6 ENSCI 0 TCIE 0 T8
5 TXINV 0 SCRIE 0 R 0 SCRF
4 M 0 ILIE 0 R 0 IDLE
3 WAKE 0 TE 0 ORIE 0 OR
2 ILTY 0 RE 0 NEIE 0 NF
1 PEN 0 RWU 0 FEIE 0 FE
Bit 0 PTY 0 SBK 0 PEIE 0 PE
$0013
LOOPS SCI Control Register 1 Write: (SCC1) Reset: 0 Read: SCI Control Register 2 Write: (SCC2) Reset: Read: SCI Control Register 3 Write: (SCC3) Reset: Read: SCI Status Register 1 Write: (SCS1) Reset: Read: SCI Status Register 2 Write: (SCS2) Reset: Read: SCI Data Register Write: (SCDR) Reset: Read: SCI Baud Rate Register Write: (SCBR) Reset: SCTIE 0 R8
$0014
Freescale Semiconductor, Inc...
$0015
U SCTE
U TC
$0016
1
1
0
0
0
0
0 BKF
0 RPF
$0017
0 R7 T7
0 R6 T6
0 R5 T5
0 R4 T4
0 R3 T3
0 R2 T2
0 R1 T1
0 R0 T0
$0018
Unaffected by reset SCP1 0 0 0 SCP0 0 R = Reserved R 0 SCR2 0 U = Unaffected SCR1 0 SCR0 0
$0019
= Unimplemented
Figure 15-2. SCI I/O Register Summary
Technical Data
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Serial Communications Interface Module (SCI) Functional Description
15.5.1 Data Format The SCI uses the standard non-return-to-zero mark/space data format illustrated in Figure 15-3.
8-BIT DATA FORMAT BIT M IN SCC1 CLEAR START BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6
PARITY BIT BIT 7 STOP BIT
NEXT START BIT
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9-BIT DATA FORMAT BIT M IN SCC1 SET START BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7
PARITY BIT BIT 8 STOP BIT
NEXT START BIT
Figure 15-3. SCI Data Formats
15.5.2 Transmitter Figure 15-4 shows the structure of the SCI transmitter.
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INTERNAL BUS
CGMXCLK
/4
PRESCALER
BAUD DIVIDER
/ 16
SCI DATA REGISTER
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SCP0 SCR1 SCR2 SCR0 TRANSMITTER CPU INTERRUPT REQUEST TRANSMITTER DMA SERVICE REQUEST TXINV
H
8 MSB
7
6
5
4
3
2
1
0
START L
SCP1 STOP
11-BIT TRANSMIT SHIFT REGISTER
PTE0/TxD
M SHIFT ENABLE PEN PTY PARITY GENERATION LOAD FROM SCDR
PREAMBLE ALL 1s
T8 R R SCTIE SCTE R SCTE SCTIE TC TCIE
TRANSMITTER CONTROL LOGIC
SCTE
LOOPS SCTIE TC TCIE ENSCI TE
Figure 15-4. SCI Transmitter
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BREAK ALL 0s SBK
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Serial Communications Interface Module (SCI) Functional Description
15.5.2.1 Character Length
The transmitter can accommodate either 8-bit or 9-bit data. The state of the M bit in SCI control register 1 (SCC1) determines character length. When transmitting 9-bit data, bit T8 in SCI control register 3 (SCC3) is the ninth bit (bit 8).
15.5.2.2 Character Transmission
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During an SCI transmission, the transmit shift register shifts a character out to the PTE0/TxD pin. The SCI data register (SCDR) is the write-only buffer between the internal data bus and the transmit shift register. To initiate an SCI transmission: 1. Enable the SCI by writing a logic 1 to the enable SCI bit (ENSCI) in SCI control register 1 (SCC1). 2. Enable the transmitter by writing a logic 1 to the transmitter enable bit (TE) in SCI control register 2 (SCC2). 3. Clear the SCI transmitter empty bit by first reading SCI status register 1 (SCS1) and then writing to the SCDR. 4. Repeat step 3 for each subsequent transmission. At the start of a transmission, transmitter control logic automatically loads the transmit shift register with a preamble of logic 1s. After the preamble shifts out, control logic transfers the SCDR data into the transmit shift register. A logic 0 start bit automatically goes into the least significant bit position of the transmit shift register. A logic 1 stop bit goes into the most significant bit position. The SCI transmitter empty bit, SCTE, in SCS1 becomes set when the SCDR transfers a byte to the transmit shift register. The SCTE bit indicates that the SCDR can accept new data from the internal data bus. If the SCI transmit interrupt enable bit, SCTIE, in SCC2 is also set, the SCTE bit generates a transmitter CPU interrupt request. When the transmit shift register is not transmitting a character, the PTE0/TxD pin goes to the idle condition, logic 1. If at any time software clears the ENSCI bit in SCI control register 1 (SCC1), the transmitter and receiver relinquish control of the port E pins.
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15.5.2.3 Break Characters
Writing a logic 1 to the send break bit, SBK, in SCC2 loads the transmit shift register with a break character. A break character contains all logic 0s and has no start, stop, or parity bit. Break character length depends on the M bit in SCC1. As long as SBK is at logic 1, transmitter logic continuously loads break characters into the transmit shift register. After software clears the SBK bit, the shift register finishes transmitting the last break character and then transmits at least one logic 1. The automatic logic 1 at the end of a break character guarantees the recognition of the start bit of the next character. The SCI recognizes a break character when a start bit is followed by eight or nine logic 0 data bits and a logic 0 where the stop bit should be. Receiving a break character has these effects on SCI registers: * * * * * * Sets the framing error bit (FE) in SCS1 Sets the SCI receiver full bit (SCRF) in SCS1 Clears the SCI data register (SCDR) Clears the R8 bit in SCC3 Sets the break flag bit (BKF) in SCS2 May set the overrun (OR), noise flag (NF), parity error (PE), or reception in progress flag (RPF) bits
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15.5.2.4 Idle Characters
An idle character contains all logic 1s and has no start, stop, or parity bit. Idle character length depends on the M bit in SCC1. The preamble is a synchronizing idle character that begins every transmission. If the TE bit is cleared during a transmission, the PTE0/TxD pin becomes idle after completion of the transmission in progress. Clearing and then setting the TE bit during a transmission queues an idle character to be sent after the character currently being transmitted.
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Serial Communications Interface Module (SCI) Functional Description
NOTE:
When queueing an idle character, return the TE bit to logic 1 before the stop bit of the current character shifts out to the TxD pin. Setting TE after the stop bit appears on TxD causes data previously written to the SCDR to be lost. Toggle the TE bit for a queued idle character when the SCTE bit becomes set and just before writing the next byte to the SCDR.
15.5.2.5 Inversion of Transmitted Output
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The transmit inversion bit (TXINV) in SCI control register 1 (SCC1) reverses the polarity of transmitted data. All transmitted values, including idle, break, start, and stop bits, are inverted when TXINV is at logic 1. (See 15.9.1 SCI Control Register 1.)
15.5.2.6 Transmitter Interrupts
These conditions can generate CPU interrupt requests from the SCI transmitter: * SCI transmitter empty (SCTE) -- The SCTE bit in SCS1 indicates that the SCDR has transferred a character to the transmit shift register. SCTE can generate a transmitter CPU interrupt request. Setting the SCI transmit interrupt enable bit, SCTIE, in SCC2 enables the SCTE bit to generate transmitter CPU interrupt requests. Transmission complete (TC) -- The TC bit in SCS1 indicates that the transmit shift register and the SCDR are empty and that no break or idle character has been generated. The transmission complete interrupt enable bit, TCIE, in SCC2 enables the TC bit to generate transmitter CPU interrupt requests.
*
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15.5.3 Receiver Figure 15-5 shows the structure of the SCI receiver.
15.5.3.1 Character Length
The receiver can accommodate either 8-bit or 9-bit data. The state of the M bit in SCI control register 1 (SCC1) determines character length. When receiving 9-bit data, bit R8 in SCI control register 2 (SCC2) is the ninth bit (bit 8). When receiving 8-bit data, bit R8 is a copy of the eighth bit (bit 7).
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15.5.3.2 Character Reception
During an SCI reception, the receive shift register shifts characters in from the PTE1/RxD pin. The SCI data register (SCDR) is the read-only buffer between the internal data bus and the receive shift register. After a complete character shifts into the receive shift register, the data portion of the character transfers to the SCDR. The SCI receiver full bit, SCRF, in SCI status register 1 (SCS1) becomes set, indicating that the received byte can be read. If the SCI receive interrupt enable bit, SCRIE, in SCC2 is also set, the SCRF bit generates a receiver CPU interrupt request.
Technical Data
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Serial Communications Interface Module (SCI) Functional Description
INTERNAL BUS
SCR1 SCP1 SCP0 CGMXCLK /4 PRESCALER BAUD DIVIDER SCR2 SCR0 START 0 L RWU / 16 DATA RECOVERY ALL 0s ALL 1s MSB SCI DATA REGISTER
STOP
11-BIT RECEIVE SHIFT REGISTER 8 7 6 5 4 3 2 1
PTE1/RxD
H
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BKF RPF ERROR CPU INTERRUPT REQUEST DMA SERVICE REQUEST
CPU INTERRUPT REQUEST
M WAKE ILTY PEN PTY WAKEUP LOGIC PARITY CHECKING IDLE ILIE R SCRF SCRIE R SCRF SCRIE R OR ORIE NF NEIE FE FEIE PE PEIE
SCRF IDLE
R8
ILIE
SCRIE
R OR ORIE NF NEIE FE FEIE PE PEIE
Figure 15-5. SCI Receiver Block Diagram
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15.5.3.3 Data Sampling
The receiver samples the PTE1/RxD pin at the RT clock rate. The RT clock is an internal signal with a frequency 16 times the baud rate. To adjust for baud rate mismatch, the RT clock is resynchronized at the following times (see Figure 15-6): * * After every start bit After the receiver detects a data bit change from logic 1 to logic 0 (after the majority of data bit samples at RT8, RT9, and RT10 returns a valid logic 1 and the majority of the next RT8, RT9, and RT10 samples returns a valid logic 0)
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To locate the start bit, data recovery logic does an asynchronous search for a logic 0 preceded by three logic 1s. When the falling edge of a possible start bit occurs, the RT clock begins to count to 16.
START BIT PTE1/RxD
LSB
SAMPLES
START BIT QUALIFICATION
START BIT VERIFICATION
DATA SAMPLING
RT CLOCK RT10 RT11 RT12 RT13 RT14 RT15 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT1 RT2 RT3 RT4 RT CLOCK STATE RT CLOCK RESET RT16
Figure 15-6. Receiver Data Sampling
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Serial Communications Interface Module (SCI) Functional Description
To verify the start bit and to detect noise, data recovery logic takes samples at RT3, RT5, and RT7. Table 15-2 summarizes the results of the start bit verification samples. Table 15-2. Start Bit Verification
RT3, RT5, and RT7 Samples 000 001 Start Bit Verification Yes Yes Yes No Yes No No No Noise Flag 0 1 1 0 1 0 0 0
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010 011 100 101 110 111
Start bit verification is not successful if any two of the three verification samples are logic 1s. If start bit verification is not successful, the RT clock is reset and a new search for a start bit begins. To determine the value of a data bit and to detect noise, recovery logic takes samples at RT8, RT9, and RT10. Table 15-3 summarizes the results of the data bit samples. Table 15-3. Data Bit Recovery
RT8, RT9, and RT10 Samples 000 001 010 011 100 101 110 111 Data Bit Determination 0 0 0 1 0 1 1 1 Noise Flag 0 1 1 1 1 1 1 0
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NOTE:
The RT8, RT9, and RT10 samples do not affect start bit verification. If any or all of the RT8, RT9, and RT10 start bit samples are logic 1s following a successful start bit verification, the noise flag (NF) is set and the receiver assumes that the bit is a start bit.
To verify a stop bit and to detect noise, recovery logic takes samples at RT8, RT9, and RT10. Table 15-4 summarizes the results of the stop bit samples. Table 15-4. Stop Bit Recovery
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RT8, RT9, and RT10 Samples 000 001 010 011 100 101 110 111
Framing Error Flag 1 1 1 0 1 0 0 0
Noise Flag 0 1 1 1 1 1 1 0
15.5.3.4 Framing Errors
If the data recovery logic does not detect a logic 1 where the stop bit should be in an incoming character, it sets the framing error bit, FE, in SCS1. A break character also sets the FE bit because a break character has no stop bit. The FE bit is set at the same time that the SCRF bit is set.
15.5.3.5 Baud Rate Tolerance
A transmitting device may be operating at a baud rate below or above the receiver baud rate. Accumulated bit time misalignment can cause one of the three stop bit data samples to fall outside the actual stop bit. Then a noise error occurs. If more than one of the samples is outside the stop bit, a framing error occurs. In most applications, the baud rate
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Serial Communications Interface Module (SCI) Functional Description
tolerance is much more than the degree of misalignment that is likely to occur. As the receiver samples an incoming character, it resynchronizes the RT clock on any valid falling edge within the character. Resynchronization within characters corrects misalignments between transmitter bit times and receiver bit times. Slow Data Tolerance
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Figure 15-7 shows how much a slow received character can be misaligned without causing a noise error or a framing error. The slow stop bit begins at RT8 instead of RT1 but arrives in time for the stop bit data samples at RT8, RT9, and RT10.
MSB
STOP
RT10
RT11
RT12
RT13
RT14
RT15
DATA SAMPLES
Figure 15-7. Slow Data For an 8-bit character, data sampling of the stop bit takes the receiver 9 bit times x 16 RT cycles + 10 RT cycles = 154 RT cycles. With the misaligned character shown in Figure 15-7, the receiver counts 154 RT cycles at the point when the count of the transmitting device is 9 bit times x 16 RT cycles + 3 RT cycles = 147 RT cycles. The maximum percent difference between the receiver count and the transmitter count of a slow 8-bit character with no errors is 154 - 147 x 100 = 4.54% ------------------------154 For a 9-bit character, data sampling of the stop bit takes the receiver 10 bit times x 16 RT cycles + 10 RT cycles = 170 RT cycles.
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Technical Data
RT16
RT1
RT2
RT3
RT4
RT5
RT6
RT7
RT8
RT9
RECEIVER RT CLOCK
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With the misaligned character shown in Figure 15-7, the receiver counts 170 RT cycles at the point when the count of the transmitting device is 10 bit times x 16 RT cycles + 3 RT cycles = 163 RT cycles. The maximum percent difference between the receiver count and the transmitter count of a slow 9-bit character with no errors is 170 - 163 x 100 = 4.12% ------------------------170 Fast Data Tolerance Figure 15-8 shows how much a fast received character can be misaligned without causing a noise error or a framing error. The fast stop bit ends at RT10 instead of RT16 but is still there for the stop bit data samples at RT8, RT9, and RT10.
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STOP
IDLE OR NEXT CHARACTER
RT10
RT11
RT12
RT13
RT14
RT15
DATA SAMPLES
Figure 15-8. Fast Data For an 8-bit character, data sampling of the stop bit takes the receiver 9 bit times x 16 RT cycles + 10 RT cycles = 154 RT cycles. With the misaligned character shown in Figure 15-8, the receiver counts 154 RT cycles at the point when the count of the transmitting device is 10 bit times x 16 RT cycles = 160 RT cycles. The maximum percent difference between the receiver count and the transmitter count of a fast 8-bit character with no errors is 154 - 160 x 100 = 3.90% ------------------------154
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RT16
RT1
RT2
RT3
RT4
RT5
RT6
RT7
RT8
RT9
RECEIVER RT CLOCK
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Serial Communications Interface Module (SCI) Functional Description
For a 9-bit character, data sampling of the stop bit takes the receiver 10 bit times x 16 RT cycles + 10 RT cycles = 170 RT cycles. With the misaligned character shown in Figure 15-8, the receiver counts 170 RT cycles at the point when the count of the transmitting device is 11 bit times x 16 RT cycles = 176 RT cycles. The maximum percent difference between the receiver count and the transmitter count of a fast 9-bit character with no errors is
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170 - 176 x 100 = 3.53% ------------------------170
15.5.3.6 Receiver Wakeup
So that the MCU can ignore transmissions intended only for other receivers in multiple-receiver systems, the receiver can be put into a standby state. Setting the receiver wakeup bit, RWU, in SCC2 puts the receiver into a standby state during which receiver interrupts are disabled. Depending on the state of the WAKE bit in SCC1, either of two conditions on the PTE1/RxD pin can bring the receiver out of the standby state: * Address mark -- An address mark is a logic 1 in the most significant bit position of a received character. When the WAKE bit is set, an address mark wakes the receiver from the standby state by clearing the RWU bit. The address mark also sets the SCI receiver full bit, SCRF. Software can then compare the character containing the address mark to the user-defined address of the receiver. If they are the same, the receiver remains awake and processes the characters that follow. If they are not the same, software can set the RWU bit and put the receiver back into the standby state. Idle input line condition -- When the WAKE bit is clear, an idle character on the PTE1/RxD pin wakes the receiver from the standby state by clearing the RWU bit. The idle character that wakes the receiver does not set the receiver idle bit, IDLE, or the
*
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SCI receiver full bit, SCRF. The idle line type bit, ILTY, determines whether the receiver begins counting logic 1s as idle character bits after the start bit or after the stop bit.
NOTE:
With the WAKE bit clear, setting the RWU bit after the RxD pin has been idle may cause the receiver to wake up immediately.
15.5.3.7 Receiver Interrupts
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The following sources can generate CPU interrupt requests from the SCI receiver: * SCI receiver full (SCRF) -- The SCRF bit in SCS1 indicates that the receive shift register has transferred a character to the SCDR. SCRF can generate a receiver CPU interrupt request. Setting the SCI receive interrupt enable bit, SCRIE, in SCC2 enables the SCRF bit to generate receiver CPU interrupts. Idle input (IDLE) -- The IDLE bit in SCS1 indicates that 10 or 11 consecutive logic 1s shifted in from the PTE1/RxD pin. The idle line interrupt enable bit, ILIE, in SCC2 enables the IDLE bit to generate CPU interrupt requests.
*
15.5.3.8 Error Interrupts
The following receiver error flags in SCS1 can generate CPU interrupt requests: * Receiver overrun (OR) -- The OR bit indicates that the receive shift register shifted in a new character before the previous character was read from the SCDR. The previous character remains in the SCDR, and the new character is lost. The overrun interrupt enable bit, ORIE, in SCC3 enables OR to generate SCI error CPU interrupt requests. Noise flag (NF) -- The NF bit is set when the SCI detects noise on incoming data or break characters, including start, data, and stop bits. The noise error interrupt enable bit, NEIE, in SCC3 enables NF to generate SCI error CPU interrupt requests.
*
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Serial Communications Interface Module (SCI) Low-Power Modes
*
Framing error (FE) -- The FE bit in SCS1 is set when a logic 0 occurs where the receiver expects a stop bit. The framing error interrupt enable bit, FEIE, in SCC3 enables FE to generate SCI error CPU interrupt requests. Parity error (PE) -- The PE bit in SCS1 is set when the SCI detects a parity error in incoming data. The parity error interrupt enable bit, PEIE, in SCC3 enables PE to generate SCI error CPU interrupt requests.
*
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15.6 Low-Power Modes
The WAIT and STOP instructions put the MCU in low powerconsumption standby modes. 15.6.1 Wait Mode The SCI module remains active after the execution of a WAIT instruction. In wait mode, the SCI module registers are not accessible by the CPU. Any enabled CPU interrupt request from the SCI module can bring the MCU out of wait mode. If SCI module functions are not required during wait mode, reduce power consumption by disabling the module before executing the WAIT instruction. Refer to 8.7 Low-Power Modes for information on exiting wait mode. 15.6.2 Stop Mode The SCI module is inactive after the execution of a STOP instruction, and thus the SCI cannot cause an interrupt to exit stop mode. The STOP instruction does not affect SCI register states. SCI module operation resumes after an external interrupt. Because the internal clock is inactive during stop mode, entering stop mode during an SCI transmission or reception results in invalid data. Refer to 8.7 Low-Power Modes for information on exiting stop mode.
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The system integration module (SIM) controls whether status bits in other modules can be cleared during the break state. The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear status bits during the break state. To allow software to clear status bits during a break interrupt, write a logic 1 to the BCFE bit. If a status bit is cleared during the break state, it remains cleared when the MCU exits the break state.
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To protect status bits during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its default state), software can read and write I/O registers during the break state without affecting status bits. Some status bits have a 2-step read/write clearing procedure. If software does the first step on such a bit before the break, the bit cannot change during the break state as long as BCFE is at logic 0. After the break, doing the second step clears the status bit.
15.8 I/O Signals
Port E shares two of its pins with the SCI module. The two SCI I/O pins are: * * PTE0/TxD -- Transmit data PTE1/RxD -- Receive data
15.8.1 PTE0/TxD (Transmit Data) The PTE0/TxD pin is the serial data output from the SCI transmitter. The SCI shares the PTE0/TxD pin with port E. When the SCI is enabled, the PTE0/TxD pin is an output regardless of the state of the DDRE2 bit in data direction register E (DDRE). 15.8.2 PTE1/RxD (Receive Data) The PTE1/RxD pin is the serial data input to the SCI receiver. The SCI shares the PTE1/RxD pin with port E. When the SCI is enabled, the PTE1/RxD pin is an input regardless of the state of the DDRE1 bit in data direction register E (DDRE).
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Serial Communications Interface Module (SCI) I/O Registers
15.9 I/O Registers
These I/O registers control and monitor SCI operation: * * * * SCI control register 1 (SCC1) SCI control register 2 (SCC2) SCI control register 3 (SCC3) SCI status register 1 (SCS1) SCI status register 2 (SCS2) SCI data register (SCDR) SCI baud rate register (SCBR)
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* * *
15.9.1 SCI Control Register 1 SCI control register 1: * * * * * * * * Enables loop mode operation Enables the SCI Controls output polarity Controls character length Controls SCI wakeup method Controls idle character detection Enables parity function Controls parity type
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Address:
$0013 Bit 7 6 ENSCI 0 5 TXINV 0 4 M 0 3 WAKE 0 2 ILTY 0 1 PEN 0 Bit 0 PTY 0
Read: LOOPS Write: Reset: 0
Figure 15-9. SCI Control Register 1 (SCC1) LOOPS -- Loop Mode Select Bit
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This read/write bit enables loop mode operation. In loop mode the PTE1/RxD pin is disconnected from the SCI, and the transmitter output goes into the receiver input. Both the transmitter and the receiver must be enabled to use loop mode. Reset clears the LOOPS bit. 1 = Loop mode enabled 0 = Normal operation enabled ENSCI -- Enable SCI Bit This read/write bit enables the SCI and the SCI baud rate generator. Clearing ENSCI sets the SCTE and TC bits in SCI status register 1 and disables transmitter interrupts. Reset clears the ENSCI bit. 1 = SCI enabled 0 = SCI disabled TXINV -- Transmit Inversion Bit This read/write bit reverses the polarity of transmitted data. Reset clears the TXINV bit. 1 = Transmitter output inverted 0 = Transmitter output not inverted
NOTE:
Setting the TXINV bit inverts all transmitted values, including idle, break, start, and stop bits.
Technical Data
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Serial Communications Interface Module (SCI) I/O Registers
M -- Mode (Character Length) Bit This read/write bit determines whether SCI characters are eight or nine bits long. (See Table 15-5.) The ninth bit can serve as an extra stop bit, as a receiver wakeup signal, or as a parity bit. Reset clears the M bit. 1 = 9-bit SCI characters 0 = 8-bit SCI characters WAKE -- Wakeup Condition Bit
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This read/write bit determines which condition wakes up the SCI: a logic 1 (address mark) in the most significant bit position of a received character or an idle condition on the PTE1/RxD pin. Reset clears the WAKE bit. 1 = Address mark wakeup 0 = Idle line wakeup ILTY -- Idle Line Type Bit This read/write bit determines when the SCI starts counting logic 1s as idle character bits. The counting begins either after the start bit or after the stop bit. If the count begins after the start bit, then a string of logic 1s preceding the stop bit may cause false recognition of an idle character. Beginning the count after the stop bit avoids false idle character recognition, but requires properly synchronized transmissions. Reset clears the ILTY bit. 1 = Idle character bit count begins after stop bit 0 = Idle character bit count begins after start bit PEN -- Parity Enable Bit This read/write bit enables the SCI parity function. (See Table 15-5.) When enabled, the parity function inserts a parity bit in the most significant bit position. (See Figure 15-3.) Reset clears the PEN bit. 1 = Parity function enabled 0 = Parity function disabled
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PTY -- Parity Bit This read/write bit determines whether the SCI generates and checks for odd parity or even parity. (See Table 15-5.) Reset clears the PTY bit. 1 = Odd parity 0 = Even parity
NOTE:
Changing the PTY bit in the middle of a transmission or reception can generate a parity error.
Table 15-5. Character Format Selection
Control Bits M 0 1 0 0 1 1 PEN and PTY 0X 0X 10 11 10 11 Start Bits 1 1 1 1 1 1 Data Bits 8 9 7 7 8 8 Character Format Parity None None Even Odd Even Odd Stop Bits 1 1 1 1 1 1 Character Length 10 bits 11 bits 10 bits 10 bits 11 bits 11 bits
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15.9.2 SCI Control Register 2 SCI control register 2: * Enables the following CPU interrupt requests: - Enables the SCTE bit to generate transmitter CPU interrupt requests - Enables the TC bit to generate transmitter CPU interrupt requests - Enables the SCRF bit to generate receiver CPU interrupt requests - Enables the IDLE bit to generate receiver CPU interrupt requests
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* * * *
Address:
Enables the transmitter Enables the receiver Enables SCI wakeup Transmits SCI break characters
$0014 Bit 7 6 TCIE 0 5 SCRIE 0 4 ILIE 0 3 TE 0 2 RE 0 1 RWU 0 Bit 0 SBK 0
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Read: SCTIE Write: Reset: 0
Figure 15-10. SCI Control Register 2 (SCC2) SCTIE -- SCI Transmit Interrupt Enable Bit This read/write bit enables the SCTE bit to generate SCI transmitter CPU interrupt requests. Reset clears the SCTIE bit. 1 = SCTE enabled to generate CPU interrupt 0 = SCTE not enabled to generate CPU interrupt TCIE -- Transmission Complete Interrupt Enable Bit This read/write bit enables the TC bit to generate SCI transmitter CPU interrupt requests. Reset clears the TCIE bit. 1 = TC enabled to generate CPU interrupt requests 0 = TC not enabled to generate CPU interrupt requests SCRIE -- SCI Receive Interrupt Enable Bit This read/write bit enables the SCRF bit to generate SCI receiver CPU interrupt requests. Reset clears the SCRIE bit. 1 = SCRF enabled to generate CPU interrupt 0 = SCRF not enabled to generate CPU interrupt ILIE -- Idle Line Interrupt Enable Bit This read/write bit enables the IDLE bit to generate SCI receiver CPU interrupt requests. Reset clears the ILIE bit. 1 = IDLE enabled to generate CPU interrupt requests 0 = IDLE not enabled to generate CPU interrupt requests
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TE -- Transmitter Enable Bit Setting this read/write bit begins the transmission by sending a preamble of 10 or 11 logic 1s from the transmit shift register to the PTE0/TxD pin. If software clears the TE bit, the transmitter completes any transmission in progress before the PTE0/TxD returns to the idle condition (logic 1). Clearing and then setting TE during a transmission queues an idle character to be sent after the character currently being transmitted. Reset clears the TE bit. 1 = Transmitter enabled 0 = Transmitter disabled
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NOTE:
Writing to the TE bit is not allowed when the enable SCI bit (ENSCI) is clear. ENSCI is in SCI control register 1.
RE -- Receiver Enable Bit Setting this read/write bit enables the receiver. Clearing the RE bit disables the receiver but does not affect receiver interrupt flag bits. Reset clears the RE bit. 1 = Receiver enabled 0 = Receiver disabled
NOTE:
Writing to the RE bit is not allowed when the enable SCI bit (ENSCI) is clear. ENSCI is in SCI control register 1.
RWU -- Receiver Wakeup Bit This read/write bit puts the receiver in a standby state during which receiver interrupts are disabled. The WAKE bit in SCC1 determines whether an idle input or an address mark brings the receiver out of the standby state and clears the RWU bit. Reset clears the RWU bit. 1 = Standby state 0 = Normal operation
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SBK -- Send Break Bit Setting and then clearing this read/write bit transmits a break character followed by a logic 1. The logic 1 after the break character guarantees recognition of a valid start bit. If SBK remains set, the transmitter continuously transmits break characters with no logic 1s between them. Reset clears the SBK bit. 1 = Transmit break characters 0 = No break characters being transmitted
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NOTE:
Do not toggle the SBK bit immediately after setting the SCTE bit. Toggling SBK before the preamble begins causes the SCI to send a break character instead of a preamble.
15.9.3 SCI Control Register 3 SCI control register 3: * * Stores the ninth SCI data bit received and the ninth SCI data bit to be transmitted Enables these interrupts: - Receiver overrun interrupts - Noise error interrupts - Framing error interrupts *
Address:
Parity error interrupts
$0015 Bit 7 6 T8 5 R 0 4 R 0 R = Reserved 3 ORIE 0 2 NEIE 0 U = Unaffected 1 FEIE 0 Bit 0 PEIE 0
Read: Write: Reset:
R8
U
U
= Unimplemented
Figure 15-11. SCI Control Register 3 (SCC3)
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R8 -- Received Bit 8 When the SCI is receiving 9-bit characters, R8 is the read-only ninth bit (bit 8) of the received character. R8 is received at the same time that the SCDR receives the other 8 bits. When the SCI is receiving 8-bit characters, R8 is a copy of the eighth bit (bit 7). Reset has no effect on the R8 bit. T8 -- Transmitted Bit 8 When the SCI is transmitting 9-bit characters, T8 is the read/write ninth bit (bit 8) of the transmitted character. T8 is loaded into the transmit shift register at the same time that the SCDR is loaded into the transmit shift register. Reset has no effect on the T8 bit. ORIE -- Receiver Overrun Interrupt Enable Bit This read/write bit enables SCI error CPU interrupt requests generated by the receiver overrun bit, OR. 1 = SCI error CPU interrupt requests from OR bit enabled 0 = SCI error CPU interrupt requests from OR bit disabled NEIE -- Receiver Noise Error Interrupt Enable Bit This read/write bit enables SCI error CPU interrupt requests generated by the noise error bit, NE. Reset clears NEIE. 1 = SCI error CPU interrupt requests from NE bit enabled 0 = SCI error CPU interrupt requests from NE bit disabled FEIE -- Receiver Framing Error Interrupt Enable Bit This read/write bit enables SCI error CPU interrupt requests generated by the framing error bit, FE. Reset clears FEIE. 1 = SCI error CPU interrupt requests from FE bit enabled 0 = SCI error CPU interrupt requests from FE bit disabled PEIE -- Receiver Parity Error Interrupt Enable Bit This read/write bit enables SCI receiver CPU interrupt requests generated by the parity error bit, PE. (See 15.9.4 SCI Status Register 1.) Reset clears PEIE. 1 = SCI error CPU interrupt requests from PE bit enabled 0 = SCI error CPU interrupt requests from PE bit disabled
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15.9.4 SCI Status Register 1 SCI status register 1 (SCS1) contains flags to signal these conditions: * * * * * Transfer of SCDR data to transmit shift register complete Transmission complete Transfer of receive shift register data to SCDR complete Receiver input idle Receiver overrun Noisy data Framing error Parity error
$0016 Bit 7 Read: Write: Reset: 1 1 0 0 0 0 0 0 SCTE 6 TC 5 SCRF 4 IDLE 3 OR 2 NF 1 FE Bit 0 PE
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* * *
Address:
= Unimplemented
Figure 15-12. SCI Status Register 1 (SCS1) SCTE -- SCI Transmitter Empty Bit This clearable, read-only bit is set when the SCDR transfers a character to the transmit shift register. SCTE can generate an SCI transmitter CPU interrupt request. When the SCTIE bit in SCC2 is set, SCTE generates an SCI transmitter CPU interrupt request. In normal operation, clear the SCTE bit by reading SCS1 with SCTE set and then writing to SCDR. Reset sets the SCTE bit. 1 = SCDR data transferred to transmit shift register 0 = SCDR data not transferred to transmit shift register
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TC -- Transmission Complete Bit This read-only bit is set when the SCTE bit is set, and no data, preamble, or break character is being transmitted. TC generates an SCI transmitter CPU interrupt request if the TCIE bit in SCC2 is also set. TC is automatically cleared when data, preamble or break is queued and ready to be sent. There may be up to 1.5 transmitter clocks of latency between queueing data, preamble, and break and the transmission actually starting. Reset sets the TC bit. 1 = No transmission in progress 0 = Transmission in progress SCRF -- SCI Receiver Full Bit This clearable, read-only bit is set when the data in the receive shift register transfers to the SCI data register. SCRF can generate an SCI receiver CPU interrupt request. When the SCRIE bit in SCC2 is set, SCRF generates a CPU interrupt request. In normal operation, clear the SCRF bit by reading SCS1 with SCRF set and then reading the SCDR. Reset clears SCRF. 1 = Received data available in SCDR 0 = Data not available in SCDR IDLE -- Receiver Idle Bit This clearable, read-only bit is set when 10 or 11 consecutive logic 1s appear on the receiver input. IDLE generates an SCI error CPU interrupt request if the ILIE bit in SCC2 is also set. Clear the IDLE bit by reading SCS1 with IDLE set and then reading the SCDR. After the receiver is enabled, it must receive a valid character that sets the SCRF bit before an idle condition can set the IDLE bit. Also, after the IDLE bit has been cleared, a valid character must again set the SCRF bit before an idle condition can set the IDLE bit. Reset clears the IDLE bit. 1 = Receiver input idle 0 = Receiver input active (or idle since the IDLE bit was cleared) OR -- Receiver Overrun Bit This clearable, read-only bit is set when software fails to read the SCDR before the receive shift register receives the next character. The OR bit generates an SCI error CPU interrupt request if the ORIE
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bit in SCC3 is also set. The data in the shift register is lost, but the data already in the SCDR is not affected. Clear the OR bit by reading SCS1 with OR set and then reading the SCDR. Reset clears the OR bit. 1 = Receive shift register full and SCRF = 1 0 = No receiver overrun Software latency may allow an overrun to occur between reads of SCS1 and SCDR in the flag-clearing sequence. Figure 15-13 shows the normal flag-clearing sequence and an example of an overrun caused by a delayed flag-clearing sequence. The delayed read of SCDR does not clear the OR bit because OR was not set when SCS1 was read. Byte 2 caused the overrun and is lost. The next flagclearing sequence reads byte 3 in the SCDR instead of byte 2. In applications that are subject to software latency or in which it is important to know which byte is lost due to an overrun, the flagclearing routine can check the OR bit in a second read of SCS1 after reading the data register. NF -- Receiver Noise Flag Bit This clearable, read-only bit is set when the SCI detects noise on the PTE1/RxD pin. NF generates an NF CPU interrupt request if the NEIE bit in SCC3 is also set. Clear the NF bit by reading SCS1 and then reading the SCDR. Reset clears the NF bit. 1 = Noise detected 0 = No noise detected FE -- Receiver Framing Error Bit This clearable, read-only bit is set when a logic 0 is accepted as the stop bit. FE generates an SCI error CPU interrupt request if the FEIE bit in SCC3 also is set. Clear the FE bit by reading SCS1 with FE set and then reading the SCDR. Reset clears the FE bit. 1 = Framing error detected 0 = No framing error detected
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NORMAL FLAG CLEARING SEQUENCE SCRF = 1 SCRF = 0 SCRF = 1 SCRF = 0 SCRF = 1 SCRF = 0 BYTE 4 READ SCS1 SCRF = 1 OR = 0 READ SCDR BYTE 3 BYTE 4 READ SCS1 SCRF = 1 OR = 1 READ SCDR BYTE 3
BYTE 1 READ SCS1 SCRF = 1 OR = 0 READ SCDR BYTE 1
BYTE 2 READ SCS1 SCRF = 1 OR = 0 READ SCDR BYTE 2
BYTE 3
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DELAYED FLAG CLEARING SEQUENCE SCRF = 1 OR = 1 SCRF = 0 OR = 1 SCRF = 1 SCRF = 1 OR = 1 SCRF = 0 OR = 0
BYTE 1
BYTE 2 READ SCS1 SCRF = 1 OR = 0 READ SCDR BYTE 1
BYTE 3
Figure 15-13. Flag Clearing Sequence
PE -- Receiver Parity Error Bit This clearable, read-only bit is set when the SCI detects a parity error in incoming data. PE generates a PE CPU interrupt request if the PEIE bit in SCC3 is also set. Clear the PE bit by reading SCS1 with PE set and then reading the SCDR. Reset clears the PE bit. 1 = Parity error detected 0 = No parity error detected
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15.9.5 SCI Status Register 2 SCI status register 2 contains flags to signal the following conditions: * *
Address:
Break character detected Incoming data
$0017 Bit 7 6 5 4 3 2 1 BKF Bit 0 RPF
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Read: Write: Reset: 0 0 0 0 0 0
0
0
= Unimplemented
Figure 15-14. SCI Status Register 2 (SCS2) BKF -- Break Flag Bit This clearable, read-only bit is set when the SCI detects a break character on the PTE1/RxD pin. In SCS1, the FE and SCRF bits are also set. In 9-bit character transmissions, the R8 bit in SCC3 is cleared. BKF does not generate a CPU interrupt request. Clear BKF by reading SCS2 with BKF set and then reading the SCDR. Once cleared, BKF can become set again only after logic 1s again appear on the PTE1/RxD pin followed by another break character. Reset clears the BKF bit. 1 = Break character detected 0 = No break character detected RPF -- Reception in Progress Flag Bit This read-only bit is set when the receiver detects a logic 0 during the RT1 time period of the start bit search. RPF does not generate an interrupt request. RPF is reset after the receiver detects false start bits (usually from noise or a baud rate mismatch) or when the receiver detects an idle character. Polling RPF before disabling the SCI module or entering stop mode can show whether a reception is in progress. 1 = Reception in progress 0 = No reception in progress
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15.9.6 SCI Data Register The SCI data register (SCDR) is the buffer between the internal data bus and the receive and transmit shift registers. Reset has no effect on data in the SCI data register.
Address: $0018 Bit 7 Read: R7 T7 6 R6 T6 5 R5 T5 4 R4 T4 3 R3 T3 2 R2 T2 1 R1 T1 Bit 0 R0 T0
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Write: Reset:
Unaffected by reset
Figure 15-15. SCI Data Register (SCDR) R7/T7-R0/T0 -- Receive/Transmit Data Bits Reading address $0018 accesses the read-only received data bits, R7:R0. Writing to address $0018 writes the data to be transmitted, T7:T0. Reset has no effect on the SCI data register.
NOTE:
Do not use read/modify/write instructions on the SCI data register.
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15.9.7 SCI Baud Rate Register The baud rate register (SCBR) selects the baud rate for both the receiver and the transmitter.
Address: $0019 Bit 7 Read: SCP1 Write: SCP0 0 R 0 R SCR2 0 = Reserved SCR1 0 SCR0 0 6 5 4 3 2 1 Bit 0
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Reset:
0
0
0
= Unimplemented
Figure 15-16. SCI Baud Rate Register (SCBR) SCP1 and SCP0 -- SCI Baud Rate Prescaler Bits These read/write bits select the baud rate prescaler divisor as shown in Table 15-6. Reset clears SCP1 and SCP0. Table 15-6. SCI Baud Rate Prescaling
SCP1 and SCP0 00 01 10 11 Prescaler Divisor (PD) 1 3 4 13
SCR2-SCR0 -- SCI Baud Rate Select Bits These read/write bits select the SCI baud rate divisor as shown in Table 15-7. Reset clears SCR2-SCR0.
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Table 15-7. SCI Baud Rate Selection
SCR2, SCR1, and SCR0 000 001 010 011 100 Baud Rate Divisor (BD) 1 2 4 8 16 32 64 128
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101 110 111
Use this formula to calculate the SCI baud rate: SCI clock source baud rate = -------------------------------------------64 x PD x BD where: SCI clock source = CGMXCLK (See 9.5.6 Crystal Output Frequency Signal (CGMXCLK).) PD = prescaler divisor BD = baud rate divisor This makes the formula: CGMXCLK baud rate = ----------------------------------64 x PD x BD Table 15-8 shows the SCI baud rates that can be generated with a 4.9152MHz CGMXCLK.
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Table 15-8. SCI Baud Rate Selection Examples
SCP1 and SCP0 00 00 00 00 00 00 Prescaler Divisor (PD) 1 1 1 1 1 1 1 1 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 13 13 13 13 13 13 13 13 SCR2, SCR1, and SCR0 000 001 010 011 100 101 110 111 000 001 010 011 100 101 110 111 000 001 010 011 100 101 110 111 000 001 010 011 100 101 110 111 Baud Rate Divisor (BD) 1 2 4 8 16 32 64 128 1 2 4 8 16 32 64 128 1 2 4 8 16 32 64 128 1 2 4 8 16 32 64 128 Baud Rate (CGMXCLK=4.9152 MHz) 76,800 38,400 19,200 9600 4800 2400 1200 600 25,600 12,800 6400 3200 1600 800 400 200 19,200 9600 4800 2400 1200 600 300 150 5908 2954 1477 739 369 185 92 46
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00 00 01 01 01 01 01 01 01 01 10 10 10 10 10 10 10 10 11 11 11 11 11 11 11 11
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Section 16. Serial Peripheral Interface Module (SPI)
16.1 Contents
16.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Pin Name Conventions and I/O Register Addresses . . . . . . . 273
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16.3 16.4
16.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 16.5.1 Master Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 16.5.2 Slave Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 16.6 Transmission Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 16.6.1 Clock Phase and Polarity Controls. . . . . . . . . . . . . . . . . . . 277 16.6.2 Transmission Format When CPHA = 0 . . . . . . . . . . . . . . . 278 16.6.3 Transmission Format When CPHA = 1 . . . . . . . . . . . . . . . 280 16.6.4 Transmission Initiation Latency . . . . . . . . . . . . . . . . . . . . . 281 16.7 Queuing Transmission Data . . . . . . . . . . . . . . . . . . . . . . . . . . 283
16.8 Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 16.8.1 Overflow Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 16.8.2 Mode Fault Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 16.9 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
16.10 Resetting the SPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 16.11 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 16.11.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 16.11.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 16.12 SPI During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 292 16.13 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 16.13.1 MISO (Master In/Slave Out) . . . . . . . . . . . . . . . . . . . . . . . . 293 16.13.2 MOSI (Master Out/Slave In) . . . . . . . . . . . . . . . . . . . . . . . . 293
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16.13.3 SPSCK (Serial Clock). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 16.13.4 SS (Slave Select) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 16.13.5 CGND (Clock Ground) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 16.14 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 16.14.1 SPI Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 16.14.2 SPI Status and Control Register . . . . . . . . . . . . . . . . . . . . 298 16.14.3 SPI Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
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16.2 Introduction
This section describes the serial peripheral interface (SPI) module, which allows full-duplex, synchronous, serial communications with peripheral devices.
16.3 Features
Features of the SPI module include the following: * * * * * * * Full-duplex operation Master and slave modes Double-buffered operation with separate transmit and receive registers Four master mode frequencies (maximum = bus frequency / 2) Maximum slave mode frequency = bus frequency Serial clock with programmable polarity and phase Two separately enabled interrupts: - SPRF (SPI receiver full) - SPTE (SPI transmitter empty) * * * * * Mode fault error flag with CPU interrupt capability Overflow error flag with CPU interrupt capability Programmable wired-OR mode I2C (inter-integrated circuit) compatibility I/O (input/output) port bit(s) software configurable with pullup device(s) if configured as input port bit(s)
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Serial Peripheral Interface Module (SPI) Pin Name Conventions and I/O Register Addresses
16.4 Pin Name Conventions and I/O Register Addresses
The text that follows describes the SPI. The SPI I/O pin names are SS (slave select), SPSCK (SPI serial clock), CGND (clock ground), MOSI (master out slave in), and MISO (master in/slave out). The SPI shares four I/O pins with four parallel I/O ports. The full names of the SPI I/O pins are shown in Table 16-1. The generic pin names appear in the text that follows.
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Table 16-1. Pin Name Conventions
SPI Generic Pin Names: MISO MOSI SS SPSCK PTE7/SPSCK CGND VSS
Full SPI Pin Names: SPI PTE5/MISO
PTE6/MOSI PTE4/SS
16.5 Functional Description
Figure 16-1 summarizes the SPI I/O registers and Figure 16-2 shows the structure of the SPI module.
Addr. Register Name Read: SPI Control Register Write: (SPCR) Reset: Read: SPI Status and Control Write: Register (SPSCR) Reset: Read: SPI Data Register Write: (SPDR) Reset: Bit 7 SPRIE 0 SPRF ERRIE 0 R7 T7 0 R6 T6 0 R5 T5 0 R4 T4 1 R3 T3 6 R 0 5 SPMSTR 1 OVRF 4 CPOL 0 MODF 3 CPHA 1 SPTE MODFEN 0 R2 T2 SPR1 0 R1 T1 SPR0 0 R0 T0 2 SPWOM 0 1 SPE 0 Bit 0 SPTIE 0
$0010
$0011
$0012
Unaffected by reset = Unimplemented R = Reserved
Figure 16-1. SPI I/O Register Summary
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INTERNAL BUS
TRANSMIT DATA REGISTER CGMOUT / 2 FROM SIM 7 /2 /8 CLOCK DIVIDER / 32 RECEIVE DATA REGISTER PIN CONTROL LOGIC CLOCK SELECT SPSCK CLOCK LOGIC M S SS 6
SHIFT REGISTER 5 4 3 2 1 0 MISO
MOSI
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/ 128
SPMSTR
SPE
SPR1
SPR0
SPMSTR
CPHA
CPOL
RESERVED TRANSMITTER CPU INTERRUPT REQUEST RESERVED RECEIVER/ERROR CPU INTERRUPT REQUEST SPI CONTROL
MODFEN ERRIE SPTIE SPRIE R SPE SPRF SPTE OVRF MODF
SPWOM
Figure 16-2. SPI Module Block Diagram The SPI module allows full-duplex, synchronous, serial communication between the MCU and peripheral devices, including other MCUs. Software can poll the SPI status flags or SPI operation can be interruptdriven. The following paragraphs describe the operation of the SPI module.
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Serial Peripheral Interface Module (SPI) Functional Description
16.5.1 Master Mode The SPI operates in master mode when the SPI master bit, SPMSTR, is set.
NOTE:
Configure the SPI modules as master or slave before enabling them. Enable the master SPI before enabling the slave SPI. Disable the slave SPI before disabling the master SPI. (See 16.14.1 SPI Control Register.)
Only a master SPI module can initiate transmissions. Software begins the transmission from a master SPI module by writing to the transmit data register. If the shift register is empty, the byte immediately transfers to the shift register, setting the SPI transmitter empty bit, SPTE. The byte begins shifting out on the MOSI pin under the control of the serial clock. (See Figure 16-3.)
MASTER MCU SLAVE MCU
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SHIFT REGISTER
MISO MOSI SPSCK
MISO MOSI SPSCK SS
SHIFT REGISTER
BAUD RATE GENERATOR
SS
VDD
Figure 16-3. Full-Duplex Master-Slave Connections
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The SPR1 and SPR0 bits control the baud rate generator and determine the speed of the shift register. (See 16.14.2 SPI Status and Control Register.) Through the SPSCK pin, the baud rate generator of the master also controls the shift register of the slave peripheral. As the byte shifts out on the MOSI pin of the master, another byte shifts in from the slave on the master's MISO pin. The transmission ends when the receiver full bit, SPRF, becomes set. At the same time that SPRF becomes set, the byte from the slave transfers to the receive data register. In normal operation, SPRF signals the end of a transmission. Software clears SPRF by reading the SPI status and control register with SPRF set and then reading the SPI data register. Writing to the SPI data register clears the SPTE bit.
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16.5.2 Slave Mode The SPI operates in slave mode when the SPMSTR bit is clear. In slave mode, the SPSCK pin is the input for the serial clock from the master MCU. Before a data transmission occurs, the SS pin of the slave SPI must be at logic 0. SS must remain low until the transmission is complete. (See 16.8.2 Mode Fault Error.) In a slave SPI module, data enters the shift register under the control of the serial clock from the master SPI module. After a byte enters the shift register of a slave SPI, it transfers to the receive data register, and the SPRF bit is set. To prevent an overflow condition, slave software then must read the receive data register before another full byte enters the shift register. The maximum frequency of the SPSCK for an SPI configured as a slave is the bus clock speed (which is twice as fast as the fastest master SPSCK clock that can be generated). The frequency of the SPSCK for an SPI configured as a slave does not have to correspond to any SPI baud rate. The baud rate only controls the speed of the SPSCK generated by an SPI configured as a master. Therefore, the frequency of the SPSCK for an SPI configured as a slave can be any frequency less than or equal to the bus speed.
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Serial Peripheral Interface Module (SPI) Transmission Formats
When the master SPI starts a transmission, the data in the slave shift register begins shifting out on the MISO pin. The slave can load its shift register with a new byte for the next transmission by writing to its transmit data register. The slave must write to its transmit data register at least one bus cycle before the master starts the next transmission. Otherwise, the byte already in the slave shift register shifts out on the MISO pin. Data written to the slave shift register during a transmission remains in a buffer until the end of the transmission.
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When the clock phase bit (CPHA) is set, the first edge of SPSCK starts a transmission. When CPHA is clear, the falling edge of SS starts a transmission. (See 16.6 Transmission Formats.)
NOTE:
SPSCK must be in the proper idle state before the slave is enabled to prevent SPSCK from appearing as a clock edge.
16.6 Transmission Formats
During an SPI transmission, data is simultaneously transmitted (shifted out serially) and received (shifted in serially). A serial clock synchronizes shifting and sampling on the two serial data lines. A slave select line allows selection of an individual slave SPI device; slave devices that are not selected do not interfere with SPI bus activities. On a master SPI device, the slave select line can optionally be used to indicate multiplemaster bus contention.
16.6.1 Clock Phase and Polarity Controls Software can select any of four combinations of serial clock (SPSCK) phase and polarity using two bits in the SPI control register (SPCR). The clock polarity is specified by the CPOL control bit, which selects an active high or low clock and has no significant effect on the transmission format.
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The clock phase (CPHA) control bit selects one of two fundamentally different transmission formats. The clock phase and polarity should be identical for the master SPI device and the communicating slave device. In some cases, the phase and polarity are changed between transmissions to allow a master device to communicate with peripheral slaves having different requirements.
NOTE:
Before writing to the CPOL bit or the CPHA bit, disable the SPI by clearing the SPI enable bit (SPE).
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16.6.2 Transmission Format When CPHA = 0 Figure 16-4 shows an SPI transmission in which CPHA is logic 0. The figure should not be used as a replacement for data sheet parametric information. Two waveforms are shown for SPSCK: one for CPOL = 0 and another for CPOL = 1. The diagram may be interpreted as a master or slave timing diagram since the serial clock (SPSCK), master in/slave out (MISO), and master out/slave in (MOSI) pins are directly connected between the master and the slave. The MISO signal is the output from the slave, and the MOSI signal is the output from the master. The SS line is the slave select input to the slave. The slave SPI drives its MISO output only when its slave select input (SS) is at logic 0, so that only the selected slave drives to the master. The SS pin of the master is not shown but is assumed to be inactive. The SS pin of the master must be high or must be reconfigured as general-purpose I/O not affecting the SPI. (See 16.8.2 Mode Fault Error.) When CPHA = 0, the first SPSCK edge is the MSB capture strobe. Therefore, the slave must begin driving its data before the first SPSCK edge, and a falling edge on the SS pin is used to start the slave data transmission. The slave's SS pin must be toggled back to high and then low again between each byte transmitted as shown in Figure 16-5.
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Serial Peripheral Interface Module (SPI) Transmission Formats
SPSCK CYCLE # FOR REFERENCE SPSCK; CPOL = 0 SPSCK; CPOL =1 MOSI FROM MASTER MISO FROM SLAVE SS; TO SLAVE CAPTURE STROBE
1
2
3
4
5
6
7
8
MSB MSB
BIT 6 BIT 6
BIT 5 BIT 5
BIT 4 BIT 4
BIT 3 BIT 3
BIT 2 BIT 2
BIT 1 BIT 1
LSB LSB
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Figure 16-4. Transmission Format (CPHA = 0)
MISO/MOSI MASTER SS SLAVE SS CPHA = 0 SLAVE SS CPHA = 1
BYTE 1
BYTE 2
BYTE 3
Figure 16-5. CPHA/SS Timing When CPHA = 0 for a slave, the falling edge of SS indicates the beginning of the transmission. This causes the SPI to leave its idle state and begin driving the MISO pin with the MSB of its data. Once the transmission begins, no new data is allowed into the shift register from the transmit data register. Therefore, the SPI data register of the slave must be loaded with transmit data before the falling edge of SS. Any data written after the falling edge is stored in the transmit data register and transferred to the shift register after the current transmission.
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16.6.3 Transmission Format When CPHA = 1 Figure 16-6 shows an SPI transmission in which CPHA is logic 1. The figure should not be used as a replacement for data sheet parametric information. Two waveforms are shown for SPSCK: one for CPOL = 0 and another for CPOL = 1. The diagram may be interpreted as a master or slave timing diagram since the serial clock (SPSCK), master in/slave out (MISO), and master out/slave in (MOSI) pins are directly connected between the master and the slave. The MISO signal is the output from the slave, and the MOSI signal is the output from the master. The SS line is the slave select input to the slave. The slave SPI drives its MISO output only when its slave select input (SS) is at logic 0, so that only the selected slave drives to the master. The SS pin of the master is not shown but is assumed to be inactive. The SS pin of the master must be high or must be reconfigured as general-purpose I/O not affecting the SPI. (See 16.8.2 Mode Fault Error.) When CPHA = 1, the master begins driving its MOSI pin on the first SPSCK edge. Therefore, the slave uses the first SPSCK edge as a start transmission signal. The SS pin can remain low between transmissions. This format may be preferable in systems having only one master and only one slave driving the MISO data line.
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SPSCK CYCLE # FOR REFERENCE SPSCK; CPOL = 0 SPSCK; CPOL =1 MOSI FROM MASTER MISO FROM SLAVE SS; TO SLAVE CAPTURE STROBE
1
2
3
4
5
6
7
8
MSB MSB
BIT 6 BIT 6
BIT 5 BIT 5
BIT 4 BIT 4
BIT 3 BIT 3
BIT 2 BIT 2
BIT 1 BIT 1
LSB LSB
Figure 16-6. Transmission Format (CPHA = 1)
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Serial Peripheral Interface Module (SPI) Transmission Formats
When CPHA = 1 for a slave, the first edge of the SPSCK indicates the beginning of the transmission. This causes the SPI to leave its idle state and begin driving the MISO pin with the MSB of its data. Once the transmission begins, no new data is allowed into the shift register from the transmit data register. Therefore, the SPI data register of the slave must be loaded with transmit data before the first edge of SPSCK. Any data written after the first edge is stored in the transmit data register and transferred to the shift register after the current transmission.
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16.6.4 Transmission Initiation Latency When the SPI is configured as a master (SPMSTR = 1), writing to the SPDR starts a transmission. CPHA has no effect on the delay to the start of the transmission, but it does affect the initial state of the SPSCK signal. When CPHA = 0, the SPSCK signal remains inactive for the first half of the first SPSCK cycle. When CPHA = 1, the first SPSCK cycle begins with an edge on the SPSCK line from its inactive to its active level. The SPI clock rate (selected by SPR1:SPR0) affects the delay from the write to SPDR and the start of the SPI transmission. (See Figure 16-7.) The internal SPI clock in the master is a free-running derivative of the internal MCU clock. To conserve power, it is enabled only when both the SPE and SPMSTR bits are set. SPSCK edges occur halfway through the low time of the internal MCU clock. Since the SPI clock is free-running, it is uncertain where the write to the SPDR occurs relative to the slower SPSCK. This uncertainty causes the variation in the initiation delay shown in Figure 16-7. This delay is no longer than a single SPI bit time. That is, the maximum delay is two MCU bus cycles for DIV2, eight MCU bus cycles for DIV8, 32 MCU bus cycles for DIV32, and 128 MCU bus cycles for DIV128.
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WRITE TO SPDR BUS CLOCK MOSI SPSCK CPHA = 1 SPSCK CPHA = 0 SPSCK CYCLE NUMBER
INITIATION DELAY
MSB
BIT 6
BIT 5
Freescale Semiconductor, Inc...
1
2
3
INITIATION DELAY FROM WRITE SPDR TO TRANSFER BEGIN
BUS CLOCK BUS CLOCK BUS CLOCK BUS CLOCK
WRITE TO SPDR
EARLIEST LATEST WRITE TO SPDR
EARLIEST WRITE TO SPDR
EARLIEST WRITE TO SPDR
EARLIEST
Figure 16-7. Transmission Start Delay (Master)
SPSCK = INTERNAL CLOCK / 2; 2 POSSIBLE START POINTS SPSCK = INTERNAL CLOCK / 8; 8 POSSIBLE START POINTS LATEST SPSCK = INTERNAL CLOCK / 32; 32 POSSIBLE START POINTS LATEST SPSCK = INTERNAL CLOCK / 128; 128 POSSIBLE START POINTS LATEST
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Serial Peripheral Interface Module (SPI) Queuing Transmission Data
16.7 Queuing Transmission Data
The double-buffered transmit data register allows a data byte to be queued and transmitted. For an SPI configured as a master, a queued data byte is transmitted immediately after the previous transmission has completed. The SPI transmitter empty flag (SPTE) indicates when the transmit data buffer is ready to accept new data. Write to the transmit data register only when the SPTE bit is high. Figure 16-8 shows the timing associated with doing back-to-back transmissions with the SPI (SPSCK has CPHA: CPOL = 1:0).
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WRITE TO SPDR SPTE SPSCK CPHA:CPOL = 1:0 MOSI
1 2
3 5
8 10
MSB BIT BIT BIT BIT BIT BIT LSB MSB BIT BIT BIT BIT BIT BIT LSB MSB BIT BIT BIT 654321 654321 654 BYTE 1 BYTE 2 BYTE 3 4 6 7 7 CPU READS SPDR, CLEARING SPRF BIT. 8 CPU WRITES BYTE 3 TO SPDR, QUEUEING BYTE 3 AND CLEARING SPTE BIT. 9 SECOND INCOMING BYTE TRANSFERS FROM SHIFT REGISTER TO RECEIVE DATA REGISTER, SETTING SPRF BIT. 10 BYTE 3 TRANSFERS FROM TRANSMIT DATA REGISTER TO SHIFT REGISTER, SETTING SPTE BIT. 11 CPU READS SPSCR WITH SPRF BIT SET. 12 CPU READS SPDR, CLEARING SPRF BIT. 9 11 12
SPRF READ SPSCR READ SPDR 1 CPU WRITES BYTE 1 TO SPDR, CLEARING SPTE BIT. 2 BYTE 1 TRANSFERS FROM TRANSMIT DATA REGISTER TO SHIFT REGISTER, SETTING SPTE BIT. 3 CPU WRITES BYTE 2 TO SPDR, QUEUEING BYTE 2 AND CLEARING SPTE BIT. 4 FIRST INCOMING BYTE TRANSFERS FROM SHIFT REGISTER TO RECEIVE DATA REGISTER, SETTING SPRF BIT. 5 BYTE 2 TRANSFERS FROM TRANSMIT DATA REGISTER TO SHIFT REGISTER, SETTING SPTE BIT. 6 CPU READS SPSCR WITH SPRF BIT SET.
Figure 16-8. SPRF/SPTE CPU Interrupt Timing The transmit data buffer allows back-to-back transmissions without the slave precisely timing its writes between transmissions as in a system with a single data buffer. Also, if no new data is written to the data buffer, the last value contained in the shift register is the next data word to be transmitted.
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For an idle master or idle slave that has no data loaded into its transmit buffer, the SPTE is set again no more than two bus cycles after the transmit buffer empties into the shift register. This allows the user to queue up a 16-bit value to send. For an already active slave, the load of the shift register cannot occur until the transmission is completed. This implies that a back-to-back write to the transmit data register is not possible. The SPTE indicates when the next write can occur.
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16.8 Error Conditions
The following flags signal SPI error conditions: * Overflow (OVRF) -- Failing to read the SPI data register before the next full byte enters the shift register sets the OVRF bit. The new byte does not transfer to the receive data register, and the unread byte still can be read. OVRF is in the SPI status and control register. Mode fault error (MODF) -- The MODF bit indicates that the voltage on the slave select pin (SS) is inconsistent with the mode of the SPI. MODF is in the SPI status and control register.
*
16.8.1 Overflow Error The overflow flag (OVRF) becomes set if the receive data register still has unread data from a previous transmission when the capture strobe of bit 1 of the next transmission occurs. The bit 1 capture strobe occurs in the middle of SPSCK cycle 7. (See Figure 16-4 and Figure 16-6.) If an overflow occurs, all data received after the overflow and before the OVRF bit is cleared does not transfer to the receive data register and does not set the SPI receiver full bit (SPRF). The unread data that transferred to the receive data register before the overflow occurred can still be read. Therefore, an overflow error always indicates the loss of data. Clear the overflow flag by reading the SPI status and control register and then reading the SPI data register. OVRF generates a receiver/error CPU interrupt request if the error interrupt enable bit (ERRIE) is also set. The SPRF, MODF, and OVRF
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Serial Peripheral Interface Module (SPI) Error Conditions
interrupts share the same CPU interrupt vector. (See Figure 16-11.) It is not possible to enable MODF or OVRF individually to generate a receiver/error CPU interrupt request. However, leaving MODFEN low prevents MODF from being set. If the CPU SPRF interrupt is enabled and the OVRF interrupt is not, watch for an overflow condition. Figure 16-9 shows how it is possible to miss an overflow. The first part of Figure 16-9 shows how it is possible to read the SPSCR and SPDR to clear the SPRF without problems. However, as illustrated by the second transmission example, the OVRF bit can be set in between the time that SPSCR and SPDR are read.
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BYTE 1 1
BYTE 2 4
BYTE 3 6
BYTE 4 8
SPRF
OVRF READ SPSCR READ SPDR 1 2 3 4 2 5
3 BYTE 1 SETS SPRF BIT. CPU READS SPSCR WITH SPRF BIT SET AND OVRF BIT CLEAR. CPU READS BYTE 1 IN SPDR, CLEARING SPRF BIT. BYTE 2 SETS SPRF BIT. 5 6 7 8
7 CPU READS SPSCR WITH SPRF BIT SET AND OVRF BIT CLEAR. BYTE 3 SETS OVRF BIT. BYTE 3 IS LOST. CPU READS BYTE 2 IN SPDR, CLEARING SPRF BIT, BUT NOT OVRF BIT. BYTE 4 FAILS TO SET SPRF BIT BECAUSE OVRF BIT IS NOT CLEARED. BYTE 4 IS LOST.
Figure 16-9. Missed Read of Overflow Condition In this case, an overflow can be missed easily. Since no more SPRF interrupts can be generated until this OVRF is serviced, it is not obvious that bytes are being lost as more transmissions are completed. To prevent this, either enable the OVRF interrupt or do another read of the SPSCR following the read of the SPDR. This ensures that the OVRF was not set before the SPRF was cleared and that future transmissions can set the SPRF bit. Figure 16-10 illustrates this process. Generally, to avoid this second SPSCR read, enable the OVRF to the CPU by setting the ERRIE bit.
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BYTE 1 SPI RECEIVE COMPLETE SPRF OVRF READ SPSCR READ SPDR 1 2 3 4 1
BYTE 2 5
BYTE 3 7
BYTE 4 11
6 8 8 9
9 10
12 13
14
BYTE 1 SETS SPRF BIT. CPU READS SPSCR WITH SPRF BIT SET AND OVRF BIT CLEAR. CPU READS BYTE 1 IN SPDR, CLEARING SPRF BIT. CPU READS SPSCR AGAIN TO CHECK OVRF BIT. BYTE 2 SETS SPRF BIT. CPU READS SPSCR WITH SPRF BIT SET AND OVRF BIT CLEAR. BYTE 3 SETS OVRF BIT. BYTE 3 IS LOST.
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2 3 4 5 6 7
CPU READS BYTE 2 IN SPDR, CLEARING SPRF BIT. CPU READS SPSCR AGAIN TO CHECK OVRF BIT.
10 CPU READS BYTE 2 SPDR, CLEARING OVRF BIT. 11 BYTE 4 SETS SPRF BIT. 12 CPU READS SPSCR. 13 CPU READS BYTE 4 IN SPDR, CLEARING SPRF BIT. 14 CPU READS SPSCR AGAIN TO CHECK OVRF BIT.
Figure 16-10. Clearing SPRF When OVRF Interrupt Is Not Enabled
16.8.2 Mode Fault Error Setting the SPMSTR bit selects master mode and configures the SPSCK and MOSI pins as outputs and the MISO pin as an input. Clearing SPMSTR selects slave mode and configures the SPSCK and MOSI pins as inputs and the MISO pin as an output. The mode fault bit, MODF, becomes set any time the state of the slave select pin, SS, is inconsistent with the mode selected by SPMSTR. To prevent SPI pin contention and damage to the MCU, a mode fault error occurs if: * * The SS pin of a slave SPI goes high during a transmission The SS pin of a master SPI goes low at any time
For the MODF flag to be set, the mode fault error enable bit (MODFEN) must be set. Clearing the MODFEN bit does not clear the MODF flag but does prevent MODF from being set again after MODF is cleared.
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Serial Peripheral Interface Module (SPI) Error Conditions
MODF generates a receiver/error CPU interrupt request if the error interrupt enable bit (ERRIE) is also set. The SPRF, MODF, and OVRF interrupts share the same CPU interrupt vector. (See Figure 16-11.) It is not possible to enable MODF or OVRF individually to generate a receiver/error CPU interrupt request. However, leaving MODFEN low prevents MODF from being set. In a master SPI with the mode fault enable bit (MODFEN) set, the mode fault flag (MODF) is set if SS goes to logic 0. A mode fault in a master SPI causes the following events to occur:
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* * * * *
If ERRIE = 1, the SPI generates an SPI receiver/error CPU interrupt request. The SPE bit is cleared. The SPTE bit is set. The SPI state counter is cleared. The data direction register of the shared I/O port regains control of port drivers.
NOTE:
To prevent bus contention with another master SPI after a mode fault error, clear all SPI bits of the data direction register of the shared I/O port before enabling the SPI.
When configured as a slave (SPMSTR = 0), the MODF flag is set if SS goes high during a transmission. When CPHA = 0, a transmission begins when SS goes low and ends once the incoming SPSCK goes back to its idle level following the shift of the eighth data bit. When CPHA = 1, the transmission begins when the SPSCK leaves its idle level and SS is already low. The transmission continues until the SPSCK returns to its idle level following the shift of the last data bit. (See 16.6 Transmission Formats.)
NOTE:
Setting the MODF flag does not clear the SPMSTR bit. The SPMSTR bit has no function when SPE = 0. Reading SPMSTR when MODF = 1 shows the difference between a MODF occurring when the SPI is a master and when it is a slave. When CPHA = 0, a MODF occurs if a slave is selected (SS is at logic 0) and later unselected (SS is at logic 1) even if no SPSCK is sent to that
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slave. This happens because SS at logic 0 indicates the start of the transmission (MISO driven out with the value of MSB) for CPHA = 0. When CPHA = 1, a slave can be selected and then later unselected with no transmission occurring. Therefore, MODF does not occur since a transmission was never begun.
In a slave SPI (MSTR = 0), the MODF bit generates an SPI receiver/error CPU interrupt request if the ERRIE bit is set. The MODF bit does not clear the SPE bit or reset the SPI in any way. Software can abort the SPI transmission by clearing the SPE bit of the slave.
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NOTE:
A logic 1 voltage on the SS pin of a slave SPI puts the MISO pin in a high impedance state. Also, the slave SPI ignores all incoming SPSCK clocks, even if it was already in the middle of a transmission.
To clear the MODF flag, read the SPSCR with the MODF bit set and then write to the SPCR register. This entire clearing mechanism must occur with no MODF condition existing or else the flag is not cleared.
16.9 Interrupts
Four SPI status flags can be enabled to generate CPU interrupt requests. Table 16-2. SPI Interrupts
Flag SPTE Transmitter empty SPRF Receiver full OVRF Overflow MODF Mode fault Request SPI transmitter CPU interrupt request (SPTIE = 1, SPE = 1) SPI receiver CPU interrupt request (SPRIE = 1) SPI receiver/error interrupt request (ERRIE = 1) SPI receiver/error interrupt request (ERRIE = 1)
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Serial Peripheral Interface Module (SPI) Interrupts
Reading the SPI status and control register with SPRF set and then reading the receive data register clears SPRF. The clearing mechanism for the SPTE flag is always just a write to the transmit data register. The SPI transmitter interrupt enable bit (SPTIE) enables the SPTE flag to generate transmitter CPU interrupt requests, provided that the SPI is enabled (SPE = 1). The SPI receiver interrupt enable bit (SPRIE) enables the SPRF bit to generate receiver CPU interrupt requests, regardless of the state of the SPE bit. (See Figure 16-11.) The error interrupt enable bit (ERRIE) enables both the MODF and OVRF bits to generate a receiver/error CPU interrupt request. The mode fault enable bit (MODFEN) can prevent the MODF flag from being set so that only the OVRF bit is enabled by the ERRIE bit to generate receiver/error CPU interrupt requests.
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NOT AVAILABLE
SPTE
SPTIE
SPE SPI TRANSMITTER CPU INTERRUPT REQUEST
R
NOT AVAILABLE
SPRIE
SPRF
SPI RECEIVER/ERROR ERRIE MODF OVRF CPU INTERRUPT REQUEST
Figure 16-11. SPI Interrupt Request Generation
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The following sources in the SPI status and control register can generate CPU interrupt requests: * SPI receiver full bit (SPRF) -- The SPRF bit becomes set every time a byte transfers from the shift register to the receive data register. If the SPI receiver interrupt enable bit, SPRIE, is also set, SPRF generates an SPI receiver/error CPU interrupt request. SPI transmitter empty (SPTE) -- The SPTE bit becomes set every time a byte transfers from the transmit data register to the shift register. If the SPI transmit interrupt enable bit, SPTIE, is also set, SPTE generates an SPTE CPU interrupt request.
*
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16.10 Resetting the SPI
Any system reset completely resets the SPI. Partial resets occur whenever the SPI enable bit (SPE) is low. Whenever SPE is low, the following occurs: * * * * * The SPTE flag is set. Any transmission currently in progress is aborted. The shift register is cleared. The SPI state counter is cleared, making it ready for a new complete transmission. All the SPI port logic is defaulted back to being general-purpose I/O.
These items are reset only by a system reset: * * * All control bits in the SPCR register All control bits in the SPSCR register (MODFEN, ERRIE, SPR1, and SPR0) The status flags SPRF, OVRF, and MODF
By not resetting the control bits when SPE is low, the user can clear SPE between transmissions without having to set all control bits again when SPE is set back high for the next transmission.
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Serial Peripheral Interface Module (SPI) Low-Power Modes
By not resetting the SPRF, OVRF, and MODF flags, the user can still service these interrupts after the SPI has been disabled. The user can disable the SPI by writing 0 to the SPE bit. The SPI can also be disabled by a mode fault occurring in an SPI that was configured as a master with the MODFEN bit set.
16.11 Low-Power Modes
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The WAIT and STOP instructions put the MCU in low powerconsumption standby modes.
16.11.1 Wait Mode The SPI module remains active after the execution of a WAIT instruction. In wait mode the SPI module registers are not accessible by the CPU. Any enabled CPU interrupt request from the SPI module can bring the MCU out of wait mode. If SPI module functions are not required during wait mode, reduce power consumption by disabling the SPI module before executing the WAIT instruction. To exit wait mode when an overflow condition occurs, enable the OVRF bit to generate CPU interrupt requests by setting the error interrupt enable bit (ERRIE). (See 16.9 Interrupts.)
16.11.2 Stop Mode The SPI module is inactive after the execution of a STOP instruction. The STOP instruction does not affect register conditions. SPI operation resumes after an external interrupt. If stop mode is exited by reset, any transfer in progress is aborted, and the SPI is reset.
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The system integration module (SIM) controls whether status bits in other modules can be cleared during the break state. The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear status bits during the break state. (See Section 8. System Integration Module (SIM).) To allow software to clear status bits during a break interrupt, write a logic 1 to the BCFE bit. If a status bit is cleared during the break state, it remains cleared when the MCU exits the break state. To protect status bits during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its default state), software can read and write I/O registers during the break state without affecting status bits. Some status bits have a 2-step read/write clearing procedure. If software does the first step on such a bit before the break, the bit cannot change during the break state as long as BCFE is at logic 0. After the break, doing the second step clears the status bit. Since the SPTE bit cannot be cleared during a break with the BCFE bit cleared, a write to the transmit data register in break mode does not initiate a transmission nor is this data transferred into the shift register. Therefore, a write to the SPDR in break mode with the BCFE bit cleared has no effect.
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16.13 I/O Signals
The SPI module has five I/O pins and shares four of them with a parallel I/O port. They are: * * * * * MISO -- Data received MOSI -- Data transmitted SPSCK -- Serial clock SS -- Slave select CGND -- Clock ground (internally connected to VSS)
Technical Data
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Serial Peripheral Interface Module (SPI) I/O Signals
The SPI has limited inter-integrated circuit (I2C) capability (requiring software support) as a master in a single-master environment. To communicate with I2C peripherals, MOSI becomes an open-drain output when the SPWOM bit in the SPI control register is set. In I2C communication, the MOSI and MISO pins are connected to a bidirectional pin from the I2C peripheral and through a pullup resistor to VDD.
16.13.1 MISO (Master In/Slave Out)
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MISO is one of the two SPI module pins that transmits serial data. In full duplex operation, the MISO pin of the master SPI module is connected to the MISO pin of the slave SPI module. The master SPI simultaneously receives data on its MISO pin and transmits data from its MOSI pin. Slave output data on the MISO pin is enabled only when the SPI is configured as a slave. The SPI is configured as a slave when its SPMSTR bit is logic 0 and its SS pin is at logic 0. To support a multipleslave system, a logic 1 on the SS pin puts the MISO pin in a highimpedance state. When enabled, the SPI controls data direction of the MISO pin regardless of the state of the data direction register of the shared I/O port.
16.13.2 MOSI (Master Out/Slave In) MOSI is one of the two SPI module pins that transmits serial data. In fullduplex operation, the MOSI pin of the master SPI module is connected to the MOSI pin of the slave SPI module. The master SPI simultaneously transmits data from its MOSI pin and receives data on its MISO pin. When enabled, the SPI controls data direction of the MOSI pin regardless of the state of the data direction register of the shared I/O port.
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16.13.3 SPSCK (Serial Clock) The serial clock synchronizes data transmission between master and slave devices. In a master MCU, the SPSCK pin is the clock output. In a slave MCU, the SPSCK pin is the clock input. In full-duplex operation, the master and slave MCUs exchange a byte of data in eight serial clock cycles. When enabled, the SPI controls data direction of the SPSCK pin regardless of the state of the data direction register of the shared I/O port.
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16.13.4 SS (Slave Select) The SS pin has various functions depending on the current state of the SPI. For an SPI configured as a slave, the SS is used to select a slave. For CPHA = 0, the SS is used to define the start of a transmission. (See 16.6 Transmission Formats.) Since it is used to indicate the start of a transmission, the SS must be toggled high and low between each byte transmitted for the CPHA = 0 format. However, it can remain low between transmissions for the CPHA = 1 format. See Figure 16-12.
MISO/MOSI MASTER SS SLAVE SS CPHA = 0 SLAVE SS CPHA = 1
BYTE 1
BYTE 2
BYTE 3
Figure 16-12. CPHA/SS Timing When an SPI is configured as a slave, the SS pin is always configured as an input. It cannot be used as a general-purpose I/O regardless of the state of the MODFEN control bit. However, the MODFEN bit can still prevent the state of the SS from creating a MODF error. (See 16.14.2 SPI Status and Control Register.)
NOTE:
A logic 1 voltage on the SS pin of a slave SPI puts the MISO pin in a highimpedance state. The slave SPI ignores all incoming SPSCK clocks, even if it was already in the middle of a transmission.
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Serial Peripheral Interface Module (SPI) I/O Signals
When an SPI is configured as a master, the SS input can be used in conjunction with the MODF flag to prevent multiple masters from driving MOSI and SPSCK. (See 16.8.2 Mode Fault Error.) For the state of the SS pin to set the MODF flag, the MODFEN bit in the SPSCK register must be set. If the MODFEN bit is low for an SPI master, the SS pin can be used as a general-purpose I/O under the control of the data direction register of the shared I/O port. With MODFEN high, it is an input-only pin to the SPI regardless of the state of the data direction register of the shared I/O port.
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The CPU can always read the state of the SS pin by configuring the appropriate pin as an input and reading the port data register. (See Table 16-3.) Table 16-3. SPI Configuration
SPE 0 1 1 1 SPMSTR X(1) 0 1 1 MODFEN X X 0 1 SPI Configuration Not enabled Slave Master without MODF Master with MODF State of SS Logic General-purpose I/O; SS ignored by SPI Input-only to SPI General-purpose I/O; SS ignored by SPI Input-only to SPI
Note 1. X = Don't care
16.13.5 CGND (Clock Ground) CGND is the ground return for the serial clock pin, SPSCK, and the ground for the port output buffers. It is internally connected to VSS as shown in Table 16-1.
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Three registers control and monitor SPI operation: * * * SPI control register (SPCR) SPI status and control register (SPSCR) SPI data register (SPDR)
16.14.1 SPI Control Register
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The SPI control register: * * * * * Enables SPI module interrupt requests Configures the SPI module as master or slave Selects serial clock polarity and phase Configures the SPSCK, MOSI, and MISO pins as open-drain outputs Enables the SPI module
Address: $0010 Bit 7 Read: SPRIE Write: Reset: 0 0 1 0 1 R 0 = Reserved 0 0 R SPMSTR CPOL CPHA SPWOM SPE SPTIE 6 5 4 3 2 1 Bit 0
= Unimplemented
Figure 16-13. SPI Control Register (SPCR) SPRIE -- SPI Receiver Interrupt Enable Bit This read/write bit enables CPU interrupt requests generated by the SPRF bit. The SPRF bit is set when a byte transfers from the shift register to the receive data register. Reset clears the SPRIE bit. 1 = SPRF CPU interrupt requests enabled 0 = SPRF CPU interrupt requests disabled
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Serial Peripheral Interface Module (SPI) I/O Registers
SPMSTR -- SPI Master Bit This read/write bit selects master mode operation or slave mode operation. Reset sets the SPMSTR bit. 1 = Master mode 0 = Slave mode CPOL -- Clock Polarity Bit This read/write bit determines the logic state of the SPSCK pin between transmissions. (See Figure 16-4 and Figure 16-6.) To transmit data between SPI modules, the SPI modules must have identical CPOL values. Reset clears the CPOL bit. CPHA -- Clock Phase Bit This read/write bit controls the timing relationship between the serial clock and SPI data. (See Figure 16-4 and Figure 16-6.) To transmit data between SPI modules, the SPI modules must have identical CPHA values. When CPHA = 0, the SS pin of the slave SPI module must be set to logic 1 between bytes. (See Figure 16-12.) Reset sets the CPHA bit. SPWOM -- SPI Wired-OR Mode Bit This read/write bit disables the pullup devices on pins SPSCK, MOSI, and MISO so that those pins become open-drain outputs. 1 = Wired-OR SPSCK, MOSI, and MISO pins 0 = Normal push-pull SPSCK, MOSI, and MISO pins SPE -- SPI Enable This read/write bit enables the SPI module. Clearing SPE causes a partial reset of the SPI. (See 16.10 Resetting the SPI.) Reset clears the SPE bit. 1 = SPI module enabled 0 = SPI module disabled SPTIE-- SPI Transmit Interrupt Enable This read/write bit enables CPU interrupt requests generated by the SPTE bit. SPTE is set when a byte transfers from the transmit data register to the shift register. Reset clears the SPTIE bit. 1 = SPTE CPU interrupt requests enabled 0 = SPTE CPU interrupt requests disabled
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16.14.2 SPI Status and Control Register The SPI status and control register contains flags to signal these conditions: * * * Receive data register full Failure to clear SPRF bit before next byte is received (overflow error) Inconsistent logic level on SS pin (mode fault error) Transmit data register empty
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*
The SPI status and control register also contains bits that perform these functions: * * * Enable error interrupts Enable mode fault error detection Select master SPI baud rate
Address: $0011 Bit 7 Read: Write: Reset: 0 0 0 0 1 0 0 0 SPRF ERRIE 6 5 OVRF 4 MODF 3 SPTE MODFEN SPR1 SPR0 2 1 Bit 0
= Unimplemented
Figure 16-14. SPI Status and Control Register (SPSCR) SPRF -- SPI Receiver Full Bit This clearable, read-only flag is set each time a byte transfers from the shift register to the receive data register. SPRF generates a CPU interrupt request if the SPRIE bit in the SPI control register is set also. During an SPRF CPU interrupt, the CPU clears SPRF by reading the SPI status and control register with SPRF set and then reading the SPI data register. Reset clears the SPRF bit. 1 = Receive data register full 0 = Receive data register not full
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Serial Peripheral Interface Module (SPI) I/O Registers
ERRIE -- Error Interrupt Enable Bit This read/write bit enables the MODF and OVRF bits to generate CPU interrupt requests. Reset clears the ERRIE bit. 1 = MODF and OVRF can generate CPU interrupt requests 0 = MODF and OVRF cannot generate CPU interrupt requests OVRF -- Overflow Bit This clearable, read-only flag is set if software does not read the byte in the receive data register before the next full byte enters the shift register. In an overflow condition, the byte already in the receive data register is unaffected, and the byte that shifted in last is lost. Clear the OVRF bit by reading the SPI status and control register with OVRF set and then reading the receive data register. Reset clears the OVRF bit. 1 = Overflow 0 = No overflow MODF -- Mode Fault Bit This clearable, read-only flag is set in a slave SPI if the SS pin goes high during a transmission with the MODFEN bit set. In a master SPI, the MODF flag is set if the SS pin goes low at any time with the MODFEN bit set. Clear the MODF bit by reading the SPI status and control register (SPSCR) with MODF set and then writing to the SPI control register (SPCR). Reset clears the MODF bit. 1 = SS pin at inappropriate logic level 0 = SS pin at appropriate logic level SPTE -- SPI Transmitter Empty Bit This clearable, read-only flag is set each time the transmit data register transfers a byte into the shift register. SPTE generates an SPTE CPU interrupt request if the SPTIE bit in the SPI control register is set also.
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NOTE:
Do not write to the SPI data register unless the SPTE bit is high.
During an SPTE CPU interrupt, the CPU clears the SPTE bit by writing to the transmit data register. Reset sets the SPTE bit. 1 = Transmit data register empty 0 = Transmit data register not empty
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MODFEN -- Mode Fault Enable Bit This read/write bit, when set to 1, allows the MODF flag to be set. If the MODF flag is set, clearing the MODFEN does not clear the MODF flag. If the SPI is enabled as a master and the MODFEN bit is low, then the SS pin is available as a general-purpose I/O. If the MODFEN bit is set, then this pin is not available as a generalpurpose I/O. When the SPI is enabled as a slave, the SS pin is not available as a general-purpose I/O regardless of the value of MODFEN. (See 16.13.4 SS (Slave Select).)
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If the MODFEN bit is low, the level of the SS pin does not affect the operation of an enabled SPI configured as a master. For an enabled SPI configured as a slave, having MODFEN low only prevents the MODF flag from being set. It does not affect any other part of SPI operation. (See 16.8.2 Mode Fault Error.) SPR1 and SPR0 -- SPI Baud Rate Select Bits In master mode, these read/write bits select one of four baud rates as shown in Table 16-4. SPR1 and SPR0 have no effect in slave mode. Reset clears SPR1 and SPR0. Table 16-4. SPI Master Baud Rate Selection
SPR1 and SPR0 00 01 10 11 Baud Rate Divisor (BD) 2 8 32 128
Use this formula to calculate the SPI baud rate: CGMOUT Baud rate = ------------------------2 x BD where: CGMOUT = base clock output of the clock generator module (CGM) BD = baud rate divisor
Technical Data
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Serial Peripheral Interface Module (SPI) I/O Registers
16.14.3 SPI Data Register The SPI data register consists of the read-only receive data register and the write-only transmit data register. Writing to the SPI data register writes data into the transmit data register. Reading the SPI data register reads data from the receive data register. The transmit data and receive data registers are separate registers that can contain different values. (See Figure 16-2.)
Address: $0012 Bit 7 Read: Write: Reset: R7 T7 6 R6 T6 5 R5 T5 4 R4 T4 3 R3 T3 2 R2 T2 1 R1 T1 Bit 0 R0 T0
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Unaffected by reset
Figure 16-15. SPI Data Register (SPDR) R7-R0/T7-T0 -- Receive/Transmit Data Bits
NOTE:
Do not use read-modify-write instructions on the SPI data register since the register read is not the same as the register written.
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Technical Data -- MC68HC08AB16A
Section 17. Input/Output (I/O) Ports
17.1 Contents
17.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
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17.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308 17.3.1 Port A Data Register (PTA) . . . . . . . . . . . . . . . . . . . . . . . . 308 17.3.2 Data Direction Register A (DDRA) . . . . . . . . . . . . . . . . . . . 308 17.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 17.4.1 Port B Data Register (PTB) . . . . . . . . . . . . . . . . . . . . . . . . 310 17.4.2 Data Direction Register B (DDRB) . . . . . . . . . . . . . . . . . . . 311 17.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 17.5.1 Port C Data Register (PTC) . . . . . . . . . . . . . . . . . . . . . . . . 312 17.5.2 Data Direction Register C (DDRC). . . . . . . . . . . . . . . . . . . 313 17.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 17.6.1 Port D Data Register (PTD) . . . . . . . . . . . . . . . . . . . . . . . . 315 17.6.2 Data Direction Register D (DDRD). . . . . . . . . . . . . . . . . . . 316 17.6.3 Port D Input Pullup Enable Register (PTDPUE). . . . . . . . . 317 17.7 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 17.7.1 Port E Data Register (PTE) . . . . . . . . . . . . . . . . . . . . . . . . 318 17.7.2 Data Direction Register E (DDRE) . . . . . . . . . . . . . . . . . . . 320 17.8 Port F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 17.8.1 Port F Data Register (PTF) . . . . . . . . . . . . . . . . . . . . . . . . 321 17.8.2 Data Direction Register F (DDRF) . . . . . . . . . . . . . . . . . . . 322 17.8.3 Port F Input Pullup Enable Register (PTFPUE) . . . . . . . . . 324 17.9 Port G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 17.9.1 Port G Data Register (PTG) . . . . . . . . . . . . . . . . . . . . . . . . 324 17.9.2 Data Direction Register G (DDRG) . . . . . . . . . . . . . . . . . . 325 17.10 Port H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 17.10.1 Port H Data Register (PTH) . . . . . . . . . . . . . . . . . . . . . . . . 327 17.10.2 Data Direction Register H (DDRH). . . . . . . . . . . . . . . . . . . 327
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Freescale Semiconductor, Inc. Input/Output (I/O) Ports 17.2 Introduction
Fifty-one bidirectional input-output (I/O) pins form eight parallel ports. All I/O pins are programmable as inputs or outputs.
NOTE:
Connect any unused I/O pins to an appropriate logic level, either VDD or VSS. Although the I/O ports do not require termination for proper operation, termination reduces excess current consumption and the possibility of electrostatic damage.
Bit 7 PTA7 6 PTA6 5 PTA5 4 PTA4 3 PTA3 2 PTA2 1 PTA1 Bit 0 PTA0
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Addr.
Register Name Read: Port A Data Register Write: (PTA) Reset: Read: Port B Data Register Write: (PTB) Reset: Read: Port C Data Register Write: (PTC) Reset: Read: Port D Data Register Write: (PTD) Reset:
$0000
Unaffected by reset PTB7 PTB6 PTB5 PTB4 PTB3 PTB2 PTB1 PTB0
$0001
Unaffected by reset 0 0 PTC5 PTC4 PTC3 PTC2 PTC1 PTC0
$0002
Unaffected by reset PTD7 PTD6 PTD5 PTD4 PTD3 PTD2 PTD1 PTD0
$0003
Unaffected by reset DDRA6 0 DDRB6 0 0 DDRA5 0 DDRB5 0 DDRC5 0 DDRD5 0 DDRA4 0 DDRB4 0 DDRC4 0 DDRD4 0 DDRA3 0 DDRB3 0 DDRC3 0 DDRD3 0 DDRA2 0 DDRB2 0 DDRC2 0 DDRD2 0 DDRA1 0 DDRB1 0 DDRC1 0 DDRD1 0 DDRA0 0 DDRB0 0 DDRC0 0 DDRD0 0
Read: DDRA7 Data Direction Register A $0004 Write: (DDRA) Reset: 0 Read: DDRB7 Data Direction Register B $0005 Write: (DDRB) Reset: 0 Read: MCLKEN Data Direction Register C $0006 Write: (DDRC) Reset: 0 Read: DDRD7 Data Direction Register D $0007 Write: (DDRD) Reset: 0
0 DDRD6 0
Figure 17-1. I/O Port Register Summary
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Input/Output (I/O) Ports Introduction
Addr.
Register Name Read: Port E Data Register Write: (PTE) Reset: Read: Port F Data Register Write: (PTF) Reset: Read: Port G Data Register Write: (PTG) Reset: Read: Port H Data Register Write: (PTH) Reset:
Bit 7 PTE7
6 PTE6
5 PTE5
4 PTE4
3 PTE3
2 PTE2
1 PTE1
Bit 0 PTE0
$0008
Unaffected by reset PTF7 PTF6 PTF5 PTF4 PTF3 PTF2 PTF1 PTF0
$0009
Unaffected by reset 0 0 0 0 0 PTG2 PTG1 PTG0
Freescale Semiconductor, Inc...
$000A
Unaffected by reset 0 0 0 0 0 0 PTH1 PTH0
$000B
Unaffected by reset DDRE6 0 DDRF6 0 0 DDRE5 0 DDRF5 0 0 DDRE4 0 DDRF4 0 0 DDRE3 0 DDRF3 0 0 DDRE2 0 DDRF2 0 DDRG2 0 0 DDRE1 0 DDRF1 0 DDRG1 0 DDRH1 0 DDRE0 0 DDRF0 0 DDRG0 0 DDRH0 0
Read: DDRE7 Data Direction Register E $000C Write: (DDRE) Reset: 0 Read: DDRF7 Data Direction Register F $000D Write: (DDRF) Reset: 0 Read: Data Direction Register G $000E Write: (DDRG) Reset: Read: Data Direction Register H $000F Write: (DDRH) Reset: 0
0 0
0 0
0 0
0 0
0 0
0
0
0
0
0
0
Read: Port D Input Pullup Enable PTDPUE7 PTDPUE6 PTDPUE5 PTDPUE4 PTDPUE3 PTDPUE2 PTDPUE1 PTDPUE0 $003D Register Write: (PTDPUE) Reset: 0 0 0 0 0 0 0 0 Read: Port F Input Pullup Enable PTFPUE7 PTFPUE6 PTFPUE5 PTFPUE4 PTFPUE3 PTFPUE2 PTFPUE1 PTFPUE0 $003E Register Write: (PTFPUE) Reset: 0 0 0 0 0 0 0 0
Figure 17-1. I/O Port Register Summary
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Table 17-1. Port Control Register Bits Summary (Sheet 1 of 2)
Port Bit 0 1 2 A 3 4 5 DDR DDRA0 DDRA1 DDRA2 DDRA3 DDRA4 DDRA5 DDRA6 DDRA7 DDRB0 DDRB1 DDRB2 DDRB3 DDRB4 DDRB5 DDRB6 DDRB7 DDRC0 DDRC1 DDRC2 DDRC3 DDRC4 DDRC5 DDRD0 DDRD1 DDRD2 DDRD3 DDRD4 DDRD5 DDRD6 DDRD7 TIMB -- TIMA -- TBSC $0040 -- TASC $0020 -- PS[2:0] -- PS[2:0] -- -- -- -- -- -- -- --
--
Module Control Module Register Control Bit
Pin PTA0 PTA1 PTA2
--
--
--
PTA3 PTA4 PTA5 PTA6 PTA7 PTB0/ATD0 PTB1/ATD1 PTB2/ATD2
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6 7 0 1 2 B 3 4 5 6 7 0 1 C 2 3 4 5 0 1 2 3 D 4 5 6 7
ADC
ADSCR $0038
ADCH[4:0]
PTB3/ATD3 PTB4/ATD4 PTB5/ATD5 PTB6/ATD6 PTB7/ATD7
--
DDRC $0006
-- MCLKEN
PTC0 PTC1 PTC2/MCLK PTC3 PTC4 PTC5 PTD0 PTD1 PTD2 PTD3 PTD4/TBCLK PTD5 PTD6/TACLK PTD7
Technical Data
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Input/Output (I/O) Ports Introduction
Table 17-1. Port Control Register Bits Summary (Sheet 2 of 2)
Port Bit 0 1 2 E 3 4 5 6 7 0 1 2 F 3 4 5 6 7 0 G 1 2 0
H
DDR DDRE0 DDRE1 DDRE2
Module Control Module SCI Register SCC1 $0013 TASC0 $0026 TASC1 $0029 Control Bit ENSCI ELS0B:ELS0A ELS1B:ELS1A SPE, SPMSTR SPI SPCR $0010
Pin PTE0/TxD PTE1/RxD PTE2/TACH0 PTE3/TACH1 PTE4/SS PTE5/MISO
TIMA DDRE3 DDRE4 DDRE5 DDRE6 DDRE7 DDRF0 TIMA DDRF1 DDRF2 DDRF3 TIMB DDRF4 DDRF5 DDRF6 DDRF7 DDRG0 DDRG1 DDRG2 DDRH0 DDRH1 KBI --
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SPE
PTE6/MOSI PTE7SPSCK
TASC2 $002C TASC3 $002F TBSC2 $0032 TBSC3 $0035 TBSC0 $0045 TBSC1 $0048 --
ELS2B:ELS2A ELS3B:ELS3A ELS2B:ELS2A ELS3B:ELS3A ELS0B:ELS0A ELS1B:ELS1A -- KBIE0 KBIE1
PTF0/TACH2 PTF1/TACH3 PTF2/TBCH2 PTF3/TBCH3 PTF4/TBCH0 PTF5/TBCH1 PTF6 PTF7 PTG0/KBD0 PTG1/KBD1 PTG2/KBD2 PTH0/KBD3 PTH1/KBD4
KBIER $0021
KBIE2 KBIE3 KBIE4
1
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307
Freescale Semiconductor, Inc. Input/Output (I/O) Ports 17.3 Port A
Port A is an 8-bit general-purpose bidirectional I/O port.
17.3.1 Port A Data Register (PTA) The port A data register contains a data latch for each of the eight port A pins.
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Address:
$0000 Bit 7 6 PTA6 5 PTA5 4 PTA4 3 PTA3 2 PTA2 1 PTA1 Bit 0 PTA0
Read: PTA7 Write: Reset: Unaffected by Reset
Figure 17-2. Port A Data Register (PTA) PTA[7:0] -- Port A Data Bits These read/write bits are software programmable. Data direction of each port A pin is under the control of the corresponding bit in data direction register A. Reset has no effect on port A data.
17.3.2 Data Direction Register A (DDRA) Data direction register A determines whether each port A pin is an input or an output. Writing a logic 1 to a DDRA bit enables the output buffer for the corresponding port A pin; a logic 0 disables the output buffer.
Address: $0004 Bit 7 Read: DDRA7 Write: Reset: 0 0 0 0 0 0 0 0 DDRA6 DDRA5 DDRA4 DDRA3 DDRA2 DDRA1 DDRA0 6 5 4 3 2 1 Bit 0
Figure 17-3. Data Direction Register A (DDRA)
Technical Data
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Input/Output (I/O) Ports Port A
DDRA[7:0] -- Data Direction Register A Bits These read/write bits control port A data direction. Reset clears DDRA[7:0], configuring all port A pins as inputs. 1 = Corresponding port A pin configured as output 0 = Corresponding port A pin configured as input
NOTE:
Avoid glitches on port A pins by writing to the port A data register before changing data direction register A bits from 0 to 1. Figure 17-4 shows the port A I/O logic.
READ DDRA ($0004)
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WRITE DDRA ($0004) INTERNAL DATA BUS RESET WRITE PTA ($0000) PTAx PTAx DDRAx
READ PTA ($0000)
Figure 17-4. Port A I/O Circuit When DDRAx is a logic 1, reading address $0000 reads the PTAx data latch. When DDRAx is a logic 0, reading address $0000 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 17-2 summarizes the operation of the port A pins. Table 17-2. Port A Pin Functions
DDRA Bit Accesses to DDRA PTA Bit I/O Pin Mode Read/Write Read Write Accesses to PTA
0 1
X(1) X
Input, Hi-Z(2) Output
DDRA[7:0] DDRA[7:0]
Pin PTA[7:0]
PTA[7:0](3) PTA[7:0]
Notes: 1. X = don't care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect input.
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Technical Data
309
Freescale Semiconductor, Inc. Input/Output (I/O) Ports 17.4 Port B
Port B is an 8-bit special function port that shares all eight of its port pins with the analog-to-digital converter (ADC) module (see Section 14. Analog-to-Digital Converter (ADC)). 17.4.1 Port B Data Register (PTB) The port B data register contains a data latch for each of the eight port B pins.
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Address:
$0001 Bit 7 6 PTB6 5 PTB5 4 PTB4 3 PTB3 2 PTB2 1 PTB1 Bit 0 PTB0
Read: PTB7 Write: Reset: Alternative Function: ATD7 ATD6 ATD5 Unaffected by reset ATD4 ATD3 ATD2 ATD2 ATD0
Figure 17-5. Port B Data Register (PTB) PTB[7:0] -- Port B Data Bits These read/write bits are software programmable. Data direction of each port B pin is under the control of the corresponding bit in data direction register B. Reset has no effect on port B data. ATD[7:0] -- ADC channels ATD[7:0] are pins used for the input channels to the analog-to-digital converter module. The channel select bits in the ADC status and control register define which port B pin will be used as an ADC input and overrides any control from the port I/O logic by forcing that pin as the input to the analog circuitry.
NOTE:
Care must be taken when reading port B while applying analog voltages to ATD[7:0] pins. If the appropriate ADC channel is not enabled, excessive current drain may occur if analog voltages are applied to the PTBx/ATDx pin, while PTB is read as a digital input. Those ports not selected as analog input channels are considered digital I/O ports.
Technical Data
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Input/Output (I/O) Ports Port B
17.4.2 Data Direction Register B (DDRB) Data direction register B determines whether each port B pin is an input or an output. Writing a logic 1 to a DDRB bit enables the output buffer for the corresponding port B pin; a logic 0 disables the output buffer.
Address: $0005 Bit 7 Read: DDRB7 Write: Reset: 0 0 0 0 0 0 0 0 6 DDRB6 5 DDRB5 4 DDRB4 3 DDRB3 2 DDRB2 1 DDRB1 Bit 0 DDRB0
Freescale Semiconductor, Inc...
Figure 17-6. Data Direction Register B (DDRB) DDRB[7:0] -- Data Direction Register B Bits These read/write bits control port B data direction. Reset clears DDRB[7:0], configuring all port B pins as inputs. 1 = Corresponding port B pin configured as output 0 = Corresponding port B pin configured as input
NOTE:
Avoid glitches on port B pins by writing to the port B data register before changing data direction register B bits from 0 to 1. Figure 17-7 shows the port B I/O logic.
READ DDRB ($0005)
WRITE DDRB ($0005) INTERNAL DATA BUS RESET WRITE PTB ($0001) PTBx PTBx DDRBx
READ PTB ($0001)
To Analog-To-Digital Converter
Figure 17-7. Port B I/O Circuit
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Freescale Semiconductor, Inc. Input/Output (I/O) Ports
When DDRBx is a logic 1, reading address $0001 reads the PTBx data latch. When DDRBx is a logic 0, reading address $0001 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 17-3 summarizes the operation of the port B pins. Table 17-3. Port B Pin Functions
DDRB Bit Accesses to DDRB PTB Bit I/O Pin Mode Read/Write Read Write Accesses to PTB
Freescale Semiconductor, Inc...
0 1
X(1) X
Input, Hi-Z(2) Output
DDRB[7:0] DDRB[7:0]
Pin PTB[7:0]
PTB[7:0](3) PTB[7:0]
Notes: 1. X = don't care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect input.
17.5 Port C
Port C is a 6-bit general-purpose bidirectional I/O port. PTC2 pin can be configured as an output pin for the system MCLK clock.
17.5.1 Port C Data Register (PTC) The port C data register contains a data latch for each of the six port C pins.
Address: $0002 Bit 7 Read: Write: Reset: Alternative Function: Unaffected by reset MCLK 0 6 0 PTC5 PTC4 PTC3 PTC2 PTC1 PTC0 5 4 3 2 1 Bit 0
Figure 17-8. Port C Data Register (PTC)
Technical Data
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Freescale Semiconductor, Inc.
Input/Output (I/O) Ports Port C
PTC[5:0] -- Port C Data Bits These read/write bits are software programmable. Data direction of each port C pin is under the control of the corresponding bit in data direction register C. Reset has no effect on port C data. MCLK -- T12 System Clock The system clock is driven out of the PTC2 pin when MCLKEN is set.
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17.5.2 Data Direction Register C (DDRC) Data direction register C determines whether each port C pin is an input or an output. Writing a logic 1 to a DDRC bit enables the output buffer for the corresponding port C pin; a logic 0 disables the output buffer.
Address: $0006 Bit 7 Read: MCLKEN Write: Reset: 0 0 0 0 0 0 0 0 6 0 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1 DDRC0 5 4 3 2 1 Bit 0
Figure 17-9. Data Direction Register B (DDRB) MCLKEN -- T12 System Clock Enable Bit This read/write bit enables MCLK to be an output signal on PTC2 pin. Reset clears MCLKEN. 1 = PTC2 pin configured as MCLK output 0 = PTC2 pin configured as standard I/O pin DDRC[5:0] -- Data Direction Register C Bits These read/write bits control port C data direction. Reset clears DDRC[5:0], configuring all port C pins as inputs. 1 = Corresponding port C pin configured as output 0 = Corresponding port C pin configured as input
NOTE:
Avoid glitches on port C pins by writing to the port C data register before changing data direction register C bits from 0 to 1. Figure 17-10 shows the port C I/O logic.
Technical Data Input/Output (I/O) Ports For More Information On This Product, Go to: www.freescale.com
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313
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READ DDRC ($0006)
WRITE DDRC ($0006) INTERNAL DATA BUS RESET WRITE PTC ($0002) PTCx PTCx DDRCx
READ PTC ($0002)
Freescale Semiconductor, Inc...
PTC2 ONLY MCLK
MCLKEN
Figure 17-10. Port C I/O Circuit When DDRCx is a logic 1, reading address $0002 reads the PTCx data latch. When DDRCx is a logic 0, reading address $0002 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 17-4 summarizes the operation of the port C pins. Table 17-4. Port C Pin Functions
DDRC Bit Accesses to DDRC PTC Bit I/O Pin Mode Read/Write Read Write Accesses to PTC
0 1 0 1
2 2 X(1) X
Input, Hi-Z Output Input, Hi-Z(2) Output
DDRC7 DDRC7 DDRC[5:0] DDRC[5:0]
Pin 0 Pin PTC[5:0]
PTC2 --
PTC[5:0](3)
PTC[5:0]
Notes: 1. X = don't care; except PTC2. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect input.
Technical Data
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Input/Output (I/O) Ports Port D
17.6 Port D
Port D is an 8-bit special function port that shares two of its pins with the timer interface module (see Section 11. Timer Interface Module A (TIMA) and Section 12. Timer Interface Module B (TIMB)). Each port D pin has 15mA current drive (sink) and programmable pullup. 17.6.1 Port D Data Register (PTD)
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The port D data register contains a data latch for each of the eight port D pins.
Address: $0003 Bit 7 Read: PTD7 Write: Reset: Alternative Function: TACLK Unaffected by reset TBCLK PTD6 PTD5 PTD4 PTD3 PTD2 PTD1 PTD0 6 5 4 3 2 1 Bit 0
Additional Functions: 15mA sink 15mA sink 15mA sink 15mA sink 15mA sink 15mA sink 15mA sink 15mA sink
Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup
Figure 17-11. Port D Data Register (PTD) PTD[7:0] -- Port D Data Bits These read/write bits are software programmable. Data direction of each port D pin is under the control of the corresponding bit in data direction register D. Reset has no effect on port D data. TACLK -- Timer A Clock Input The PTD6 pin becomes TACLK, the timer A (TIMA) external clock input when the TIMA prescaler select bits, PS[2:0] = 111. See Section 11. Timer Interface Module A (TIMA). TBCLK -- Timer B Clock Input The PTD4 pin becomes TBCLK, the timer B (TIMB) external clock input when the TIMB prescaler select bits, PS[2:0] = 111. See Section 12. Timer Interface Module B (TIMB).
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Input/Output (I/O) Ports For More Information On This Product, Go to: www.freescale.com Technical Data
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Freescale Semiconductor, Inc. Input/Output (I/O) Ports
17.6.2 Data Direction Register D (DDRD) Data direction register D determines whether each port D pin is an input or an output. Writing a logic 1 to a DDRD bit enables the output buffer for the corresponding port D pin; a logic 0 disables the output buffer.
Address: $0007 Bit 7 Read: DDRD7 Write: Reset: 0 0 0 0 0 0 0 0 6 DDRD6 5 DDRD5 4 DDRD4 3 DDRD3 2 DDRD2 1 DDRD1 Bit 0 DDRD0
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Figure 17-12. Data Direction Register D (DDRD) DDRD[7:0] -- Data Direction Register D Bits These read/write bits control port D data direction. Reset clears DDRD[7:0], configuring all port D pins as inputs. 1 = Corresponding port D pin configured as output 0 = Corresponding port D pin configured as input
NOTE:
Avoid glitches on port D pins by writing to the port D data register before changing data direction register D bits from 0 to 1. Figure 17-13 shows the port D I/O logic.
READ DDRD ($0007) PTDPUEx DDRDx VDD
WRITE DDRD ($0007) INTERNAL DATA BUS RESET WRITE PTD ($0003) PTDx
PTDx
READ PTD ($0003)
PTD6 to TACLK of TIMA PTD4 to TBCLK of TIMB
Figure 17-13. Port D I/O Circuit
Technical Data
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Input/Output (I/O) Ports Port D
When DDRDx is a logic 1, reading address $0003 reads the PTDx data latch. When DDRDx is a logic 0, reading address $0003 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 17-5 summarizes the operation of the port D pins. Table 17-5. Port D Pin Functions
DDRD Bit PTD Bit X(1) X I/O Pin Mode Input, Hi-Z(2) Output Accesses to DDRD Read/Write 0 1 DDRD[7:0] DDRD[7:0] Accesses to PTD Read Pin PTD[7:0] Write PTD[7:0](3) PTD[7:0]
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Notes: 1. X = don't care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect the input.
17.6.3 Port D Input Pullup Enable Register (PTDPUE) The port D input pullup enable register (PTDPUE) controls the input pullup device for each of the eight port D pins. Each bit is individually configurable and requires that the data direction register, DDRD, bit be configured as an input. Each pullup is automatically and dynamically disabled when a port bit's DDRD is configured for output mode.
Address: $003D Bit 7 Read:
PTDPUE7 PTDPUE6 PTDPUE5 PTDPUE4 PTDPUE3 PTDPUE2 PTDPUE1 PTDPUE0
6
5
4
3
2
1
Bit 0
Write: Reset: 0 0 0 0 0 0 0 0
Figure 17-14. Port D Input Pullup Enable Register (PTDPUE) PTDPUE[7:0] -- Port D Input Pullup Enable Bits These writable bits are software programmable to enable pullup devices on an input port pin. 1 = Corresponding port D pin configured to have internal pullup 0 = Corresponding port D pin internal pullup disconnected
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Technical Data
317
Freescale Semiconductor, Inc. Input/Output (I/O) Ports 17.7 Port E
Port E is an 8-bit special function port that shares two of its pins with the timer interface module (TIMA), two of its pins with the serial communications interface module (SCI) and four of its pins with the serial peripheral interface module (SPI).
17.7.1 Port E Data Register (PTE)
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The port E data register contains a data latch for each of the eight port E pins.
Address: $0008 Bit 7 Read: PTE7 Write: Reset: Alternative Function: SPSCK MOSI MISO Unaffected by reset SS TACH1 TACH0 RxD TxD PTE6 PTE5 PTE4 PTE3 PTE2 PTE1 PTE0 6 5 4 3 2 1 Bit 0
Figure 17-15. Port E Data Register (PTE) PTE[7:0] -- Port E Data Bits These read/write bits are software programmable. Data direction of each port E pin is under the control of the corresponding bit in data direction register E. Reset has no effect on port E data. SPSCK -- SPI Serial Clock The PTE7/SPSCK pin is the serial clock input of a SPI slave module and serial clock output of a SPI master modules. When the SPE bit is clear, the PTE7/SPSCK pin is available for general-purpose I/O. See 16.14.1 SPI Control Register. MOSI -- Master Out/Slave In The PTE6/MOSI pin is the master out/slave in terminal of the SPI module. When the SPE bit is clear, the PTE6/MOSI pin is available for general-purpose I /O. See 16.14.1 SPI Control Register.
Technical Data
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Freescale Semiconductor, Inc.
Input/Output (I/O) Ports Port E
MISO -- Master In/Slave Out The PTE5/MISO pin is the master in/slave out terminal of the SPI module. When the SPI enable bit, SPE, is clear, the SPI module is disabled, and the PTE5/MISO pin is available for general-purpose I/O. See 16.14.1 SPI Control Register. SS -- Slave Select The PTE4/SS pin is the slave select input of the SPI module. When the SPE bit is clear, or when the SPI master bit, SPMSTR, is set, the PTE4/SS pin is available for general-purpose I/O. See 16.14.1 SPI Control Register. When the SPI is enabled as a slave, the DDRE4 bit in data direction register E (DDRE) has no effect on the PTE4/SS pin. TACH[1:0] -- Timer A Channel I/O Bits The PTE3/TACH1-PTE2/TACH0 pins are the TIMA input capture/output compare pins. The edge/level select bits, ELSxB:ELSxA, determine whether the PTE3/TACH1-PTE2/TACH0 pins are timer channel I/O pins or general-purpose I/O pins. See 11.10.4 TIMA Channel Status and Control Registers. RxD -- SCI Receive Data Input The PTE1/RxD pin is the receive data input for the SCI module. When the enable SCI bit, ENSCI, is clear, the SCI module is disabled, and the PTE1/RxD pin is available for general-purpose I/O. See 15.9.1 SCI Control Register 1. TxD -- SCI Transmit Data Output The PTE0/TxD pin is the transmit data output for the SCI module. When the enable SCI bit, ENSCI, is clear, the SCI module is disabled, and the PTE0/TxD pin is available for general-purpose I/O. See 15.9.1 SCI Control Register 1.
Freescale Semiconductor, Inc...
NOTE:
Data direction register E (DDRE) does not affect the data direction of port E pins that are being used by the SPI module, TIMA, and SCI module. However, the DDRE bits always determine whether reading port E returns the states of the latches or the states of the pins. See Table 17-6.
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Freescale Semiconductor, Inc. Input/Output (I/O) Ports
17.7.2 Data Direction Register E (DDRE) Data direction register E determines whether each port E pin is an input or an output. Writing a logic 1 to a DDRE bit enables the output buffer for the corresponding port E pin; a logic 0 disables the output buffer.
Address: $000C Bit 7 Read: DDRE7 Write: Reset: 0 0 0 0 0 0 0 0 6 DDRE6 5 DDRE5 4 DDRE4 3 DDRE3 2 DDRE2 1 DDRE1 Bit 0 DDRE0
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Figure 17-16. Data Direction Register E (DDRE) DDRE[7:0] -- Data Direction Register E Bits These read/write bits control port E data direction. Reset clears DDRE[7:0], configuring all port E pins as inputs. 1 = Corresponding port E pin configured as output 0 = Corresponding port E pin configured as input
NOTE:
Avoid glitches on port E pins by writing to the port E data register before changing data direction register E bits from 0 to 1. Figure 17-17 shows the port E I/O logic.
READ DDRE ($000C)
WRITE DDRE ($000C) INTERNAL DATA BUS RESET WRITE PTE ($0008) PTEx PTEx DDREx
READ PTE ($0008)
Figure 17-17. Port E I/O Circuit
Technical Data
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Input/Output (I/O) Ports Port F
When DDREx is a logic 1, reading address $0008 reads the PTEx data latch. When DDREx is a logic 0, reading address $0008 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 17-6 summarizes the operation of the port E pins. Table 17-6. Port E Pin Functions
DDRE Bit PTE Bit X(1) X I/O Pin Mode Input, Hi-Z(2) Output Accesses to DDRE Read/Write 0 1 DDRE[7:0] DDRE[7:0] Accesses to PTE Read Pin PTE[7:0] Write PTE[7:0](3) PTE[7:0]
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Notes: 1. X = don't care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect the input.
17.8 Port F
Port F is an 8-bit special function port that shares six of its pins with the timer interface modules (TIMA and TIMB). 17.8.1 Port F Data Register (PTF) The port F data register contains a data latch for each of the eight port F pins.
Address: $0009 Bit 7 Read: PTF7 Write: Reset: Alternative Function: TBCH1 Unaffected by reset TBCH0 TBCH3 TBCH2 TACH3 TACH2 PTF6 PTF5 PTF4 PTF3 PTF2 PTF1 PTF0 6 5 4 3 2 1 Bit 0
Additional Function: Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup
Figure 17-18. Port F Data Register (PTF)
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Freescale Semiconductor, Inc. Input/Output (I/O) Ports
PTF[7:0] -- Port F Data Bits These read/write bits are software programmable. Data direction of each port F pin is under the control of the corresponding bit in data direction register F. Reset has no effect on port F data. TACH[3:2] and TBCH[3:0] -- Timer channel I/O bits The PTF5/TBCH1-PTF0/TACH2 pins are the TIMA and TIMB input capture/output compare pins. The edge/level select bits, ELSxB:ELSxA, determine whether the PTF5/TBCH1-PTF0/TACH2 pins are timer channel I/O pins or general-purpose I/O pins. See 11.10.4 TIMA Channel Status and Control Registers and 12.10.4 TIMB Channel Status and Control Registers.
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NOTE:
Data direction register F (DDRF) does not affect the data direction of port F pins that are being used by TIMA and TIMB. However, the DDRF bits always determine whether reading port F returns the states of the latches or the states of the pins. See Table 17-7.
17.8.2 Data Direction Register F (DDRF) Data direction register F determines whether each port F pin is an input or an output. Writing a logic 1 to a DDRF bit enables the output buffer for the corresponding port F pin; a logic 0 disables the output buffer.
Address: $000D Bit 7 Read: DDRF7 Write: Reset: 0 0 0 0 0 0 0 0 DDRF6 DDRF5 DDRF4 DDRF3 DDRF2 DDRF1 DDRF0 6 5 4 3 2 1 Bit 0
Figure 17-19. Data Direction Register F (DDRF) DDRF[7:0] -- Data Direction Register F Bits These read/write bits control port F data direction. Reset clears DDRF[7:0], configuring all port F pins as inputs. 1 = Corresponding port F pin configured as output 0 = Corresponding port F pin configured as input
Technical Data
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Freescale Semiconductor, Inc.
Input/Output (I/O) Ports Port F
NOTE:
Avoid glitches on port F pins by writing to the port F data register before changing data direction register F bits from 0 to 1. Figure 17-20 shows the port F I/O logic.
VDD PTFPUEx DDRFx
READ DDRF ($000D)
WRITE DDRF ($000D) INTERNAL DATA BUS RESET WRITE PTF ($0009) PTFx
Freescale Semiconductor, Inc...
PTFx
READ PTF ($0009)
PTF5 to TBCH1, PTF4 to TBCH0, PTF3 to TBCH3, PTF2 to TBCH2 of TIMB PTF1 to TACH3, PTF0 to TACH2 of TIMA
Figure 17-20. Port F I/O Circuit When DDRFx is a logic 1, reading address $0009 reads the PTFx data latch. When DDRFx is a logic 0, reading address $0009 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 17-7 summarizes the operation of the port F pins. Table 17-7. Port F Pin Functions
DDRF Bit 0 1 PTF Bit X(1) X I/O Pin Mode Input, Hi-Z(2) Output Accesses to DDRF Read/Write DDRF[7:0] DDRF[7:0] Accesses to PTF Read Pin PTF[7:0] Write PTF[7:0](3) PTF[7:0]
Notes: 1. X = don't care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect the input.
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Freescale Semiconductor, Inc. Input/Output (I/O) Ports
17.8.3 Port F Input Pullup Enable Register (PTFPUE) The port F input pullup enable register (PTFPUE) controls the input pullup device for each of the eight port F pins. Each bit is individually configurable and requires that the data direction register, DDRF, bit be configured as an input. Each pullup is automatically and dynamically disabled when a port bit's DDRF is configured for output mode.
Address: $003E Bit 7 6 5 4 3 2 1 Bit 0
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Read:
PTFPUE7 PTFPUE6 PTFPUE5 PTFPUE4 PTFPUE3 PTFPUE2 PTFPUE1 PTFPUE0
Write: Reset: 0 0 0 0 0 0 0 0
Figure 17-21. Port F Input Pullup Enable Register (PTFPUE) PTFPUE[7:0] -- Port F Input Pullup Enable Bits These writable bits are software programmable to enable pullup devices on an input port pin. 1 = Corresponding port F pin configured to have internal pullup 0 = Corresponding port F pin internal pullup disconnected
17.9 Port G
Port G is a 3-bit special-function port that shares all three of its pins with the keyboard interrupt (KBI) module.
17.9.1 Port G Data Register (PTG) The port G data register (PTG) contains a data latch for each of the three port G pins.
Technical Data
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Freescale Semiconductor, Inc.
Input/Output (I/O) Ports Port G
Address:
$000A Bit 7 6 0 5 0 4 0 3 0 PTG2 PTG1 PTG0 2 1 Bit 0
Read: Write: Reset: Alternative Function:
0
Unaffected by reset KBD2 KBD1 KBD0
Figure 17-22. Port G Data Register (PTG)
Freescale Semiconductor, Inc...
PTG[2:0] -- Port G Data Bits These read/write bits are software programmable. Data direction of each port G pin is under the control of the corresponding bit in data direction register G. Reset has no effect on port G data. KBD[2:0] -- The keyboard interrupt enable bits, KBIE[2:0], in the keyboard interrupt enable register (KBIER), enable the port G pins as external interrupt pins. See Section 19. Keyboard Interrupt Module (KBI).
17.9.2 Data Direction Register G (DDRG) Data direction register G determines whether each port G pin is an input or an output. Writing logic 1 to a DDRG bit enables the output buffer for the corresponding port G pin; a logic 0 disables the output buffer.
Address: $000E Bit 7 Read: Write: Reset: 0 0 0 0 0 0 0 0 0 6 0 5 0 4 0 3 0 DDRG2 DDRG1 DDRG0 2 1 Bit 0
Figure 17-23. Data Direction Register G (DDRG)
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Freescale Semiconductor, Inc. Input/Output (I/O) Ports
DDRG[2:0] -- Data Direction Register G Bits These read/write bits control port G data direction. Reset clears DDRG[2:0], configuring all port G pins as inputs. 1 = Corresponding port G pin configured as output 0 = Corresponding port G pin configured as input
NOTE:
Avoid glitches on port G pins by writing to the port G data register before changing data direction register G bits from 0 to 1. Figure 17-24 shows the port G I/O logic.
READ DDRG ($000E)
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WRITE DDRG ($000E) INTERNAL DATA BUS RESET WRITE PTG ($000A) PTGx PTGx DDRGx
READ PTG ($000A) KBI
Figure 17-24. Port G I/O Circuit When DDRGx is a logic 1, reading address $000A reads the PTGx data latch. When DDRGx is a logic 0, reading address $000A reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 17-6 summarizes the operation of the port G pins. Table 17-8. Port G Pin Functions
DDRG Bit 0 1 PTG Bit X(1) X I/O Pin Mode Input, Hi-Z(2) Output Accesses to DDRG Read/Write DDRG[2:0] DDRG[2:0] Accesses to PTG Read Pin PTG[2:0] Write PTG[2:0](3) PTG[2:0]
Notes: 1. X = don't care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect the input.
Technical Data
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Freescale Semiconductor, Inc.
Input/Output (I/O) Ports Port H
17.10 Port H
Port H is a 2-bit special-function port that shares all two of its pins with the keyboard interrupt (KBI) module.
17.10.1 Port H Data Register (PTH) The port H data register (PTH) contains a data latch for each of the two port H pins.
Freescale Semiconductor, Inc...
Address:
$000B Bit 7 6 0 5 0 4 0 3 0 2 0 PTH1 PTH0 1 Bit 0
Read: Write: Reset: Alternative Function:
0
Unaffected by reset KBD4 KBD3
Figure 17-25. Port H Data Register (PTH) PTH[1:0] -- Port H Data Bits These read/write bits are software programmable. Data direction of each port H pin is under the control of the corresponding bit in data direction register H. Reset has no effect on port H data. KBD[4:3] -- The keyboard interrupt enable bits, KBIE[4:3], in the keyboard interrupt enable register (KBIER), enable the port H pins as external interrupt pins. See Section 19. Keyboard Interrupt Module (KBI). 17.10.2 Data Direction Register H (DDRH) Data direction register H determines whether each port H pin is an input or an output. Writing logic 1 to a DDRH bit enables the output buffer for the corresponding port H pin; a logic 0 disables the output buffer.
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Technical Data
327
Freescale Semiconductor, Inc. Input/Output (I/O) Ports
Address:
$000F Bit 7 6 0 5 0 4 0 3 0 2 0 DDRH1 DDRH0 0 1 Bit 0
Read: Write: Reset:
0
0
0
0
0
0
0
0
Figure 17-26. Data Direction Register H (DDRH) DDRH[1:0] -- Data Direction Register H Bits
Freescale Semiconductor, Inc...
These read/write bits control port H data direction. Reset clears DDRH[1:0], configuring all port H pins as inputs. 1 = Corresponding port H pin configured as output 0 = Corresponding port H pin configured as input
NOTE:
Avoid glitches on port H pins by writing to the port H data register before changing data direction register H bits from 0 to 1. Figure 17-27 shows the port H I/O logic.
READ DDRH ($000F)
WRITE DDRH ($000F) INTERNAL DATA BUS RESET WRITE PTH ($000B) PTHx PTHx DDRHx
READ PTH ($000B) KBI
Figure 17-27. Port H I/O Circuit When DDRHx is a logic 1, reading address $000B reads the PTHx data latch. When DDRHx is a logic 0, reading address $000B reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 17-6 summarizes the operation of the port H pins.
Technical Data
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Input/Output (I/O) Ports Port H
Table 17-9. Port H Pin Functions
DDRH Bit 0 1 PTH Bit X(1) X I/O Pin Mode Input, Hi-Z(2) Output Accesses to DDRH Read/Write DDRH[1:0] DDRH[1:0] Accesses to PTH Read Pin PTH[1:0] Write PTH[1:0](3) PTH[1:0]
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Notes: 1. X = don't care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect the input.
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329
Freescale Semiconductor, Inc. Input/Output (I/O) Ports
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Technical Data
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Technical Data -- MC68HC08AB16A
Section 18. External Interrupt (IRQ)
18.1 Contents
18.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
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18.3
18.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 18.4.1 IRQ Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 18.5 18.6 IRQ Status and Control Register (ISCR) . . . . . . . . . . . . . . . . 335 IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . 336
18.2 Introduction
The external interrupt (IRQ) module provides a maskable interrupt input.
18.3 Features
Features of the IRQ module include the following: * * * * * A dedicated external interrupt pin, IRQ Hysteresis buffer Programmable edge-only or edge and level interrupt sensitivity Automatic interrupt acknowledge Internal pullup resistor
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331
Freescale Semiconductor, Inc. External Interrupt (IRQ) 18.4 Functional Description
A logic 0 applied to the external interrupt pin can latch a CPU interrupt request. Figure 18-1 shows the structure of the IRQ module. Interrupt signals on the IRQ pin are latched into the IRQ latch. An interrupt latch remains set until one of the following actions occurs: * Vector fetch -- A vector fetch automatically generates an interrupt acknowledge signal that clears the IRQ latch. Software clear -- Software can clear the interrupt latch by writing to the acknowledge bit in the interrupt status and control register (ISCR). Writing a logic 1 to the ACK bit clears the IRQ latch. Reset -- A reset automatically clears the interrupt latch.
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*
*
The external interrupt pin is falling-edge-triggered and is softwareconfigurable to be either falling-edge or falling-edge and low-leveltriggered. The MODE bit in the ISCR controls the triggering sensitivity of the IRQ pin. When the interrupt pin is edge-triggered only, the CPU interrupt request remains set until a vector fetch, software clear, or reset occurs. When the interrupt pin is both falling-edge and low-level-triggered, the CPU interrupt request remains set until both of the following occur: * * Vector fetch or software clear Return of the interrupt pin to logic 1
The vector fetch or software clear may occur before or after the interrupt pin returns to logic 1. As long as the pin is low, the interrupt request remains pending. A reset will clear the latch and the MODE control bit, thereby clearing the interrupt even if the pin stays low. When set, the IMASK bit in the ISCR mask all external interrupt requests. A latched interrupt request is not presented to the interrupt priority logic unless the IMASK bit is clear.
Technical Data
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External Interrupt (IRQ) Functional Description
NOTE:
The interrupt mask (I) in the condition code register (CCR) masks all interrupt requests, including external interrupt requests. (See 8.6 Exception Control.)
ACK RESET INTERNAL ADDRESS BUS VECTOR FETCH DECODER VDD
INTERNAL
PULLUP DEVICE
TO CPU FOR BIL/BIH INSTRUCTIONS
Freescale Semiconductor, Inc...
VDD D CLR Q SYNCHRONIZER
IRQF
IRQ
CK IRQ FF IMASK
IRQ INTERRUPT REQUEST
MODE HIGH VOLTAGE DETECT TO MODE SELECT LOGIC
Figure 18-1. IRQ Module Block Diagram
Addr. Register Name Read: IRQ Status and Control Register Write: (ISCR) Reset: Bit 7 0 6 0 5 0 4 0 3 IRQF 2 0 ACK 0 0 0 0 0 0 1 IMASK 0 Bit 0 MODE 0
$001A
= Unimplemented
Figure 18-2. IRQ I/O Register Summary
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333
Freescale Semiconductor, Inc. External Interrupt (IRQ)
18.4.1 IRQ Pin A logic 0 on the IRQ pin can latch an interrupt request into the IRQ latch. A vector fetch, software clear, or reset clears the IRQ latch. If the MODE bit is set, the IRQ pin is both falling-edge-sensitive and lowlevel-sensitive. With MODE set, both of the following actions must occur to clear IRQ latch: * Vector fetch or software clear -- A vector fetch generates an interrupt acknowledge signal to clear the latch. Software may generate the interrupt acknowledge signal by writing a logic 1 to the ACK bit in the interrupt status and control register (ISCR). The ACK bit is useful in applications that poll the IRQ pin and require software to clear the IRQ latch. Writing to the ACK bit prior to leaving an interrupt service routine can also prevent spurious interrupts due to noise. Setting ACK does not affect subsequent transitions on the IRQ pin. A falling edge that occurs after writing to the ACK bit latches another interrupt request. If the IRQ mask bit, IMASK, is clear, the CPU loads the program counter with the vector address at locations $FFFA and $FFFB. Return of the IRQ pin to logic 1 -- As long as the IRQ pin is at logic 0, IRQ remains active.
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*
The vector fetch or software clear and the return of the IRQ pin to logic 1 may occur in any order. The interrupt request remains pending as long as the IRQ pin is at logic 0. A reset will clear the latch and the MODE control bit, thereby clearing the interrupt even if the pin stays low. If the MODE bit is clear, the IRQ pin is falling-edge-sensitive only. With MODE clear, a vector fetch or software clear immediately clears the IRQ latch. The IRQF bit in the ISCR register can be used to check for pending interrupts. The IRQF bit is not affected by the IMASK bit, which makes it useful in applications where polling is preferred. Use the BIH or BIL instruction to read the logic level on the IRQ pin.
NOTE:
When using the level-sensitive interrupt trigger, avoid false interrupts by masking interrupt requests in the interrupt routine.
Technical Data
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External Interrupt (IRQ) IRQ Status and Control Register (ISCR)
18.5 IRQ Status and Control Register (ISCR)
The IRQ status and control register (ISCR) controls and monitors operation of the IRQ module. The ISCR has the following functions: * * * * Shows the state of the IRQ flag Clears the IRQ latch Masks IRQ interrupt request Controls triggering sensitivity of the IRQ interrupt pin
$001A Bit 7 Read: Write: Reset: 0 0 0 0 0 0 6 0 5 0 4 0 3 IRQF 2 0 IMASK ACK 0 0 0 MODE 1 Bit 0
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Address:
= Unimplemented
Figure 18-3. IRQ Status and Control Register (ISCR) IRQF -- IRQ Flag This read-only status bit is high when the IRQ interrupt is pending. 1 = IRQ interrupt pending 0 = IRQ interrupt not pending ACK -- IRQ Interrupt Request Acknowledge Bit Writing a logic 1 to this write-only bit clears the IRQ latch. ACK always reads as logic 0. Reset clears ACK. IMASK -- IRQ Interrupt Mask Bit Writing a logic 1 to this read/write bit disables IRQ interrupt requests. Reset clears IMASK. 1 = IRQ interrupt requests disabled 0 = IRQ interrupt requests enabled MODE -- IRQ Edge/Level Select Bit This read/write bit controls the triggering sensitivity of the IRQ pin. Reset clears MODE. 1 = IRQ interrupt requests on falling edges and low levels 0 = IRQ interrupt requests on falling edges only
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Freescale Semiconductor, Inc. External Interrupt (IRQ) 18.6 IRQ Module During Break Interrupts
The system integration module (SIM) controls whether the IRQ latch can be cleared during the break state. The BCFE bit in the break flag control register (BFCR) enables software to clear the latches during the break state. (See Section 8. System Integration Module (SIM).) To allow software to clear the IRQ latch during a break interrupt, write a logic 1 to the BCFE bit. If a latch is cleared during the break state, it remains cleared when the MCU exits the break state.
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To protect the latches during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its default state), writing to the ACK bit in the IRQ status and control register during the break state has no effect on the IRQ latch.
Technical Data
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Technical Data -- MC68HC08AB16A
Section 19. Keyboard Interrupt Module (KBI)
19.1 Contents
19.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
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19.3 19.4
19.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 19.5.1 Keyboard Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 19.5.2 Keyboard Status and Control Register. . . . . . . . . . . . . . . . 341 19.5.3 Keyboard Interrupt Enable Register . . . . . . . . . . . . . . . . . . 343 19.6 19.7 19.8 Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 Keyboard Module During Break Interrupts . . . . . . . . . . . . . . . 344
19.2 Introduction
The keyboard interrupt module (KBI) provides five independently maskable external interrupts which are accessible via PTG0-PTG2 and PTH0-PTH1 pins.
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337
Freescale Semiconductor, Inc. Keyboard Interrupt Module (KBI) 19.3 Features
Features of the keyboard interrupt module include the following: * * * * Five keyboard interrupt pins with pullup devices Separate keyboard interrupt enable bits and one keyboard interrupt mask Built-in pull-up device if input pin is configured as input port bit Programmable edge-only or edge- and level- interrupt sensitivity Exit from low-power modes
Bit 7 0 6 0 5 0 4 0 3 KEYF 2 0 IMASKK ACKK 0 0 0 0 0 0 KBIE4 0 0 0 0 KBIE3 0 KBIE2 0 KBIE1 0 KBIE0 0 0 0 0 0 0 MODEK 1 Bit 0
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*
Addr. Register Name Read: Keyboard Status and Control Register Write: (KBSCR) Reset:
$001B
Read: Keyboard Interrupt Enable $0021 Write: Register (KBIER) Reset:
= Unimplemented
Figure 19-1. KBI I/O Register Summary
19.4 I/O Pins
The five keyboard interrupt pins are shared with standard port I/O pins. The full name of the KBI pins are listed in Table 19-1. The generic pin name appear in the text that follows. Table 19-1. Pin Name Conventions
KBI Generic Pin Name KBD0 KBD1 KBD2 KBD3 KBD4 Full MCU Pin Name PTG0/KBD0 PTG1/KBD1 PTG2/KBD2 PTH0/KBD3 PTH1/KBD4 Pin Selected for KBI Function by KBIEx Bit in KBIER KBIE0 KBIE1 KBIE2 KBIE3 KBIE4
Technical Data
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338
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Keyboard Interrupt Module (KBI) Functional Description
19.5 Functional Description
INTERNAL BUS
KBD0 VDD . KBIE0 TO PULLUP ENABLE . . KBD4 D CLR Q
ACKK RESET
VECTOR FETCH DECODER KEYF SYNCHRONIZER Keyboard Interrupt Request
CK
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KEYBOARD INTERRUPT FF
IMASKK
MODEK KBIE4
TO PULLUP ENABLE
Figure 19-2. Keyboard Interrupt Block Diagram Writing to the KBIE4-KBIE0 bits in the keyboard interrupt enable register independently enables or disables the corresponding port pin as a keyboard interrupt pin. Enabling a keyboard interrupt pin also enables its internal pull-up device. A logic 0 applied to an enabled keyboard interrupt pin latches a keyboard interrupt request. A keyboard interrupt is latched when one or more keyboard pins goes low after all were high. The MODEK bit in the keyboard status and control register controls the triggering mode of the keyboard interrupt. * If the keyboard interrupt is edge-sensitive only, a falling edge on a keyboard pin does not latch an interrupt request if another keyboard pin is already low. To prevent losing an interrupt request on one pin because another pin is still low, software can disable the latter pin while it is low. If the keyboard interrupt is falling edge- and low level-sensitive, an interrupt request is present as long as any keyboard pin is low.
*
If the MODEK bit is set, the keyboard interrupt pins are both falling edgeand low level-sensitive, and both of the following actions must occur to clear a keyboard interrupt request:
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Freescale Semiconductor, Inc. Keyboard Interrupt Module (KBI)
* Vector fetch or software clear -- A vector fetch generates an interrupt acknowledge signal to clear the interrupt request. Software may generate the interrupt acknowledge signal by writing a logic 1 to the ACKK bit in the keyboard status and control register KBSCR. The ACKK bit is useful in applications that poll the keyboard interrupt pins and require software to clear the keyboard interrupt request. Writing to the ACKK bit prior to leaving an interrupt service routine can also prevent spurious interrupts due to noise. Setting ACKK does not affect subsequent transitions on the keyboard interrupt pins. A falling edge that occurs after writing to the ACKK bit latches another interrupt request. If the keyboard interrupt mask bit, IMASKK, is clear, the CPU loads the program counter with the vector address at locations $FFD2 and $FFD3. Return of all enabled keyboard interrupt pins to logic 1 -- As long as any enabled keyboard interrupt pin is at logic 0, the keyboard interrupt remains set.
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*
The vector fetch or software clear and the return of all enabled keyboard interrupt pins to logic 1 may occur in any order. If the MODEK bit is clear, the keyboard interrupt pin is falling-edgesensitive only. With MODEK clear, a vector fetch or software clear immediately clears the keyboard interrupt request. Reset clears the keyboard interrupt request and the MODEK bit, clearing the interrupt request even if a keyboard interrupt pin stays at logic 0. The keyboard flag bit (KEYF) in the keyboard status and control register can be used to see if a pending interrupt exists. The KEYF bit is not affected by the keyboard interrupt mask bit (IMASKK) which makes it useful in applications where polling is preferred. To determine the logic level on a keyboard interrupt pin, disable the pullup device, use the data direction register to configure the pin as an input and then read the data register.
NOTE:
Setting a keyboard interrupt enable bit (KBIEx) forces the corresponding keyboard interrupt pin to be an input, overriding the data direction register. However, the data direction register bit must be a logic 0 for software to read the pin.
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Keyboard Interrupt Module (KBI) Functional Description
19.5.1 Keyboard Initialization When a keyboard interrupt pin is enabled, it takes time for the internal pull-up to reach a logic 1. Therefore a false interrupt can occur as soon as the pin is enabled. To prevent a false interrupt on keyboard initialization: 1. Mask keyboard interrupts by setting the IMASKK bit in the keyboard status and control register.
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2. Enable the KBI pins by setting the appropriate KBIEx bits in the keyboard interrupt enable register. 3. Write to the ACKK bit in the keyboard status and control register to clear any false interrupts. 4. Clear the IMASKK bit. An interrupt signal on an edge-triggered pin can be acknowledged immediately after enabling the pin. An interrupt signal on an edge- and level-triggered interrupt pin must be acknowledged after a delay that depends on the external load. Another way to avoid a false interrupt: 1. Configure the keyboard pins as outputs by setting the appropriate DDR bits in the data direction register. 2. Write logic 1s to the appropriate port data register bits. 3. Enable the KBI pins by setting the appropriate KBIEx bits in the keyboard interrupt enable register.
19.5.2 Keyboard Status and Control Register * * * * Flags keyboard interrupt requests. Acknowledges keyboard interrupt requests. Masks keyboard interrupt requests. Controls keyboard interrupt triggering sensitivity.
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Technical Data
341
Freescale Semiconductor, Inc. Keyboard Interrupt Module (KBI)
Address:
$001B Bit 7 6 0 5 0 4 0 3 KEYF 2 0 IMASKK MODEK 0 ACKK 0 0 0 0 0 0 0 1 Bit 0
Read: Write: Reset:
0
= Unimplemented
Figure 19-3. Keyboard Status and Control Register (KBSCR)
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Bits 7-4 -- Not used These read-only bits always read as logic 0s. KEYF -- Keyboard Flag Bit This read-only bit is set when a keyboard interrupt is pending. Reset clears the KEYF bit. 1 = Keyboard interrupt pending 0 = No keyboard interrupt pending ACKK -- Keyboard Acknowledge Bit Writing a logic 1 to this write-only bit clears the keyboard interrupt request. ACKK always reads as logic 0. Reset clears ACKK. IMASKK-- Keyboard Interrupt Mask Bit Writing a logic 1 to this read/write bit prevents the output of the keyboard interrupt mask from generating interrupt requests. Reset clears the IMASKK bit. 1 = Keyboard interrupt requests masked 0 = Keyboard interrupt requests not masked MODEK -- Keyboard Triggering Sensitivity Bit This read/write bit controls the triggering sensitivity of the keyboard interrupt pins. Reset clears MODEK. 1 = Keyboard interrupt requests on falling edges and low levels 0 = Keyboard interrupt requests on falling edges only
Technical Data
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Keyboard Interrupt Module (KBI) Wait Mode
19.5.3 Keyboard Interrupt Enable Register The keyboard interrupt enable register enables or disables the corresponding port pin to operate as a keyboard interrupt pin.
Address: $0021 Bit 7 Read: Write: 0 6 0 5 0 KBIE4 KBIE3 PTH0/ KBD3 0 KBIE2 PTG2/ KBD2 0 KBIE1 PTG1/ KBD1 0 KBIE0 PTG0 /KBD0 0 4 3 2 1 Bit 0
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Port Pin: Reset: 0 0 0
PTH1/ KBD4 0
Figure 19-4. Keyboard Interrupt Enable Register (KBIER) KBIE4-KBIE0 -- Keyboard Interrupt Enable Bits Each of these read/write bits enables the corresponding keyboard interrupt pin to latch interrupt requests. Reset clears the keyboard interrupt enable register. 1 = KBDx pin enabled as keyboard interrupt pin 0 = KBDx pin not enabled as keyboard interrupt pin
19.6 Wait Mode
The keyboard modules remain active in wait mode. Clearing the IMASKK bit in the keyboard status and control register enables keyboard interrupt requests to bring the MCU out of wait mode.
19.7 Stop Mode
The keyboard module remains active in stop mode. Clearing the IMASKK bit in the keyboard status and control register enables keyboard interrupt requests to bring the MCU out of stop mode.
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Technical Data
343
Freescale Semiconductor, Inc. Keyboard Interrupt Module (KBI) 19.8 Keyboard Module During Break Interrupts
The system integration module (SIM) controls whether the keyboard interrupt latch can be cleared during the break state. The BCFE bit in the break flag control register (BFCR) enables software to clear status bits during the break state. To allow software to clear the keyboard interrupt latch during a break interrupt, write a logic 1 to the BCFE bit. If a latch is cleared during the break state, it remains cleared when the MCU exits the break state.
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To protect the latch during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its default state), writing to the keyboard acknowledge bit (ACKK) in the keyboard status and control register during the break state has no effect.
Technical Data
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Technical Data -- MC68HC08AB16A
Section 20. Computer Operating Properly (COP)
20.1 Contents
20.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
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20.3
20.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.4.1 CGMXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.4.2 STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.4.3 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.4.4 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.4.5 Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 20.4.6 Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 20.4.7 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 20.4.8 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . 348 20.5 20.6 20.7 COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
20.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 20.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 20.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 20.9 COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . 350
20.2 Introduction
The computer operating properly (COP) module contains a free-running counter that generates a reset if allowed to overflow. The COP module helps software recover from runaway code. Prevent a COP reset by clearing the COP counter periodically. The COP module can be disabled via a mask option, the COPD bit in mask option register A (MORA).
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Freescale Semiconductor, Inc. Computer Operating Properly (COP) 20.3 Functional Description
Figure 20-1 shows the structure of the COP module.
CGMXCLK
12-BIT COP PRESCALER CLEAR ALL STAGES CLEAR STAGES 5-12
RESET CIRCUIT RESET STATUS REGISTER
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STOP INSTRUCTION INTERNAL RESET SOURCES RESET VECTOR FETCH COPCTL WRITE
COP CLOCK COP MODULE 6-BIT COP COUNTER COPEN (FROM SIM) COP DISABLE (COPD FROM MORA) RESET COPCTL WRITE COP RATE SEL (COPRS FROM MORA)
CLEAR COP COUNTER
Figure 20-1. COP Block Diagram The COP counter is a free-running 6-bit counter preceded by a 12-bit prescaler counter. If not cleared by software, the COP counter overflows and generates an asynchronous reset after 218 - 24 or 213 - 24 CGMXCLK cycles, depending on the state of the COP rate select bit, COPRS, in mask option register A (MORA). With a 218 - 24 CGMXCLK cycle overflow option, a 4.9152MHz crystal gives a COP timeout period of 53.3ms. Writing any value to location $FFFF before an overflow occurs prevents a COP reset by clearing the COP counter and stages 12 through 5 of the prescaler.
NOTE:
Service the COP immediately after reset and before entering or after exiting stop mode to guarantee the maximum time before the first COP counter overflow.
Technical Data
COP TIMEOUT
MC68HC08AB16A -- Rev. 2.0 Computer Operating Properly (COP) For More Information On This Product, Go to: www.freescale.com MOTOROLA
346
Freescale Semiconductor, Inc.
Computer Operating Properly (COP) I/O Signals
A COP reset pulls the RST pin low for 32 CGMXCLK cycles and sets the COP bit in the SIM reset status register (SRSR). In monitor mode, the COP is disabled if the RST pin or the IRQ pin is held at VTST During the break state, VTST on the RST pin disables the COP.
NOTE:
Freescale Semiconductor, Inc...
Place COP clearing instructions in the main program and not in an interrupt subroutine. Such an interrupt subroutine could keep the COP from generating a reset even while the main program is not working properly.
20.4 I/O Signals
The following paragraphs describe the signals shown in Figure 20-1.
20.4.1 CGMXCLK CGMXCLK is the crystal oscillator output signal. CGMXCLK frequency is equal to the crystal frequency.
20.4.2 STOP Instruction The STOP instruction clears the COP prescaler.
20.4.3 COPCTL Write Writing any value to the COP control register (COPCTL) (see 20.5 COP Control Register) clears the COP counter and clears bits 12 through 5 of the prescaler. Reading the COP control register returns the low byte of the reset vector.
20.4.4 Power-On Reset The power-on reset (POR) circuit clears the COP prescaler 4096 CGMXCLK cycles after power-up.
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Technical Data
347
Freescale Semiconductor, Inc. Computer Operating Properly (COP)
20.4.5 Internal Reset An internal reset clears the COP prescaler and the COP counter. 20.4.6 Reset Vector Fetch A reset vector fetch occurs when the vector address appears on the data bus. A reset vector fetch clears the COP prescaler. 20.4.7 COPD (COP Disable) The COPD signal reflects the state of the COP disable bit (COPD) in the mask option register A. (See Figure 20-2.) 20.4.8 COPRS (COP Rate Select) The COPRS signal reflects the state of the COP rate select bit (COPRS) in the mask option register A. (See Figure 20-2.)
Address: $001F Bit 7 Read: LVISTOP Write: Reset: Unaffected by reset 6 SEC 5 4 3 SSREC 2 COPRS 1 STOP Bit 0 COPD
Freescale Semiconductor, Inc...
LVIRSTD LVIPWRD
Figure 20-2. Mask Option Register A (MORA) COPRS -- COP Rate Select Bit COPRS selects the COP timeout period. Reset clears COPRS. 1 = COP timeout period = 218 - 24 CGMXCLK cycles 0 = COP timeout period = 213 - 24 CGMXCLK cycles COPD -- COP Disable Bit COPD disables the COP module. 1 = COP module disabled 0 = COP module enabled
Technical Data
MC68HC08AB16A -- Rev. 2.0 Computer Operating Properly (COP) For More Information On This Product, Go to: www.freescale.com MOTOROLA
348
Freescale Semiconductor, Inc.
Computer Operating Properly (COP) COP Control Register
20.5 COP Control Register
The COP control register is located at address $FFFF and overlaps the reset vector. Writing any value to $FFFF clears the COP counter and starts a new timeout period. Reading location $FFFF returns the low byte of the reset vector.
Address:
$FFFF Bit 7 6 5 4 3 2 1 Bit 0
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Read: Write: Reset:
Low byte of reset vector Clear COP counter Unaffected by reset
Figure 20-3. COP Control Register (COPCTL)
20.6 Interrupts
The COP does not generate CPU interrupt requests.
20.7 Monitor Mode
When monitor mode is entered with VTST on the IRQ pin, the COP is disabled as long as VTST remains on the IRQ pin or the RST pin. When monitor mode is entered by having blank reset vectors and not having VTST on the IRQ pin, the COP is automatically disabled until a POR occurs.
20.8 Low-Power Modes
The WAIT and STOP instructions put the MCU in low powerconsumption standby modes.
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349
Freescale Semiconductor, Inc. Computer Operating Properly (COP)
20.8.1 Wait Mode The COP remains active during wait mode. To prevent a COP reset during wait mode, periodically clear the COP counter in a CPU interrupt routine.
20.8.2 Stop Mode Stop mode turns off the CGMXCLK input to the COP and clears the COP prescaler. Service the COP immediately before entering or after exiting stop mode to ensure a full COP timeout period after entering or exiting stop mode. To prevent inadvertently turning off the COP with a STOP instruction, a configuration option is available that disables the STOP instruction. When the STOP bit in the mask option register has the STOP instruction is disabled, execution of a STOP instruction results in an illegal opcode reset.
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20.9 COP Module During Break Mode
The COP is disabled during a break interrupt when VTST is present on the RST pin.
Technical Data
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Technical Data -- MC68HC08AB16A
Section 21. Low-Voltage Inhibit (LVI)
21.1 Contents
21.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
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21.3
21.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 21.4.1 Polled LVI Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 21.4.2 Forced Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 21.4.3 False Reset Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 21.5 21.6 LVI Status Register (LVISR) . . . . . . . . . . . . . . . . . . . . . . . . . . 354 LVI Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
21.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 21.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 21.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
21.2 Introduction
This section describes the low-voltage inhibit module, which monitors the voltage on the VDD pin and can force a reset when the VDD voltage falls to the LVI trip voltage.
21.3 Features
Features of the LVI module include the following: * * * Programmable LVI reset Programmable LVI module power Programmable stop mode operation
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Technical Data
351
Freescale Semiconductor, Inc. Low-Voltage Inhibit (LVI) 21.4 Functional Description
Figure 21-1 shows the structure of the LVI module. The LVI is enabled out of reset. The LVI module contains a bandgap reference circuit and comparator. The LVI power bit, LVIPWRD, enables the LVI to monitor VDD voltage. The LVI reset bit, LVIRSTD, enables the LVI module to generate a reset when VDD falls below a voltage, LVITRIPF, and remains at or below that level for 9 or more consecutive CPU cycles. Setting the LVI enable in stop mode bit, LVISTOP, enables the LVI to operate in stop mode.
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LVISTOP, LVIPWRD, and LVIRSTD are in the mask option register A (MORA). See Section 6. Mask Options (MOR) for details of the LVI's configuration bits. Once an LVI reset occurs, the MCU remains in reset until VDD rises above a voltage, LVITRIPR, which causes the MCU to exit reset. See 8.4.2.5 Low-Voltage Inhibit (LVI) Reset for details of the interaction between the SIM and the LVI. The output of the comparator controls the state of the LVIOUT flag in the LVI status register (LVISR). An LVI reset also drives the RST pin low to provide low-voltage protection to external peripheral devices.
NOTE:
Where LVI trip falling voltage LVITRIPF = VLVII and LVI trip rising voltage LVITRIPR = VLVII + HLVI (See Section 23. Electrical Specifications.)
VDD STOP INSTRUCTION LVISTOP FROM MORA FROM MORA LVIRSTD LVIPWRD FROM MORA LOW VDD DETECTOR VDD > LVITrip = 0 VDD LVITrip = 1 LVIOUT TO LVISR LVI RESET
Figure 21-1. LVI Module Block Diagram
Technical Data
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Low-Voltage Inhibit (LVI) Functional Description
Address:
$FE0F Bit 7 6 0 5 0 4 0 3 0 2 0 1 0 Bit 0 0
Read: Write: Reset:
LVIOUT
0
0
0
0
0
0
0
0
= Unimplemented
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Figure 21-2. LVI I/O Register Summary
21.4.1 Polled LVI Operation In applications that can operate at VDD levels below the LVITRIPF level, software can monitor VDD by polling the LVIOUT bit. In mask option register A, the LVIPWRD bit must be at logic 0 to enable the LVI module, and the LVIRSTD bit must be at logic 1 to disable LVI resets.
21.4.2 Forced Reset Operation In applications that require VDD to remain above the LVITRIPF level, enabling LVI resets allows the LVI module to reset the MCU when VDD falls below the LVITRIPF level and remains at or below that level for 9 or more consecutive CPU cycles. In mask option register A, the LVIPWRD and LVIRSTD bits must be at logic 0 to enable the LVI module and to enable LVI resets.
21.4.3 False Reset Protection The VDD pin level is digitally filtered to reduce false resets due to power supply noise. In order for the LVI module to reset the MCU, VDD must remain at or below the LVITRIPF level for 9 or more consecutive CPU cycles. VDD must be above LVITRIPR for only one CPU cycle to bring the MCU out of reset.
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Technical Data
353
Freescale Semiconductor, Inc. Low-Voltage Inhibit (LVI) 21.5 LVI Status Register (LVISR)
The LVI status register flags VDD voltages below the LVITRIPF level.
Address: $FE0F Bit 7 Read: Write: Reset: 0 0 0 0 0 0 0 0 LVIOUT 6 0 5 0 4 0 3 0 2 0 1 0 Bit 0 0
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= Unimplemented
Figure 21-3. LVI Status Register (LVISR) LVIOUT -- LVI Output Bit This read-only flag becomes set when VDD falls below the LVITRIPF voltage for 32 to 40 CGMXCLK cycles. (See Table 21-2.) Reset clears the LVIOUT bit. Table 21-1. LVIOUT Bit Indication
VDD At level: VDD > LVITRIPR VDD < LVITRIPF VDD < LVITRIPF VDD < LVITRIPF LVITRIPF < VDD < LVITRIPR For number of CGMXCLK cycles: Any < 32 CGMXCLK cycles 32 to 40 CGMXCLK cycles > 40 CGMXCLK cycles Any LVIOUT 0 0 0 or 1 1 Previous value
21.6 LVI Interrupts
The LVI module does not generate interrupt requests.
Technical Data
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Low-Voltage Inhibit (LVI) Low-Power Modes
21.7 Low-Power Modes
The STOP and WAIT instructions put the MCU in low powerconsumption standby modes.
21.7.1 Wait Mode If enabled, the LVI module remains active in wait mode. If enabled to generate resets, the LVI module can generate a reset and bring the MCU out of wait mode.
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21.7.2 Stop Mode If enabled in stop mode (LVISTOP set), the LVI module remains active in stop mode. If enabled to generate resets, the LVI module can generate a reset and bring the MCU out of stop mode.
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Technical Data
355
Freescale Semiconductor, Inc. Low-Voltage Inhibit (LVI)
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Technical Data
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Technical Data -- MC68HC08AB16A
Section 22. Break Module (BRK)
22.1 Contents
22.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
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22.3
22.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 22.4.1 Flag Protection During Break Interrupts . . . . . . . . . . . . . . . 360 22.4.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 360 22.4.3 PIT, TIMA, and TIMB During Break Interrupts . . . . . . . . . . 360 22.4.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 360 22.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 22.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 22.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 22.6 Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 22.6.1 Break Status and Control Register. . . . . . . . . . . . . . . . . . . 361 22.6.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 362 22.6.3 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 362 22.6.4 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 364
22.2 Introduction
This section describes the break module (BRK). The break module can generate a break interrupt that stops normal program flow at a defined address to enter a background program.
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Technical Data
357
Freescale Semiconductor, Inc. Break Module (BRK) 22.3 Features
Features of the break module include: * * * * Accessible input/output (I/O) registers during the break interrupt CPU-generated break interrupts Software-generated break interrupts COP disabling during break interrupts
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22.4 Functional Description
When the internal address bus matches the value written in the break address registers, the break module issues a breakpoint signal to the CPU. The CPU then loads the instruction register with a software interrupt instruction (SWI) after completion of the current CPU instruction. The program counter vectors to $FFFC and $FFFD ($FEFC and $FEFD in monitor mode). The following events can cause a break interrupt to occur: * * A CPU-generated address (the address in the program counter) matches the contents of the break address registers. Software writes a logic 1 to the BRKA bit in the break status and control register.
When a CPU-generated address matches the contents of the break address registers, the break interrupt begins after the CPU completes its current instruction. A return-from-interrupt instruction (RTI) in the break routine ends the break interrupt and returns the MCU to normal operation. Figure 22-1 shows the structure of the break module.
Technical Data
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Break Module (BRK) Functional Description
IAB15-IAB8
BREAK ADDRESS REGISTER HIGH 8-BIT COMPARATOR IAB15-IAB0 8-BIT COMPARATOR BREAK ADDRESS REGISTER LOW CONTROL BREAK
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IAB7-IAB0
Figure 22-1. Break Module Block Diagram
Addr.
Register Name
Bit 7 R 0 BCFE 0 Bit 15 0 Bit 7 0 BRKE 0
6 R 0 R
5 R 0 R
4 R 0 R
3 R 0 R
2 R 0 R
1 SBSW Note 0 R
Bit 0 R 0 R
Read: SIM Break Status Register $FE00 Write: (SBSR) Reset: Read: SIM Break Flag Control Write: Register (SBFCR) Reset: Read: Break Address Register Write: High (BRKH) Reset: Read: Break Address Register Write: Low (BRKL) Reset:
$FE03
$FE0C
14 0 6 0 BRKA 0
13 0 5 0 0
12 0 4 0 0
11 0 3 0 0
10 0 2 0 0
9 0 1 0 0
Bit 8 0 Bit 0 0 0
$FE0D
Read: Break Status and Control $FE0E Write: Register (BRKSCR) Reset:
Note: Writing a logic 0 clears SBSW.
0
0
0 R
0 = Reserved
0
0
= Unimplemented
Figure 22-2. Break Module I/O Register Summary
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Technical Data
359
Freescale Semiconductor, Inc. Break Module (BRK)
22.4.1 Flag Protection During Break Interrupts The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear status bits during the break state.
22.4.2 CPU During Break Interrupts The CPU starts a break interrupt by: * Loading the instruction register with the SWI instruction Loading the program counter with $FFFC and $FFFD ($FEFC and $FEFD in monitor mode)
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*
The break interrupt begins after completion of the CPU instruction in progress. If the break address register match occurs on the last cycle of a CPU instruction, the break interrupt begins immediately.
22.4.3 PIT, TIMA, and TIMB During Break Interrupts A break interrupt stops all timer counters.
22.4.4 COP During Break Interrupts The COP is disabled during a break interrupt when VTST is present on the RST pin.
22.5 Low-Power Modes
The WAIT and STOP instructions put the MCU in low powerconsumption standby modes.
22.5.1 Wait Mode If enabled, the break module is active in wait mode. In the break routine, the user can subtract one from the return address on the stack if SBSW is set (see Section 8. System Integration Module (SIM)). Clear the SBSW bit by writing logic 0 to it.
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Freescale Semiconductor, Inc.
Break Module (BRK) Break Module Registers
22.5.2 Stop Mode A break interrupt causes exit from stop mode and sets the SBSW bit in the break status register.
22.6 Break Module Registers
These registers control and monitor operation of the break module:
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* * * * *
Break status and control register (BRKSCR) Break address register high (BRKH) Break address register low (BRKL) SIM Break status register (SBSR) SIM Break flag control register (SBFCR)
22.6.1 Break Status and Control Register The break status and control register (BRKSCR) contains break module enable and status bits.
Address: $FE0E Bit 7 Read: BRKE Write: Reset: 0 0 0 0 0 0 0 0 BRKA 6 5 0 4 0 3 0 2 0 1 0 Bit 0 0
= Unimplemented
Figure 22-3. Break Status and Control Register (BRKSCR) BRKE -- Break Enable Bit This read/write bit enables breaks on break address register matches. Clear BRKE by writing a logic 0 to bit 7. Reset clears the BRKE bit. 1 = Breaks enabled on 16-bit address match 0 = Breaks disabled on 16-bit address match
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Freescale Semiconductor, Inc. Break Module (BRK)
BRKA -- Break Active Bit This read/write status and control bit is set when a break address match occurs. Writing a logic 1 to BRKA generates a break interrupt. Clear BRKA by writing a logic 0 to it before exiting the break routine. Reset clears the BRKA bit. 1 = (When read) Break address match 0 = (When read) No break address match
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22.6.2 Break Address Registers The break address registers (BRKH and BRKL) contain the high and low bytes of the desired breakpoint address. Reset clears the break address registers.
Address: $FE0C Bit 7 Read: Bit 15 Write: Reset: 0 0 0 0 0 0 0 0 14 13 12 11 10 9 Bit 8 6 5 4 3 2 1 Bit 0
Figure 22-4. Break Address Register High (BRKH)
Address: $FE0D Bit 7 Read: Bit 7 Write: Reset: 0 0 0 0 0 0 0 0 6 5 4 3 2 1 Bit 0 6 5 4 3 2 1 Bit 0
Figure 22-5. Break Address Register Low (BRKL)
22.6.3 SIM Break Status Register The SIM break status register (SBSR) contains a flag to indicate that a break caused an exit from wait mode. The flag is useful in applications requiring a return to wait mode after exiting from a break interrupt.
Technical Data
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Freescale Semiconductor, Inc.
Break Module (BRK) Break Module Registers
Address:
$FE00 Bit 7 6 R 0 5 R 0 R 4 R 0 = Reserved 3 R 0 2 R Note 0 0 0 0 1 SBSW R R Bit 0
Read: Write: Reset:
Note: Writing a logic 0 clears SBSW.
Figure 22-6. SIM Break Status Register (SBSR)
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SBSW -- SIM Break Stop/Wait Bit This status bit is useful in applications requiring a return to wait or stop mode after exiting from a break interrupt. Clear SBSW by writing a logic 0 to it. Reset clears SBSW. 1 = Stop mode or wait mode was exited by break interrupt 0 = Stop mode or wait mode was not exited by break interrupt SBSW can be read within the break interrupt routine. The user can modify the return address on the stack by subtracting one from it. The following code is an example.
; This code works if the H register has been pushed onto the stack in the break ; service routine software. This code should be executed at the end of the break ; service routine software. HIBYTE LOBYTE ; EQU EQU 5 6
If not SBSW, do RTI BRCLR TST BNE DEC DOLO RETURN DEC PULH RTI SBSW,SBSR, RETURN LOBYTE,SP DOLO HIBYTE,SP LOBYTE,SP ; See if wait mode or stop mode was exited by ; break. ;If RETURNLO is not zero, ;then just decrement low byte. ;Else deal with high byte, too. ;Point to WAIT/STOP opcode. ;Restore H register.
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Technical Data
363
Freescale Semiconductor, Inc. Break Module (BRK)
22.6.4 SIM Break Flag Control Register The SIM break flag control register (SBFCR) contains a bit that enables software to clear status bits while the MCU is in a break state.
Address: $FE03 Bit 7 Read: BCFE Write: R R R R R R R 6 5 4 3 2 1 Bit 0
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Reset:
0 R = Reserved
Figure 22-7. SIM Break Flag Control Register (SBFCR) BCFE -- Break Clear Flag Enable Bit This read/write bit enables software to clear status bits by accessing status registers while the MCU is in a break state. To clear status bits during the break state, the BCFE bit must be set. 1 = Status bits clearable during break 0 = Status bits not clearable during break
Technical Data
MC68HC08AB16A -- Rev. 2.0 Break Module (BRK) For More Information On This Product, Go to: www.freescale.com MOTOROLA
364
Freescale Semiconductor, Inc.
Technical Data -- MC68HC08AB16A
Section 23. Electrical Specifications
23.1 Contents
23.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 366 Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . 367 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 5.0-V DC Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . 368 EEPROM and Memory Characteristics . . . . . . . . . . . . . . . . . 369 5.0-V Control Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 Timer Interface Module Characteristics . . . . . . . . . . . . . . . . . 370
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23.3 23.4 23.5 23.6 23.7 23.8 23.9
23.10 ADC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371 23.11 SPI Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372 23.12 Clock Generation Module Characteristics . . . . . . . . . . . . . . . 375 23.12.1 CGM Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . 375 23.12.2 CGM Component Information . . . . . . . . . . . . . . . . . . . . . . 375 23.12.3 CGM Acquisition/Lock Time Information . . . . . . . . . . . . . . 376
23.2 Introduction
This section contains electrical and timing specifications.
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Technical Data
365
Freescale Semiconductor, Inc. Electrical Specifications 23.3 Absolute Maximum Ratings
Maximum ratings are the extreme limits to which the MCU can be exposed without permanently damaging it.
NOTE:
This device is not guaranteed to operate properly at the maximum ratings. Refer to 23.6 5.0-V DC Electrical Characteristics for guaranteed operating conditions.
Characteristic(1) Supply voltage Input voltage Maximum current per pin excluding VDD , VSS , and PTD0-PTD7 Maximum current for pins PTD0-PTD7 Maximum current into VDD Maximum current out of VSS Storage temperature
Notes: 1. Voltages referenced to VSS
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Symbol VDD VIn I
Value -0.3 to + 6.0 VSS - 0.3 to VDD + 0.3 15 25 100 100 -55 to +150
Unit V V mA
IPTD0-PTD7 Imvdd Imvss Tstg
mA mA mA C
NOTE:
This device contains circuitry to protect the inputs against damage due to high static voltages or electric fields; however, it is advised that normal precautions be taken to avoid application of any voltage higher than maximum-rated voltages to this high-impedance circuit. For proper operation, it is recommended that VIn and VOut be constrained to the range VSS (VIn or VOut) VDD. Reliability of operation is enhanced if unused inputs are connected to an appropriate logic voltage level (for example, either VSS or VDD).
Technical Data
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Electrical Specifications Functional Operating Range
23.4 Functional Operating Range
Characteristic Operating temperature range Operating voltage range Symbol TA VDD Value -40 to +85 5.0 10% -40 to +125 5.0 10% Unit C V
23.5 Thermal Characteristics
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Characteristic Thermal resistance QFP (64-pin) I/O pin power dissipation Power dissipation(1)
Symbol JA PI/O PD
Value 70 User-Determined PD = (IDD x VDD) + PI/O = K/(TJ + 273 C) PD x (TA + 273 C) + PD2 x JA TA + (PD x JA)
Unit C/W W W
Constant(2) Average junction temperature
K TJ
W/C C
Notes: 1. Power dissipation is a function of temperature. 2. K is a constant unique to the device. K can be determined for a known TA and measured PD. With this value of K, PD and TJ can be determined for any value of TA.
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Electrical Specifications For More Information On This Product, Go to: www.freescale.com
Technical Data
367
Freescale Semiconductor, Inc. Electrical Specifications 23.6 5.0-V DC Electrical Characteristics
Characteristic(1) Output high voltage (ILoad = -2.0 mA) all I/O pins (ILoad = -10.0 mA) all I/O pins (ILoad = -10.0 mA) pins PTD0-PTD7 only Maximum combined IOH for port C, port E, port F, port G, port H Maximum combined IOH for port D, port A, port B Maximum total IOH for all port pins Output low voltage (ILoad = 1.6 mA) all I/O pins (ILoad = 10 mA) all I/O pins (ILoad = 15 mA) pins PTD0-PTD7 only Maximum combined IOL for port C, port E, port F, port G, port H Maximum combined IOL for port D, port A, port B Maximum total IOL for all port pins Input high voltage All ports, IRQ, RST, OSC1 Input low voltage All ports, IRQ, RST, OSC1 VDD supply current Run(3) Wait(4) Stop(5) LVI enabled, TA = 25 C LVI disabled, TA = 25 C LVI enabled, TA = -40 C to 125 C LVI disabled, TA = -40 C to 125 C I/O ports Hi-Z leakage current(6) Input current Pullup resistors (as input only) Capacitance Ports (as input or output) Monitor mode entry voltage Low-voltage inhibit, trip falling voltage Symbol VOH VOH VOH IOH1 IOH2 IOHT VOL VOL VOL IOL1 IOL2 IOLT VIH VIL Min VDD - 0.8 VDD - 1.5 VDD - 0.8 -- -- -- -- -- -- -- -- -- 0.7 x VDD VSS Typ(2) -- -- -- -- -- -- -- -- -- -- -- -- -- -- Max -- -- -- 50 50 100 0.4 1.5 1.0 50 50 100 VDD 0.3 x VDD Unit V V V mA mA mA V V V mA mA mA V V
Freescale Semiconductor, Inc...
-- -- IDD -- -- -- -- -- -- 20 -- -- VDD + 2.5 --
-- -- 300 20 400 50 1 -- 33 -- -- -- 4.11
30 12 400 50 500 100 10 1 50 12 8 8 --
mA mA A A A A A A k pF V V
IIL IIn RPU COut CIn VTST VLVII
Technical Data
MC68HC08AB16A -- Rev. 2.0 Electrical Specifications For More Information On This Product, Go to: www.freescale.com MOTOROLA
368
Freescale Semiconductor, Inc.
Electrical Specifications EEPROM and Memory Characteristics
Characteristic(1) Low-voltage inhibit reset/recover hysteresis POR rearm voltage(7) POR reset voltage(8) POR rise time ramp rate(9)
Symbol HLVI VPOR VPORRST RPOR
Min 100 0 0 0.02
Typ(2) 150 -- -- --
Max -- 200 800 --
Unit mV mV mV V/ms
Freescale Semiconductor, Inc...
Notes: 1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted 2. Typical values reflect average measurements at midpoint of voltage range, 25 C only. 3. Run (operating) IDD measured using external square wave clock source (fBUS = 8.4MHz). All inputs 0.2 V from rail. No dc loads. Less than 100 pF on all outputs. CL = 20 pF on OSC2. All ports configured as inputs. OSC2 capacitance linearly affects run IDD. Measured with all modules enabled. 4. Wait IDD measured using external square wave clock source (fBUS = 8.4MHz). All inputs 0.2 V from rail. No dc loads. Less than 100 pF on all outputs. CL = 20 pF on OSC2. All ports configured as inputs. OSC2 capacitance linearly affects wait IDD. Measured with PLL and LVI enabled. 5. Stop IDD is measured with OSC1 = VSS. 6. Pullups are disabled. Port B leakage is specified in 23.10 ADC Characteristics. 7. Maximum is highest voltage that POR is guaranteed. 8. Maximum is highest voltage that POR is possible. 9. If minimum VDD is not reached before the internal POR reset is released, RST must be driven low externally until minimum VDD is reached.
23.7 EEPROM and Memory Characteristics
Characteristic RAM data retention voltage EEPROM programming time per byte EEPROM erasing time per byte EEPROM erasing time per block EEPROM erasing time per bulk EEPROM programming voltage discharge period Number of programming operations to the same EEPROM byte before erase(1) EEPROM write/erase cycles at 10ms write time (85C) EEPROM data retention after 10,000 write/erase cycles Symbol VRDR tEEPGM tEBYTE tEBLOCK tEBULK tEEFPV -- -- -- Min 0.7 10 10 10 10 100 -- 10,000 10 Max -- -- -- -- -- -- 8 -- -- Unit V ms ms ms ms s -- Cycles Years
Notes: 1. Programming a byte more times than the specified maximum may affect the data integrity of that byte. The byte must be erased before it can be programmed again.
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Electrical Specifications For More Information On This Product, Go to: www.freescale.com
Technical Data
369
Freescale Semiconductor, Inc. Electrical Specifications 23.8 5.0-V Control Timing
Characteristic(1) Frequency of operation Crystal option(2) External clock option(3) Internal operating frequency RESET input pulse width low(6) Symbol fOSC fBUS tIRL tILIH tILIL tTH,tTL tTLTL Min 1 dc(4) Note(5) 1.5 1.5 Note(8) 2 Note(9) Max 8.4 33.6 8.4 -- -- -- Unit MHz MHz MHz tcyc tcyc tcyc tcyc tcyc
Freescale Semiconductor, Inc...
IRQ interrupt pulse width low(7) (Edge-triggered) IRQ interrupt pulse period 16-bit timer Input capture pulse width Input capture period
-- --
Notes: 1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted 2. See 23.12 Clock Generation Module Characteristics for more information. 3. No more than 10% duty cycle deviation from 50% 4. Some modules may require a minimum frequency greater than dc for proper operation. See appropriate table for this information. 5. Some modules may require a minimum frequency greater than dc for proper operation. See appropriate table for this information. 6. Minimum pulse width reset is guaranteed to be recognized. It is possible for a smaller pulse width to cause a reset. 7. Minimum pulse width is for guaranteed interrupt. It is possible for a smaller pulse width to be recognized. 8. Minimum pulse width is for guaranteed interrupt. It is possible for a smaller pulse width to be recognized. The minimum period, tILIL or tTLTL, should not be less than the number of cycles it takes to execute the interrupt service routine plus TBD tcyc. 9. The minimum period, tILIL or tTLTL, should not be less than the number of cycles it takes to execute the interrupt service routine plus TBD tcyc.
23.9 Timer Interface Module Characteristics
Characteristic Input capture pulse width Input clock pulse width Symbol tTIH, tTIL tTCH, tTCL Min 125 (1/fBUS)+5 Max -- -- Unit ns ns
Technical Data
MC68HC08AB16A -- Rev. 2.0 Electrical Specifications For More Information On This Product, Go to: www.freescale.com MOTOROLA
370
Freescale Semiconductor, Inc.
Electrical Specifications ADC Characteristics
23.10 ADC Characteristics
Characteristic(1) Symbol Min 4.5 (VDD min) Max 5.5 (VDD max) VDDAREF VDDAREF 8 1 Unit Comments VDDAREF should be tied to the same potential as VDD via separate traces. VADIN VREFH
Supply voltage
VDDAD
V
Input voltages
VADIN VREFH BAD AAD
0 1.5 8 1/2
V Bits LSB
Freescale Semiconductor, Inc...
Resolution Absolute accuracy (VREFL = 0 V, VREFH = VDDAD = 5 V 10%) ADC internal clock Conversion range Power-up time Conversion time Sample time(2) Zero input reading(3) Full-scale reading(3) Input capacitance Input leakage(4) Port B
Includes quantization tAIC = 1/fADIC, tested only at 1 MHz VREFL = VSSA
fADIC RAD tADPU tADC tADS ZADI FADI CADI --
0.5 VREFL 16 16 5 00 FE -- --
1.048 VREFH -- 17 -- 01 FF 8 1
MHz V tAIC cycles tAIC cycles tAIC cycles Hex Hex pF A
VIN = VREFL VIN = VREFH Not tested
Notes: 1. VDD = 5.0 Vdc 10%, VDDA = VDDAREF = 5.0 Vdc 10%, VREFH = 5.0 Vdc 10%, VSS = 0 Vdc, VREFL = VSSA = 0 Vdc 2. Source impedances greater than 10 k adversely affect internal RC charging time during input sampling. 3. Zero-input/full-scale reading requires sufficient decoupling measures for accurate conversions. 4. The external system error caused by input leakage current is approximately equal to the product of R source and input current.
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Electrical Specifications For More Information On This Product, Go to: www.freescale.com
Technical Data
371
Freescale Semiconductor, Inc. Electrical Specifications 23.11 SPI Characteristics
Diagram Number(1) Characteristic(2) Operating frequency Master Slave Cycle time Master Slave Enable lead time Enable lag time Clock (SPSCK) high time Master Slave Clock (SPSCK) low time Master Slave Data setup time (inputs) Master Slave Data hold time (inputs) Master Slave Access time, slave(3) CPHA = 0 CPHA = 1 Disable time, slave(4) Data valid time, after enable edge Master Slave(5) Data hold time, outputs, after enable edge Master Slave Symbol Min Max Unit
fBUS(M) fBUS(S) tcyc(M) tcyc(S) tLead(S) tLag(S) tSCKH(M) tSCKH(S) tSCKL(M) tSCKL(S) tSU(M) tSU(S) tH(M) tH(S) tA(CP0) tA(CP1) tDIS(S) tV(M) tV(S) tHO(M) tHO(S)
fBUS/128 DC 2 1 15 15 100 50
fBUS/2 fBUS 128 -- -- -- -- -- -- -- -- --
MHz MHz tcyc tcyc ns ns
1
Freescale Semiconductor, Inc...
2 3 4
ns ns
5
100 50
ns ns
6
45 5
ns ns
7
0 15
-- --
ns ns
8 9 10
0 0 -- -- --
40 20 25 10 40
ns ns ns ns ns
11
0 5
-- --
ns ns
Notes: 1. Numbers refer to dimensions in Figure 23-1 and Figure 23-2. 2. All timing is shown with respect to 20% VDD and 70% VDD, unless noted; 100 pF load on all SPI pins. 3. Time to data active from high-impedance state 4. Hold time to high-impedance state 5. With 100 pF on all SPI pins
Technical Data
MC68HC08AB16A -- Rev. 2.0 Electrical Specifications For More Information On This Product, Go to: www.freescale.com MOTOROLA
372
Freescale Semiconductor, Inc.
Electrical Specifications SPI Characteristics
SS INPUT
SS PIN OF MASTER HELD HIGH 1
SPSCK OUTPUT CPOL = 0
NOTE
5 4
SPSCK OUTPUT CPOL = 1
NOTE
5 4 6 7 LSB IN 10 BITS 6-1 11 MASTER LSB OUT
MISO INPUT
MSB IN 11
BITS 6-1
Freescale Semiconductor, Inc...
MOSI OUTPUT
MASTER MSB OUT
Note: This first clock edge is generated internally, but is not seen at the SPSCK pin.
a) SPI Master Timing (CPHA = 0)
SS INPUT
SS PIN OF MASTER HELD HIGH 1
SPSCK OUTPUT CPOL = 0
5 4
NOTE
SPSCK OUTPUT CPOL = 1
5 4 6 7 LSB IN 10 BITS 6-1 MASTER LSB OUT
NOTE
MISO INPUT 10 MOSI OUTPUT
MSB IN 11 MASTER MSB OUT
BITS 6-1
Note: This last clock edge is generated internally, but is not seen at the SPSCK pin.
b) SPI Master Timing (CPHA = 1)
Figure 23-1. SPI Master Timing
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Electrical Specifications For More Information On This Product, Go to: www.freescale.com
Technical Data
373
Freescale Semiconductor, Inc. Electrical Specifications
SS INPUT 1 SPSCK INPUT CPOL = 0 2 SPSCK INPUT CPOL = 1 8 MISO INPUT SLAVE 6 MOSI OUTPUT MSB IN MSB OUT 7 10 BITS 6-1 BITS 6-1 11 LSB IN SLAVE LSB OUT 11 5 4 9 NOTE 5 4 3
Freescale Semiconductor, Inc...
Note: Not defined but normally MSB of character just received
a) SPI Slave Timing (CPHA = 0)
SS INPUT 1 SPSCK INPUT CPOL = 0 2 SPSCK INPUT CPOL = 1 8 MISO OUTPUT 5 4 10 NOTE SLAVE 6 MOSI INPUT MSB IN MSB OUT 7 10 BITS 6-1 BITS 6-1 11 LSB IN 9 SLAVE LSB OUT 5 4 3
Note: Not defined but normally LSB of character previously transmitted
b) SPI Slave Timing (CPHA = 1)
Figure 23-2. SPI Slave Timing
Technical Data
MC68HC08AB16A -- Rev. 2.0 Electrical Specifications For More Information On This Product, Go to: www.freescale.com MOTOROLA
374
Freescale Semiconductor, Inc.
Electrical Specifications Clock Generation Module Characteristics
23.12 Clock Generation Module Characteristics
23.12.1 CGM Operating Conditions
Characteristic Operating Voltage Crystal Reference Frequency Module Crystal Reference Frequency Range Nom. Multiplier (MHz) VCO Center-of-Range Frequency (MHz) VCO Operating Frequency (MHz) Symbol VDD fRCLK fXCLK fNOM fVRS fVCLK Min 4.5 V 1 -- -- 4.9152 4.9152 Typ -- -- 4.9152 MHz 4.9152 -- -- Max 5.5 V 8.4 -- -- 32.0 32.0 Same Frequency as fRCLK 4.5 to 5.5 V, VDD only 4.5 to 5.5 V, VDD only Comments
Freescale Semiconductor, Inc...
23.12.2 CGM Component Information
Characteristic Crystal load capacitance Crystal fixed capacitance Crystal tuning capacitance Feedback bias resistor Series resistor Filter capacitor multiply factor Filter capacitor Symbol CL C1 C2 RB RS CFact CF Min -- -- -- -- -- -- -- Typ -- 2 x CL 2 x CL 22M 330k 0.0154 CFact x (VDDA/fXCLK) Max -- -- -- -- 1M -- -- Not required F/s V See 9.5.3 External Filter Capacitor Pin (CGMXFC). CBYP must provide low AC impedance from f = fXCLK/100 to 100 x fXCLK, so series resistance must be considered. Technical Data Electrical Specifications For More Information On This Product, Go to: www.freescale.com Comments Consult crystal manufacturer's data Consult crystal manufacturer's data Consult crystal manufacturer's data
Bypass capacitor
CBYP
--
0.1 F
--
MC68HC08AB16A -- Rev. 2.0 MOTOROLA
375
Freescale Semiconductor, Inc. Electrical Specifications
23.12.3 CGM Acquisition/Lock Time Information
Description(1) Manual mode time to stable Manual stable to lock time Manual acquisition time Tracking mode entry frequency tolerance Acquisition mode entry frequency tolerance LOCK entry freq. tolerance LOCK exit freq. tolerance Reference cycles per Acquisition mode measurement Reference cycles per Tracking mode measurement Automatic mode time to stable Automatic stable to lock time Automatic lock time PLL jitter, deviation of average bus frequency over 2 ms Symbol tACQ tAL tLock DTRK DUNT DLOCK DUNL nACQ Min -- -- -- 0 6.3% 0 0.9% -- Typ (8 x VDDA)/(fXCLK x KACQ) (4 x VDDA)/(fXCLK x KTRK) tACQ + tAL -- -- -- -- 32 Max -- -- -- 3.6% 7.2% 0.9% 1.8% -- Comments If CF chosen correctly If CF chosen correctly
Freescale Semiconductor, Inc...
nTRK
--
128 (8 x VDDA)/(fXCLK x KACQ) (4 x VDDA)/(fXCLK x KTRK) tACQ + tAL --
-- If CF Chosen Correctly -- -- (fCRYS) x (.025%) x (N/4) N = VCO Freq. Mult. (GBNT)(2) If CF Chosen Correctly
tACQ tAL tLock
nACQ/fXCLK nTRK/fXCLK -- 0
Notes: 1. VDD = 5.0 Vdc 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted. 2. GBNT guaranteed but not tested.
Technical Data
MC68HC08AB16A -- Rev. 2.0 Electrical Specifications For More Information On This Product, Go to: www.freescale.com MOTOROLA
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Freescale Semiconductor, Inc.
Technical Data -- MC68HC08AB16A
Section 24. Mechanical Specifications
24.1 Contents
24.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 64-Pin Plastic Quad Flat Pack (QFP) . . . . . . . . . . . . . . . . . . . 378
Freescale Semiconductor, Inc...
24.3
24.2 Introduction
This section gives the dimensions for: * 64-pin plastic quad flat pack (case 840B-01)
Figure 24-1 shows the latest package drawing at the time of this publication. To make sure that you have the latest package specifications, contact one of the following: * * Local Motorola Sales Office World Wide Web at http://www.motorola.com/semiconductors/
Follow the World Wide Web on-line instructions to retrieve the current mechanical specifications.
MC68HC08AB16A -- Rev. 2.0 MOTOROLA Mechanical Specifications For More Information On This Product, Go to: www.freescale.com
Technical Data
377
Freescale Semiconductor, Inc. Mechanical Specifications 24.3 64-Pin Plastic Quad Flat Pack (QFP)
L
48 49 33 32 S S
D
D
0.05 (0.002) A-B
B B P
S
C A-B
-A- L
-B- B
V
M
Freescale Semiconductor, Inc...
0.20 (0.008)
0.20 (0.008)
M
H A-B
S
-A-, -B-, -D-
DETAIL A
DETAIL A
64 17
1
F
16
-D- A 0.20 (0.008)
M
C A-B
S
D
S
J
N
0.05 (0.002) A-B S 0.20 (0.008) M H A-B E
S
D M
S
D DETAILC 0.02 (0.008)
M
BASE METAL
C A-B
S
D
S
C -C-
SEATING PLANE
-H- H M G
DATUM PLANE
SECTION B-B
0.01 (0.004)
U T R -H-
DATUM PLANE
Q K W X DETAIL C
NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DATUM PLANE -H- IS LOCATED AT BOTTOM OF LEAD AND IS COINCIDENT WITH THE LEAD WHERE THE LEAD EXITS THE PLASTIC BODY AT THE BOTTOM OF THE PARTING LINE. 4. DATUMS -A-, -B- AND -D- TO BE DETERMINED AT DATUM PLANE -H-. 5. DIMENSIONS S AND V TO BE DETERMINED AT SEATING PLANE -C-. 6. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. ALLOWABLE PROTRUSION IS 0.25 (0.010) PER SIDE. DIMENSIONS A AND B DO INCLUDE MOLD MISMATCH AND ARE DETERMINED AT DATUM PLANE -H-. 7. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.08 (0.003) PER SIDE. TOTAL IN EXCESS OF THE D DIMENSION AT MAXIMUM MATERIAL CONDITION. DAMBAR CANNOT BE LOCATED ON THE LOWER RADIUS OR THE FOOT.
DIM A B C D E F G H J K L M N P Q R S T U V W X
MILLIMETERS MIN MAX 13.90 14.10 13.90 14.10 2.15 2.45 0.30 0.45 2.00 2.40 0.30 0.40 0.80 BSC -- 0.25 0.13 0.23 0.65 0.95 12.00 REF 5 10 0.13 0.17 0.40 BSC 0 7 0.13 0.30 16.95 17.45 0.13 -- 0 -- 16.95 17.45 0.35 0.45 1.6 REF
INCHES MIN MAX 0.547 0.555 0.547 0.555 0.085 0.096 0.012 0.018 0.079 0.094 0.012 0.016 0.031 BSC -- 0.010 0.005 0.009 0.026 0.037 0.472 REF 5 10 0.005 0.007 0.016 BSC 0 7 0.005 0.012 0.667 0.687 0.005 -- 0 -- 0.667 0.687 0.014 0.018 0.063 REF
Figure 24-1. 64-Pin Plastic Quad Flat Pack (QFP)
Technical Data MC68HC08AB16A -- Rev. 2.0 Mechanical Specifications For More Information On This Product, Go to: www.freescale.com MOTOROLA
378
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
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Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. "Typical" parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer.
How to reach us: USA/EUROPE/Locations Not Listed: Motorola Literature Distribution; P.O. Box 5405, Denver, Colorado 80217. 1-303-675-2140 or 1-800-441-2447 JAPAN: Motorola Japan Ltd.; SPS, Technical Information Center, 3-20-1, Minami-Azabu, Minato-ku, Tokyo 106-8573 Japan. 81-3-3440-3569 ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; Silicon Harbour Center, 2 Dai King Street, Tai Po Industrial Estate, Tai Po, N.T., Hong Kong. 852-26668334 Technical Information Center: 1-800-521-6274 HOME PAGE: http://www.motorola.com/semiconductors/
(c) Motorola, Inc., 2000
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