MOTOROLA MC68HC908BD48IFB

MC68HC908BD48/D
REV. 1.0
MC68HC908BD48
HCMOS Microcontroller Unit
TECHNICAL DATA
Technical Data — MC68HC908BD48
List of Sections
Section 1. General Description . . . . . . . . . . . . . . . . . . . .25
Section 2. Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . .35
Section 3. Random-Access Memory (RAM) . . . . . . . . . .53
Section 4. FLASH Memory . . . . . . . . . . . . . . . . . . . . . . . .55
Section 5. Configuration Register (CONFIG) . . . . . . . . .63
Section 6. Central Processor Unit (CPU) . . . . . . . . . . . .67
Section 7. System Integration Module (SIM) . . . . . . . . .87
Section 8. Oscillator (OSC) . . . . . . . . . . . . . . . . . . . . . .111
Section 9. Monitor ROM (MON) . . . . . . . . . . . . . . . . . . .115
Section 10. Timer Interface Module (TIM) . . . . . . . . . . .125
Section 11. Pulse Width Modulator (PWM) . . . . . . . . . .147
Section 12. Analog-to-Digital Converter (ADC) . . . . . .153
Section 13. Universal Serial Bus Module (USB) . . . . . .163
Section 14. Multi-Master IIC Interface (MMIIC) . . . . . . .179
Section 15. DDC12AB Interface . . . . . . . . . . . . . . . . . . .193
Section 16. Sync Processor . . . . . . . . . . . . . . . . . . . . . .209
Section 17. Input/Output (I/O) Ports . . . . . . . . . . . . . . .229
Section 18. External Interrupt (IRQ) . . . . . . . . . . . . . . .251
Section 19. Computer Operating Properly (COP) . . . .257
Section 20. Break Module (BRK) . . . . . . . . . . . . . . . . . .263
Section 21. Electrical Specifications . . . . . . . . . . . . . . .271
Section 22. Mechanical Specifications . . . . . . . . . . . . .283
Section 23. Ordering Information . . . . . . . . . . . . . . . . .287
MC68HC908BD48 — Rev. 1.0
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List of Sections
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List of Sections
Technical Data
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MC68HC908BD48 — Rev. 1.0
List of Sections
MOTOROLA
Technical Data — MC68HC908BD48
Table of Contents
Section 1. General Description
1.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1.4
MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.5
Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1.6
Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Section 2. Memory Map
2.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.3
Unimplemented Memory Locations . . . . . . . . . . . . . . . . . . . . . 35
2.4
Reserved Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.5
Input/Output (I/O) Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Section 3. Random-Access Memory (RAM)
3.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Section 4. FLASH Memory
4.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
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4.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.4
FLASH Control Register (FLCR) . . . . . . . . . . . . . . . . . . . . . . . 56
4.5
FLASH Block Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.6
FLASH Mass Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.7
FLASH Program Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.8
FLASH Block Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.9
FLASH Block Protect Register (FLBPR). . . . . . . . . . . . . . . . . . 61
Section 5. Configuration Register (CONFIG)
5.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.3.1
Configuration Register 0. . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.3.2
Configuration Register 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Section 6. Central Processor Unit (CPU)
6.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
6.4
CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
6.4.1
Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
6.4.2
Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
6.4.3
Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
6.4.4
Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
6.4.5
Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
6.5
Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
6.6
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
6.6.1
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
6.6.2
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.7
CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 75
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6.8
Instruction Set Summary
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.9
Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Section 7. System Integration Module (SIM)
7.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
7.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
7.3
SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . . 91
7.3.1
Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.3.2
Clock Start-Up from POR . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.3.3
Clocks in Stop Mode and Wait Mode . . . . . . . . . . . . . . . . . . 91
7.4
Reset and System Initialization. . . . . . . . . . . . . . . . . . . . . . . . . 92
7.4.1
External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
7.4.2
Active Resets from Internal Sources . . . . . . . . . . . . . . . . . . 93
7.4.2.1
Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
7.4.2.2
Computer Operating Properly (COP) Reset . . . . . . . . . . 95
7.4.2.3
Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.4.2.4
Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.5
SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.5.1
SIM Counter During Power-On Reset . . . . . . . . . . . . . . . . . 96
7.5.2
SIM Counter During Stop Mode Recovery . . . . . . . . . . . . . . 97
7.5.3
SIM Counter and Reset States. . . . . . . . . . . . . . . . . . . . . . . 97
7.6
Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.6.1
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.6.1.1
Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
7.6.1.2
SWI Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
7.6.2
Interrupt Status Registers. . . . . . . . . . . . . . . . . . . . . . . . . . 101
7.6.2.1
Interrupt Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . 103
7.6.2.2
Interrupt Status Register 2 . . . . . . . . . . . . . . . . . . . . . . . 103
7.6.3
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
7.6.4
Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
7.6.5
Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . 104
7.7
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
7.7.1
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
7.7.2
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
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7.8
SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
7.8.1
SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . 108
7.8.2
SIM Reset Status Register (SRSR) . . . . . . . . . . . . . . . . . . 109
7.8.3
SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . 110
Section 8. Oscillator (OSC)
8.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
8.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
8.3
Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . . 112
8.4
I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
8.4.1
Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . 113
8.4.2
Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . 113
8.4.3
Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . 113
8.4.4
External Clock Source (OSCXCLK) . . . . . . . . . . . . . . . . . . 113
8.4.5
Oscillator Out (OSCOUT). . . . . . . . . . . . . . . . . . . . . . . . . . 113
8.5
Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.5.1
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.5.2
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.6
Oscillator During Break Mode. . . . . . . . . . . . . . . . . . . . . . . . . 114
Section 9. Monitor ROM (MON)
9.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
9.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
9.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
9.4
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
9.4.1
Entering Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
9.4.2
Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
9.4.3
Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
9.4.4
Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
9.4.5
Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
9.4.6
Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
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Section 10. Timer Interface Module (TIM)
10.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
10.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
10.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
10.4
Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
10.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
10.5.1 TIM Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
10.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
10.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
10.5.3.1
Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 130
10.5.3.2
Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . 131
10.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 131
10.5.4.1
Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 132
10.5.4.2
Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 133
10.5.4.3
PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
10.6
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
10.7
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
10.8
TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 136
10.9
I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
10.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
10.10.1 TIM Status and Control Register (TSC) . . . . . . . . . . . . . . . 137
10.10.2 TIM Counter Registers (TCNTH:TCNTL) . . . . . . . . . . . . . . 139
10.10.3 TIM Counter Modulo Registers (TMODH:TMODL) . . . . . . 140
10.10.4 TIM Channel Status and Control Registers (TSC0:TSC1) . 141
10.10.5 TIM Channel Registers (TCH0H/L:TCH1H/L) . . . . . . . . . . 145
Section 11. Pulse Width Modulator (PWM)
11.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
11.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
11.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
11.4
PWM Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
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11.4.1
11.4.2
PWM Data Registers 0 to 15 (0PWM–15PWM). . . . . . . . . 150
PWM Control Registers 1 and 2 (PWMCR1:PWMCR2) . . 151
Section 12. Analog-to-Digital Converter (ADC)
12.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
12.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
12.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
12.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
12.4.1 ADC Port I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
12.4.2 Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
12.4.3 Conversion Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
12.4.4 Continuous Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
12.4.5 Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.5
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.7 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.7.1 ADC Voltage In (ADCVIN) . . . . . . . . . . . . . . . . . . . . . . . . . 158
12.8 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
12.8.1 ADC Status and Control Register. . . . . . . . . . . . . . . . . . . . 158
12.8.2 ADC Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
12.8.3 ADC Input Clock Register . . . . . . . . . . . . . . . . . . . . . . . . . 161
Section 13. Universal Serial Bus Module (USB)
13.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
13.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
13.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
13.4
I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
13.5 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
13.5.1 USB Address Register (UADR) . . . . . . . . . . . . . . . . . . . . . 166
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13.5.2
13.5.3
13.5.4
13.5.5
13.5.6
13.5.7
13.5.8
13.5.9
USB Interrupt Register (UINTR). . . . . . . . . . . . . . . . . . . . . 166
USB Interrupt Register 1 (UIR1). . . . . . . . . . . . . . . . . . . . . 169
USB Control Register 0 (UCR0). . . . . . . . . . . . . . . . . . . . . 171
USB Control Register 1 (UCR1). . . . . . . . . . . . . . . . . . . . . 172
USB Control Register 2 (UCR2). . . . . . . . . . . . . . . . . . . . . 174
USB Status Register (USR) . . . . . . . . . . . . . . . . . . . . . . . . 175
USB Endpoint 0 Data Registers 0 to 7
(UD0R0–UD0R7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
USB Endpoint 1/2 Data Registers 0 to 7
(UD1R0–UD1R7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Section 14. Multi-Master IIC Interface (MMIIC)
14.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
14.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
14.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
14.4
I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
14.5 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
14.5.1 Multi-Master IIC Address Register (MMADR) . . . . . . . . . . 182
14.5.2 Multi-Master IIC Control Register (MMCR) . . . . . . . . . . . . 183
14.5.3 Multi-Master IIC Master Control Register (MIMCR) . . . . . . 184
14.5.4 Multi-Master IIC Status Register (MMSR) . . . . . . . . . . . . . 186
14.5.5 Multi-Master IIC Data Transmit Register (MMDTR) . . . . . . 188
14.5.6 Multi-Master IIC Data Receive Register (MMDRR) . . . . . . 189
14.6
Programming Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 190
Section 15. DDC12AB Interface
15.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
15.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
15.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
15.4
I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
15.5
DDC Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
15.6
Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
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15.6.1
15.6.2
15.6.3
15.6.4
15.6.5
15.6.6
15.6.7
15.7
DDC Address Register (DADR) . . . . . . . . . . . . . . . . . . . . . 196
DDC2 Address Register (D2ADR) . . . . . . . . . . . . . . . . . . . 197
DDC Control Register (DCR) . . . . . . . . . . . . . . . . . . . . . . . 198
DDC Master Control Register (DMCR) . . . . . . . . . . . . . . . 199
DDC Status Register (DSR) . . . . . . . . . . . . . . . . . . . . . . . . 202
DDC Data Transmit Register (DDTR) . . . . . . . . . . . . . . . . 204
DDC Data Receive Register (DDRR). . . . . . . . . . . . . . . . . 205
Programming Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 206
Section 16. Sync Processor
16.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
16.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
16.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
16.4
I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
16.5 Functional Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
16.5.1 Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
16.5.1.1
Hsync Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . 214
16.5.1.2
Vsync Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . 214
16.5.1.3
Composite Sync Polarity Detection . . . . . . . . . . . . . . . . 214
16.5.2 Sync Signal Counters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
16.5.3 Polarity Controlled HSYNCO and VSYNCO Outputs. . . . . 215
16.5.4 Clamp Pulse Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
16.5.5 Low Vertical Frequency Detect . . . . . . . . . . . . . . . . . . . . . 217
16.6 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
16.6.1 Sync Processor Control & Status Register (SPCSR). . . . . 217
16.6.2 Sync Processor Input/Output Control Register (SPIOCR) . 219
16.6.3 Vertical Frequency Registers (VFRs). . . . . . . . . . . . . . . . . 221
16.6.4 Hsync Frequency Registers (HFRs). . . . . . . . . . . . . . . . . . 223
16.6.5 Sync Processor Control Register 1 (SPCR1). . . . . . . . . . . 225
16.6.6 H&V Sync Output Control Register (HVOCR) . . . . . . . . . . 226
16.7
System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
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Section 17. Input/Output (I/O) Ports
17.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
17.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
17.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
17.3.1 Port A Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
17.3.2 Data Direction Register A . . . . . . . . . . . . . . . . . . . . . . . . . 234
17.3.3 Port A Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
17.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
17.4.1 Port B Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
17.4.2 Data Direction Register B . . . . . . . . . . . . . . . . . . . . . . . . . 237
17.4.3 Port B Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
17.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
17.5.1 Port C Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
17.5.2 Data Direction Register C . . . . . . . . . . . . . . . . . . . . . . . . . 240
17.5.3 Port C Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
17.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
17.6.1 Port D Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
17.6.2 Data Direction Register D. . . . . . . . . . . . . . . . . . . . . . . . . . 243
17.6.3 Port D Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
17.7 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
17.7.1 Port E Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
17.7.2 Data Direction Register E. . . . . . . . . . . . . . . . . . . . . . . . . . 248
17.7.3 Port E Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Section 18. External Interrupt (IRQ)
18.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
18.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
18.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
18.4
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
18.5
IRQ Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
18.6
IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . 255
18.7
IRQ Status and Control Register . . . . . . . . . . . . . . . . . . . . . . 255
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Section 19. Computer Operating Properly (COP)
19.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
19.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
19.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
19.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.1 OSCXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.2 STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.3 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.4 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.5 Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
19.4.6 Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
19.4.7 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
19.4.8 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . 260
19.5
COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
19.6
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
19.7
Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
19.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
19.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
19.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
19.9
COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . 262
Section 20. Break Module (BRK)
20.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
20.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
20.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
20.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
20.4.1 Flag Protection During Break Interrupts . . . . . . . . . . . . . . . 266
20.4.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 266
20.4.3 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . 266
20.4.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 266
20.5
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
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20.5.1
20.5.2
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
20.6 Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
20.6.1 Break Status and Control Register. . . . . . . . . . . . . . . . . . . 267
20.6.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 268
20.6.3 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 268
20.6.4 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 270
Section 21. Electrical Specifications
21.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
21.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
21.3
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 272
21.4
Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . 273
21.5
Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
21.6
DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 274
21.7
Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
21.8
Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
21.9
ADC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
21.10 USB DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . 277
21.11 USB Low Speed Source Electrical Characteristics. . . . . . . . . 278
21.12 Timer Interface Module Characteristics . . . . . . . . . . . . . . . . . 278
21.13 DDC12AB/MMIIC Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
21.13.1 DDC12AB/MMIIC Interface Input Signal Timing . . . . . . . . 279
21.13.2 DDC12AB/MMIIC Interface Output Signal Timing . . . . . . . 279
21.14 Sync Processor Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
21.15 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
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Section 22. Mechanical Specifications
22.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
22.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
22.3
28-Pin Plastic Dual In-Line Package (PDIP). . . . . . . . . . . . . . 284
22.4
42-Pin Shrink Dual in-Line Package (SDIP) . . . . . . . . . . . . . . 284
22.5
44-Pin Plastic Quad Flat Pack (QFP) . . . . . . . . . . . . . . . . . . . 285
Section 23. Ordering Information
23.1
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
23.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
23.3
MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
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List of Figures
Figure
Title
1-1
1-2
1-3
1-4
MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
44-Pin QFP Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . 29
42-Pin SDIP Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . 30
28-Pin PDIP Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . 31
2-1
2-2
Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Control, Status, and Data Registers . . . . . . . . . . . . . . . . . . . . . 39
4-1
4-2
4-3
4-4
FLASH Control Register (FLCR) . . . . . . . . . . . . . . . . . . . . . . . 56
FLASH Programming Flowchart . . . . . . . . . . . . . . . . . . . . . . . . 60
FLASH Block Protect Register (FLBPR). . . . . . . . . . . . . . . . . . 61
FLASH Block Protect Start Address . . . . . . . . . . . . . . . . . . . . . 62
5-1
5-2
Configuration Register 0 (CONFIG0) . . . . . . . . . . . . . . . . . . . . 64
Configuration Register 1 (CONFIG1) . . . . . . . . . . . . . . . . . . . . 65
6-1
6-2
6-3
6-4
6-5
6-6
CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Accumulator (A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Index Register (H:X) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Stack Pointer (SP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Program Counter (PC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Condition Code Register (CCR) . . . . . . . . . . . . . . . . . . . . . . . . 72
7-1
7-2
7-3
7-4
7-5
7-6
7-7
SIM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
OSC Clock Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
External Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Internal Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Sources of Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
POR Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Interrupt Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
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List of Figures
Figure
Title
Page
7-8
Interrupt Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7-9
Interrupt Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
7-10 Interrupt Recognition Example . . . . . . . . . . . . . . . . . . . . . . . . 100
7-11 Interrupt Status Register 1 (INT1). . . . . . . . . . . . . . . . . . . . . . 103
7-12 Interrupt Status Register 2 (INT2). . . . . . . . . . . . . . . . . . . . . . 103
7-13 Wait Mode Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
7-14 Wait Recovery from Interrupt or Break . . . . . . . . . . . . . . . . . . 106
7-15 Wait Recovery from Internal Reset. . . . . . . . . . . . . . . . . . . . . 106
7-16 Stop Mode Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
7-17 Stop Mode Recovery from Interrupt or Break . . . . . . . . . . . . . 107
7-18 SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . . . 108
7-19 SIM Reset Status Register (SRSR) . . . . . . . . . . . . . . . . . . . . 109
7-20 SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . . . 110
8-1
Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . . 112
9-1
9-2
9-3
9-4
9-5
Monitor Mode Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Monitor Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Sample Monitor Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Read Transaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Break Transaction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
10-1
10-2
10-3
10-4
10-5
10-6
10-7
10-8
TIM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
PWM Period and Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . 132
TIM Status and Control Register (TSC) . . . . . . . . . . . . . . . . . 137
TIM Counter Registers (TCNTH:TCNTL) . . . . . . . . . . . . . . . . 140
TIM Counter Modulo Registers (TMODH:TMODL). . . . . . . . . 141
TIM Channel Status and Control Registers (TSC0:TSC1) . . . 142
CHxMAX Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
TIM Channel Registers (TCH0H/L:TCH1H/L). . . . . . . . . . . . . 146
11-1
11-2
11-3
PWM Data Registers 0 to 15 (0PWM–15PWM) . . . . . . . . . . . 150
PWM Control Register 1 and 2 (PWMCR1:PWMCR2). . . . . . 151
8-Bit PWM Output Waveforms . . . . . . . . . . . . . . . . . . . . . . . . 152
12-1
ADC Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Technical Data
18
MC68HC908BD48 — Rev. 1.0
List of Figures
MOTOROLA
List of Figures
Figure
Title
12-2
12-3
12-4
ADC Status and Control Register (ADSCR) . . . . . . . . . . . . . . 158
ADC Data Register (ADR) . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
ADC Input Clock Register (ADICLK) . . . . . . . . . . . . . . . . . . . 161
13-1
13-2
13-3
13-4
13-5
13-6
13-7
13-8
13-9
USB Address Register (UADR) . . . . . . . . . . . . . . . . . . . . . . . 166
USB Interrupt Register (UINTR) . . . . . . . . . . . . . . . . . . . . . . . 166
USB Interrupt Register 1 (UIR1) . . . . . . . . . . . . . . . . . . . . . . . 169
USB Control Register 0 (UCR0) . . . . . . . . . . . . . . . . . . . . . . . 171
USB Control Register 1 (UCR1) . . . . . . . . . . . . . . . . . . . . . . . 172
USB Control Register 2 (UCR2) . . . . . . . . . . . . . . . . . . . . . . . 174
USB Status Register (USR) . . . . . . . . . . . . . . . . . . . . . . . . . . 175
USB Endpoint 0 Data Registers 0 to 7 (UD0R0–UD0R7) . . . 177
USB Endpoint 1 Data Registers 0 to 7 (UD1R0–UD1R7) . . . 177
14-1
14-2
14-3
14-4
14-5
14-6
14-7
Multi-Master IIC Address Register (MMADR). . . . . . . . . . . . . 182
Multi-Master IIC Control Register (MMCR). . . . . . . . . . . . . . . 183
Multi-Master IIC Master Control Register (MIMCR) . . . . . . . . 184
Multi-Master IIC Status Register (MMSR) . . . . . . . . . . . . . . . 186
Multi-Master IIC Data Transmit Register (MMDTR) . . . . . . . . 188
Multi-Master IIC Data Receive Register (MMDRR) . . . . . . . . 189
Data Transfer Sequences for Master/Slave
Transmit/Receive Modes . . . . . . . . . . . . . . . . . . . . . . . . . . 191
15-1
15-2
15-3
15-4
15-5
15-6
15-7
15-8
DDC Address Register (DADR) . . . . . . . . . . . . . . . . . . . . . . . 196
DDC2 Address Register (D2ADR) . . . . . . . . . . . . . . . . . . . . . 197
DDC Control Register (DCR) . . . . . . . . . . . . . . . . . . . . . . . . . 198
DDC Master Control Register (DMCR). . . . . . . . . . . . . . . . . . 199
DDC Status Register (DSR) . . . . . . . . . . . . . . . . . . . . . . . . . . 202
DDC Data Transmit Register (DDTR). . . . . . . . . . . . . . . . . . . 204
DDC Data Receive Register (DDRR) . . . . . . . . . . . . . . . . . . . 205
Data Transfer Sequences for Master/Slave
Transmit/Receive Modes . . . . . . . . . . . . . . . . . . . . . . . . . . 207
16-1
16-2
16-3
Sync Processor Block Diagram . . . . . . . . . . . . . . . . . . . . . . . 213
Clamp Pulse Output Timing . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Sync Processor Control & Status Register (SPCSR) . . . . . . . 217
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Page
Technical Data
List of Figures
19
List of Figures
Figure
Title
16-4
16-5
16-6
16-7
16-8
16-9
16-10
Sync Processor Input/Output Control Register (SPIOCR) . . . 219
Vertical Frequency High Register . . . . . . . . . . . . . . . . . . . . . . 221
Vertical Frequency Low Register . . . . . . . . . . . . . . . . . . . . . . 221
Hsync Frequency High Register . . . . . . . . . . . . . . . . . . . . . . . 223
Hsync Frequency Low Register . . . . . . . . . . . . . . . . . . . . . . . 223
Sync Processor Control Register 1 (SPCR1) . . . . . . . . . . . . . 225
H&V Sync Output Control Register (HVOCR) . . . . . . . . . . . . 226
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
Port A Data Register (PTA) . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Data Direction Register A (DDRA) . . . . . . . . . . . . . . . . . . . . . 234
Port A I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
PWM Control Register 1 (PWMCR1) . . . . . . . . . . . . . . . . . . . 235
Port B Data Register (PTB) . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Data Direction Register B (DDRB) . . . . . . . . . . . . . . . . . . . . . 237
Port B I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
PWM Control Register 1 (PWMCR1) . . . . . . . . . . . . . . . . . . . 238
Port C Data Register (PTC) . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Data Direction Register C (DDRC) . . . . . . . . . . . . . . . . . . . . . 240
Port C I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Port D Data Register (PTD) . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Data Direction Register D (DDRD) . . . . . . . . . . . . . . . . . . . . . 243
Port D I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Port D Configuration Register (PDCR) . . . . . . . . . . . . . . . . . . 245
Port E Data Register (PTE) . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Data Direction Register E (DDRE) . . . . . . . . . . . . . . . . . . . . . 248
Port E I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Configuration Register 0 (CONFIG0) . . . . . . . . . . . . . . . . . . . 250
18-1
18-2
IRQ Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 253
IRQ Status and Control Register (INTSCR) . . . . . . . . . . . . . . 256
19-1
19-2
19-3
COP Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
Configuration Register 1 (CONFIG1) . . . . . . . . . . . . . . . . . . . 260
COP Control Register (COPCTL) . . . . . . . . . . . . . . . . . . . . . . 261
20-1
Break Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 265
Technical Data
20
Page
MC68HC908BD48 — Rev. 1.0
List of Figures
MOTOROLA
List of Figures
Figure
Title
20-2
20-3
20-4
20-5
20-6
Break Status and Control Register (BRKSCR). . . . . . . . . . . . 267
Break Address Register High (BRKH) . . . . . . . . . . . . . . . . . . 268
Break Address Register Low (BRKL) . . . . . . . . . . . . . . . . . . . 268
SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . . . 269
SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . . . 270
21-1
ADC Input Voltage vs. Step Readings . . . . . . . . . . . . . . . . . . 277
22-1
22-2
22-3
28-Pin PDIP (Case 710) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
42-Pin SDIP (Case 858) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
44-Pin QFP (Case 824E) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Page
Technical Data
List of Figures
21
List of Figures
Technical Data
22
MC68HC908BD48 — Rev. 1.0
List of Figures
MOTOROLA
Technical Data — MC68HC908BD48
List of Tables
Table
Title
1-1
1-2
I/Os on 28-Pin Device. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2-1
Vector Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
6-1
6-2
Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7-1
7-2
7-3
7-4
7-5
SIM I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Signal Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
PIN Bit Set Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Interrupt Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
SIM Registers Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
9-1
9-2
9-3
9-4
9-5
9-6
9-7
9-8
9-9
Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Mode Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
READ (Read Memory) Command . . . . . . . . . . . . . . . . . . . . . 121
WRITE (Write Memory) Command. . . . . . . . . . . . . . . . . . . . . 122
IREAD (Indexed Read) Command . . . . . . . . . . . . . . . . . . . . . 122
IWRITE (Indexed Write) Command . . . . . . . . . . . . . . . . . . . . 123
READSP (Read Stack Pointer) Command . . . . . . . . . . . . . . . 123
RUN (Run User Program) Command . . . . . . . . . . . . . . . . . . . 124
Monitor Baud Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . 124
10-1
10-2
10-3
10-4
Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
TIM I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Prescaler Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Mode, Edge, and Level Selection . . . . . . . . . . . . . . . . . . . . . . 144
11-1
11-2
PWM I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . 148
PWM Channels and Port I/O pins. . . . . . . . . . . . . . . . . . . . . . 151
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Page
Technical Data
List of Tables
23
List of Tables
Table
Title
12-1
12-2
12-3
ADC Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
MUX Channel Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
ADC Clock Divide Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
13-1
13-2
Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
USB I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 165
14-1
14-2
14-3
Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
MMIIC I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . 181
Baud Rate Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
15-1
15-2
15-3
Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
DDC I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Baud Rate Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
16-1
16-2
16-3
16-4
16-5
16-6
16-7
16-8
16-9
16-10
Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Sync Processor I/O Register Summary . . . . . . . . . . . . . . . . . 212
Sync Output Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Sync Output Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
ATPOL, VINVO, and HINVO setting. . . . . . . . . . . . . . . . . . . . 219
Sample Vertical Frame Frequencies . . . . . . . . . . . . . . . . . . . 222
Clamp Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
HSYNC Polarity Detection Pulse Width . . . . . . . . . . . . . . . . . 225
ATPOL, VINVO, and HINVO setting. . . . . . . . . . . . . . . . . . . . 226
Free-Running HSYNC and VSYNC Options . . . . . . . . . . . . . 227
17-1
17-2
17-3
17-4
17-5
17-6
17-7
I/O Port Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Port Control Register Bits Summary. . . . . . . . . . . . . . . . . . . . 232
Port A Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Port B Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Port C Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Port D Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Port E Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
18-1
IRQ I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . 253
20-1
Break Module I/O Register Summary . . . . . . . . . . . . . . . . . . . 265
23-1
MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Technical Data
24
Page
MC68HC908BD48 — Rev. 1.0
List of Tables
MOTOROLA
Technical Data — MC68HC908BD48
Section 1. General Description
1.1 Contents
1.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1.4
MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.5
Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1.6
Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1.2 Introduction
The MC68HC908BD48 is a member of the low-cost, high-performance
M68HC08 Family of 8-bit microcontroller units (MCUs). The M68HC08
Family is based on the customer-specified integrated circuit (CSIC)
design strategy. 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.
With special modules such as the sync processor, analog-to-digital
converter, pulse modulator module, DDC12AB interface, multi-master
IIC interface, and universal serial bus interface, the MC68HC908BD48
is designed specifically for use in digital monitor systems.
1.3 Features
Features of the MC68HC908BD48 MCU include the following:
•
High-performance M68HC08 architecture
•
Fully upward-compatible object code with M6805, M146805, and
M68HC05 families
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
General Description
25
General Description
•
Low-power design; fully static with stop and wait modes
•
5V operating voltage
•
6MHz internal bus frequency; with 24MHz external crystal
•
48,128 bytes of on-chip FLASH memory
•
1,024 bytes of on-chip random access memory (RAM)
•
Sync signal processor with the following features:
– Horizontal and vertical frequency counters
– Low vertical frequency indicator (40.7Hz)
– Polarity controlled Hsync and Vsync outputs from separate
sync or composite sync inputs
– Internal generated free-running Hsync and Vsync pulses
– CLAMP pulse output to the external pre-amp chip
•
6-channel, 8-bit analog-to-digital converter (ADC)
•
16-channel, 8-bit pulse width modulator (PWM)
•
Full universal serial bus (USB) specification 1.0 compliant lowspeed bus with 3 endpoints:
– 1 Control endpoint (two 8-byte buffer)
– 2 Interrupt endpoints (one 8-byte buffer shared)
•
On-chip 3.3V regulator for USB pull-up resistor
•
DDC12AB1 module with the following:
– DDC1 hardware
– Multi-master IIC2 hardware for DDC2AB; with dual address
•
Additional multi-master IIC module
•
16-bit, 2-channel timer interface modules (TIM) with selectable
input capture, output compare, and PWM capability on one
channel
•
Up to 32 general purpose input/output (I/O) pins, including:
– 32 shared-function I/O pin for 42-pin and 44-pin packages
1. DDC is a VESA bus standard.
2. IIC is a proprietary Philips interface bus.
Technical Data
26
MC68HC908BD48 — Rev. 1.0
General Description
MOTOROLA
General Description
MCU Block Diagram
– 4 open-drain I/O pins for 42-pin and 44-pin packages
– 19 shared-function I/O pin for 28-pin package
– 2 open-drain I/O pins for 28-pin package
•
System protection features:
– Optional computer operating properly (COP) reset
– Illegal opcode detection with reset
– Illegal address detection with reset
•
FLASH memory security1
•
Master reset pin with internal pull-up and power-on reset
•
IRQ with programmable pull-up and schmitt-trigger input
•
28-pin PDIP, 42-pin SDIP, and 44-pin QFP packages
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 × 8 Multiply Instruction
•
Fast 16/8 Divide Instruction
•
Binary-Coded Decimal (BCD) Instructions
•
Optimization for Controller Applications
•
Third Party C Language Support
1.4 MCU Block Diagram
Figure 1-1 shows the structure of the MC68HC908BD48.
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or
copying the FLASH difficult for unauthorized users.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
General Description
27
DDRA
PORTA
PTA7/PWM15–PTA0/PWM8
PORTB
PTB7/PWM7–PTB0/PWM0
PORTC
PULSE WIDTH MODULATOR
MODULE
DDRB
ARITHMETIC/LOGIC
UNIT (ALU)
DDRC
CPU
REGISTERS
PTC5/ADC5–PTC0/ADC0
CONTROL AND STATUS REGISTERS — 80 BYTES
8-BIT ANALOG-TO-DIGITAL
CONVERTER MODULE
USER FLASH — 48,128 BYTES
MULTI-MASTER IIC
INTERFACE MODULE
USER RAM — 1024 BYTES
MONITOR ROM — 512+470 BYTES
DDC12AB
INTERFACE MODULE
USER FLASH VECTOR SPACE — 26 BYTES
General Description
OSC1‡
UNIVERSAL SERIAL BUS
INTERFACE MODULE
OSCILLATOR
OSC2‡
÷2
HSYNC
VSYNC
EXTERNAL IRQ
MODULE
PORTD
IRQ
2-CHANNEL TIMER INTERFACE
MODULE
PTD6/IICSDA†
PTD5/IICSCL†
PTD4/CLAMP
PTD3/DDCSCL†
PTD2/DDCSDA†
PTD1/D–‡
PTD0/D+‡
PORTE
RST
SYSTEM INTEGRATION
MODULE
DDRD
SYNC PROCESSOR
MODULE
PTE2/VSYNCO
PTE1/HSYNCO
PTE0/SOG/TCH0
MONITOR MODULE
MOTOROLA
MC68HC908BD48 — Rev. 1.0
POWER-ON RESET
MODULE
VDD
VSS
VDD3
VSS1
POWER
SECURITY
MODULE
MONITOR MODE ENTRY
MODULE
USB VOLATGE REGULATOR
Figure 1-1. MCU Block Diagram
DDRE
COMPUTER OPERATING
PROPERLY MODULE
† Pin is +5V open-drain
‡ Pin is +3.3V
General Description
Technical Data
28
INTERNAL BUS
M68HC08 CPU
General Description
Pin Assignments
PD0/D+
PD1/D–
VDD3
VSYNC
HSYNC
PTC0/ADC0
PTC1/ADC1
PTC2/ADC2
42
41
40
39
38
37
36
35
34 PTC3/ADC3
NC
OSC2 1
43
44 VDD
1.5 Pin Assignments
33 PTE2/VSYNCO
28
PTB3/PWM3
PTB5/PWM5
7
27
PTB4/PWM4
PTC5/ADC5
8
26
VSS1
PTC4/ADC4
9
25
NC
10
24
PTD2/DDCSDA
PTA7/PWM15 12
PTE0/SOG/TCH0 11
23 PTD3/DDCSCL
PTD4/CLAMP 22
IRQ
21
6
PTD5/IICSCL
PTB6/PWM6
20
PTB2/PWM2
PTD6/IICSDA
29
19
5
PTA0/PWM8
PTB7/PWM7
18
PTB1/PWM1
PTA1/PWM9
30
17
4
PTA2/PWM10
RST
16
PTB0/PWM0
PTA3/PWM11
31
15
3
PTA4/PWM12
VSS
14
PTE1/HSYNCO
PTA5/PWM13
32
13
2
PTA6/PWM14
OSC1
Figure 1-2. 44-Pin QFP Pin Assignments
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
General Description
29
General Description
VSYNC
1
42
HSYNC
VDD3
2
41
PTC0/ADC0
PD1/D–
3
40
PTC1/ADC1
PD0/D+
4
39
PTC2/ADC2
VDD
5
38
PTC3/ADC3
OSC2
6
37
PTE2/VSYNCO
OSC1
7
36
PTE1/HSYNCO
VSS
8
35
PTB0/PWM0
RST
9
34
PTB1/PWM1
PTB7/PWM7
10
33
PTB2/PWM2
PTB6/PWM6
11
32
PTB3/PWM3
PTB5/PWM5
12
31
PTB4/PWM4
PTC5/ADC5
13
30
VSS1
PTC4/ADC4
14
29
PTD2/DDCSDA
IRQ
15
28
PTD3/DDCSCL
PTE0/SOG/TCH0
16
27
PTD4/CLAMP
PTA7/PWM15
17
26
PTD5/IICSCL
PTA6/PWM14
18
25
PTD6/IICSDA
PTA5/PWM13
19
24
PTA0/PWM8
PTA4/PWM12
20
23
PTA1/PWM9
PTA3/PWM11
21
22
PTA2/PWM10
Figure 1-3. 42-Pin SDIP Pin Assignments
Technical Data
30
MC68HC908BD48 — Rev. 1.0
General Description
MOTOROLA
General Description
Pin Assignments
HSYNC
1
28
PTC0/ADC0
VSYNC
2
27
PTC1/ADC1
VDD3
3
26
PTC2/ADC2
VDD
4
25
PTC3/ADC3
OSC2
5
24
PTE2/VSYNCO
OSC1
6
23
PTE1/HSYNCO
VSS
7
22
PTB0/PWM0
RST
8
21
PTB1/PWM1
PTC4/ADC4
9
20
PTD2/DDCSDA
IRQ
10
19
PTD3/DDCSCL
PTA7/PWM15
11
18
PTA0/PWM8
PTB6/PWM14
12
17
PTA1/PWM9
PTA5/PWM13
13
16
PTA2/PWM10
PTA4/PWM12
14
15
PTA3/PWM11
Figure 1-4. 28-Pin PDIP Pin Assignments
Table 1-1. I/Os on 28-Pin Device
Signals Not Bonded Out on 28-Pin Device
PD1/D–
PTB2/PWM2
PD0/D+
PTB3/PWM3
PTB7/PWM7
PTB4/PWM4
PTB6/PWM6
VSS1
PTB5/PWM5
PTD4/CLAMP
PTC5/ADC5
PTD5/IICSCL
PTE0/SOG/TCH0
PTD6/IICSDA
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
General Description
31
General Description
1.6 Pin Functions
Description of the pin functions are provided in Table 1-2.
Table 1-2. Pin Functions
PIN NAME
PIN DESCRIPTION
VDD
Power supply input to the MCU.
VSS
Power supply ground.
VDD3
3.3V regulated output from the MCU.
VSS1
Power supply ground.
OSC1
OSC2
Connections to the on-chip oscillator.
An external clock can be connected directly to
OSC1; with OSC2 floating.
See Section 8. Oscillator (OSC).
RST
A logic 0 on the RST pin forces the MCU to a
known startup 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 7. System Integration Module
(SIM).
IRQ
External IRQ pin; with software programmable
internal pull-up and schmitt trigger input.
This pin is also used for mode entry selection.
See Section 7. System Integration Module
(SIM).
VSYNC
Vsync input to the sync processor.
See Section 16. Sync Processor.
HSYNC
Hsync input to the sync processor.
See Section 16. Sync Processor.
PTA7/PWM15–PTA0/PWM8
These are shared-function pins. Each pin can be
configured as a standard I/O pin or a PWM output
channel.
See Section 17. Input/Output (I/O) Ports and
Section 11. Pulse Width Modulator (PWM).
PTB7/PWM7–PTB0/PWM0
These are shared-function pins. Each pin can be
configured as a standard I/O pin or a PWM output
channel.
See Section 17. Input/Output (I/O) Ports and
Section 11. Pulse Width Modulator (PWM).
Technical Data
32
MC68HC908BD48 — Rev. 1.0
General Description
MOTOROLA
General Description
Pin Functions
Table 1-2. Pin Functions
PIN NAME
PIN DESCRIPTION
PTC5/ADC5–PTC0/ADC0
These are shared-function pins. Each pin can be
configured as a standard I/O pin or an ADC input
channel.
See Section 17. Input/Output (I/O) Ports and
Section 12. Analog-to-Digital Converter (ADC).
PTD6/IICSDA
This is a shared function pin. It can be configured
as a standard I/O pin or the data line of the multimaster IIC module. This pin is open-drain when
configured as output.
See Section 17. Input/Output (I/O) Ports and
Section 14. Multi-Master IIC Interface (MMIIC).
PTD5/IICSCL
This is a shared function pin. It can be configured
as a standard I/O pin or the clock line of the multimaster IIC module. This pin is open-drain when
configured as output.
See Section 17. Input/Output (I/O) Ports and
Section 14. Multi-Master IIC Interface (MMIIC).
PTD4/CLAMP
This is a shared function pin. It can be configured
as a standard I/O pin or the clamp output from the
sync processor.
See Section 17. Input/Output (I/O) Ports and
Section 16. Sync Processor.
PTD3/DDCSCL
This is a shared function pin. It can be configured
as a standard I/O pin or as the clock line of the
DDC12AB module. This pin is open-drain when
configured as output.
See Section 17. Input/Output (I/O) Ports and
Section 15. DDC12AB Interface.
PTD2/DDCSDA
This is a shared function pin. It can be configured
as a standard I/O pin or the data line of the
DDC12AB module. This pin is open-drain when
configured as output.
See Section 17. Input/Output (I/O) Ports and
Section 15. DDC12AB Interface.
PTD1/D–
PTD0/D+
These are 3.3V, shared function pins. The pins
can be configured as standard I/O pins or USB
interface differential data lines.
See Section 17. Input/Output (I/O) Ports and
Section 13. Universal Serial Bus Module (USB).
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
General Description
33
General Description
Table 1-2. Pin Functions
NOTE:
PIN NAME
PIN DESCRIPTION
PTE2/VSYNCO
This is a shared function pin. It can be configured
as a standard I/O pin or the Hsync output from the
sync processor.
See Section 17. Input/Output (I/O) Ports and
Section 16. Sync Processor.
PTE1/HSYNCO
This is a shared function pin. It can be configured
as a standard I/O pin or the Vsync output from the
sync processor.
See Section 17. Input/Output (I/O) Ports and
Section 16. Sync Processor.
PTE0/SOG/TCH0
This is a shared function pin. It can be configured
as a standard I/O pin, the SOG input to the sync
processor, or the timer channel 0 I/O pin.
See Section 17. Input/Output (I/O) Ports,
Section 16. Sync Processor, and Section 10.
Timer Interface Module (TIM).
Any unused inputs and I/O ports should be tied to an appropriate logic
level (either VDD or VSS). Although the I/O ports of the
MC68HC908BD48 do not require termination, termination is
recommended to reduce the possibility of static damage.
Technical Data
34
MC68HC908BD48 — Rev. 1.0
General Description
MOTOROLA
Technical Data — MC68HC908BD48
Section 2. Memory Map
2.1 Contents
2.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.3
Unimplemented Memory Locations . . . . . . . . . . . . . . . . . . . . . 35
2.4
Reserved Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.5
Input/Output (I/O) Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.2 Introduction
The CPU08 can address 64 Kbytes of memory space. The memory
map, shown in Figure 2-1, includes:
•
48,128 bytes of FLASH memory
•
1,024 bytes of random-access memory (RAM)
•
26 bytes of user-defined vectors
•
512 + 470 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.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Memory Map
35
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
Most of the control, status, and data registers are in the zero page area
of $0000–$005F. Additional I/O registers have these addresses:
•
$FE00; SIM Break Status Register, SBSR
•
$FE01; SIM Reset Status Register, SRSR
•
$FE02; reserved
•
$FE03; SIM Break Flag Control Register, SBFCR
•
$FE04; Interrupt Status Register 1, INT1
•
$FE05; Interrupt Status Register 2, INT2
•
$FE06; reserved
•
$FE07; FLASH Control Register, FLCR
•
$FE08; FLASH block protect register, FLBPR
•
$FE09; reserved
•
$FE0A; reserved
•
$FE0B; reserved
•
$FE0C; Break Address Register High, BRKH
•
$FE0D; Break Address Register Low, BRKL
•
$FE0E; Break Status and Control Register, BRKSCR
Data registers are shown in Figure 2-2. Table 2-1 is a list of vector
locations.
Technical Data
36
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Memory Map
Input/Output (I/O) Section
$0000
I/O Registers
96 Bytes
↓
$005F
$0060
Unimplemented
32 Bytes
↓
$007F
$0080
RAM
1,024 Bytes
↓
$047F
$0480
Unimplemented
1,920 Bytes
↓
$0BFF
$0C00
Reserved
256 Bytes
↓
$0CFF
$0D00
Unimplemented
13,056 Bytes
↓
$3FFF
$4000
FLASH Memory
48,128 Bytes
↓
$FBFF
$FC00
Monitor ROM
512 Bytes
↓
$FDFF
$FE00
SIM Break Status Register (SBSR)
$FE01
SIM Reset Status Register (SRSR)
$FE02
Reserved
$FE03
SIM Break Flag Control Register (SBFCR)
$FE04
Interrupt Status Register 1 (INT1)
Figure 2-1. Memory Map
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Memory Map
37
Memory Map
$FE05
Interrupt Status Register 2 (INT2)
$FE06
Reserved
$FE07
FLASH Control Register (FLCR)
$FE08
FLASH Block Protect Register (FLBPR)
$FE09
Reserved
$FE0A
Reserved
$FE0B
Reserved
$FE0C
Break Address Register High (BRKH)
$FE0D
Break Address Register Low (BRKL)
$FE0E
Break Status and Control Register (BRKSCR)
$FE0F
Reserved
$FE10
↓
Monitor ROM
470 Bytes
$FFE5
$FFE6
↓
FLASH Vectors
26 Bytes
$FFFF
Figure 2-1. Memory Map (Continued)
Technical Data
38
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Memory Map
Input/Output (I/O) Section
Addr.
Register Name
$0000
Read:
Port A Data Register
Write:
(PTA)
Reset:
$0001
$0002
$0003
Read:
Port B Data Register
Write:
(PTB)
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
PTA7
PTA6
PTA5
PTA4
PTA3
PTA2
PTA1
PTA0
PTB2
PTB1
PTB0
PTC2
PTC1
PTC0
PTD2
PTD1
PTD0
Unaffected by reset
PTB7
PTB6
PTB5
PTB4
PTB3
Unaffected by reset
Read:
Port C Data Register
Write:
(PTC)
Reset:
0
Read:
Port D Data Register
Write:
(PTD)
Reset:
0
0
PTC5
PTC4
PTC3
Unaffected by reset
PTD6
PTD5
PTD4
PTD3
Unaffected by reset
Read:
DDRA7
Data Direction Register A
$0004
Write:
(DDRA)
Reset:
0
Read:
DDRB7
Data Direction Register B
$0005
Write:
(DDRB)
Reset:
0
DDRA6
DDRA5
DDRA4
DDRA3
DDRA2
DDRA1
DDRA0
0
0
0
0
0
0
0
DDRB6
DDRB5
DDRB4
DDRB3
DDRB2
DDRB1
DDRB0
0
0
0
0
0
0
0
DDRC5
DDRC4
DDRC3
DDRC2
DDRC1
DDRC0
Read:
Data Direction Register C
$0006
Write:
(DDRC)
Reset:
0
0
0
0
0
0
0
0
0
0
Read:
Data Direction Register D
$0007
Write:
(DDRD)
Reset:
0
DDRD6
DDRD5
DDRD4
DDRD3
DDRD2
DDRD1
DDRD0
0
0
0
0
0
0
0
0
Read:
Port E Data Register
Write:
(PTE)
Reset:
0
0
0
0
0
PTE2
PTE1
PTE0
Read:
Data Direction Register E
$0009
Write:
(DDRE)
Reset:
0
0
0
0
0
DDRE2
DDRE1
DDRE0
0
0
0
0
0
0
0
0
$0008
Unaffected by reset
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 1 of 12)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Memory Map
39
Memory Map
Addr.
6
5
TOIE
TSTOP
0
0
1
0
0
0
0
Read:
TIM Counter Register
High Write:
(TCNTH)
Reset:
Bit15
Bit14
0
Read:
TIM Counter Register Low
$000D
Write:
(TCNTL)
Reset:
$000A
Register Name
Bit 7
Read:
TIM Status and Control
Register Write:
(TSC)
Reset:
2
1
Bit 0
PS2
PS1
PS0
0
0
0
0
0
0
0
0
0
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
0
0
0
0
0
0
0
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
0
0
0
0
0
0
0
0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
1
1
1
1
1
1
1
1
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
1
1
1
1
1
1
1
1
CH0IE
MS0B
MS0A
ELS0B
ELS0A
TOV0
CH0MAX
0
0
0
0
0
0
0
0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Bit2
Bit1
Bit0
TOF
0
4
3
0
0
TRST
Read:
$000B
Unimplemented Write:
Reset:
$000C
$000E
$000F
Read:
TIM Counter Modulo
Register High Write:
(TMODH)
Reset:
Read:
TIM Counter Modulo
Register Low Write:
(TMODL)
Reset:
Read:
TIM Channel 0 Status and
$0010
Control Register Write:
(TSC0)
Reset:
$0011
$0012
Read:
TIM Channel 0
Register High Write:
(TCH0H)
Reset:
Read:
TIM Channel 0
Register Low Write:
(TCH0L)
Reset:
Read:
TIM Channel 1 Status and
$0013
Control Register Write:
(TSC1)
Reset:
CH0F
0
Indeterminate after reset
Bit7
Bit6
Bit5
Bit4
Bit3
Indeterminate after reset
CH1F
0
0
CH1IE
0
0
0
= Unimplemented
MS1A
ELS1B
ELS1A
TOV1
CH1MAX
0
0
0
0
0
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 2 of 12)
Technical Data
40
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Memory Map
Input/Output (I/O) Section
Addr.
Register Name
Read:
TIM Channel 1
Register High Write:
(TCH1H)
Reset:
$0014
Read:
TIM Channel 1
Register Low Write:
(TCH1L)
Reset:
$0015
$0016
$0017
$0018
$0019
$001A
$001B
$001C
$001D
Read:
DDC Master Control
Write:
Register (DMCR)
Reset:
Read:
DDC Address Register
Write:
(DADR)
Reset:
Read:
DDC Control Register
Write:
(DCR)
Reset:
Read:
DDC Status Register
Write:
(DSR)
Reset:
Read:
DDC
Data Transmit Register Write:
(DDTR)
Reset:
DDC Read:
Data Receive Register
Write:
(DDRR)
Reset:
Read:
DDC2 Address Register
Write:
(D2ADR)
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Bit2
Bit1
Bit0
Indeterminate after reset
Bit7
Bit6
Bit5
Bit4
Bit3
Indeterminate after reset
ALIF
NAKIF
BB
MAST
MRW
BR2
BR1
BR0
0
0
0
0
0
0
0
0
DAD7
DAD6
DAD5
DAD4
DAD3
DAD2
DAD1
EXTAD
1
0
1
0
0
0
0
0
DEN
DIEN
0
0
TXAK
SCLIEN
DDC1EN
0
0
0
0
0
0
0
0
RXIF
TXIF
MATCH
SRW
RXAK
SCLIF
TXBE
RXBF
0
0
0
0
0
0
1
0
1
0
DTD7
DTD6
DTD5
DTD4
DTD3
DTD2
DTD1
DTD0
1
1
1
1
1
1
1
1
DRD7
DRD6
DRD5
DRD4
DRD3
DRD2
DRD1
DRD0
0
0
0
0
0
0
0
0
D2AD7
D2AD6
D2AD5
D2AD4
D2AD3
D2AD2
D2AD1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Read:
HSYNCOE VSYNCOE
Configuration Register 0
Write:
(CONFIG0)
Reset:
0
0
0
0
SOGE
0
= Unimplemented
R
0
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 3 of 12)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Memory Map
41
Memory Map
Addr.
$001E
$001F
Register Name
Bit 7
6
5
4
3
2
Read:
IRQ Status and Control
Write:
Register (INTSCR)
Reset:
0
0
0
0
IRQF
0
0
0
0
0
Read:
Configuration Register 1
Write:
(CONFIG1)†
Reset:
0
0
0
0
0
0
0
0PWM3
ACK
1
Bit 0
IMASK
MODE
0
0
0
0
SSREC
COPRS
STOP
COPD
0
0
0
0
0
0PWM2
0PWM1
0PWM0
0BRM2
0BRM1
0BRM0
0
0
0
0
0
0
0
1PWM3
1PWM2
1PWM1
1PWM0
1BRM2
1BRM1
1BRM0
0
0
0
0
0
0
0
2PWM3
2PWM2
2PWM1
2PWM0
2BRM2
2BRM1
2BRM0
0
0
0
0
0
0
0
3PWM3
3PWM2
3PWM1
3PWM0
3BRM2
3BRM1
3BRM0
0
0
0
0
0
0
0
4PWM3
4PWM2
4PWM1
4PWM0
4BRM2
4BRM1
4BRM0
0
0
0
0
0
0
0
5PWM3
5PWM2
5PWM1
5PWM0
5BRM2
5BRM1
5BRM0
0
0
0
0
0
0
0
6PWM3
6PWM2
6PWM1
6PWM0
6BRM2
6BRM1
6BRM0
0
0
0
0
0
0
0
7PWM3
7PWM2
7PWM1
7PWM0
7BRM2
7BRM1
7BRM0
0
0
0
0
0
0
0
† One-time writable register after each reset.
$0020
$0021
$0022
$0023
$0024
$0025
$0026
$0027
Read:
0PWM4
PWM0 Data Register
Write:
(0PWM)
Reset:
0
Read:
1PWM4
PWM1 Data Register
Write:
(1PWM)
Reset:
0
Read:
2PWM4
PWM2 Data Register
Write:
(2PWM)
Reset:
0
Read:
3PWM4
PWM3 Data Register
Write:
(3PWM)
Reset:
0
Read:
4PWM4
PWM4 Data Register
Write:
(4PWM)
Reset:
0
Read:
5PWM4
PWM5 Data Register
Write:
(5PWM)
Reset:
0
Read:
6PWM4
PWM6 Data Register
Write:
(6PWM)
Reset:
0
Read:
7PWM4
PWM7 Data Register
Write:
(7PWM)
Reset:
0
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 4 of 12)
Technical Data
42
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Memory Map
Input/Output (I/O) Section
Addr.
$0028
$0029
$002A
$002B
$002C
$002D
$002E
Register Name
Bit 7
5
4
3
2
1
Bit 0
PWM6E
PWM5E
PWM4E
PWM3E
PWM2E
PWM1E
PWM0E
0
0
0
0
0
0
0
UADD6
UADD5
UADD4
UADD3
UADD2
UADD1
UADD0
0
0
0
0
0
0
0
TBEF
RBFF
EOPIF
RSTIF
TBIE
RBIE
EOPIE
RSTIE
0
0
0
0
0
0
0
0
T0SEQ
STALL0
TX0E
RX0E
TP0SIZ3
TP0SIZ2
TP0SIZ1
TP0SIZ0
0
0
0
0
0
0
0
0
RSEQ
SETUP
TX1ST
0
RPSIZ3
RPSIZ2
RPSIZ1
RPSIZ0
STALL2
STALL1
Read:
PWM7E
PWM Control Register 1
Write:
(PWMCR1)
Reset:
0
Read:
USBEN
USB Address Register
Write:
(UADR)
Reset:
0
Read:
USB Interrupt Register
Write:
(UINTR)
Reset:
Read:
USB Control Register 0
Write:
(UCR0)
Reset:
Read:
USB Status Register
Write:
(USR)
Reset:
Indeterminate after reset
Read:
USB Control Register 2
Write:
(UCR2)
Reset:
0
0
0
0
Read:
USB Interrupt Register 1
(UIR1) Write:
TXD1F
Reset:
$002F
6
Read:
USB Control Register 1
Write:
(UCR1)
Reset:
TXD1IE
PULLEN
SUSPND ENABLE2 ENABLE1
0
0
0
0
0
0
RESUMF
0
0
0
0
0
RESUMFR
TBEFR
RBFFR
TXD1FR
EOPFR
0
0
0
0
0
TP1SIZ2
TP1SIZ1
TP1SIZ0
0
0
0
0
0
0
T1SEQ
ENDADD
TX1E
0
0
0
FRESUM TP1SIZ3
0
0
$0030
Read: UE0RD07 UE0RD06 UE0RD05 UE0RD04 UE0RD03 UE0RD02 UE0RD01 UE0RD00
USB Endpoint 0 Data
Write: UE0TD07 UE0TD06 UE0TD05 UE0TD04 UE0TD03 UE0TD02 UE0TD01 UE0TD00
Register 0 (UD0R0)
Reset:
Indeterminate after reset
$0031
Read: UE0RD17 UE0RD16 UE0RD15 UE0RD14 UE0RD13 UE0RD12 UE0RD11 UE0RD10
USB Endpoint 0 Data
Write: UE0TD17 UE0TD16 UE0TD15 UE0TD14 UE0TD13 UE0TD12 UE0TD11 UE0TD10
Register 1 (UD0R1)
Reset:
Indeterminate after reset
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 5 of 12)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Memory Map
43
Memory Map
Addr.
Register Name
Bit 7
6
5
$0032
Read: UE0RD27 UE0RD26 UE0RD25 UE0RD24 UE0RD23 UE0RD22 UE0RD21 UE0RD20
USB Endpoint 0 Data
Write: UE0TD27 UE0TD26 UE0TD25 UE0TD24 UE0TD23 UE0TD22 UE0TD21 UE0TD20
Register 2 (UD0R2)
Reset:
Indeterminate after reset
$0033
Read: UE0RD37 UE0RD36 UE0RD35 UE0RD34 UE0RD33 UE0RD32 UE0RD31 UE0RD30
USB Endpoint 0 Data
Write: UE0TD37 UE0TD36 UE0TD35 UE0TD34 UE0TD33 UE0TD32 UE0TD31 UE0TD30
Register 3 (UD0R3)
Reset:
Indeterminate after reset
$0034
Read: UE0RD47 UE0RD46 UE0RD45 UE0RD44 UE0RD43 UE0RD42 UE0RD41 UE0RD40
USB Endpoint 0 Data
Write: UE0TD47 UE0TD46 UE0TD45 UE0TD44 UE0TD43 UE0TD42 UE0TD41 UE0TD40
Register 4 (UD0R4)
Indeterminate after reset
Reset:
$0035
Read: UE0RD57 UE0RD56 UE0RD55 UE0RD54 UE0RD53 UE0RD52 UE0RD51 UE0RD50
USB Endpoint 0 Data
Write: UE0TD57 UE0TD56 UE0TD55 UE0TD54 UE0TD53 UE0TD52 UE0TD51 UE0TD50
Register 5 (UD0R5)
Indeterminate after reset
Reset:
$0036
Read: UE0RD67 UE0RD66 UE0RD65 UE0RD64 UE0RD63 UE0RD62 UE0RD61 UE0RD60
USB Endpoint 0 Data
Write: UE0TD67 UE0TD66 UE0TD65 UE0TD64 UE0TD63 UE0TD62 UE0TD61 UE0TD60
Register 6 (UD0R6)
Indeterminate after reset
Reset:
$0037
Read: UE0RD77 UE0RD76 UE0RD75 UE0RD74 UE0RD73 UE0RD72 UE0RD71 UE0RD70
USB Endpoint 0 Data
Write: UE0TD77 UE0TD76 UE0TD75 UE0TD74 UE0TD73 UE0TD72 UE0TD71 UE0TD70
Register 7 (UD0R7)
Indeterminate after reset
Reset:
$0038
Read:
USB Endpoint 1/2 Data
Write: UE1TD07 UE1TD06 UE1TD05 UE1TD04 UE1TD03 UE1TD02 UE1TD01 UE1TD00
Register 0 (UD1R0)
Indeterminate after reset
Reset:
$0039
Read:
USB Endpoint 1/2 Data
Write: UE1TD17 UE1TD16 UE1TD15 UE1TD14 UE1TD13 UE1TD12 UE1TD11 UE1TD10
Register 1 (UD1R1)
Indeterminate after reset
Reset:
$003A
Read:
USB Endpoint 1/2 Data
Write: UE1TD27 UE1TD26 UE1TD25 UE1TD24 UE1TD23 UE1TD22 UE1TD21 UE1TD20
Register 2 (UD1R2)
Indeterminate after reset
Reset:
$003B
Read:
USB Endpoint 1/2 Data
Write: UE1TD37 UE1TD36 UE1TD35 UE1TD34 UE1TD33 UE1TD32 UE1TD31 UE1TD30
Register 3 (UD1R3)
Indeterminate after reset
Reset:
= Unimplemented
4
3
R
2
1
Bit 0
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 6 of 12)
Technical Data
44
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Memory Map
Input/Output (I/O) Section
Addr.
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
$003C
Read:
USB Endpoint 1/2 Data
Write: UE1TD47 UE1TD46 UE1TD45 UE1TD44 UE1TD43 UE1TD42 UE1TD41 UE1TD40
Register 4 (UD1R4)
Indeterminate after reset
Reset:
$003D
Read:
USB Endpoint 1/2 Data
Write: UE1TD57 UE1TD56 UE1TD55 UE1TD54 UE1TD53 UE1TD52 UE1TD51 UE1TD50
Register 5 (UD1R5)
Indeterminate after reset
Reset:
$003E
Read:
USB Endpoint 1/2 Data
Write: UE1TD67 UE1TD66 UE1TD65 UE1TD64 UE1TD63 UE1TD62 UE1TD61 UE1TD60
Register 6 (UD1R6)
Indeterminate after reset
Reset:
$003F
Read:
USB Endpoint 1/2 Data
Write: UE1TD77 UE1TD76 UE1TD75 UE1TD74 UE1TD73 UE1TD72 UE1TD71 UE1TD70
Register 7 (UD1R7)
Indeterminate after reset
Reset:
$0040
Read:
Sync Processor Control
and Status Register Write:
(SPCSR)
Reset:
$0041
$0042
$0043
$0044
VPOL
HPOL
0
0
0
VF11
VF10
VF9
VF8
0
0
0
0
0
VF5
VF4
VF3
VF2
VF1
VF0
0
0
0
0
0
0
0
HFH7
HFH6
HFH5
HFH4
HFH3
HFH2
HFH1
HFH0
0
0
0
0
0
0
0
0
0
0
HFL4
HFL3
HFL2
HFL1
HFL0
0
0
0
0
0
0
0
COINV
R
BPOR
SOUT
0
0
0
0
VSIE
VEDGE
0
0
Read:
Vertical Frequency High
Register Write:
(VFHR)
Reset:
VOF
VSIF
COMP
VINVO
HINVO
0
0
0
0
0
VF12
CPW1
CPW0
0
0
0
Read:
Vertical Frequency Low
Register Write:
(VFLR)
Reset:
VF7
VF6
0
Read:
Hsync Frequency High
Register Write:
(HFHR)
Reset:
Read: HOVER
Hsync Frequency Low
Register Write:
(HFLR)
Reset:
0
$0045
Read: VSYNCS HSYNCS
Sync Processor I/O
Control Register Write:
(SPIOCR)
Reset:
0
0
0
= Unimplemented
SOGSEL CLAMPOE
0
R
0
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 7 of 12)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Memory Map
45
Memory Map
Addr.
$0046
Register Name
Bit 7
Read:
Sync Processor Control
Register 1 Write:
(SPCR1)
Reset:
Read:
H&V Sync Output Control
$0047
Register Write:
(HVOCR)
Reset:
LVSIE
0
R
0
6
5
4
3
2
1
Bit 0
HPS1
HPS0
R
R
ATPOL
FSHF
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
IICDATE
IICSCLE
0
0
0
0
0
0
0
MMNAKIF
MMBB
MMAST
MMRW
MMBR2
MMBR1
MMBR0
0
0
0
0
0
0
0
MMAD6
MMAD5
MMAD4
MMAD3
MMAD2
MMAD1
MMEXTAD
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
LVSIF
0
HVOCR2 HVOCR1 HVOCR0
0
0
0
Read:
$0048
Unimplemented Write:
Reset:
$0049
$004A
Read:
Port D Configuration
Write:
Register (PDCR)
Reset:
0
0
Read:
Multi-Master IIC
MMALIF
Master Control Register Write:
(MIMCR)
Reset:
0
Read:
Multi-Master IIC Address
MMAD7
$004B
Register Write:
(MMADR)
Reset:
1
Read:
Multi-Master IIC
Control Register Write:
(MMCR)
Reset:
$004C
$004F
MMIEN
0
0
Read: MMRXIF
Multi-Master IIC
Status Register Write:
0
(MMSR)
Reset:
0
$004D
$004E
MMEN
Read:
Multi-Master IIC
MMTD7
Data Transmit Register Write:
(MMDTR)
Reset:
1
Multi-Master IIC Read: MMRD7
Data Receive Register
Write:
(MMDRR)
Reset:
0
CLAMPE DDCSCLE DDCDATE USBD–E
MMTXAK
0
MMTXIF MMATCH MMSRW MMRXAK
0
USBD+E
MMTXBE MMRXBF
0
0
0
0
1
0
1
0
MMTD6
MMTD5
MMTD4
MMTD3
MMTD2
MMTD1
MMTD0
1
1
1
1
1
1
1
MMRD6
MMRD5
MMRD4
MMRD3
MMRD2
MMRD1
MMRD0
0
0
0
0
0
0
0
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 8 of 12)
Technical Data
46
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Memory Map
Input/Output (I/O) Section
Addr.
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
8PWM3
8PWM2
8PWM1
8PWM0
8BRM2
8BRM1
8BRM0
0
0
0
0
0
0
0
9PWM3
9PWM2
9PWM1
9PWM0
9BRM2
9BRM1
9BRM0
0
0
0
0
0
0
0
10BRM2
10BRM1
10BRM0
0
0
0
11BRM2
11BRM1
11BRM0
0
0
0
12BRM2
12BRM1
12BRM0
0
0
0
13BRM2
13BRM1
13BRM0
0
0
0
14BRM2
14BRM1
14BRM0
0
0
0
15BRM2
15BRM1
15BRM0
0
0
0
PWM9E
PWM8E
0
0
Read:
$0050
Unimplemented Write:
Reset:
$0051
$0052
$0053
$0054
$0055
$0056
$0057
$0058
$0059
Read:
8PWM4
PWM8 Data Register
Write:
(8PWM)
Reset:
0
Read:
9PWM4
PWM9 Data Register
Write:
(9PWM)
Reset:
0
Read:
10PWM4 10PWM3 10PWM2 10PWM1 10PWM0
PWM10 Data Register
Write:
(10PWM)
Reset:
0
0
0
0
0
Read:
11PWM4 11PWM3 11PWM2 11PWM1 11PWM0
PWM11 Data Register
Write:
(11PWM)
Reset:
0
0
0
0
0
Read:
12PWM4 12PWM3 12PWM2 12PWM1 12PWM0
PWM12 Data Register
Write:
(12PWM)
Reset:
0
0
0
0
0
Read:
13PWM4 13PWM3 13PWM2 13PWM1 13PWM0
PWM13 Data Register
Write:
(13PWM)
Reset:
0
0
0
0
0
Read:
14PWM4
PWM14 Data Register
Write:
(14PWM)
Reset:
0
PWM3
0
14PWM2 14PWM1 14PWM0
0
0
0
Read:
15PWM4 15PWM3 15PWM2 15PWM1 15PWM0
PWM15 Data Register
Write:
(15PWM)
Reset:
0
0
0
0
0
Read:
PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E
PWM Control Register 2
Write:
(PWMCR2)
Reset:
0
0
0
0
0
0
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 9 of 12)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Memory Map
47
Memory Map
Addr.
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
AIEN
ADCO
ADCH4
ADCH3
ADCH2
ADCH1
ADCH0
0
0
0
1
1
1
1
1
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
Read:
$005A
Unimplemented Write:
Reset:
Read:
$005B
Unimplemented Write:
Reset:
Read:
$005C
Unimplemented Write:
Reset:
$005D
$005E
Read:
ADC Status and Control
Write:
Register (ADSCR)
Reset:
Read:
ADC Data Register
Write:
(ADR)
Reset:
Read:
ADC Input Clock Register
$005F
Write:
(ADICLK)
Reset:
Read:
SIM Break Status Register
$FE00
Write:
(SBSR)
Reset:
COCO
Unaffected after Reset
0
0
0
0
0
0
0
0
0
0
0
R
R
R
R
R
0
0
0
0
0
0
0
0
POR
PIN
COP
ILOP
ILAD
0
0
0
1
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
ADIV2
ADIV1
ADIV0
0
0
R
SBSW
Note
R
Note: Writing a logic 0 clears SBSW.
Read:
SIM Reset Status Register
$FE01
Write:
(SRSR)
POR:
Read:
$FE02
Reserved Write:
Reset:
= Unimplemented
R
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 10 of 12)
Technical Data
48
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Memory Map
Input/Output (I/O) Section
Addr.
$FE03
Register Name
Read:
SIM Break Flag Control
Write:
Register (SBFCR)
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
BCFE
R
R
R
R
R
R
R
0
Read:
Interrupt Status Register 1
$FE04
Write:
(INT1)
Reset:
IF6
IF5
IF4
IF3
IF2
IF1
0
0
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
Read:
Interrupt Status Register 2
$FE05
Write:
(INT2)
Reset:
0
0
0
0
IF10
IF9
IF8
IF7
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
Reset:
0
0
0
0
0
0
0
0
Read:
FLASH Control Register
Write:
(FLCR)
Reset:
0
0
0
0
HVEN
MASS
ERASE
PGM
0
0
0
0
0
0
0
0
BPR7
BPR6
BPR5
BPR4
BPR3
BPR2
BPR1
0
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
0
0
0
0
0
0
0
0
Read:
$FE06
$FE07
$FE08
Reserved Write:
Read:
FLASH Block Protect
Write:
Register (FLBPR)
Reset:
Read:
$FE09
Reserved Write:
Reset:
Read:
$FE0A
Reserved Write:
Reset:
Read:
$FE0B
Reserved Write:
Reset:
$FE0C
Read:
Break Address High
Write:
Register (BRKH)
Reset:
= Unimplemented
R
0
= Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 11 of 12)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Memory Map
49
Memory Map
Addr.
$FE0D
Register Name
Read:
Break Address low
Write:
Register (BRKL)
Reset:
Read:
Break Status and Control
$FE0E
Write:
Register (BRKSCR)
Reset:
$FFFF
Read:
COP Control Register
Write:
(COPCTL)
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
0
0
0
0
0
0
0
0
BRKE
BRKA
0
0
0
0
0
0
0
0
0
0
0
0
0
0
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 12 of 12)
Technical Data
50
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Memory Map
Input/Output (I/O) Section
.
Table 2-1. Vector Addresses
Vector Priority
Lowest
Vector
—
IF10
IF9
IF8
IF7
IF6
IF5
IF4
IF3
IF2
IF1
—
Highest
—
Address
$FFE6
Reserved
$FFE7
Reserved
$FFE8
ADC Interrupt Vector (High)
$FFE9
ADC Interrupt Vector (Low)
$FFEA
MMIIC Vector (High)
$FFEB
MMIIC Vector (Low)
$FFEC
Sync Processor Vector (High)
$FFED
Sync Processor Vector (Low)
$FFEE
TIM Overflow Vector (High)
$FFEF
TIM Overflow Vector (Low)
$FFF0
TIM Channel 1 Vector (High)
$FFF1
TIM Channel 1 Vector (Low)
$FFF2
TIM Channel 0 Vector (High)
$FFF3
TIM Channel 0 Vector (Low)
$FFF4
Reserved
$FFF5
Reserved
$FFF6
DDC12AB Vector (High)
$FFF7
DDC12AB Vector (Low)
$FFF8
USB Vector (High)
$FFF9
USB Vector (Low)
$FFFA
IRQ Vector (High)
$FFFB
IRQ Vector (Low)
$FFFC
SWI Vector (High)
$FFFD
SWI Vector (Low)
$FFFE
Reset Vector (High)
$FFFF
Reset Vector (Low)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Vector
Technical Data
Memory Map
51
Memory Map
Technical Data
52
MC68HC908BD48 — Rev. 1.0
Memory Map
MOTOROLA
Technical Data — MC68HC908BD48
Section 3. Random-Access Memory (RAM)
3.1 Contents
3.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.2 Introduction
This section describes the 1,024 bytes of RAM (random-access
memory).
3.3 Functional Description
Addresses $0080 through $047F are RAM locations. The location of the
stack RAM is programmable. The 16-bit stack pointer allows the stack to
be anywhere in the 64-Kbyte memory space.
NOTE:
For correct operation, the stack pointer must point only to RAM
locations.
Within page zero are 128 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.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Random-Access Memory (RAM)
53
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.
Technical Data
54
MC68HC908BD48 — Rev. 1.0
Random-Access Memory (RAM)
MOTOROLA
Technical Data — MC68HC908BD48
Section 4. FLASH Memory
4.1 Contents
4.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.4
FLASH Control Register (FLCR) . . . . . . . . . . . . . . . . . . . . . . . 56
4.5
FLASH Block Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.6
FLASH Mass Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.7
FLASH Program Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.8
FLASH Block Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.9
FLASH Block Protect Register (FLBPR). . . . . . . . . . . . . . . . . . 61
4.2 Introduction
This section describes the operation of the embedded FLASH memory.
The FLASH memory can be read, programmed, and erased from a
single external supply through the use of the internal charge pump for
program and erase.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
FLASH Memory
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FLASH Memory
4.3 Functional Description
The FLASH memory is an array of 48,128 bytes with an additional 26
bytes of user vectors. An erased bit reads as logic 1 and a programmed
bit reads as a logic 0. Program and erase operations are facilitated
through control bits in a memory mapped FLASH control register
(FLCR). The address ranges for the user memory and vectors are:
•
$4000–$FBFF; user memory
•
$FE07; FLASH control register
•
$FE08; FLASH block protect register
•
$FFE6–$FFFF; these locations are reserved for user-defined
interrupt and reset vectors
Programming tools are available from Motorola. Contact your local
Motorola representative for more information.
4.4 FLASH Control Register (FLCR)
The FLASH control register (FLCR) controls FLASH program and erase
operations.
Address:
Read:
$FE07
Bit 7
6
5
4
0
0
0
0
3
2
1
Bit 0
HVEN
MASS
ERASE
PGM
0
0
0
0
Write:
Reset:
0
0
0
0
= Unimplemented
Figure 4-1. FLASH Control Register (FLCR)
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FLASH Memory
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FLASH Memory
FLASH Block Erase Operation
HVEN — High-Voltage Enable Bit
This read/write bit enables the charge pump to drive high voltages for
program and erase operations in the array. HVEN can only be set if
either PGM = 1 or ERASE = 1 and the proper sequence for program
or erase is followed.
1 = High voltage enabled to array and charge pump on
0 = High voltage disabled to array and charge pump off
MASS — Mass Erase Control Bit
Setting this read/write bit configures the 48,128 bytes FLASH array
for mass erase operation.
1 = Mass Erase operation selected
0 = Mass Erase operation not selected
ERASE — Erase Control Bit
This read/write bit configures the memory for erase operation. ERASE
is interlocked with the PGM bit such that both bits cannot be equal to
1 or set to 1 at the same time.
1 = Erase operation selected
0 = Erase operation not selected
PGM — Program Control Bit
This read/write bit configures the memory for program operation.
PGM is interlocked with the ERASE bit such that both bits cannot be
equal to 1 or set to 1 at the same time.
1 = Program operation selected
0 = Program operation not selected
4.5 FLASH Block Erase Operation
Use the following procedure to erase a block (512 bytes) of FLASH
memory:
1. Set the ERASE bit, and clear the MASS bit in the FLASH control
register.
2. Write any data to any FLASH address within the block address
range desired.
3. Wait for a time, tnvs (min. 5µs)
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FLASH Memory
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FLASH Memory
4. Set the HVEN bit.
5. Wait for a time, tErase (min. 2ms)
6. Clear the ERASE bit.
7. Wait for a time, tnvh (min. 5µs)
8. Clear the HVEN bit.
9. After a time, trcv (min. 1µs), the memory can be accessed again in
read mode.
NOTE:
Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order as shown, but other unrelated operations
may occur between the steps.
4.6 FLASH Mass Erase Operation
Use the following procedure to erase entire FLASH memory:
1. Set both the ERASE bit, and the MASS bit in the FLASH control
register.
2. Write any data to any FLASH address within the FLASH memory
address range.
3. Wait for a time, tnvs (5µs).
4. Set the HVEN bit.
5. Wait for a time, tMErase (4ms).
6. Clear the ERASE bit.
7. Wait for a time, tnvhl (100µs).
8. Clear the HVEN bit.
9. After time, trcv (1µs), the memory can be accessed again in read
mode.
NOTE:
Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order as shown, but other unrelated operations
may occur between the steps.
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FLASH Memory
FLASH Program Operation
4.7 FLASH Program Operation
Programming of the FLASH memory is done on a row basis. A row
consists of 64 consecutive bytes starting from addresses $XX00,
$XX40, $XX80, and $XXC0. Use this step-by-step procedure to program
a row of FLASH memory (Figure 4-2 is a flowchart representation):
NOTE:
In order to avoid program disturbs, the row must be erased before any
byte on that row is programmed.
1. Set the PGM bit. This configures the memory for program
operation and enables the latching of address and data for
programming.
2. Write any data to any FLASH address within the row address
range desired.
3. Wait for a time, tnvs (min. 5µs).
4. Set the HVEN bit.
5. Wait for a time, tpgs (min. 10µs).
6. Write data to the FLASH address to be programmed.
7. Wait for time, tPROG (min. 20µs).
8. Repeat step 6 and 7 until all the bytes within the row are
programmed.
9. Clear the PGM bit.
10. Wait for time, tnvh (min. 5µs).
11. Clear the HVEN bit.
12. After time, trcv (min 1µs), the memory can be accessed in read
mode again.
This program sequence is repeated throughout the memory until all data
is programmed.
NOTE:
Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order shown, other unrelated operations may
occur between the steps. Do not exceed tPROG maximum. See 21.15
Memory Characteristics.
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Technical Data
FLASH Memory
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FLASH Memory
Algorithm for programming
a row (64 bytes) of FLASH memory
1
Set PGM bit
2
Write any data to any FLASH address
within the row address range desired
3
Wait for a time, tnvs
4
Set HVEN bit
5
Wait for a time, tpgs
6
Write data to the FLASH address
to be programmed
7
Wait for a time, tPROG
Completed
programming
this row?
Y
N
NOTE:
The time between each FLASH address change (step 7 to step 7), or
the time between the last FLASH address programmed
to clearing PGM bit (step 6 to step 9)
must not exceed the maximum programming
time, tPROG max.
9
Clear PGM bit
10
Wait for a time, tnvh
11
Clear HVEN bit
12
Wait for a time, trcv
This row program algorithm assumes the row/s
to be programmed are initially erased.
End of programming
Figure 4-2. FLASH Programming Flowchart
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FLASH Memory
FLASH Block Protection
4.8 FLASH Block Protection
Due to the ability of the on-board charge pump to erase and program the
FLASH memory in the target application, provision is made for protecting
blocks of memory from unintentional erase or program operations due to
system malfunction. This protection is done by use of a FLASH Block
Protect Register (FLBPR). The FLBPR determines the range of the
FLASH memory which is to be protected. The range of the protected
area starts from a location defined by FLBPR and ends at the bottom of
the FLASH memory ($FFFF). When the memory is protected, the HVEN
bit cannot be set in either ERASE or PROGRAM operations.
4.9 FLASH Block Protect Register (FLBPR)
The FLASH block protect register is implemented as an 7-bit I/O register.
The BPR bit content of the register determines the starting location of the
protected range within the FLASH memory.
Address:
$FE08
Bit 7
6
5
4
3
2
1
BPR7
BPR6
BPR5
BPR4
BPR3
BPR2
BPR1
0
0
0
0
0
0
0
Read:
Bit 0
0
Write:
Reset:
0
= Unimplemented
Figure 4-3. FLASH Block Protect Register (FLBPR)
BPR[7:1] — FLASH Block Protect Bits
These seven bits represent bits [15:9] of a 16-bit memory address.
Bits [8:0] are logic 0s.
The resultant 16-bit address is used for specifying the start address
of the FLASH memory for block protection. The FLASH is protected
from this start address to the end of FLASH memory, at $FFFF.
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FLASH Memory
16-bit memory address
Start address of FLASH block protect
FLBPR value
0
0
0
0
0
0
0
0
0
Figure 4-4. FLASH Block Protect Start Address
Examples of protect FLASH memory:
BPR[7:0]
FLASH Memory Protected Range
$00–3E
The entire FLASH memory is not protected.
$40
The entire FLASH memory is protected.
$42 (0100 0010)
$4200 (0100 0010 0000 0000) to $FFFF
$44 (0100 0100)
$4400 (0100 0100 0000 0000) to $FFFF
and so on...
$F8 (1111 1000)
$F800 (1111 1000 0000 0000) to $FFFF
$FA (1111 1010)
$FA00 (1111 1010 0000 0000) to $FFFF
Note:
The user FLASH vectors from $FFE6 to $FFFF are always protected,
and can only be erased by a FLASH mass erase operation.
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Technical Data — MC68HC908BD48
Section 5. Configuration Register (CONFIG)
5.1 Contents
5.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.3.1
Configuration Register 0. . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.3.2
Configuration Register 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.2 Introduction
This section describes the configuration registers, CONFIG0 and
CONFIG1. The configuration registers enable or disable these options:
•
Sync Processor HSYNCO output pin
•
Sync Processor VSYNCO output pin
•
Sync Processor SOG input pin
•
Stop mode recovery time (32 OSCXCLK cycles or 4096
OSCXCLK cycles)
•
COP timeout period (218 – 24 or 213 – 24 OSCXCLK cycles)
•
STOP instruction
•
Computer operating properly module (COP)
5.3 Functional Description
The configuration registers are used in the initialization of various
options. The configuration registers can be written once after each reset.
All of the configuration register bits are cleared during reset. Since the
various options affect the operation of the MCU, it is recommended that
these registers be written immediately after reset. The configuration
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Configuration Register (CONFIG)
registers are located at $001D and $001F. The configuration register
may be read at anytime.
5.3.1 Configuration Register 0
Address:
$001D
Bit 7
6
5
Read:
HSYNCOE VSYNCOE
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
0
0
SOGE
Write:
Reset:
0
0
0
= Unimplemented
Figure 5-1. Configuration Register 0 (CONFIG0)
HSYNCOE — VSYNCO Enable
This bit is set to configure the PTE1/HSYNCO pin for HSYNCO output
function. Reset clears this bit.
1 = PTE1/HSYNCO pin configured as HSYNCO pin
0 = PTE1/HSYNCO pin configured as standard I/O pin
VSYNCOE — VSYNCO Enable
This bit is set to configure the PTE2/VSYNCO pin for VSYNCO output
function. Reset clears this bit.
1 = PTE2/VSYNCO pin configured as VSYNCO pin
0 = PTE2/VSYNCO pin configured as standard I/O pin
SOGE — SOG Enable
This bit is set to configure the PTE0/SOG/TCH0 pin for SOG output
function. Reset clears this bit.
1 = PTE0/SOG/TCH0 pin configured as SOG pin
0 = PTE0/SOG/TCH0 pin configured as standard I/O or TCH0 pin.
TCH0 function is configured by ELS0B and ELS0A bits in
TSC0 (bits 3 and 2 in $0010). (See 10.10.4 TIM Channel
Status and Control Registers (TSC0:TSC1).)
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MOTOROLA
Configuration Register (CONFIG)
Functional Description
5.3.2 Configuration Register 1
Address:
Read:
$001F
Bit 7
6
5
4
0
0
0
0
3
2
1
Bit 0
SSREC
COPRS
STOP
COPD
0
0
0
0
Write:
Reset:
0
0
0
0
= Unimplemented
Figure 5-2. Configuration Register 1 (CONFIG1)
SSREC — Short Stop Recovery Bit
SSREC enables the CPU to exit stop mode with a delay of 32
OSCXCLK cycles instead of a 4096-OSCXCLK cycle delay.
1 = Stop mode recovery after 32 OSCXCLK cycles
0 = Stop mode recovery after 4096 OSCXCLKC cycles
NOTE:
Exiting stop mode by pulling reset will result in the long stop recovery.
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 19. Computer Operating Properly (COP).)
1 = COP timeout period = 213 – 24 CGMXCLK cycles
0 = COP timeout period = 218 – 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 19. Computer
Operating Properly (COP).)
1 = COP module disabled
0 = COP module enabled
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Technical Data
Configuration Register (CONFIG)
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Configuration Register (CONFIG)
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Technical Data — MC68HC908BD48
Section 6. Central Processor Unit (CPU)
6.1 Contents
6.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
6.4
CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
6.4.1
Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
6.4.2
Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
6.4.3
Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
6.4.4
Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
6.4.5
Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
6.5
Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
6.6
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
6.6.1
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
6.6.2
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.7
CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.8
Instruction Set Summary
6.9
Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.2 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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Central Processor Unit (CPU)
6.3 Features
•
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
•
64-Kbyte 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 64 Kbytes
•
Low-power stop and wait modes
6.4 CPU Registers
Figure 6-1 shows the five CPU registers. CPU registers are not part of
the memory map.
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Central Processor Unit (CPU)
CPU Registers
0
7
ACCUMULATOR (A)
0
15
H
X
INDEX REGISTER (H:X)
15
0
STACK POINTER (SP)
15
0
PROGRAM COUNTER (PC)
7
0
V 1 1 H I N Z C
CONDITION CODE REGISTER (CCR)
CARRY/BORROW FLAG
ZERO FLAG
NEGATIVE FLAG
INTERRUPT MASK
HALF-CARRY FLAG
TWO’S COMPLEMENT OVERFLOW FLAG
Figure 6-1. CPU Registers
6.4.1 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
6
5
4
3
2
1
Bit 0
Read:
Write:
Reset:
Unaffected by reset
Figure 6-2. Accumulator (A)
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Central Processor Unit (CPU)
6.4.2 Index Register
The 16-bit index register allows indexed addressing of a 64-Kbyte
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.
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Bit
0
0
0
0
0
0
0
0
0
X
X
X
X
X
X
X
X
Read:
Write:
Reset:
X = Indeterminate
Figure 6-3. Index Register (H:X)
6.4.3 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.
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Central Processor Unit (CPU)
CPU Registers
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Bit
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Read:
Write:
Reset:
Figure 6-4. Stack Pointer (SP)
NOTE:
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.
6.4.4 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
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Bit
0
Read:
Write:
Reset:
Loaded with Vector from $FFFE and $FFFF
Figure 6-5. Program Counter (PC)
6.4.5 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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Central Processor Unit (CPU)
5 are set permanently to logic 1. The following paragraphs describe the
functions of the condition code register.
Bit 7
6
5
4
3
2
1
Bit 0
V
1
1
H
I
N
Z
C
X
1
1
X
1
X
X
X
Read:
Write:
Reset:
X = Indeterminate
Figure 6-6. Condition Code Register (CCR)
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
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MOTOROLA
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
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
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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
6.5 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.
6.6 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption
standby modes.
6.6.1 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
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Central Processor Unit (CPU)
CPU During Break Interrupts
6.6.2 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
After exiting stop mode, the CPU clock begins running after the oscillator
stabilization delay.
6.7 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.
6.8 Instruction Set Summary
6.9 Opcode Map
See Table 6-2.
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Central Processor Unit (CPU)
V H I N Z C
ADC #opr
ADC opr
ADC opr
ADC opr,X
ADC opr,X
ADC ,X
ADC opr,SP
ADC opr,SP
A ← (A) + (M) + (C)
Add with Carry
IMM
DIR
EXT
IX2
↕ ↕ – ↕ ↕ ↕
IX1
IX
SP1
SP2
A9
B9
C9
D9
E9
F9
9EE9
9ED9
ii
dd
hh ll
ee ff
ff
IMM
DIR
EXT
IX2
↕ ↕ – ↕ ↕ ↕
IX1
IX
SP1
SP2
AB
BB
CB
DB
EB
FB
9EEB
9EDB
ii
dd
hh ll
ee ff
ff
ADD #opr
ADD opr
ADD opr
ADD opr,X
ADD opr,X
ADD ,X
ADD opr,SP
ADD opr,SP
Add without Carry
AIS #opr
Add Immediate Value (Signed) to SP
SP ← (SP) + (16 « M)
– – – – – – IMM
AIX #opr
Add Immediate Value (Signed) to H:X
H:X ← (H:X) + (16 « M)
A ← (A) & (M)
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
Logical AND
Arithmetic Shift Left
(Same as LSL)
ASR opr
ASRA
ASRX
ASR opr,X
ASR opr,X
ASR opr,SP
Arithmetic Shift Right
BCC rel
Branch if Carry Bit Clear
BCLR n, opr
A ← (A) + (M)
C
0
b7
b0
C
b7
Clear Bit n in M
b0
PC ← (PC) + 2 + rel ? (C) = 0
Mn ← 0
Technical Data
76
ff
ee ff
Cycles
Effect on
CCR
Description
Operand
Operation
Opcode
Source
Form
Address
Mode
Table 6-1. Instruction Set Summary
2
3
4
4
3
2
4
5
ff
ee ff
2
3
4
4
3
2
4
5
A7
ii
2
– – – – – – IMM
AF
ii
2
IMM
DIR
EXT
IX2
0 – – ↕ ↕ –
IX1
IX
SP1
SP2
A4
B4
C4
D4
E4
F4
9EE4
9ED4
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
2
4
5
DIR
INH
INH
↕ – – ↕ ↕ ↕
IX1
IX
SP1
38
48
58
68
78
9E68
dd
DIR
INH
INH
↕ – – ↕ ↕ ↕
IX1
IX
SP1
37
47
57
67
77
9E67
dd
ff
4
1
1
4
3
5
– – – – – – REL
24
rr
3
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
– – – – – –
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
11
13
15
17
19
1B
1D
1F
dd
dd
dd
dd
dd
dd
dd
dd
4
4
4
4
4
4
4
4
ff
ee ff
ff
ff
ff
4
1
1
4
3
5
MC68HC908BD48 — Rev. 1.0
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
Opcode Map
Effect on
CCR
V H I N Z C
Cycles
Description
Operand
Operation
Opcode
Source
Form
Address
Mode
Table 6-1. Instruction Set Summary (Continued)
BCS rel
Branch if Carry Bit Set (Same as BLO)
PC ← (PC) + 2 + rel ? (C) = 1
– – – – – – REL
25
rr
3
BEQ rel
Branch if Equal
PC ← (PC) + 2 + rel ? (Z) = 1
– – – – – – REL
27
rr
3
BGE opr
Branch if Greater Than or Equal To
(Signed Operands)
PC ← (PC) + 2 + rel ? (N ⊕ V) = 0
– – – – – – REL
90
rr
3
BGT opr
Branch if Greater Than (Signed
Operands)
PC ← (PC) + 2 + rel ? (Z) | (N ⊕ V) =
– – – – – – REL
0
92
rr
3
BHCC rel
Branch if Half Carry Bit Clear
PC ← (PC) + 2 + rel ? (H) = 0
– – – – – – REL
28
rr
3
BHCS rel
Branch if Half Carry Bit Set
PC ← (PC) + 2 + rel ? (H) = 1
– – – – – – REL
29
rr
BHI rel
Branch if Higher
PC ← (PC) + 2 + rel ? (C) | (Z) = 0
– – – – – – REL
22
rr
3
BHS rel
Branch if Higher or Same
(Same as BCC)
PC ← (PC) + 2 + rel ? (C) = 0
– – – – – – REL
24
rr
3
BIH rel
Branch if IRQ Pin High
PC ← (PC) + 2 + rel ? IRQ = 1
– – – – – – REL
2F
rr
3
BIL rel
Branch if IRQ Pin Low
PC ← (PC) + 2 + rel ? IRQ = 0
– – – – – – REL
2E
rr
3
(A) & (M)
IMM
DIR
EXT
IX2
0 – – ↕ ↕ –
IX1
IX
SP1
SP2
A5
B5
C5
D5
E5
F5
9EE5
9ED5
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
93
rr
3
BIT #opr
BIT opr
BIT opr
BIT opr,X
BIT opr,X
BIT ,X
BIT opr,SP
BIT opr,SP
Bit Test
BLE opr
Branch if Less Than or Equal To
(Signed Operands)
BLO rel
Branch if Lower (Same as BCS)
BLS rel
PC ← (PC) + 2 + rel ? (Z) | (N ⊕ V) =
– – – – – – REL
1
3
PC ← (PC) + 2 + rel ? (C) = 1
– – – – – – REL
25
rr
3
Branch if Lower or Same
PC ← (PC) + 2 + rel ? (C) | (Z) = 1
– – – – – – REL
23
rr
3
BLT opr
Branch if Less Than (Signed Operands)
PC ← (PC) + 2 + rel ? (N ⊕ V) =1
– – – – – – REL
91
rr
3
BMC rel
Branch if Interrupt Mask Clear
PC ← (PC) + 2 + rel ? (I) = 0
– – – – – – REL
2C
rr
3
BMI rel
Branch if Minus
PC ← (PC) + 2 + rel ? (N) = 1
– – – – – – REL
2B
rr
3
BMS rel
Branch if Interrupt Mask Set
PC ← (PC) + 2 + rel ? (I) = 1
– – – – – – REL
2D
rr
3
BNE rel
Branch if Not Equal
PC ← (PC) + 2 + rel ? (Z) = 0
– – – – – – REL
26
rr
3
BPL rel
Branch if Plus
PC ← (PC) + 2 + rel ? (N) = 0
– – – – – – REL
2A
rr
3
BRA rel
Branch Always
PC ← (PC) + 2 + rel
– – – – – – REL
20
rr
3
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Central Processor Unit (CPU)
77
Central Processor Unit (CPU)
Table 6-1. Instruction Set Summary (Continued)
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
– – – – – ↕
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
01
03
05
07
09
0B
0D
0F
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
5
5
5
5
5
5
5
5
– – – – – – REL
21
rr
3
PC ← (PC) + 3 + rel ? (Mn) = 1
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
– – – – – ↕
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
00
02
04
06
08
0A
0C
0E
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
5
5
5
5
5
5
5
5
Mn ← 1
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
– – – – – –
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
10
12
14
16
18
1A
1C
1E
dd
dd
dd
dd
dd
dd
dd
dd
4
4
4
4
4
4
4
4
– – – – – – REL
AD
rr
4
dd rr
ii rr
ii rr
ff rr
rr
ff rr
5
4
4
5
4
6
Description
V H I N Z C
BRCLR n,opr,rel Branch if Bit n in M Clear
BRN rel
Branch Never
BRSET n,opr,rel Branch if Bit n in M Set
BSET n,opr
BSR rel
Set Bit n in M
Branch to Subroutine
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
PC ← (PC) + 3 + rel ? (Mn) = 0
PC ← (PC) + 2
PC ← (PC) + 2; push (PCL)
SP ← (SP) – 1; push (PCH)
SP ← (SP) – 1
PC ← (PC) + rel
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
31
41
51
61
71
9E61
Cycles
Operand
Effect on
CCR
Opcode
Operation
Address
Mode
Source
Form
CLC
Clear Carry Bit
C←0
– – – – – 0 INH
98
1
CLI
Clear Interrupt Mask
I←0
– – 0 – – – INH
9A
2
M ← $00
A ← $00
X ← $00
H ← $00
M ← $00
M ← $00
M ← $00
DIR
INH
INH
0 – – 0 1 – INH
IX1
IX
SP1
3F
4F
5F
8C
6F
7F
9E6F
CLR opr
CLRA
CLRX
CLRH
CLR opr,X
CLR ,X
CLR opr,SP
Clear
Technical Data
78
dd
ff
ff
3
1
1
1
3
2
4
MC68HC908BD48 — Rev. 1.0
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
Opcode Map
Effect on
CCR
V H I N Z C
CMP #opr
CMP opr
CMP opr
CMP opr,X
CMP opr,X
CMP ,X
CMP opr,SP
CMP opr,SP
Compare A with M
(A) – (M)
COM opr
COMA
COMX
COM opr,X
COM ,X
COM opr,SP
Complement (One’s Complement)
CPHX #opr
CPHX opr
Compare H:X with M
CPX #opr
CPX opr
CPX opr
CPX ,X
CPX opr,X
CPX opr,X
CPX opr,SP
CPX opr,SP
Compare X with M
DAA
Decimal Adjust A
(H:X) – (M:M + 1)
(X) – (M)
(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
Decrement
DIV
Divide
M ← (M) = $FF – (M)
A ← (A) = $FF – (M)
X ← (X) = $FF – (M)
M ← (M) = $FF – (M)
M ← (M) = $FF – (M)
M ← (M) = $FF – (M)
A1
B1
C1
D1
E1
F1
9EE1
9ED1
ii
dd
hh ll
ee ff
ff
DIR
INH
INH
0 – – ↕ ↕ 1
IX1
IX
SP1
33
43
53
63
73
9E63
dd
ff
ee ff
2
3
4
4
3
2
4
5
ff
4
1
1
4
3
5
65
75
ii ii+1
dd
3
4
IMM
DIR
EXT
IX2
↕ – – ↕ ↕ ↕
IX1
IX
SP1
SP2
A3
B3
C3
D3
E3
F3
9EE3
9ED3
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
2
4
5
U – – ↕ ↕ ↕ INH
72
↕ – – ↕ ↕ ↕
IMM
DIR
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
ff
ff
ee ff
2
3B
4B
5B
6B
7B
9E6B
dd rr
rr
rr
ff rr
rr
ff rr
dd
M ← (M) – 1
A ← (A) – 1
X ← (X) – 1
M ← (M) – 1
M ← (M) – 1
M ← (M) – 1
DIR
INH
INH
↕ – – ↕ ↕ –
IX1
IX
SP1
3A
4A
5A
6A
7A
9E6A
A ← (H:A)/(X)
H ← Remainder
– – – – ↕ ↕ INH
52
MC68HC908BD48 — Rev. 1.0
MOTOROLA
IMM
DIR
EXT
IX2
↕ – – ↕ ↕ ↕
IX1
IX
SP1
SP2
Cycles
Description
Operand
Operation
Opcode
Source
Form
Address
Mode
Table 6-1. Instruction Set Summary (Continued)
ff
ff
5
3
3
5
4
6
4
1
1
4
3
5
7
Technical Data
Central Processor Unit (CPU)
79
Central Processor Unit (CPU)
V H I N Z C
EOR #opr
EOR opr
EOR opr
EOR opr,X
EOR opr,X
EOR ,X
EOR opr,SP
EOR opr,SP
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
ii
dd
hh ll
ee ff
ff
M ← (M) + 1
A ← (A) + 1
X ← (X) + 1
M ← (M) + 1
M ← (M) + 1
M ← (M) + 1
DIR
INH
INH
↕ – – ↕ ↕ –
IX1
IX
SP1
3C
4C
5C
6C
7C
9E6C
dd
PC ← Jump Address
DIR
EXT
– – – – – – IX2
IX1
IX
BC
CC
DC
EC
FC
dd
hh ll
ee ff
ff
2
3
4
3
2
PC ← (PC) + n (n = 1, 2, or 3)
Push (PCL); SP ← (SP) – 1
Push (PCH); SP ← (SP) – 1
PC ← Unconditional Address
DIR
EXT
– – – – – – IX2
IX1
IX
BD
CD
DD
ED
FD
dd
hh ll
ee ff
ff
4
5
6
5
4
A ← (M)
IMM
DIR
EXT
IX2
0 – – ↕ ↕ –
IX1
IX
SP1
SP2
A6
B6
C6
D6
E6
F6
9EE6
9ED6
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
ii jj
dd
3
4
2
3
4
4
3
2
4
5
A ← (A ⊕ M)
Jump
Load A from M
LDHX #opr
LDHX opr
Load H:X from M
LSL opr
LSLA
LSLX
LSL opr,X
LSL ,X
LSL opr,SP
A8
B8
C8
D8
E8
F8
9EE8
9ED8
Increment
LDA #opr
LDA opr
LDA opr
LDA opr,X
LDA opr,X
LDA ,X
LDA opr,SP
LDA opr,SP
LDX #opr
LDX opr
LDX opr
LDX opr,X
LDX opr,X
LDX ,X
LDX opr,SP
LDX opr,SP
IMM
DIR
EXT
IX2
0 – – ↕ ↕ –
IX1
IX
SP1
SP2
Exclusive OR M with A
Jump to Subroutine
H:X ← (M:M + 1)
0 – – ↕ ↕ –
X ← (M)
Load X from M
Logical Shift Left
(Same as ASL)
C
0
b7
b0
Technical Data
80
Cycles
Effect on
CCR
Description
Operand
Operation
Opcode
Source
Form
Address
Mode
Table 6-1. Instruction Set Summary (Continued)
IMM
DIR
45
55
ff
ee ff
ff
ff
IMM
DIR
EXT
IX2
0 – – ↕ ↕ –
IX1
IX
SP1
SP2
AE
BE
CE
DE
EE
FE
9EEE
9EDE
ii
dd
hh ll
ee ff
ff
DIR
INH
INH
↕ – – ↕ ↕ ↕
IX1
IX
SP1
38
48
58
68
78
9E68
dd
ff
ee ff
ff
ff
2
3
4
4
3
2
4
5
4
1
1
4
3
5
4
1
1
4
3
5
MC68HC908BD48 — Rev. 1.0
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
Opcode Map
V H I N Z C
LSR opr
LSRA
LSRX
LSR opr,X
LSR ,X
LSR opr,SP
Logical Shift Right
DIR
INH
INH
↕ – – 0 ↕ ↕
IX1
IX
SP1
34
44
54
64
74
9E64
DD
DIX+
0 – – ↕ ↕ –
IMD
IX+D
4E
5E
6E
7E
X:A ← (X) × (A)
– 0 – – – 0 INH
42
M ← –(M) = $00 – (M)
A ← –(A) = $00 – (A)
X ← –(X) = $00 – (X)
M ← –(M) = $00 – (M)
M ← –(M) = $00 – (M)
DIR
INH
INH
↕ – – ↕ ↕ ↕
IX1
IX
SP1
30
40
50
60
70
9E60
0
C
b7
MOV opr,opr
MOV opr,X+
MOV #opr,opr
MOV X+,opr
Move
MUL
Unsigned multiply
b0
(M)Destination ← (M)Source
H:X ← (H:X) + 1 (IX+D, DIX+)
dd
Cycles
Effect on
CCR
Description
Operand
Operation
Opcode
Source
Form
Address
Mode
Table 6-1. Instruction Set Summary (Continued)
ff
4
1
1
4
3
5
dd dd
dd
ii dd
dd
5
4
4
4
ff
5
NEG opr
NEGA
NEGX
NEG opr,X
NEG ,X
NEG opr,SP
Negate (Two’s Complement)
NOP
No Operation
None
– – – – – – INH
9D
1
NSA
Nibble Swap A
A ← (A[3:0]:A[7:4])
– – – – – – INH
62
3
A ← (A) | (M)
IMM
DIR
EXT
IX2
0 – – ↕ ↕ –
IX1
IX
SP1
SP2
AA
BA
CA
DA
EA
FA
9EEA
9EDA
dd
ff
ff
4
1
1
4
3
5
ORA #opr
ORA opr
ORA opr
ORA opr,X
ORA opr,X
ORA ,X
ORA opr,SP
ORA opr,SP
Inclusive OR A and M
PSHA
Push A onto Stack
Push (A); SP ← (SP) – 1
– – – – – – INH
87
2
PSHH
Push H onto Stack
Push (H); SP ← (SP) – 1
– – – – – – INH
8B
2
PSHX
Push X onto Stack
Push (X); SP ← (SP) – 1
– – – – – – INH
89
2
PULA
Pull A from Stack
SP ← (SP + 1); Pull (A)
– – – – – – INH
86
2
PULH
Pull H from Stack
SP ← (SP + 1); Pull (H)
– – – – – – INH
8A
2
PULX
Pull X from Stack
SP ← (SP + 1); Pull (X)
– – – – – – INH
88
2
C
DIR
INH
INH
↕ – – ↕ ↕ ↕
IX1
IX
SP1
39
49
59
69
79
9E69
ROL opr
ROLA
ROLX
ROL opr,X
ROL ,X
ROL opr,SP
Rotate Left through Carry
b7
b0
MC68HC908BD48 — Rev. 1.0
MOTOROLA
ii
dd
hh ll
ee ff
ff
ff
ee ff
dd
ff
ff
2
3
4
4
3
2
4
5
4
1
1
4
3
5
Technical Data
Central Processor Unit (CPU)
81
Central Processor Unit (CPU)
V H I N Z C
ROR opr
RORA
RORX
ROR opr,X
ROR ,X
ROR opr,SP
Rotate Right through Carry
RSP
Reset Stack Pointer
RTI
Return from Interrupt
RTS
Return from Subroutine
DIR
INH
INH
↕ – – ↕ ↕ ↕
IX1
IX
SP1
36
46
56
66
76
9E66
SP ← $FF
– – – – – – INH
9C
1
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)
↕ ↕ ↕ ↕ ↕ ↕ INH
80
7
SP ← SP + 1; Pull (PCH)
SP ← SP + 1; Pull (PCL)
– – – – – – INH
81
4
A ← (A) – (M) – (C)
IMM
DIR
EXT
IX2
↕ – – ↕ ↕ ↕
IX1
IX
SP1
SP2
A2
B2
C2
D2
E2
F2
9EE2
9ED2
C
b7
b0
dd
Cycles
Effect on
CCR
Description
Operand
Operation
Opcode
Source
Form
Address
Mode
Table 6-1. Instruction Set Summary (Continued)
ff
ff
4
1
1
4
3
5
SBC #opr
SBC opr
SBC opr
SBC opr,X
SBC opr,X
SBC ,X
SBC opr,SP
SBC opr,SP
Subtract with Carry
SEC
Set Carry Bit
C←1
– – – – – 1 INH
99
1
SEI
Set Interrupt Mask
I←1
– – 1 – – – INH
9B
2
M ← (A)
DIR
EXT
IX2
0 – – ↕ ↕ – IX1
IX
SP1
SP2
B7
C7
D7
E7
F7
9EE7
9ED7
(M:M + 1) ← (H:X)
0 – – ↕ ↕ – DIR
35
I ← 0; Stop Oscillator
– – 0 – – – INH
8E
M ← (X)
DIR
EXT
IX2
0 – – ↕ ↕ – IX1
IX
SP1
SP2
BF
CF
DF
EF
FF
9EEF
9EDF
STA opr
STA opr
STA opr,X
STA opr,X
STA ,X
STA opr,SP
STA opr,SP
Store A in M
STHX opr
Store H:X in M
STOP
Enable IRQ Pin; Stop Oscillator
STX opr
STX opr
STX opr,X
STX opr,X
STX ,X
STX opr,SP
STX opr,SP
Store X in M
Technical Data
82
ii
dd
hh ll
ee ff
ff
ff
ee ff
dd
hh ll
ee ff
ff
2
3
4
4
3
2
4
5
ff
ee ff
3
4
4
3
2
4
5
dd
4
1
dd
hh ll
ee ff
ff
ff
ee ff
3
4
4
3
2
4
5
MC68HC908BD48 — Rev. 1.0
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
Opcode Map
Effect on
CCR
V H I N Z C
SUB #opr
SUB opr
SUB opr
SUB opr,X
SUB opr,X
SUB ,X
SUB opr,SP
SUB opr,SP
Subtract
A ← (A) – (M)
ii
dd
hh ll
ee ff
ff
Cycles
Description
Operand
Operation
Opcode
Source
Form
Address
Mode
Table 6-1. Instruction Set Summary (Continued)
IMM
DIR
EXT
IX2
↕ – – ↕ ↕ ↕
IX1
IX
SP1
SP2
A0
B0
C0
D0
E0
F0
9EE0
9ED0
– – 1 – – – INH
83
9
ff
ee ff
2
3
4
4
3
2
4
5
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
TAP
Transfer A to CCR
CCR ← (A)
↕ ↕ ↕ ↕ ↕ ↕ INH
84
2
TAX
Transfer A to X
X ← (A)
– – – – – – INH
97
1
TPA
Transfer CCR to A
A ← (CCR)
– – – – – – INH
85
1
(A) – $00 or (X) – $00 or (M) – $00
DIR
INH
INH
0 – – ↕ ↕ –
IX1
IX
SP1
3D
4D
5D
6D
7D
9E6D
H:X ← (SP) + 1
– – – – – – INH
95
2
A ← (X)
– – – – – – INH
9F
1
(SP) ← (H:X) – 1
– – – – – – INH
94
2
TST opr
TSTA
TSTX
TST opr,X
TST ,X
TST opr,SP
Test for Negative or Zero
TSX
Transfer SP to H:X
TXA
Transfer X to A
TXS
Transfer H:X to SP
MC68HC908BD48 — Rev. 1.0
MOTOROLA
dd
ff
ff
3
1
1
3
2
4
Technical Data
Central Processor Unit (CPU)
83
Central Processor Unit (CPU)
V H I N Z C
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
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
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
84
Cycles
Effect on
CCR
Description
Operand
Operation
Opcode
Source
Form
Address
Mode
Table 6-1. Instruction Set Summary (Continued)
MC68HC908BD48 — Rev. 1.0
Central Processor Unit (CPU)
MOTOROLA
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Table 6-2. Opcode Map
Bit Manipulation
DIR
DIR
MSB
Branch
REL
DIR
INH
3
4
1
2
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
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
3
BRA
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
5
6
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
4
NEG
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
IX
9E6
7
Control
INH
INH
8
9
Register/Memory
IX2
SP2
IMM
DIR
EXT
A
B
C
D
9ED
4
SUB
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
4
SUB
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
5
SUB
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
SP1
IX
E
9EE
F
LSB
0
1
2
3
4
Central Processor Unit (CPU)
0
Read-Modify-Write
INH
IX1
5
6
7
8
9
A
B
C
E
F
4
1
NEG
NEGA
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
2
Technical Data
85
INH Inherent
REL Relative
IMM Immediate
IX
Indexed, No Offset
DIR Direct
IX1 Indexed, 8-Bit Offset
EXT Extended
IX2 Indexed, 16-Bit Offset
DD Direct-Direct
IMD Immediate-Direct
IX+D Indexed-Direct DIX+ Direct-Indexed
*Pre-byte for stack pointer indexed instructions
2
5
3
NEG
NEG
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
3
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
7
3
RTI
BGE
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
1
2
SUB
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
3
SUB
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
2
2
MSB
3
0
3
3
SUB
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
4
2
4
SUB
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
2
SUB
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
3
High Byte of Opcode in Hexadecimal
LSB
Low Byte of Opcode in Hexadecimal
0
5
Cycles
BRSET0 Opcode Mnemonic
3 DIR Number of Bytes / Addressing Mode
1
Central Processor Unit (CPU)
Opcode Map
D
2
Central Processor Unit (CPU)
Technical Data
86
MC68HC908BD48 — Rev. 1.0
Central Processor Unit (CPU)
MOTOROLA
Technical Data — MC68HC908BD48
Section 7. System Integration Module (SIM)
7.1 Contents
7.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
7.3
SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . . 91
7.3.1
Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.3.2
Clock Start-Up from POR . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.3.3
Clocks in Stop Mode and Wait Mode . . . . . . . . . . . . . . . . . . 91
7.4
Reset and System Initialization. . . . . . . . . . . . . . . . . . . . . . . . . 92
7.4.1
External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
7.4.2
Active Resets from Internal Sources . . . . . . . . . . . . . . . . . . 93
7.4.2.1
Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
7.4.2.2
Computer Operating Properly (COP) Reset . . . . . . . . . . 95
7.4.2.3
Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.4.2.4
Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.5
SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.5.1
SIM Counter During Power-On Reset . . . . . . . . . . . . . . . . . 96
7.5.2
SIM Counter During Stop Mode Recovery . . . . . . . . . . . . . . 97
7.5.3
SIM Counter and Reset States. . . . . . . . . . . . . . . . . . . . . . . 97
7.6
Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.6.1
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.6.1.1
Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
7.6.1.2
SWI Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
7.6.2
Interrupt Status Registers. . . . . . . . . . . . . . . . . . . . . . . . . . 101
7.6.2.1
Interrupt Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . 103
7.6.2.2
Interrupt Status Register 2 . . . . . . . . . . . . . . . . . . . . . . . 103
7.6.3
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
7.6.4
Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
7.6.5
Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . 104
7.7
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
System Integration Module (SIM)
87
System Integration Module (SIM)
7.7.1
7.7.2
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
7.8
SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
7.8.1
SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . 108
7.8.2
SIM Reset Status Register (SRSR) . . . . . . . . . . . . . . . . . . 109
7.8.3
SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . 110
7.2 Introduction
This section describes the system integration module, which supports up
to 16 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 7-1. Table 7-1 shows 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
Technical Data
88
MC68HC908BD48 — Rev. 1.0
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
Introduction
MODULE STOP
MODULE WAIT
CPU STOP (FROM CPU)
CPU WAIT (FROM CPU)
STOP/WAIT
CONTROL
SIMOSCEN (TO OSCILLATOR)
SIM
COUNTER
COP CLOCK
OSCXCLK (FROM OSCILLATOR)
OSCOUT (FROM OSCILLATOR)
÷2
CLOCK
CONTROL
RESET
PIN LOGIC
CLOCK GENERATORS
INTERNAL CLOCKS
LVI (FROM LVI MODULE)
POR CONTROL
MASTER
RESET
CONTROL
RESET PIN CONTROL
SIM RESET STATUS REGISTER
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 7-1. SIM Block Diagram
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System Integration Module (SIM)
Table 7-1. SIM I/O Register Summary
Addr.
Register Name
Bit 7
6
5
4
3
2
R
R
R
R
R
R
0
0
0
0
0
0
0
0
POR
PIN
COP
ILOP
ILAD
0
0
0
1
0
0
0
0
0
0
0
BCFE
R
R
R
R
R
R
R
Read:
SIM Break Status Register
$FE00
Write:
(SBSR)
Reset:
$FE01
$FE03
Read:
SIM Reset Status
Write:
Register (SRSR)
POR:
Read:
SIM Break Flag Control
Write:
Register (SBFCR)
Reset:
1
Bit 0
SBSW
Note
R
0
Read:
Interrupt Status Register 1
$FE04
Write:
(INT1)
Reset:
IF6
IF5
IF4
IF3
IF2
IF1
0
0
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
Read:
Interrupt Status Register 2
$FE05
(INT2) Write:
0
0
0
0
IF10
IF9
IF8
IF7
R
R
R
R
R
R
R
R
Reset:
0
0
0
0
0
0
0
0
= Unimplemented
Note: Writing a logic 0 clears SBSW.
R
= Reserved
Table 7-2 shows the internal signal names used in this section.
Table 7-2. Signal Name Conventions
Signal Name
Description
OSCXCLK
Buffered version of OSC1 from the oscillator
OSCOUT
The OSCXCLK frequency divided by two. This signal is again
divided by two in the SIM to generate the internal bus clocks.
(Bus clock = OSCXCLK divided by four)
IAB
Internal address bus
IDB
Internal data bus
PORRST
Signal from the power-on reset module to the SIM
IRST
Internal reset signal
R/W
Read/write signal
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System Integration Module (SIM)
SIM Bus Clock Control and Generation
7.3 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, OSCOUT, as shown in Figure 7-2.
From
SIM
OSCXCLK
÷2
OSCOUT
SIM COUNTER
BUS CLOCK
GENERATORS
÷2
SIMOSCEN
OSCILLATOR
OSC1
SIM
OSC2
Figure 7-2. OSC Clock Signals
7.3.1 Bus Timing
In user mode, the internal bus frequency is the oscillator frequency
(OSCXCLK) divided by four.
7.3.2 Clock Start-Up from POR
When the power-on reset module generates a reset, the clocks to the
CPU and peripherals are inactive and held in an inactive phase until after
the 4096 OSCXCLK cycle POR timeout has completed. The RST is
driven low by the SIM during this entire period. The IBUS clocks start
upon completion of the timeout.
7.3.3 Clocks in Stop Mode and Wait Mode
Upon exit from stop mode (by an interrupt, break, or reset), the SIM
allows OSCXCLK 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 OSCXCLK cycles. (See 7.7.2 Stop
Mode.)
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System Integration Module (SIM)
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.
7.4 Reset and System Initialization
The MCU has the following reset sources:
•
Power-on reset module (POR)
•
External reset pin (RST)
•
Computer operating properly module (COP)
•
Illegal opcode
•
Illegal address
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 7.5 SIM Counter), but an
external reset does not. Each of the resets sets a corresponding bit in
the SIM reset status register (SRSR) (see 7.8 SIM Registers).
7.4.1 External Pin Reset
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 OSCXCLK cycles, assuming that the POR was the
source of the reset (see Table 7-3. PIN Bit Set Timing). Figure 7-3
shows the relative timing.
Table 7-3. PIN Bit Set Timing
Reset Type
Number of Cycles Required to Set PIN
POR
4163 (4096 + 64 + 3)
All others
67 (64 + 3)
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MOTOROLA
System Integration Module (SIM)
Reset and System Initialization
OSCOUT
RST
IAB
VECT H VECT L
PC
Figure 7-3. External Reset Timing
7.4.2 Active Resets from Internal Sources
SIM module in HC08 has the capability to drive the RST pin low when
internal reset events occur.
All internal reset sources actively pull the RST pin low for 32 OSCXCLK
cycles to allow resetting of external peripherals. The internal reset signal
IRST continues to be asserted for an additional 32 cycles (see Figure 74. Internal Reset Timing). An internal reset can be caused by an illegal
address, illegal opcode, COP timeout, or POR (see Figure 7-5. Sources
of Internal Reset). Note that for POR resets, the SIM cycles through
4096 OSCXCLK cycles during which the SIM forces the RST pin low.
The internal reset signal then follows the sequence from the falling edge
of RST shown in Figure 7-4.
IRST
RST
RST PULLED LOW BY MCU
32 CYCLES
32 CYCLES
OSCXCLK
IAB
VECTOR HIGH
Figure 7-4. Internal Reset Timing
The COP reset is asynchronous to the bus clock.
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ILLEGAL ADDRESS RST
ILLEGAL OPCODE RST
COPRST
INTERNAL
RESET
POR
Figure 7-5. 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.
7.4.2.1 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 OSCXCLK cycles. Sixty-four OSCXCLK 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 the oscillator to drive OSCXCLK.
•
Internal clocks to the CPU and modules are held inactive for 4096
OSCXCLK cycles to allow stabilization of the oscillator.
•
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.
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System Integration Module (SIM)
Reset and System Initialization
OSC1
PORRST
4096
CYCLES
32
CYCLES
32
CYCLES
OSCXCLK
OSCOUT
RST
$FFFE
IAB
$FFFF
Figure 7-6. POR Recovery
7.4.2.2 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, write any value to location $FFFF.
Writing to location $FFFF clears the COP counter and bits 12 through 5
of the SIM counter. The SIM counter output, which occurs at least every
212 – 24 OSCXCLK 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 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 pin 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)
7.4.2.3 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 configure register 1 (CONFIG1) is
logic zero, 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.
7.4.2.4 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.
7.5 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 module (COP). The SIM
counter overflow supplies the clock for the COP module. The SIM
counter is 12 bits long and is clocked by the falling edge of OSCXCLK.
7.5.1 SIM Counter During Power-On Reset
The power-on reset module (POR) detects power applied to the MCU.
At power-on, the POR circuit asserts the signal PORRST. Once the SIM
is initialized, it enables the oscillator to drive the bus clock state machine.
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Exception Control
7.5.2 SIM Counter During Stop Mode Recovery
The SIM counter also is 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
configure register 1 (CONFIG1). If the SSREC bit is a logic one, then the
stop recovery is reduced from the normal delay of 4096 OSCXCLK
cycles down to 32 OSCXCLK 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.
7.5.3 SIM Counter and Reset States
External reset has no effect on the SIM counter (see 7.7.2 Stop Mode).
The SIM counter is free-running after all reset states (see 7.4.2 Active
Resets from Internal Sources for counter control and internal reset
recovery sequences).
7.6 Exception Control
Normally, sequential program execution can be changed in three
different ways:
•
Interrupts
– Maskable hardware CPU interrupts
– Non-maskable software interrupt instruction (SWI)
•
Reset
•
Break interrupts
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System Integration Module (SIM)
7.6.1 Interrupts
An interrupt temporarily changes the sequence of program execution to
respond to a particular event. Figure 7-9 flow charts the handling of
system interrupts.
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 can take precedence, regardless of priority,
until the latched interrupt is serviced (or the I bit is cleared).
At the beginning of an interrupt, the CPU saves the CPU register
contents on 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 7-7 shows interrupt entry timing. Figure
7-8 shows interrupt recovery timing.
MODULE
INTERRUPT
I BIT
IAB
IDB
DUMMY
DUMMY
SP
SP – 1
SP – 2
PC – 1[7:0] PC – 1[15:8]
SP – 3
X
SP – 4
A
VECT H
CCR
VECT L
V DATA H
START ADDR
V DATA L
OPCODE
R/W
Figure 7-7.Interrupt Entry
MODULE
INTERRUPT
I BIT
IAB
IDB
SP – 4
SP – 3
CCR
SP – 2
A
SP – 1
X
SP
PC
PC – 1[7:0] PC – 1[15:8]
PC + 1
OPCODE
OPERAND
R/W
Figure 7-8. Interrupt Recovery
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Exception Control
FROM RESET
BREAK
INTERRUPT?
I BIT
SET?
YES
NO
YES
I BIT SET?
NO
IRQ
INTERRUPT?
YES
NO
USB
INTERRUPT?
YES
NO
STACK CPU REGISTERS.
SET I BIT.
LOAD PC WITH INTERRUPT VECTOR.
(As many interrupts as exist on chip)
FETCH NEXT
INSTRUCTION.
SWI
INSTRUCTION?
YES
NO
RTI
INSTRUCTION?
YES
UNSTACK CPU REGISTERS.
NO
EXECUTE INSTRUCTION.
Figure 7-9. Interrupt Processing
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System Integration Module (SIM)
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
7-9. Interrupt Processing.)
7.6.1.1 Hardware Interrupts
A hardware interrupt does not stop the current instruction. Processing of
a hardware interrupt begins after completion of the current instruction.
When the current 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.
If more than one interrupt is pending at the end of an instruction
execution, the highest priority interrupt is serviced first. Figure 7-10
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
INT1
BACKGROUND ROUTINE
PSHH
INT1 INTERRUPT SERVICE ROUTINE
PULH
RTI
INT2
PSHH
INT2 INTERRUPT SERVICE ROUTINE
PULH
RTI
Figure 7-10.Interrupt Recognition Example
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Exception Control
The LDA opcode is pre-fetched by both the INT1 and INT2 RTI
instructions. However, in the case of the INT1 RTI pre-fetch, 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.
7.6.1.2 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.
7.6.2 Interrupt Status Registers
The flags in the interrupt status registers identify maskable interrupt
sources. Table 7-4 summarizes the interrupt sources and the interrupt
status register flags that they set. The interrupt status registers can be
useful for debugging.
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System Integration Module (SIM)
Table 7-4. Interrupt Sources
Flag
Mask1
INT Register
Flag
Priority2
Vector Address
Reset
None
None
None
0
$FFFE–$FFFF
SWI Instruction
None
None
None
0
$FFFC–$FFFD
IRQ pin
IRQF
IMASK
IF1
1
$FFFA–$FFFB
TBEF
TBIE
RBFF
RBIE
EOPIF
EOPIE
IF2
2
$FFF8–$FFF9
RSTIF
RSTIE
TXD1F
TXD1IE
IF3
3
$FFF6–$FFF7
Source
USB
ALIF
NAKIF
DIEN
DDC12AB
RXIF
TXIF
SCLIF
SCLIEN
—
—
—
—
$FFF4–$FFF5
TIM channel 0
CH0F
CH0IE
IF5
5
$FFF2–$FFF3
TIM channel 1
CH1F
CH1IE
IF6
6
$FFF0–$FFF1
TOF
TOIE
IF7
7
$FFEE–$FFEF
VSIF
VSIE
IF8
8
$FFEC–$FFED
LVSIF
LVSIE
MMIEN
IF9
9
$FFEA–FFEB
COCO
AIEN
IF10
10
$FFE8–$FFE9
—
—
—
—
$FFE6–$FFE7
Reserved
TIM overflow
Sync processor
MMALIF
MMNAKIF
Multi-master IIC
MMRXIF
MMTXIF
ADC conversion complete
Reserved
1. The I bit in the condition code register is a global mask for all interrupts sources except the SWI instruction.
2. 0 = highest priority
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Exception Control
7.6.2.1 Interrupt Status Register 1
Address:
$FE04
Bit 7
6
5
4
3
2
1
Bit 0
Read:
IF6
IF5
IF4
IF3
IF2
IF1
0
0
Write:
R
R
R
R
R
R
R
R
Reset:
0
0
0
0
0
0
0
0
R
= Reserved
Figure 7-11. Interrupt Status Register 1 (INT1)
IF6–IF1 — Interrupt Flags 6–1
These flags indicate the presence of interrupt requests from the
sources shown in Table 7-4.
1 = Interrupt request present
0 = No interrupt request present
Bit 1and Bit 0 — Always read 0
7.6.2.2 Interrupt Status Register 2
Address:
$FE05
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
0
0
0
IF10
IF9
IF8
IF7
Write:
R
R
R
R
R
R
R
R
Reset:
0
0
0
0
0
0
0
0
R
= Reserved
Figure 7-12. Interrupt Status Register 2 (INT2)
IF10–IF7 — Interrupt Flags 6–1
These flags indicate the presence of interrupt requests from the
sources shown in Table 7-4.
1 = Interrupt request present
0 = No interrupt request present
Bit 7 and Bit 4 — Always read 0
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7.6.3 Reset
All reset sources always have equal and highest priority and cannot be
arbitrated.
7.6.4 Break Interrupts
The break module can stop normal program flow at a softwareprogrammable break point by asserting its break interrupt output (see
Section 20. 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.
7.6.5 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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System Integration Module (SIM)
Low-Power Modes
7.7 Low-Power Modes
Executing the WAIT or STOP 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.
7.7.1 Wait Mode
In wait mode, the CPU clocks are inactive while the peripheral clocks
continue to run. Figure 7-13 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
configuration register 1 (CONFIG1) is logic zero, then the computer
operating properly module (COP) is enabled and remains active in wait
mode.
IAB
IDB
WAIT ADDR
WAIT ADDR + 1
PREVIOUS DATA
NEXT OPCODE
SAME
SAME
SAME
SAME
R/W
NOTE: Previous data can be operand data or the WAIT opcode, depending on the last instruction.
Figure 7-13. Wait Mode Entry Timing
Figure 7-14 and Figure 7-15 show the timing for WAIT recovery.
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System Integration Module (SIM)
IAB
IDB
$6E0B
$A6
$A6
$6E0C
$A6
$00FF
$01
$0B
$00FE
$00FD
$00FC
$6E
EXITSTOPWAIT
NOTE: EXITSTOPWAIT = RST pin OR CPU interrupt OR break interrupt
Figure 7-14. Wait Recovery from Interrupt or Break
32
Cycles
$6E0B
IAB
IDB
$A6
$A6
32
Cycles
RST VCT H RST VCT L
$A6
RST
OSCXCLK
Figure 7-15. Wait Recovery from Internal Reset
7.7.2 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 oscillator signals (OSCOUT and OSCXCLK) in
stop mode, stopping the CPU and peripherals. Stop recovery time is
selectable using the SSREC bit in configuration register 1 (CONFIG1). If
SSREC is set, stop recovery is reduced from the normal delay of 4096
OSCXCLK 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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System Integration Module (SIM)
Low-Power Modes
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 7-16 shows stop mode entry timing.
CPUSTOP
IAB
IDB
STOP ADDR
STOP ADDR + 1
PREVIOUS DATA
SAME
NEXT OPCODE
SAME
SAME
SAME
R/W
NOTE: Previous data can be operand data or the STOP opcode, depending on the last instruction.
Figure 7-16. Stop Mode Entry Timing
STOP RECOVERY PERIOD
OSCXCLK
INT/BREAK
IAB
STOP +1
STOP + 2
STOP + 2
SP
SP – 1
SP – 2
SP – 3
Figure 7-17. Stop Mode Recovery from Interrupt or Break
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System Integration Module (SIM)
7.8 SIM Registers
The SIM has three memory mapped registers. Table 7-5 shows the
mapping of these registers.
Table 7-5. SIM Registers Summary
Address
Register
Access Mode
$FE00
SBSR
User
$FE01
SRSR
User
$FE03
SBFCR
User
7.8.1 SIM Break Status Register (SBSR)
The SIM break status register contains a flag to indicate that a break
caused an exit from stop or wait mode.
Address:
$FE00
Bit 7
6
5
4
3
2
R
R
R
R
R
R
Read:
Bit 0
SBSW
Write:
Reset:
1
R
Note
0
0
Note: Writing a logic 0 clears SBSW.
0
0
R
= Reserved
0
0
0
0
Figure 7-18. SIM Break Status Register (SBSR)
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
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SIM Registers
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
EQU
5
LOBYTE
EQU
6
;
If not SBSW, do RTI
BRCLR
SBSW,SBSR, RETURN
; See if wait mode or stop mode was exited by
; break.
TST
LOBYTE,SP
;If RETURNLO is not zero,
BNE
DOLO
;then just decrement low byte.
DEC
HIBYTE,SP
;Else deal with high byte, too.
DOLO
DEC
LOBYTE,SP
;Point to WAIT/STOP opcode.
RETURN
PULH
RTI
;Restore H register.
7.8.2 SIM Reset Status Register (SRSR)
This register contains six flags that show the source of the last reset.
Clear the SIM reset status register by reading it. A power-on reset sets
the POR bit and clears all other bits in the register.
Address:
Read:
$FE01
Bit 7
6
5
4
3
2
1
Bit 0
POR
PIN
COP
ILOP
ILAD
0
0
0
1
0
0
0
0
0
0
0
Write:
POR:
= Unimplemented
Figure 7-19. SIM Reset Status Register (SRSR)
POR — Power-On Reset Bit
1 = Last reset caused by POR circuit
0 = Read of SRSR
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
System Integration Module (SIM)
109
System Integration Module (SIM)
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
7.8.3 SIM Break Flag Control Register (SBFCR)
The SIM break flag control register contains a bit that enables software
to clear status bits while the MCU is in a break state.
Address:
$FE03
Bit 7
6
5
4
3
2
1
Bit 0
BCFE
R
R
R
R
R
R
R
Read:
Write:
Reset:
0
R
= Reserved
Figure 7-20. 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
110
MC68HC908BD48 — Rev. 1.0
System Integration Module (SIM)
MOTOROLA
Technical Data — MC68HC908BD48
Section 8. Oscillator (OSC)
8.1 Contents
8.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
8.3
Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . . 112
8.4
I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
8.4.1
Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . 113
8.4.2
Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . 113
8.4.3
Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . 113
8.4.4
External Clock Source (OSCXCLK) . . . . . . . . . . . . . . . . . . 113
8.4.5
Oscillator Out (OSCOUT). . . . . . . . . . . . . . . . . . . . . . . . . . 113
8.5
Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.5.1
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.5.2
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.6
Oscillator During Break Mode. . . . . . . . . . . . . . . . . . . . . . . . . 114
8.2 Introduction
The oscillator circuit is designed for use with crystals or ceramic
resonators. The oscillator circuit generates the crystal clock signal,
OSCXCLK, at the frequency of the crystal. This signal is divided by two
before being passed on to the SIM for bus clock generation. Figure 8-1
shows the structure of the oscillator. The oscillator requires various
external components.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Oscillator (OSC)
111
Oscillator (OSC)
8.3 Oscillator External Connections
In its typical configuration, the oscillator requires five external
components. The crystal oscillator is normally connected in a Pierce
oscillator configuration, as shown in Figure 8-1. This figure shows only
the logical representation of the internal components and may not
represent actual circuitry. The oscillator configuration uses five
components:
•
Crystal, X1
•
Fixed capacitor, C1
•
Tuning capacitor, C2 (can also be a fixed capacitor)
•
Feedback resistor, RB
•
Series resistor, RS (optional)
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.
From
SIM
To SIM
OSCXCLK
To SIM
÷2
OSCOUT
SIMOSCEN
MCU
OSC1
OSC2
RS*
RB
X1
C1
*RS can be zero (shorted) when used with
higher-frequency crystals. Refer to manufacturer’s data.
C2
Figure 8-1. Oscillator External Connections
Technical Data
112
MC68HC908BD48 — Rev. 1.0
Oscillator (OSC)
MOTOROLA
Oscillator (OSC)
I/O Signals
8.4 I/O Signals
The following paragraphs describe the oscillator I/O signals.
8.4.1 Crystal Amplifier Input Pin (OSC1)
The OSC1 pin is an input to the crystal oscillator amplifier.
An externally generated clock also can feed the OSC1 pin of the crystal
oscillator circuit. Connect the external clock to the OSC1 pin and let the
OSC2 pin float.
8.4.2 Crystal Amplifier Output Pin (OSC2)
The OSC2 pin is the output of the crystal oscillator inverting amplifier.
8.4.3 Oscillator Enable Signal (SIMOSCEN)
The SIMOSCEN signal comes from the SIM and enables the oscillator.
8.4.4 External Clock Source (OSCXCLK)
OSCXCLK is the crystal oscillator output signal. It runs at the full speed
of the crystal (fXCLK) and comes directly from the crystal oscillator circuit.
Figure 8-1 shows only the logical relation of OSCXCLK to OSC1 and
OSC2 and may not represent the actual circuitry. The duty cycle of
OSCXCLK is unknown and may depend on the crystal and other
external factors. Also, the frequency and amplitude of OSCXCLK can be
unstable at start-up.
8.4.5 Oscillator Out (OSCOUT)
The clock driven to the SIM is the crystal frequency divided by two. This
signal is driven to the SIM for generation of the bus clocks used by the
CPU and other modules on the MCU. OSCOUT will be divided again in
the SIM and results in the internal bus frequency being one fourth of the
OSCXCLK frequency.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Oscillator (OSC)
113
Oscillator (OSC)
8.5 Low Power Modes
The WAIT and STOP instructions put the MCU in low-powerconsumption standby modes.
8.5.1 Wait Mode
The WAIT instruction has no effect on the oscillator logic. OSCXCLK
continues to drive to the SIM module.
8.5.2 Stop Mode
The STOP instruction disables the OSCXCLK output.
8.6 Oscillator During Break Mode
The oscillator continues drive OSCXCLK when the chip enters the break
state.
Technical Data
114
MC68HC908BD48 — Rev. 1.0
Oscillator (OSC)
MOTOROLA
Technical Data — MC68HC908BD48
Section 9. Monitor ROM (MON)
9.1 Contents
9.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
9.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
9.4
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
9.4.1
Entering Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
9.4.2
Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
9.4.3
Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
9.4.4
Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
9.4.5
Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
9.4.6
Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
9.2 Introduction
This section describes the monitor ROM. The monitor ROM allows
complete testing of the MCU through a single-wire interface with a host
computer.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Monitor ROM (MON)
115
Monitor ROM (MON)
9.3 Features
Features of the monitor ROM include:
•
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
•
9600 Baud communication with host computer
•
Execution of code in RAM or FLASH
•
FLASH memory programming
9.4 Functional Description
The monitor ROM receives and executes commands from a host
computer. Figure 9-1 shows a sample circuit used to enter monitor
mode and communicate with a host computer via a standard RS-232
interface.
Simple monitor commands can access any memory address. In monitor
mode, the MCU can execute host-computer code in RAM while all MCU
pins 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 pull-up resistor.
Technical Data
116
MC68HC908BD48 — Rev. 1.0
Monitor ROM (MON)
MOTOROLA
Monitor ROM (MON)
Functional Description
VDD
68HC908
10 kΩ
RST
0.1 µF
VTST
10 Ω
IRQ
1
10 µF
10 µF
MC145407
20
+
+
+
3
18
4
17
2
19
10 µF
OSC1
+
10 µF
VDD
X1
9.83 MHz
20 pF
10 MΩ
OSC2
20 pF
DB-25
2
5
16
3
6
15
VSS
VSS1
VDD
VDD
7
0.1 µF
VDD
1
MC74HC125
14
2
3
6
5
VDD
10 kΩ
4
7
NOTES:
VDD
VDD
10 kΩ
10 kΩ
PTC0
PTC1
A
(See
NOTES)
Position A — Bus clock = OSCXCLK ÷ 4
Position B — Bus clock = OSCXCLK ÷ 2
PTA0
PTC3
B
Figure 9-1. Monitor Mode Circuit
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Monitor ROM (MON)
117
Monitor ROM (MON)
9.4.1 Entering Monitor Mode
Table 9-1 shows the pin conditions for entering monitor mode.
NOTE:
IRQ Pin
PTC0 Pin
PTC1 Pin
PTA0 Pin
PTC3 Pin
Table 9-1. Mode Selection
Mode
VTST
1
0
1
1
Monitor
OSCXCLK
---------------------------2
OSCXCLK
---------------------------4
VTST
1
0
1
0
Monitor
OSCXCLK
OSCXCLK
---------------------------2
OSCOUT
Bus
Frequency
Holding the PTC3 pin low when entering monitor mode causes a bypass
of a divide-by-two stage at the oscillator. The OSCOUT frequency is
equal to the OSCXCLK 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.
Enter monitor mode with the pin configuration shown above by pulling
RST low and then high. The rising edge of RST latches monitor mode.
Once monitor mode is latched, the values on the specified pins can
change.
Once out of reset, the MCU monitor mode firmware then sends a break
signal (10 consecutive logic zeros) 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 different vectors for reset and SWI. 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.
When the host computer has completed downloading code into the MCU
RAM, This code can be executed by driving PTA0 low while asserting
RST low and then high. The internal monitor ROM firmware will interpret
the low on PTA0 as an indication to jump to RAM, and execution control
will then continue from RAM. Execution of an SWI from the downloaded
code will return program control to the internal monitor ROM firmware.
Technical Data
118
MC68HC908BD48 — Rev. 1.0
Monitor ROM (MON)
MOTOROLA
Monitor ROM (MON)
Functional Description
Alternatively, the host can send a RUN command, which executes an
RTI, and this can be used to send control to the address on the stack
pointer.
The COP module is disabled in monitor mode as long as VTST is applied
to the IRQ or the RST pin. (See Section 7. System Integration Module
(SIM) for more information on modes of operation.)
Table 9-2 is a summary of the differences between user mode and
monitor mode.
Table 9-2. Mode Differences
Functions
Modes
COP
Reset
Vector
High
Reset
Vector
Low
SWI
Vector
High
SWI
Vector
Low
User
Enabled
$FFFE
$FFFF
$FFFC
$FFFD
Monitor
Disabled(1)
$FEFE
$FEFF
$FEFC
$FEFD
Notes:
1. If the high voltage (VTST) is removed from the IRQ pin, the SIM asserts its COP enable
output. The COP is a mask option enabled or disabled by the COPD bit in the configuration
register.
9.4.2 Data Format
Communication with the monitor ROM is in standard non-return-to-zero
(NRZ) mark/space data format. (See Figure 9-2 and Figure 9-3.)
START
BIT
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
STOP
BIT
NEXT
START
BIT
Figure 9-2. Monitor Data Format
$A5
START
BIT
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
BREAK
START
BIT
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
STOP
BIT
NEXT
START
BIT
STOP
BIT
Figure 9-3. Sample Monitor Waveforms
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Monitor ROM (MON)
119
Monitor ROM (MON)
The data transmit and receive rate can be anywhere from 4800 baud to
28.8 kbaud. Transmit and receive baud rates must be identical.
9.4.3 Echoing
As shown in Figure 9-4, the monitor ROM immediately echoes each
received byte back to the PTA0 pin for error checking.
SENT TO
MONITOR
READ
READ
ADDR. HIGH ADDR. HIGH ADDR. LOW
ADDR. LOW
DATA
ECHO
RESULT
Figure 9-4. Read Transaction
Any result of a command appears after the echo of the last byte of the
command.
9.4.4 Break Signal
A start bit followed by nine low bits is a break signal (see Figure 9-5).
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 9-5. Break Transaction
Technical Data
120
MC68HC908BD48 — Rev. 1.0
Monitor ROM (MON)
MOTOROLA
Monitor ROM (MON)
Functional Description
9.4.5 Commands
The monitor ROM uses the following commands:
•
READ (read memory)
•
WRITE (write memory)
•
IREAD (indexed read)
•
IWRITE (indexed write)
•
READSP (read stack pointer)
•
RUN (run user program)
Table 9-3. READ (Read Memory) Command
Description
Read byte from memory
Operand
Specifies 2-byte address in high byte:low byte order
Data
Returned
Returns contents of specified address
Opcode
$4A
Command Sequence
SENT TO
MONITOR
READ
READ
ADDRESS
HIGH
ADDRESS
HIGH
ECHO
ADDRESS
LOW
DATA
RETURN
MC68HC908BD48 — Rev. 1.0
MOTOROLA
ADDRESS
LOW
Technical Data
Monitor ROM (MON)
121
Monitor ROM (MON)
Table 9-4. WRITE (Write Memory) Command
Description
Write byte to memory
Operand
Specifics 2-byte address in high byte:low byte order; low byte
followed by data byte
Data
Returned
None
Opcode
$49
Command Sequence
SENT TO
MONITOR
WRITE
WRITE
ADDRESS
HIGH
ADDRESS
HIGH
ADDRESS
LOW
ADDRESS
LOW
DATA
DATA
ECHO
Table 9-5. IREAD (Indexed Read) Command
Description
Read Next 2 Bytes in Memory from Last Address Accessed
Operand
Specifies 2-byte address in high byte:low byte order
Data
Returned
Returns contents of next two addresses
Opcode
$1A
Command Sequence
SENT TO
MONITOR
IREAD
IREAD
ECHO
Technical Data
122
DATA
DATA
RETURN
MC68HC908BD48 — Rev. 1.0
Monitor ROM (MON)
MOTOROLA
Monitor ROM (MON)
Functional Description
Table 9-6. IWRITE (Indexed Write) Command
Description
Write to last address accessed + 1
Operand
Specifies single data byte
Data
Returned
None
Opcode
$19
Command Sequence
SENT TO
MONITOR
IWRITE
IWRITE
DATA
DATA
ECHO
A sequence of IREAD or IWRITE commands can sequentially access a
block of memory over the full 64-kbyte memory map.
Table 9-7. READSP (Read Stack Pointer) Command
Description
Reads stack pointer
Operand
None
Data
Returned
Returns stack pointer in high byte:low byte order
Opcode
$0C
Command Sequence
SENT TO
MONITOR
READSP
READSP
ECHO
MC68HC908BD48 — Rev. 1.0
MOTOROLA
SP
HIGH
SP
LOW
RETURN
Technical Data
Monitor ROM (MON)
123
Monitor ROM (MON)
Table 9-8. RUN (Run User Program) Command
Description
Executes RTI instruction
Operand
None
Data
Returned
None
Opcode
$28
Command Sequence
SENT TO
MONITOR
RUN
RUN
ECHO
9.4.6 Baud Rate
The communication baud rate is controlled by crystal frequency and the
state of the PTC3 pin upon entry into monitor mode. When PTC3 is high,
the divide by ratio is 1024. If the PTC3 pin is at logic zero upon entry into
monitor mode, the divide by ratio is 512.
Table 9-9. Monitor Baud Rate Selection
Crystal Frequency
PTC3 Pin
Baud Rate
19.66 MHz
0
19200 bps
9.83 MHz
0
9600 bps
9.83 MHz
1
4800 bps
Technical Data
124
MC68HC908BD48 — Rev. 1.0
Monitor ROM (MON)
MOTOROLA
Technical Data — MC68HC908BD48
Section 10. Timer Interface Module (TIM)
10.1 Contents
10.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
10.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
10.4
Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
10.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
10.5.1 TIM Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
10.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
10.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
10.5.3.1
Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 130
10.5.3.2
Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . 131
10.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 131
10.5.4.1
Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 132
10.5.4.2
Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 133
10.5.4.3
PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
10.6
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
10.7
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
10.8
TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 136
10.9
I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
10.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
10.10.1 TIM Status and Control Register (TSC) . . . . . . . . . . . . . . . 137
10.10.2 TIM Counter Registers (TCNTH:TCNTL) . . . . . . . . . . . . . . 139
10.10.3 TIM Counter Modulo Registers (TMODH:TMODL) . . . . . . 140
10.10.4 TIM Channel Status and Control Registers (TSC0:TSC1) . 141
10.10.5 TIM Channel Registers (TCH0H/L:TCH1H/L) . . . . . . . . . . 145
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Timer Interface Module (TIM)
125
Timer Interface Module (TIM)
10.2 Introduction
This section describes the timer interface module (TIM2, Version B). The
TIM is a two-channel timer that provides a timing reference with input
capture, output compare, and pulse-width-modulation functions. Figure
10-1 is a block diagram of the TIM.
10.3 Features
Features of the TIM include the following:
NOTE:
•
Two 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 TIM Clock Input
– Seven-Frequency Internal Bus Clock Prescaler Selection
•
Free-Running or Modulo Up-Count Operation
•
Toggle Any Channel Pin on Overflow
•
TIM Counter Stop and Reset Bits
•
Modular Architecture Expandable to Eight Channels
TCH1 (timer channel 1) is not bonded to an external pin on this MCU.
Therefore, any references to the timer TCH1 pin in the following text
should be interpreted as not available — but the internal status and
control registers are still available.
10.4 Pin Name Conventions
The TIM share one I/O pin with one port E I/O pin. The full name of the
TIM I/O pin is listed in Table 10-1. The generic pin name appear in the
text that follows.
Table 10-1. Pin Name Conventions
TIM Generic Pin Names:
TCH0
TCH1
Full TIM Pin Names:
PTE0/SOG/TCH0
Not Available
Technical Data
126
MC68HC908BD48 — Rev. 1.0
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Functional Description
10.5 Functional Description
Figure 10-1 shows the structure of the TIM. The central component of
the TIM is the 16-bit TIM counter that can operate as a free-running
counter or a modulo up-counter. The TIM counter provides the timing
reference for the input capture and output compare functions. The TIM
counter modulo registers, TMODH:TMODL, control the modulo value of
the TIM counter. Software can read the TIM counter value at any time
without affecting the counting sequence.
The two TIM channels are programmable independently as input
capture or output compare channels.
PRESCALER SELECT
INTERNAL
BUS CLOCK
PRESCALER
TSTOP
PS2
TRST
PS1
PS0
16-BIT COUNTER
TOF
TOIE
INTERRUPT
LOGIC
16-BIT COMPARATOR
TMODH:TMODL
TOV0
CHANNEL 0
ELS0B
ELS0A
CH0MAX
16-BIT COMPARATOR
TCH0H:TCH0L
PORT
LOGIC
TCH0
CH0F
INTERRUPT
LOGIC
16-BIT LATCH
CH0IE
MS0A
MS0B
INTERNAL BUS
TOV1
CHANNEL 1
ELS1B
ELS1A
CH1MAX
PORT
LOGIC
16-BIT COMPARATOR
TCH1
(Not available)
TCH1H:TCH1L
CH1F
INTERRUPT
LOGIC
16-BIT LATCH
MS1A
CH1IE
Figure 10-1. TIM Block Diagram
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Timer Interface Module (TIM)
Table 10-2. TIM I/O Register Summary
Addr.
$000A
$000C
$000D
Register Name
TIM Status and Control
Register
(TSC)
TIM Counter Register High
(TCNTH)
TIM Counter Register Low
(TCNTL)
Bit 7
Read:
$000E
TIM Counter Modulo
Register Low
(TMODL)
$000F
$0010
TIM Channel 0
Status/Control Register
(TSC0)
TIM Channel 0
Register High
(TCH0H)
$0011
TIM Channel 0
Register Low
(TCH0L)
$0012
$0013
TIM Channel 1
Status/Control Register
(TSC1)
5
TOIE
TSTOP
TOF
3
0
0
2
1
Bit 0
PS2
PS1
PS0
0
TRST
Reset:
0
0
1
0
0
0
0
0
Read:
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Reset:
0
0
0
0
0
0
0
0
Read:
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
0
0
0
0
0
0
0
0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
1
1
1
1
1
1
1
1
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
Reset:
1
1
1
1
1
1
1
1
Read:
CH0F
CH0IE
MS0B
MS0A
ELS0B
ELS0A
TOV0
CH0MAX
Write:
0
Reset:
0
0
0
0
0
0
0
0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Bit2
Bit1
Bit0
Write:
Write:
Read:
Write:
Reset:
Read:
Write:
Read:
Write:
Reset:
Indeterminate after reset
Read:
Bit7
Bit6
Bit5
Bit4
Bit3
Write:
Reset:
Read:
Indeterminate after reset
CH1F
0
CH1IE
Write:
0
Reset:
0
0
MS1A
ELS1B
ELS1A
TOV1
CH1MAX
0
0
0
0
0
0
Technical Data
128
4
Write:
Reset:
TIM Counter Modulo
Register High
(TMODH)
6
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Timer Interface Module (TIM)
Functional Description
$0014
$0015
TIM Channel 1
Register High
(TCH1H)
TIM Channel 1
Register Low
(TCH1L)
Read:
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Bit2
Bit1
Bit0
Write:
Reset:
Indeterminate after reset
Read:
Bit7
Bit6
Bit5
Bit4
Bit3
Write:
Reset:
Indeterminate after reset
= Unimplemented
10.5.1 TIM Counter Prescaler
The TIM 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, PS[2:0], in the TIM status and control register
(TSC) select the TIM clock source.
10.5.2 Input Capture
With the input capture function, the TIM can capture the time at which an
external event occurs. When an active edge occurs on the pin of an input
capture channel, the TIM latches the contents of the TIM counter into the
TIM channel registers, TCHxH:TCHxL. The polarity of the active edge is
programmable. Input captures can generate TIM CPU interrupt
requests.
10.5.3 Output Compare
With the output compare function, the TIM 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 TIM can set, clear, or toggle the channel pin. Output compares can
generate TIM CPU interrupt requests.
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Timer Interface Module (TIM)
10.5.3.1 Unbuffered Output Compare
Any output compare channel can generate unbuffered output compare
pulses as described in 10.5.3 Output Compare. The pulses are
unbuffered because changing the output compare value requires writing
the new value over the old value currently in the TIM channel registers.
An unsynchronized write to the TIM 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 TIM overflow interrupt routine to write a new, smaller output
compare value may cause the compare to be missed. The TIM 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 TIM overflow interrupts and write the new value in the
TIM overflow interrupt routine. The TIM 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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Timer Interface Module (TIM)
Functional Description
10.5.3.2 Buffered Output Compare
Channels 0 and 1 can be linked to form a buffered output compare
channel whose output appears on the TCH0 pin. The TIM channel
registers of the linked pair alternately control the output.
Setting the MS0B bit in TIM channel 0 status and control register (TSC0)
links channel 0 and channel 1. The output compare value in the TIM
channel 0 registers initially controls the output on the TCH0 pin. Writing
to the TIM channel 1 registers enables the TIM channel 1 registers to
synchronously control the output after the TIM overflows. At each
subsequent overflow, the TIM channel registers (0 or 1) that control the
output are the ones written to last. TSC0 controls and monitors the
buffered output compare function, and TIM channel 1 status and control
register (TSC1) is unused. While the MS0B bit is set, the channel 1 pin,
TCH1, is available as a general-purpose I/O pin.
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.
10.5.4 Pulse Width Modulation (PWM)
By using the toggle-on-overflow feature with an output compare channel,
the TIM can generate a PWM signal. The value in the TIM counter
modulo registers determines the period of the PWM signal. The channel
pin toggles when the counter reaches the value in the TIM counter
modulo registers. The time between overflows is the period of the PWM
signal.
As Figure 10-2 shows, the output compare value in the TIM channel
registers determines the pulse width of the PWM signal. The time
between overflow and output compare is the pulse width. Program the
TIM to clear the channel pin on output compare if the state of the PWM
pulse is logic one. Program the TIM to set the pin if the state of the PWM
pulse is logic zero.
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Timer Interface Module (TIM)
OVERFLOW
OVERFLOW
OVERFLOW
PERIOD
PULSE
WIDTH
PTDx/TCHx
OUTPUT
COMPARE
OUTPUT
COMPARE
OUTPUT
COMPARE
Figure 10-2. PWM Period and Pulse Width
The value in the TIM 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 TIM counter modulo registers produces a PWM
period of 256 times the internal bus clock period if the prescaler select
value is 000 (see 10.10.1 TIM Status and Control Register (TSC)).
The value in the TIM 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 TIM channel registers produces
a duty cycle of 128/256 or 50%.
10.5.4.1 Unbuffered PWM Signal Generation
Any output compare channel can generate unbuffered PWM pulses as
described in 10.5.4 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 TIM channel
registers.
An unsynchronized write to the TIM 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 TIM overflow interrupt routine to
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Timer Interface Module (TIM)
Functional Description
write a new, smaller pulse width value may cause the compare to be
missed. The TIM 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:
NOTE:
•
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 TIM
overflow interrupts and write the new value in the TIM overflow
interrupt routine. The TIM 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.
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.
10.5.4.2 Buffered PWM Signal Generation
Channels 0 and 1 can be linked to form a buffered PWM channel whose
output appears on the TCH0 pin. The TIM channel registers of the linked
pair alternately control the pulse width of the output.
Setting the MS0B bit in TIM channel 0 status and control register (TSC0)
links channel 0 and channel 1. The TIM channel 0 registers initially
control the pulse width on the TCH0 pin. Writing to the TIM channel 1
registers enables the TIM channel 1 registers to synchronously control
the pulse width at the beginning of the next PWM period. At each
subsequent overflow, the TIM channel registers (0 or 1) that control the
pulse width are the ones written to last. TSC0 controls and monitors the
buffered PWM function, and TIM channel 1 status and control register
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Timer Interface Module (TIM)
(TSC1) is unused. While the MS0B bit is set, the channel 1 pin, TCH1,
is available as a general-purpose I/O pin.
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.
10.5.4.3 PWM Initialization
To ensure correct operation when generating unbuffered or buffered
PWM signals, use the following initialization procedure:
1. In the TIM status and control register (TSC):
a. Stop the TIM counter by setting the TIM stop bit, TSTOP.
b. Reset the TIM counter by setting the TIM reset bit, TRST.
2. In the TIM counter modulo registers (TMODH:TMODL), write the
value for the required PWM period.
3. In the TIM channel x registers (TCHxH:TCHxL), write the value for
the required pulse width.
4. In TIM channel x status and control register (TSCx):
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 10-4.)
b. Write 1 to the toggle-on-overflow bit, TOVx.
c.
NOTE:
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 10-4.)
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 TIM status control register (TSC), clear the TIM stop bit,
TSTOP.
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Timer Interface Module (TIM)
Interrupts
Setting MS0B links channels 0 and 1 and configures them for buffered
PWM operation. The TIM channel 0 registers (TCH0H:TCH0L) initially
control the buffered PWM output. TIM status control register 0 (TSCR0)
controls and monitors the PWM signal from the linked channels. MS0B
takes priority over MS0A.
Clearing the toggle-on-overflow bit, TOVx, inhibits output toggles on TIM
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.
Setting the channel x maximum duty cycle bit (CHxMAX) and clearing
the TOVx bit generates a 100% duty cycle output. See 10.10.4 TIM
Channel Status and Control Registers (TSC0:TSC1).
10.6 Interrupts
The following TIM sources can generate interrupt requests:
•
TIM overflow flag (TOF) — The TOF bit is set when the TIM
counter value rolls over to $0000 after matching the value in the
TIM counter modulo registers. The TIM overflow interrupt enable
bit, TOIE, enables TIM overflow CPU interrupt requests. TOF and
TOIE are in the TIM status and control register.
•
TIM channel flags (CH1F: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 TIM
channel x status and control register.
10.7 Wait Mode
The WAIT instruction puts the MCU in low-power-consumption standby
mode.
The TIM remains active after the execution of a WAIT instruction. In wait
mode the TIM registers are not accessible by the CPU. Any enabled
CPU interrupt request from the TIM can bring the MCU out of wait mode.
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Timer Interface Module (TIM)
If TIM functions are not required during wait mode, reduce power
consumption by stopping the TIM before executing the WAIT instruction.
10.8 TIM During Break Interrupts
A break interrupt stops the TIM 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 break flag control register (BFCR) enables software to clear status
bits during the break state. (See 8.8.3 Break Flag Control Register
(BFCR).)
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.
10.9 I/O Signals
Port E shares one of its pins with the TIM. The TIM channel I/O pin is
PTE0/SOG/TCH0.
TCH0 pin is programmable independently as an input capture pin or an
output compare pin. It also can be configured as a buffered output
compare or buffered PWM pin.
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Timer Interface Module (TIM)
I/O Registers
10.10 I/O Registers
The following I/O registers control and monitor operation of the TIM:
•
TIM status and control register (TSC)
•
TIM control registers (TCNTH:TCNTL)
•
TIM counter modulo registers (TMODH:TMODL)
•
TIM channel status and control registers (TSC0 and TSC1)
•
TIM channel registers (TCH0H:TCH0L and TCH1H:TCH1L)
10.10.1 TIM Status and Control Register (TSC)
The TIM status and control register does the following:
•
Enables TIM overflow interrupts
•
Flags TIM overflows
•
Stops the TIM counter
•
Resets the TIM counter
•
Prescales the TIM counter clock
Address:
$000A
Bit 7
Read:
6
5
TOIE
TSTOP
TOF
Write:
0
Reset:
0
4
3
0
0
2
1
Bit 0
PS2
PS1
PS0
0
0
0
TRST
0
1
0
0
= Unimplemented
Figure 10-3. TIM Status and Control Register (TSC)
TOF — TIM Overflow Flag Bit
This read/write flag is set when the TIM counter resets to $0000 after
reaching the modulo value programmed in the TIM counter modulo
registers. Clear TOF by reading the TIM status and control register
when TOF is set and then writing a logic zero to TOF. If another TIM
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Timer Interface Module (TIM)
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 = TIM counter has reached modulo value
0 = TIM counter has not reached modulo value
TOIE — TIM Overflow Interrupt Enable Bit
This read/write bit enables TIM overflow interrupts when the TOF bit
becomes set. Reset clears the TOIE bit.
1 = TIM overflow interrupts enabled
0 = TIM overflow interrupts disabled
TSTOP — TIM Stop Bit
This read/write bit stops the TIM counter. Counting resumes when
TSTOP is cleared. Reset sets the TSTOP bit, stopping the TIM
counter until software clears the TSTOP bit.
1 = TIM counter stopped
0 = TIM counter active
NOTE:
Do not set the TSTOP bit before entering wait mode if the TIM is required
to exit wait mode.
TRST — TIM Reset Bit
Setting this write-only bit resets the TIM counter and the TIM
prescaler. Setting TRST has no effect on any other registers.
Counting resumes from $0000. TRST is cleared automatically after
the TIM counter is reset and always reads as logic zero. Reset clears
the TRST bit.
1 = Prescaler and TIM counter cleared
0 = No effect
NOTE:
Setting the TSTOP and TRST bits simultaneously stops the TIM counter
at a value of $0000.
PS[2:0] — Prescaler Select Bits
These read/write bits select either the TCLK pin or one of the seven
prescaler outputs as the input to the TIM counter as Table 10-3
shows. Reset clears the PS[2:0] bits.
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I/O Registers
Table 10-3. Prescaler Selection
PS2
PS1
PS0
TIM Clock Source
0
0
0
Internal Bus Clock ÷ 1
0
0
1
Internal Bus Clock ÷ 2
0
1
0
Internal Bus Clock ÷ 4
0
1
1
Internal Bus Clock ÷ 8
1
0
0
Internal Bus Clock ÷ 16
1
0
1
Internal Bus Clock ÷ 32
1
1
0
Internal Bus Clock ÷ 64
1
1
1
Not available
10.10.2 TIM Counter Registers (TCNTH:TCNTL)
The two read-only TIM counter registers contain the high and low bytes
of the value in the TIM counter. Reading the high byte (TCNTH) latches
the contents of the low byte (TCNTL) into a buffer. Subsequent reads of
TCNTH do not affect the latched TCNTL value until TCNTL is read.
Reset clears the TIM counter registers. Setting the TIM reset bit (TRST)
also clears the TIM counter registers.
NOTE:
If you read TCNTH during a break interrupt, be sure to unlatch TCNTL
by reading TCNTL before exiting the break interrupt. Otherwise, TCNTL
retains the value latched during the break.
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Timer Interface Module (TIM)
Address:
Read:
$000C
TCNTH
Bit 7
6
5
4
3
2
1
Bit 0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
0
0
0
0
0
0
0
0
$000D
TCNTL
Bit 7
6
5
4
3
2
1
Bit 0
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
0
0
0
0
0
0
0
0
Write:
Reset:
Address:
Read:
Write:
Reset:
= Unimplemented
Figure 10-4. TIM Counter Registers (TCNTH:TCNTL)
10.10.3 TIM Counter Modulo Registers (TMODH:TMODL)
The read/write TIM modulo registers contain the modulo value for the
TIM counter. When the TIM counter reaches the modulo value, the
overflow flag (TOF) becomes set, and the TIM counter resumes counting
from $0000 at the next clock. Writing to the high byte (TMODH) inhibits
the TOF bit and overflow interrupts until the low byte (TMODL) is written.
Reset sets the TIM counter modulo registers.
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I/O Registers
Address:
$000E
TMODH
Bit 7
6
5
4
3
2
1
Bit 0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
1
1
1
1
1
1
1
1
$000F
TMODL
Bit 7
6
5
4
3
2
1
Bit 0
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
1
1
1
1
1
1
1
1
Read:
Write:
Reset:
Address:
Read:
Write:
Reset:
Figure 10-5. TIM Counter Modulo Registers (TMODH:TMODL)
NOTE:
Reset the TIM counter before writing to the TIM counter modulo registers.
10.10.4 TIM Channel Status and Control Registers (TSC0:TSC1)
Each of the TIM 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 TIM overflow
•
Selects 100% PWM duty cycle
•
Selects buffered or unbuffered output compare/PWM operation
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Timer Interface Module (TIM)
Address:
$0010
TSC0
Bit 7
6
5
4
3
2
1
Bit 0
CH0IE
MS0B
MS0A
ELS0B
ELS0A
TOV0
CH0MAX
0
0
0
0
0
0
5
4
3
2
1
Bit 0
MS1A
ELS1B
ELS1A
TOV1
CH1MAX
0
0
0
0
0
Read:
CH0F
Write:
0
Reset:
0
0
$0013
TSC1
Bit 7
6
Address:
Read:
CH1F
0
CH1IE
Write:
0
Reset:
0
0
0
= Unimplemented
Figure 10-6. TIM Channel Status and Control Registers (TSC0:TSC1)
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 TIM
counter registers matches the value in the TIM channel x registers.
When TIM CPU interrupt requests are enabled (CHxIE=1), clear
CHxF by reading the TIM 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 TIM CPU interrupt service requests 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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I/O Registers
MSxB — Mode Select Bit B
This read/write bit selects buffered output compare/PWM operation.
MSxB exists only in the TIM channel 0 status and control register.
Setting MS0B disables the channel 1 status and control register and
reverts TCH1 to general-purpose I/O.
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 10-4.
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 TCHx pin. (See Table 10-4.). 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 TIM status and control register
(TSC).
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 an I/O port , and pin TCHx is available as a general-purpose port
I/O pin. Table 10-4 shows how ELSxB and ELSxA work. Reset clears
the ELSxB and ELSxA bits.
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Timer Interface Module (TIM)
143
Timer Interface Module (TIM)
Table 10-4. Mode, Edge, and Level Selection
MSxB
MSxA
ELSxB
ELSxA
X
0
0
0
Mode
Output
Preset
NOTE:
X
1
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
1
0
1
1
0
0
1
1
1
1
X
0
1
1
X
1
0
1
X
1
1
Configuration
Pin under Port Control;
Initial Output Level High
Pin under Port Control;
Initial Output Level Low
Capture on Rising Edge Only
Input
Capture
Capture on Falling Edge Only
Capture on Rising or Falling Edge
Output
Compare
or PWM
Toggle Output on Compare
Clear Output on Compare
Set Output on Compare
Toggle Output on Compare
Buffered
Output
Clear Output on Compare
Compare or
Buffered
Set Output on Compare
PWM
Before enabling a TIM channel register for input capture operation, make
sure that the PTDx/TCHx 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 TIM 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 TIM counter overflow.
0 = Channel x pin does not toggle on TIM counter overflow.
NOTE:
When TOVx is set, a TIM 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 10-7 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.
Technical Data
144
MC68HC908BD48 — Rev. 1.0
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
I/O Registers
OVERFLOW
OVERFLOW
OVERFLOW
OVERFLOW
OVERFLOW
PERIOD
PTDx/TCHx
OUTPUT
COMPARE
OUTPUT
COMPARE
OUTPUT
COMPARE
OUTPUT
COMPARE
CHxMAX
Figure 10-7. CHxMAX Latency
10.10.5 TIM Channel Registers (TCH0H/L:TCH1H/L)
These read/write registers contain the captured TIM counter value of the
input capture function or the output compare value of the output
compare function. The state of the TIM channel registers after reset is
unknown.
In input capture mode (MSxB:MSxA = 0:0), reading the high byte of the
TIM channel x registers (TCHxH) inhibits input captures until the low
byte (TCHxL) is read.
In output compare mode (MSxB:MSxA ≠ 0:0), writing to the high byte of
the TIM channel x registers (TCHxH) inhibits output compares until the
low byte (TCHxL) is written.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Timer Interface Module (TIM)
145
Timer Interface Module (TIM)
Address:
$0011
TCH0H
Bit 7
6
5
4
3
2
1
Bit 0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Read:
Write:
Reset:
Address:
Indeterminate after reset
$0012
TCH0L
Bit 7
6
5
4
3
2
1
Bit 0
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
Read:
Write:
Reset:
Address:
Indeterminate after reset
$0014
TCH1H
Bit 7
6
5
4
3
2
1
Bit 0
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Read:
Write:
Reset:
Address:
Indeterminate after reset
$0015
TCH1L
Bit 7
6
5
4
3
2
1
Bit 0
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
Read:
Write:
Reset:
Indeterminate after reset
Figure 10-8. TIM Channel Registers (TCH0H/L:TCH1H/L)
Technical Data
146
MC68HC908BD48 — Rev. 1.0
Timer Interface Module (TIM)
MOTOROLA
Technical Data — MC68HC908BD48
Section 11. Pulse Width Modulator (PWM)
11.1 Contents
11.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
11.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
11.4 PWM Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
11.4.1 PWM Data Registers 0 to 15 (0PWM–15PWM). . . . . . . . . 150
11.4.2 PWM Control Registers 1 and 2 (PWMCR1:PWMCR2) . . 151
11.2 Introduction
Sixteen 8-bits PWM channels are available on the MC68HC908BD48.
Channels 0 to 7 are shared with port-B I/O pins under the control of the
PWM control register 1. Channels 8 to 15 are shared with port-A I/O pins
under the control of the PWM control register 2.
11.3 Functional Description
Each 8-bit PWM channel is composed of an 8-bit register which contains
a 5-bit PWM in MSB portion and a 3-bit binary rate multiplier (BRM) in
LSB portion. There are 16 PWM data registers as shown in Table 11-1.
The value programmed in the 5-bit PWM portion will determine the pulse
length of the output. The clock to the 5-bit PWM portion is the system
clock, the repetition rate of the output is hence 187.5KHz at 6MHz clock.
The 3-bit BRM will generate a number of narrow pulses which are
equally distributed among an 8-PWM-cycle frame. The number of pulses
generated is equal to the number programmed in the 3-bit BRM portion.
Examples of the waveforms are shown in Figure 11-3.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Pulse Width Modulator (PWM)
147
Pulse Width Modulator (PWM)
Combining the 5-bit PWM together with the 3-bit BRM, the average duty
cycle at the output will be (M+N/8)/32, where M is the content of the 5-bit
PWM portion, and N is the content of the 3-bit BRM portion. Using this
mechanism, a true 8-bit resolution PWM type DAC with reasonably high
repetition rate can be obtained.
The value of each PWM Data Register is continuously compared with
the content of an internal counter to determine the state of each PWM
channel output pin. Double buffering is not used in this PWM design.
Table 11-1. PWM I/O Register Summary
Addr.
$0020
$0021
$0022
$0023
$0024
$0025
$0026
$0027
Register Name
PWM0 Data Register
(0PWM)
Read:
PWM1 Data Register
(1PWM)
Read:
PWM2 Data Register
(2PWM)
Read:
PWM3 Data Register
(3PWM)
Read:
PWM4 Data Register
(4PWM)
Read:
PWM5 Data Register
(5PWM)
Read:
PWM6 Data Register
(6PWM)
Read:
PWM7 Data Register
(7PWM)
Read:
PWM Control
Register 1
(PWMCR1)
Read:
$0028
Bit 7
6
5
4
3
2
1
Bit 0
0PWM4
0PWM3
0PWM2
0PWM1
0PWM0
0BRM2
0BRM1
0BRM0
1PWM4
1PWM3
1PWM2
1PWM1
1PWM0
1BRM2
1BRM1
1BRM0
2PWM4
2PWM3
2PWM2
2PWM1
2PWM0
2BRM2
2BRM1
2BRM0
3PWM4
3PWM3
3PWM2
3PWM1
3PWM0
3BRM2
3BRM1
3BRM0
4PWM4
4PWM3
4PWM2
4PWM1
4PWM0
4BRM2
4BRM1
4BRM0
5PWM4
5PWM3
5PWM2
5PWM1
5PWM0
5BRM2
5BRM1
5BRM0
6PWM4
6PWM3
6PWM2
6PWM1
6PWM0
6BRM2
6BRM1
6BRM0
7PWM4
7PWM3
7PWM2
7PWM1
7PWM0
7BRM2
7BRM1
7BRM0
PWM7E
PWM6E
PWM5E
PWM4E
PWM3E
PWM2E
PWM1E
PWM0E
0
0
0
0
0
0
0
0
Write:
Write:
Write:
Write:
Write:
Write:
Write:
Write:
Write:
Reset:
Technical Data
148
MC68HC908BD48 — Rev. 1.0
Pulse Width Modulator (PWM)
MOTOROLA
Pulse Width Modulator (PWM)
PWM Registers
Table 11-1. PWM I/O Register Summary
$0051
$0052
$0053
$0054
$0055
$0056
$0057
$0058
PWM8 Data Register
(8PWM)
Read:
PWM9 Data Register
(9PWM)
Read:
PWM10 Data Register
(10PWM)
Read:
PWM11 Data Register
(11PWM)
Read:
PWM12 Data Register
(12PWM)
Read:
PWM13 Data Register
(13PWM)
Read:
PWM14 Data Register
(14PWM)
Read:
PWM15 Data Register
(15PWM)
Read:
PWM Control
Register 2
(PWMCR2)
Read:
$0059
8PWM4
8PWM3
8PWM2
8PWM1
8PWM0
8BRM2
8BRM1
8BRM0
9PWM4
9PWM3
9PWM2
9PWM1
9PWM0
9BRM2
9BRM1
9BRM0
10PWM4 10PWM3 10PWM2 10PWM1 10PWM0
10BRM2
10BRM1
10BRM0
11PWM4 11PWM3 11PWM2 11PWM1 11PWM0
11BRM2
11BRM1
11BRM0
12PWM4 12PWM3 12PWM2 12PWM1 12PWM0
12BRM2
12BRM1
12BRM0
13PWM4 13PWM3 13PWM2 13PWM1 13PWM0
13BRM2
13BRM1
13BRM0
14PWM4
14PWM2 14PWM1 14PWM0
14BRM2
14BRM1
14BRM0
15PWM4 15PWM3 15PWM2 15PWM1 15PWM0
15BRM2
15BRM1
15BRM0
PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E
PWM9E
PWM8E
0
0
Write:
Write:
Write:
Write:
Write:
Write:
PWM3
Write:
Write:
Write:
Reset:
0
0
0
0
0
0
11.4 PWM Registers
The PWM module uses of 18 registers for data and control functions.
•
16 PWM data registers ($0020–$0027 and $0051–$0058)
•
2 PWM control registers ($0028 and $0059)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Pulse Width Modulator (PWM)
149
Pulse Width Modulator (PWM)
11.4.1 PWM Data Registers 0 to 15 (0PWM–15PWM)
Address:
$0020–$0027 and $0051–$0058
Bit 7
6
5
4
3
2
1
Bit 0
xPWM4
xPWM3
xPWM2
xPWM1
xPWM0
xBRM2
xBRM1
xBRM0
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 11-1. PWM Data Registers 0 to 15 (0PWM–15PWM)
The output waveform of the 16 PWM channels are each configured by
an 8-bit register, which contains a 5-bit PWM in MSB portion and a 3-bit
binary rate multiplier (BRM) in LSB portion
xPWM4–xPWM0 — PWM Bits
The value programmed in the 5-bit PWM portion will determine the pulse
length of the output. The clock to the 5-bit PWM portion is the system
clock (CPU clock), the repetition rate of the output is hence fOP ÷ 32.
Examples of PWM output waveforms are shown in Figure 11-3.
xBRM2–xBRM0 — Binary Rate Multiplier Bits
The 3-bit BRM will generate a number of narrow pulses which are
equally distributed among an 8-PWM-cycle frame. The number of pulses
generated is equal to the number programmed in the 3-bit BRM portion.
Examples of PWM output waveforms are shown in Figure 11-3.
Technical Data
150
MC68HC908BD48 — Rev. 1.0
Pulse Width Modulator (PWM)
MOTOROLA
Pulse Width Modulator (PWM)
PWM Registers
11.4.2 PWM Control Registers 1 and 2 (PWMCR1:PWMCR2)
$0028
$0059
PWM Control
Register 1
(PWMCR1)
Read:
PWM Control
Register 2
(PWMCR2)
Read:
PWM7E
PWM6E
PWM5E
PWM4E
PWM3E
PWM2E
PWM1E
PWM0E
PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E
PWM9E
PWM8E
0
0
Write:
Write:
Reset:
0
0
0
0
0
0
Figure 11-2. PWM Control Register 1 and 2 (PWMCR1:PWMCR2)
PWM15E–PWM0E — PWM Output Enable
Setting a bit to 1 will enable the corresponding PWM channel to use
as PWM output. A zero configures the corresponding PWM pin as a
standard I/O port pin. Reset clears these bits.
1 = Port pin configured as PWM output
0 = Port pin configured as standard I/O port pin.
Table 11-2. PWM Channels and Port I/O pins
Port Pin
PWM
Channel
Control
Bit
Port Pin
PWM
Channel
Control
Bit
PTB0
PWM0
PWM0E
PTA0
PWM8
PWM8E
PTB1
PWM1
PWM1E
PTA1
PWM9
PWM9E
PTB2
PWM2
PWM2E
PTA2
PWM10
PWM10E
PTB3
PWM3
PWM3E
PTA3
PWM11
PWM11E
PTB4
PWM4
PWM4E
PTA4
PWM12
PWM12E
PTB5
PWM5
PWM5E
PTA5
PWM13
PWM13E
PTB6
PWM6
PWM6E
PTA6
PWM14
PWM14E
PTB7
PWM7
PWM7E
PTA7
PWM15
PWM15E
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Pulse Width Modulator (PWM)
151
Pulse Width Modulator (PWM)
1 PWM cycle = 32T
M=$00
T
M=$01
31T
16T
M=$0F
16T
31T
M=$1F
Pulse inserted at end of PWM cycle
depends on setting of N.
T
T=1 CPU clock period (0.167µs if CPU clock=6MHz)
M = value set in 5-bit PWM (bit3-bit7)
N = value set in 3-bit BRM (bit0-bit2)
N
xx1
x1x
1xx
PWM cycles where pulses are Number of inserted pulses
inserted in a 8-cycle frame
in a 8-cycle frame
4
1
2, 6
2
1, 3, 5, 7
4
Figure 11-3. 8-Bit PWM Output Waveforms
Technical Data
152
MC68HC908BD48 — Rev. 1.0
Pulse Width Modulator (PWM)
MOTOROLA
Technical Data — MC68HC908BD48
Section 12. Analog-to-Digital Converter (ADC)
12.1 Contents
12.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
12.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
12.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
12.4.1 ADC Port I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
12.4.2 Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
12.4.3 Conversion Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
12.4.4 Continuous Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
12.4.5 Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.5
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.7 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.7.1 ADC Voltage In (ADCVIN) . . . . . . . . . . . . . . . . . . . . . . . . . 158
12.8 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
12.8.1 ADC Status and Control Register. . . . . . . . . . . . . . . . . . . . 158
12.8.2 ADC Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
12.8.3 ADC Input Clock Register . . . . . . . . . . . . . . . . . . . . . . . . . 161
12.2 Introduction
This section describes the analog-to-digital converter (ADC). The ADC
is an 8-bit 6-channels analog-to-digital converter.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Analog-to-Digital Converter (ADC)
153
Analog-to-Digital Converter (ADC)
12.3 Features
Features of the ADC module include:
•
6 Channels ADC with Multiplexed Input
•
Linear Successive Approximation
•
8-Bit Resolution
•
Single or Continuous Conversion
•
Conversion Complete Flag or Conversion Complete Interrupt
•
Selectable ADC Clock
Table 12-1. ADC Register Summary
Addr.
Register Name
$005D ADC Status and Control
Register
(ADSCR)
$005E
ADC Data Register
(ADR)
Bit 7
Read:
6
5
4
3
2
1
Bit 0
AIEN
ADCO
ADCH4
ADCH3
ADCH2
ADCH1
ADCH0
COCO
Write:
Reset:
0
0
0
1
1
1
1
1
Read:
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
Write:
Reset:
$005F
ADC Input Clock
Register
(ADICLK)
Indeterminate after Reset
Read:
ADIV2
ADIV1
ADIV0
0
0
0
0
0
0
0
0
0
0
0
0
0
Write:
Reset:
= Unimplemented
12.4 Functional Description
Four ADC channels are available for sampling external sources at pins
PTC5–PTC0. An analog multiplexer allows the single ADC converter to
select one of the 6 ADC channels as ADC voltage input (ADCVIN).
ADCVIN is converted by the successive approximation register-based
counters. The ADC resolution is 8 bits. When the conversion is
completed, ADC puts the result in the ADC data register and sets a flag
or generates an interrupt. Figure 12-1 shows a block diagram of the
ADC.
Technical Data
154
MC68HC908BD48 — Rev. 1.0
Analog-to-Digital Converter (ADC)
MOTOROLA
Analog-to-Digital Converter (ADC)
Functional Description
INTERNAL
DATA BUS
READ DDRC
DISABLE
WRITE DDRC
DDRCx
RESET
WRITE PTC
PTCx/ADCx
PTCx
READ PTC
DISABLE
ADC CHANNEL x
ADC DATA REGISTER
INTERRUPT
LOGIC
AIEN
CONVERSION
COMPLETE
ADC
ADC VOLTAGE IN
ADCVIN
CHANNEL
SELECT
(1 OF 6 CHANNELS)
ADCH[4:0]
ADC CLOCK
COCO
CLOCK
GENERATOR
BUS CLOCK
ADIV[2:0]
ADICLK
Figure 12-1. ADC Block Diagram
12.4.1 ADC Port I/O Pins
PTC5–PTC0 are general-purpose I/O pins that are shared with the ADC
channels. The channel select bits (ADC status control register, $005D),
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
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Analog-to-Digital Converter (ADC)
155
Analog-to-Digital Converter (ADC)
or DDR will not have any affect on the port pin that is selected by the
ADC. Read of a port pin which is in use by the ADC will return an
unknown state if the corresponding DDR bit is at logic 0. If the DDR bit
is at logic 1, the value in the port data latch is read.
12.4.2 Voltage Conversion
2
3
When the input voltage to the ADC equals ------- VDD, the ADC converts the
signal to $FF (full scale). If the input voltage equals VSS, the ADC
2
3
converts it to $00. Input voltage between ------- VDD and VSS are a
straight-line linear conversion. All other input voltages will result in $FF
2
3
if greater than ------- VDD and $00 if less than VSS.
NOTE:
Input voltage should not exceed the analog supply voltages.
12.4.3 Conversion Time
Twelve ADC internal clocks are required to perform one conversion. The
ADC starts a conversion on the first rising edge of the ADC internal clock
immediately following a write to the ADSCR. If the ADC internal clock is
selected to run at 1MHz, then one conversion will take 12µs to complete.
With a 1MHz ADC internal clock the maximum sample rate is 83.3kHz.
Conversion Time =
12 ADC Clock Cycles
ADC Clock Frequency
Number of Bus Cycles = Conversion Time × Bus Frequency
12.4.4 Continuous Conversion
In the continuous conversion mode, the ADC continuously converts the
selected channel filling the ADC data register 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 (ADC status control register,
$005D) is set after each conversion and can be cleared by writing the
ADC status and control register or reading of the ADC data register.
Technical Data
156
MC68HC908BD48 — Rev. 1.0
Analog-to-Digital Converter (ADC)
MOTOROLA
Analog-to-Digital Converter (ADC)
Interrupts
12.4.5 Accuracy and Precision
The conversion process is monotonic and has no missing codes.
12.5 Interrupts
When the AIEN bit is set, the ADC module is capable of generating a
CPU interrupt 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.
12.6 Low-Power Modes
The following subsections describe the low-power modes.
12.6.1 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 the ADCH[4:0] bits in the ADC status
and control register to logic 1’s before executing the WAIT instruction.
12.6.2 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. Allow one conversion cycle to stabilize the analog
circuitry before attempting a new ADC conversion after exiting stop
mode.
12.7 I/O Signals
The ADC module has 6 channels that are shared with I/O port C.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Analog-to-Digital Converter (ADC)
157
Analog-to-Digital Converter (ADC)
12.7.1 ADC Voltage In (ADCVIN)
ADCVIN is the input voltage signal from one of the 6 ADC channels to
the ADC module.
12.8 I/O Registers
Three I/O registers control and monitor ADC operation:
•
ADC status and control register (ADSCR, $005D)
•
ADC data register (ADR, $005E)
•
ADC clock register (ADICLK, $005F)
12.8.1 ADC Status and Control Register
The following paragraphs describe the function of the ADC status and
control register.
Address:
$005D
Bit 7
Read:
6
5
4
3
2
1
Bit 0
AIEN
ADCO
ADCH4
ADCH3
ADCH2
ADCH1
ADCH0
0
0
1
1
1
1
1
COCO
Write:
Reset:
0
= Unimplemented
Figure 12-2. ADC Status and Control Register (ADSCR)
COCO — Conversions Complete Bit
When the AIEN bit is a logic 0, the COCO is a read-only bit which is
set each time a conversion is completed. This bit is cleared whenever
the ADC status and control register is written or whenever the ADC
data register is read. Reset clears this bit.
1 = conversion completed (AIEN = 0)
0 = conversion not completed (AIEN = 0)
When the AIEN bit is a logic 1 (CPU interrupt enabled), the COCO is
a read-only bit, and will always be logic 0 when read.
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Analog-to-Digital Converter (ADC)
I/O Registers
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
allowed when this bit is cleared. Reset clears the ADCO bit.
1 = Continuous ADC conversion
0 = One ADC conversion
ADCH[4:0] — ADC Channel Select Bits
ADCH[4:0] form a 5-bit field which is used to select one of the ADC
channels. The five channel select bits are detailed in the following
table. Care should be taken when using a port pin as both an analog
and a digital input simultaneously to prevent switching noise from
corrupting the analog signal. (See Table 12-2.)
The ADC subsystem is turned off when the channel select bits are all
set to one. This feature allows for reduced power consumption for the
MCU when the ADC is not used. Reset sets all of these bits to a
logic 1.
NOTE:
Recovery from the disabled state requires one conversion cycle to
stabilize.
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Analog-to-Digital Converter (ADC)
Table 12-2. MUX Channel Select
ADCH4
ADCH3
ADCH2
ADCH1
ADCH0
ADC Channel
Input Select
0
0
0
0
0
ADC0
PTC0
0
0
0
0
1
ADC1
PTC1
0
0
0
1
0
ADC2
PTC2
0
0
0
1
1
ADC3
PTC3
0
0
1
0
0
ADC4
PTC4
0
0
1
0
1
ADC5
PTC5
0
0
1
1
0
:
:
:
:
:
—
Unused
(see Note 1)
1
1
0
1
0
1
1
0
1
1
—
Reserved
1
1
1
0
0
—
Unused
1
1
1
0
1
VDDA (see Note 2)
1
1
1
1
0
VSSA (see Note 2)
1
1
1
1
1
ADC power off
NOTES:
1. If any unused channels are selected, the resulting ADC conversion will be unknown.
2. The voltage levels supplied from internal reference nodes as specified in the table are used to verify the
operation of the ADC converter both in production test and for user applications.
12.8.2 ADC Data Register
One 8-bit result register is provided. This register is updated each time
an ADC conversion completes.
Address:
Read:
$005E
Bit 7
6
5
4
3
2
1
Bit 0
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
Write:
Reset:
Indeterminate after Reset
= Unimplemented
Figure 12-3. ADC Data Register (ADR)
Technical Data
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MOTOROLA
Analog-to-Digital Converter (ADC)
I/O Registers
12.8.3 ADC Input Clock Register
This register selects the clock frequency for the ADC.
Address:
$005F
Bit 7
6
5
ADIV2
ADIV1
ADIV0
0
0
0
Read:
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
0
0
Write:
Reset:
= Unimplemented
Figure 12-4. ADC Input Clock Register (ADICLK)
ADIV2:ADIV0 — ADC Clock Prescaler Bits
ADIV2, ADIV1, and ADIV0 form a 3-bit field which selects the divide
ratio used by the ADC to generate the internal ADC clock. Table 12-3
shows the available clock configurations. The ADC clock should be
set to approximately 1MHz. With an internal bus frequency of 6MHz,
set ADIV[2:0] = 010, for a divide by four ADC clock rate.
Table 12-3. ADC Clock Divide Ratio
ADIV2
ADIV1
ADIV0
ADC Clock Rate
0
0
0
Internal bus clock ÷ 1
0
0
1
Internal bus clock ÷ 2
0
1
0
Internal bus clock ÷ 4
0
1
1
Internal bus clock ÷ 8
1
X
X
Internal bus clock ÷ 16
X = don’t care
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Technical Data
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Technical Data
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MOTOROLA
Technical Data — MC68HC908BD48
Section 13. Universal Serial Bus Module (USB)
13.1 Contents
13.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
13.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
13.4
I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
13.5 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
13.5.1 USB Address Register (UADR) . . . . . . . . . . . . . . . . . . . . . 166
13.5.2 USB Interrupt Register (UINTR). . . . . . . . . . . . . . . . . . . . . 166
13.5.3 USB Interrupt Register 1 (UIR1). . . . . . . . . . . . . . . . . . . . . 169
13.5.4 USB Control Register 0 (UCR0). . . . . . . . . . . . . . . . . . . . . 171
13.5.5 USB Control Register 1 (UCR1). . . . . . . . . . . . . . . . . . . . . 172
13.5.6 USB Control Register 2 (UCR2). . . . . . . . . . . . . . . . . . . . . 174
13.5.7 USB Status Register (USR) . . . . . . . . . . . . . . . . . . . . . . . . 175
13.5.8 USB Endpoint 0 Data Registers 0 to 7
(UD0R0–UD0R7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
13.5.9 USB Endpoint 1/2 Data Registers 0 to 7
(UD1R0–UD1R7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
13.2 Introduction
This USB module is designed to serve as a low-speed (LS) USB device
per the Universal Serial Bus Specification Rev 1.0.
Three types of USB data transfers are supported: control, interrupt, and
bulk (transmit only). Endpoint 0 functions as a receive/transmit control
endpoint. Endpoints 1 and 2 can function as interrupt or bulk, but only in
transmit direction.
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Universal Serial Bus Module (USB)
13.3 Features
Features of the USB (universal serial bus) module include the following:
•
Integrated 3.3-volt regulator with 3.3-volt output pin
•
Integrated USB transceiver supporting low-speed functions
•
USB data control logic
– Packet decoding/generation
– CRC (cyclic redundancy check) generation and checking
– NRZI (non-return-to zero inserted) encoding/decoding
– Bit-stuffing
•
USB reset support
•
Control endpoint 0 and interrupt endpoints 1 and 2
•
Two 8-byte transmit buffers
•
One 8-byte receive buffer
•
Suspend and resume operations
– Remote wakeup support
•
USB generated interrupts
– Transaction interrupt driven
– Resume interrupt
– End-of-pack (EOP) interrupt
•
STALL, NAK, and ACK handshake generation
13.4 I/O Pins
The USB module uses two I/O pins, shared with standard port I/O pins.
The full name of the USB I/O pins are listed in Table 13-1. The generic
pin name appear in the text that follows.
Table 13-1. Pin Name Conventions
USB
Generic Pin Names:
Full MCU Pin Names:
Pin Selected for
USB Function By:
D+
PTD0/D+
USBD+E bit in PDCR ($0049)
D–
PTD1/D–
USBD–E bit in PDCR ($0049)
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MOTOROLA
Universal Serial Bus Module (USB)
Registers
Table 13-2. USB I/O Register Summary
Addr.
$0029
$002A
$002B
$002C
$002D
$002E
Register Name
Bit 7
5
4
3
2
1
Bit 0
UADD6
UADD5
UADD4
UADD3
UADD2
UADD1
UADD0
0
0
0
0
0
0
0
TBEF
RBFF
EOPIF
RSTIF
TBIE
RBIE
EOPIE
RSTIE
0
0
0
0
0
0
0
0
T0SEQ
STALL0
TX0E
RX0E
TP0SIZ3
TP0SIZ2
TP0SIZ1
TP0SIZ0
0
0
0
0
0
0
0
0
RSEQ
SETUP
TX1ST
0
RPSIZ3
RPSIZ2
RPSIZ1
RPSIZ0
STALL2
STALL1
Read:
USBEN
USB Address Register
Write:
(UADR)
Reset:
0
Read:
USB Interrupt Register
Write:
(UINTR)
Reset:
Read:
USB Control Register 0
Write:
(UCR0)
Reset:
Read:
USB Status Register
Write:
(USR)
Reset:
Indeterminate after reset
Read:
USB Control Register 2
Write:
(UCR2)
Reset:
0
0
0
0
Read:
USB Interrupt Register 1
(UIR1) Write:
TXD1F
Reset:
$002F
6
Read:
USB Control Register 1
Write:
(UCR1)
Reset:
TXD1IE
PULLEN
SUSPND ENABLE2 ENABLE1
0
0
0
0
0
0
RESUMF
0
0
0
0
0
RESUMFR
TBEFR
RBFFR
TXD1FR
EOPFR
0
0
0
0
0
TP1SIZ2
TP1SIZ1
TP1SIZ0
0
0
0
0
0
0
T1SEQ
ENDADD
TX1E
0
0
0
FRESUM TP1SIZ3
0
0
$0030
to
$0037
Read: UE0RDx7 UE0RDx6 UE0RDx5 UE0RDx4 UE0RDx3 UE0RDx2 UE0RDx1 UE0RDx0
USB Endpoint 0 Data
Register 0–7 Write: UE0TDx7 UE0TDx6 UE0TDx5 UE0TDx4 UE0TDx3 UE0TDx2 UE0TDx1 UE0TDx0
(UD0R0–UD0R7)
Reset:
Indeterminate after reset
$0038
to
$003F
Read:
USB Endpoint 1/2 Data
Register 0–7 Write: UE1TDx7 UE1TDx6 UE1TDx5 UE1TDx4 UE1TDx3 UE1TDx2 UE1TDx1 UE1TDx0
(UD1R0–UD1R7)
Indeterminate after reset
Reset:
13.5 Registers
There are seven control/status registers and 24 data buffers in the USB
module. These registers are discussed in the following paragraphs.
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Universal Serial Bus Module (USB)
13.5.1 USB Address Register (UADR)
Address:
$0029
Bit 7
6
5
4
3
2
1
Bit 0
USBEN
UADD6
UADD5
UADD4
UADD3
UADD2
UADD1
UADD0
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 13-1. USB Address Register (UADR)
USBEN — USB Enable
This read/write bit enables/disables the USB module. When USBEN
bit is clear, USB will not respond to any tokens, but still can detect
USB reset signal, or EOP signals, and non-IDLE state if in Suspend
Mode. Reset clears this bit. After USB reset, software will set this bit
to enable USB.
1 = USB module enabled
0 = USB module disabled
UADD[6:0] — USB Address
These bits specify the USB address of the device. Reset clears these
bits to $00, the default address.
13.5.2 USB Interrupt Register (UINTR)
Address:
Read:
$002A
Bit 7
6
5
4
TBEF
RBFF
EOPIF
RSTIF
3
2
1
Bit 0
TBIE
RBIE
EORIE
RSTIE
0
0
0
0
Write:
Reset:
0
0
0
0
= Unimplemented
Figure 13-2. USB Interrupt Register (UINTR)
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MOTOROLA
Universal Serial Bus Module (USB)
Registers
TBEF — Transmit Buffer Empty Flag
This flag is set after the data stored in endpoint 0 transmit buffer has
been sent and ACK handshake packet is received. Software must
clear this flag by writing a logic "1" to TBEFR bit after the data is ready
in the transmit buffer. This enables the next data packet transmission
when endpoint 0 transmit is enabled (TX0E = 1). TBEF generates an
interrupt request to the CPU if the TBIE bit is also set. Reset clears
this bit.
1 = Transmit on endpoint 0 has occurred
0 = Transmit on endpoint 0 has not occurred
RBFF — Receive Buffer Full Flag
This flag is set when the module has received one data packet and
replied with ACK handshake packet. Software must clear this flag by
writing "1" to RBFFR bit after all the received data have been read to
enable the next data packet reception. RBFF generates an interrupt
request to the CPU if the RBIE bit is also set. Reset clears this bit.
1 = Receive on endpoint 0 has occurred
0 = Receive on endpoint 0 has not occurred
EOPIF — End Of Packet Interrupt Flag
This flag is set when a valid EOP signal transition is detected on the
D+ and D– lines. This flag can be cleared by writing "1" to EOPIFR bit.
EOPIF generates an interrupt request to the CPU if the EOPIE bit is
also set. Reset clears this bit.
1 = End-of-packet sequence has been detected
0 = End-of-packet sequence has not been detected
RSTIF — Reset Interrupt Flag
The flag is set when a valid reset signal state is detected on the D+
and D– lines. This flag can be cleared by writing "1" to RSTIFR bit.
RSTIF generates an interrupt request to the CPU if the RSTIE bit is
also set. Reset clears this bit.
1 = USB reset condition has been detected
0 = USB reset condition has not been detected
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Universal Serial Bus Module (USB)
TBIE — Transmit Buffer Interrupt Enable
When this bit is set, the TBEF flag is enabled to generate an interrupt
request to the CPU. When TBIE is cleared, the TBEF flag is prevented
from generating an interrupt request to the CPU. Reset clears this bit.
1 = TBEF bit set will generate interrupt request to CPU
0 = TBEF bit set does not generate interrupt request to CPU
RBIE — Receive Buffer Interrupt Enable
When this bit is set, the RBFF flag is enabled to generate an interrupt
request to the CPU. When RBIE is cleared, the RBFF flag is
prevented from generating an interrupt request to the CPU. Reset
clears this bit.
1 = RBFF bit set will generate interrupt request to CPU
0 = RBFF bit set does not generate interrupt request to CPU
EOPIE — End Of Packet Interrupt Enable
When this bit is set, the EOPIF flag is enabled to generate an interrupt
request to the CPU. When EOPIE is cleared, the EOPIF flag is
prevented from generating an interrupt request to the CPU. Reset
clears this bit.
1 = EOPIF bit set will generate interrupt request to CPU
0 = EOPIF bit set does not generate interrupt request to CPU
RSTIE — Reset Interrupt Enable
When this bit is set, the RSTIF flag is enabled to generate an interrupt
request to the CPU. When RSTIE is cleared, the RSTIF flag is
prevented from generating an interrupt request to the CPU. Reset
clears this bit.
1 = RSTIF bit set will generate interrupt request to CPU
0 = RSTIF bit set does not generate interrupt request to CPU
NOTE:
Since there are more than one interrupt flags in the register, it is possible
that program use Read-Modify-Write instruction to clear one flag, will
occasionally clear the other flags which was just set after Read cycle of
Read-Modify-Write operation.
Technical Data
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MOTOROLA
Universal Serial Bus Module (USB)
Registers
13.5.3 USB Interrupt Register 1 (UIR1)
Address:
$002E
Bit 7
Read:
6
TXD1F
5
4
3
2
1
Bit 0
RESUMF
0
0
0
0
0
0
RESUMFR
TBEFR
RBFFR
TXD1FR
EOPFR
0
0
0
0
0
0
TXD1IE
Write:
0
Reset:
0
0
Figure 13-3. USB Interrupt Register 1 (UIR1)
TXD1F — Endpoint 1/2 Data Buffer Transmit Flag
The flag is set after the data stored in endpoint 1/2 transmit buffer has
been sent and ACK handshake packet from host is received.
Software must clear this flag by writing a logic 1 to TXD1FR bit after
the data is ready in the transmit buffer to enable the next data packet
transmission when TX1E is enabled. Reset clears this bit.
1 = Transmit on endpoint 1/2 has occurred
0 = Transmit on endpoint 1/2 has not occurred
TXD1IE — Transmit Buffer Interrupt Enable
When this bit is set, the TXD1F flag is enabled to generate an interrupt
request to the CPU. When TXD1IE is cleared, the TXD1F flag is
prevented from generating an interrupt request to the CPU. Reset
clears this bit.
1 = TXD1F bit set will generate interrupt request to CPU
0 = TXD1F bit set does not generate interrupt request to CPU
RESUMF — Resume Flag
This flag is set if the transaction from idle state to non-idle state is
detected while in suspend mode (SUSPND = 1). An interrupt will be
generated to wake up CPU to indicate a resume signalling from host
and software will clear SUSPND bit and exit from suspend mode.
USB reset signals cannot be detected while in suspend mode until
SUSPND bit is cleared. The RESUMF interrupt service routine is
generated by SE0 to wake up the USB module. This bit can be
cleared by writing "1" to RESUMFR bit. Reset clears this bit.
1 = USB bus activity detected while in suspend mode
0 = If in suspend mode, no USB bus activity has been detected
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Universal Serial Bus Module (USB)
RESUMFR — Resume Flag Clear
Writing a logic "1" to this bit clears the RESUMF flag. Writing a "0" has
no effect. Reset clears this bit.
1 = Writing 1 clears RESUMFR
0 = No effect
TBEFR — Transmit Buffer Empty Flag Clear
Writing a logic "1" to this bit clears the TBEF flag. Writing a "0" has no
effect. Reset clears this bit.
1 = Writing 1 clears TBEF
0 = No effect
RBFFR — Receive Buffer Full Flag Clear
Writing a logic "1" to this bit clears the RBFF flag. Writing a "0" has no
effect. Reset clears this bit.
1 = Writing 1 clears RBFF
0 = No effect
TXD1FR — Endpoint 1 and 2 Data Buffer Transmit Flag Clear
Writing a logic "1" to this bit clears the TXD1F flag. Writing a "0" has
no effect. Reset clears this bit.
1 = Writing 1 clears TXD1F
0 = No effect
EOPIFR — End Of Packet Interrupt Flag Clear
Writing a logic "1" to this bit clears the EOPIF flag. Writing a "0" has
no effect. Reset clears this bit.
1 = Writing 1 clears EOPIF
0 = No effect
Technical Data
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Universal Serial Bus Module (USB)
MOTOROLA
Universal Serial Bus Module (USB)
Registers
13.5.4 USB Control Register 0 (UCR0)
Address:
$002B
Bit 7
6
5
4
3
2
1
Bit 0
T0SEQ
STALL0
TX0E
RX0E
TP0SIZ3
TP0SIZ2
TP0SIZ1
TP0SIZ0
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 13-4. USB Control Register 0 (UCR0)
T0SEQ — Endpoint 0 Data Packet PID Select
This bit will determine the transmit data packet PID of endpoint 0.
When it is "0", the DATA0 PID (b0011) will be sent. When it is "1", the
DATA1 PID (b1011) will be sent. Reset clears this bit.
1 = DATA1 PID will be sent on endpoint 0
0 = DATA0 PID will be sent on endpoint 0
STALL0 — Endpoint 0 STALL Handshake
This bit is set to generate the STALL handshake packet as next IN or
OUT transactions handshake packet from endpoint 0. The USB
hardware clears the STALL0 bit when a SETUP packet is received.
Reset clears this bit.
1 = Send STALL handshake on endpoint 0
0 = Do not send STALL handshake on endpoint 0
TX0E — Endpoint 0 Transmit Enable
This bit is set to enable data packet transmission from endpoint 0.
Software should set this bit when data is ready for data packet
transmission. It must be cleared when no more data needs to be
transmitted. If TX0E is "0" or TXD0F is "1", a NAK handshake will be
returned for the next IN token. Reset clears this bit.
1 = Data is ready to be sent on endpoint 0
0 = Data is not ready; respond with ACK
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Universal Serial Bus Module (USB)
RX0E — Endpoint 0 Receive Enable
This bit is set to enable data packet reception from endpoint 0.
Software should set this bit when it is ready for data packet reception.
It must be cleared when data cannot be received. If RX0E "0" or RBFF
is "1", a NAK handshake will be returned for the next OUT token.
Reset clears this bit.
1 = Data is read to be received on endpoint 0
0 = Not ready for data; respond with NAK
TP0SIZ[3:0] — Endpoint 0 Transmit Data Size
The TP0SIZ[3:0] is used to store the number of transmit data bytes
from endpoint 0. The default size of transmit data is "0" after reset.
13.5.5 USB Control Register 1 (UCR1)
Address:
$002F
Bit 7
6
5
T1SEQ
ENDADD
TX1E
0
0
0
4
3
2
1
Bit 0
TP1SIZ2
TP1SIZ1
TP1SIZ0
0
0
0
Read:
FRESUM TP1SIZ3
Write:
Reset:
0
0
Figure 13-5. USB Control Register 1 (UCR1)
T1SEQ — Endpoint 1/2 Data Packet PID Select
This bit will determine the transmit data packet PID of endpoint 1/2.
When it is "0", the DATA0 PID (b0011) will be sent. When it is "1", the
DATA1 PID (b1011) will be sent. Reset clears this bit.
1 = DATA1 PID will be sent on endpoint 1/2
0 = DATA0 PID will be sent on endpoint 1/2
ENDADD — Endpoint Address Select
This bit specifies the which endpoint (1 or 2) uses the eight data
registers, UD1R0–UD1R7, for data transmit buffers. Clearing this bit
selects endpoint 1 to use the data registers. Setting this bit selects
endpoint 2 to use the data registers.
Technical Data
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MOTOROLA
Universal Serial Bus Module (USB)
Registers
If all the conditions for a successful endpoint 2 USB response to a
host’s IN token are satisfied (TXD1F = 0, TX1E = 1, STALL2 = 0,
ENABLE2 = 1), but endpoint 1 is selected (ENDADD = 0), the module
will respond with an NAK handshake packet. Reset clears this bit.
1 = The transmit buffer is used for endpoint 2
0 = The transmit buffer is used for endpoint 1
TX1E — Endpoint 1/2 Transmit Enable
This bit is set to enable data packet transmission from endpoint 1/2.
Software should set this bit when data is ready for data packet
transmission. It must be cleared when no more data needs to be
transmitted. If TX1E is "0" or TXD1F is "1", a NAK handshake will be
returned for the next IN token. Reset clears this bit.
1 = Data is ready to be sent on endpoint 1/2
0 = Data is not ready; respond with ACK
FRESUM — Force Resume
This bit is set to force a resume state on USB bus lines until software
clears this bit. Before setting the FRESUM bit, the SUSPND bit must
to be cleared in order to drive the USB bus lines. Setting the FRESUM
bit will not cause RESUMF to be set. Reset clears this bit.
1 = Resume state forced on USB bus; only if SUSPND is cleared
0 = No effect
TP1SIZ[3:0] — Endpoint 1/2 Transmit Data Size
The TP1SIZ[3:0] is used to store the number of transmit data bytes
from endpoint 1/2. The default size of transmit data is "0" after reset.
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Universal Serial Bus Module (USB)
13.5.6 USB Control Register 2 (UCR2)
Address:
Read:
$002D
Bit 7
6
0
0
5
PULLEN
Write: RSTIFR
Reset:
0
4
3
2
SUSPND ENABLE2 ENABLE1
1
Bit 0
STALL2
STALL1
0
0
TX1STR
0
0
0
0
0
Figure 13-6. USB Control Register 2 (UCR2)
RSTIFR — Reset Interrupt Flag Clear
Writing a logic "1" to this bit clears the RSTIFR flag. Writing a "0" has
no effect. Reset clears this bit.
1 = Writing 1 clears RSTIFR
0 = No effect
TX1STR — TX1ST Clear
Writing a logic "1" to this bit clears the TX1STR flag. Writing a "0" has
no effect. Reset clears this bit.
1 = Writing 1 clears TX1STR
0 = No effect
PULLEN — Pullup Enable on D–
This bit is set to enable the internal 1.5kΩ pullup resister connected
between the USB D– line and 3.3V. Reset clears this bit.
1 = Enable 1.5kΩ pullup resistor between D– and 3.3V
0 = Disable 1.5kΩ pullup resistor between D– and 3.3V
SUSPND — USB Suspend
If the 3ms constant idle state is detected on the USB bus, user
software should set this bit to allow the USB module to enter suspend
mode. In the suspend mode, the clock to USB module will be stopped,
and other unnecessary analog circuitry will be powered down. When
a resume is detected (RESUMF = 1), user software must clear
SUSPND in the interrupt service routine.
1 = Enable USB suspend mode
0 = Disable USB suspend mode
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Universal Serial Bus Module (USB)
Registers
ENABLE2 — Endpoint 2 Enable
This bit is set to enable endpoint 2 to respond to addressed IN packet
tokens. Reset clears this bit.
1 = Endpoint 2 enabled; and responds to IN tokens
0 = Endpoint 2 disabled
ENABLE1 — Endpoint 1 Enable
This bit is set to enable endpoint 1 to respond to addressed IN packet
tokens. Reset clears this bit.
1 = Endpoint 1 enabled; and responds to IN tokens
0 = Endpoint 1 disabled
STALL2 — Endpoint 2 STALL Handshake
This bit is set to generate the STALL handshake packet as next IN
transaction handshake packet from endpoint 2. Reset clears this bit.
1 = Send STALL handshake on endpoint 2
0 = Do not send STALL handshake on endpoint 2
STALL1 — Endpoint 1 STALL Handshake
This bit is set to generate the STALL handshake packet as next IN
transaction handshake packet from endpoint 1. Reset clears this bit.
1 = Send STALL handshake on endpoint 1
0 = Do not send STALL handshake on endpoint 1
13.5.7 USB Status Register (USR)
Address:
Read:
$002C
Bit 7
6
5
4
3
2
1
Bit 0
RSEQ
SETUP
TX1ST
0
RPSIZ3
RPSIZ2
RPSIZ1
RPSIZ0
Write:
Reset:
Indeterminate after reset
= Unimplemented
Figure 13-7. USB Status Register (USR)
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Universal Serial Bus Module (USB)
RSEQ — Received Data Sequence
This bit indicates the type of data packet of the last received data
packet on endpoint 0. RSEQ = 0 indicates the last received data
packet is type DATA0. RSEQ = 1 indicates the last received data
packet is type DATA1.
1 = Last token received on endpoint 0 is a DATA1 token
0 = Last token received on endpoint 0 is a DATA0 token
SETUP — SETUP Token
This bit is set when the received token packet for endpoint 0 is a
SETUP token (PID = b1101).
1 = Last token received on endpoint 0 is a SETUP token
0 = Last token received on endpoint 0 is not a SETUP token
TX1ST — Transmit First Flag
This bit is set if the endpoint 0 transmit buffer empty flag (TBEF) is set
when the control logic is setting the endpoint 0 receive buffer full flag
(RBFF). This happens when TBEF is still set at the end of an
endpoint 0 reception.
1 = IN transaction occurred before SETUP or OUT
0 = IN transaction occurred after SETUP or OUT
RPSIZ[3:0] — Received Data Size
The RPSIZ[3:0] indicates the number of received data bytes in a data
packet. Reset will not affect these bits
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Universal Serial Bus Module (USB)
MOTOROLA
Universal Serial Bus Module (USB)
Registers
13.5.8 USB Endpoint 0 Data Registers 0 to 7 (UD0R0–UD0R7)
Address:
$0030–$0037
Bit 7
6
5
4
3
2
1
Bit 0
Read: UE0RDx7 UE0RDx6 UE0RDx5 UE0RDx4 UE0RDx3 UE0RDx2 UE0RDx1 UE0RDx0
Write: UE0TDx7 UE0TDx6 UE0TDx5 UE0TDx4 UE0TDx3 UE0TDx2 UE0TDx1 UE0TDx0
Reset:
Indeterminate after reset
Figure 13-8. USB Endpoint 0 Data Registers 0 to 7 (UD0R0–UD0R7)
UE0RDx[7:0] — Endpoint 0 Receive Data Buffers
These eight 8-bit buffers are serially loaded with OUT token or
SETUP token data received over the USB’s D+ and D– lines. These
buffers are for endpoint 0.
UE0TDx[7:0] — Endpoint 0 Transmit Data Buffers
These eight 8-bit buffers are loaded by user software with data to be
sent on the USB bus on the next IN token directed at endpoint 0.
13.5.9 USB Endpoint 1/2 Data Registers 0 to 7 (UD1R0–UD1R7)
Address:
$0038–$003F
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Write: UE1TDx7 UE1TDx6 UE1TDx5 UE1TDx4 UE1TDx UE1TDx2 UE1TDx1 UE1TDx0
Reset:
Indeterminate after reset
Figure 13-9. USB Endpoint 1 Data Registers 0 to 7 (UD1R0–UD1R7)
UE1TDx[7:0] — Endpoint 1/2 Transmit Data Buffers
These eight 8-bit buffers are loaded by user software with data to be
sent on the USB bus on the next IN token directed at endpoint 1 or
endpoint 2. The ENDADD bit in the USB control register 1 determines
either endpoint 1 or endpoint 2 uses these buffers.
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Universal Serial Bus Module (USB)
Technical Data
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Universal Serial Bus Module (USB)
MOTOROLA
Technical Data — MC68HC908BD48
Section 14. Multi-Master IIC Interface (MMIIC)
14.1 Contents
14.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
14.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
14.4
I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
14.5 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
14.5.1 Multi-Master IIC Address Register (MMADR) . . . . . . . . . . 182
14.5.2 Multi-Master IIC Control Register (MMCR) . . . . . . . . . . . . 183
14.5.3 Multi-Master IIC Master Control Register (MIMCR) . . . . . . 184
14.5.4 Multi-Master IIC Status Register (MMSR) . . . . . . . . . . . . . 186
14.5.5 Multi-Master IIC Data Transmit Register (MMDTR) . . . . . . 188
14.5.6 Multi-Master IIC Data Receive Register (MMDRR) . . . . . . 189
14.6
Programming Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 190
14.2 Introduction
This Multi-master IIC (MMIIC) Interface is designed for internal serial
communication between the MCU and other IIC devices. A hardware
circuit generates "start" and "stop" signal, while byte by byte data
transfer is interrupt driven by the software algorithm. Therefore, it can
greatly help the software in dealing with other devices to have higher
system efficiency in a typical digital monitor system.
This module not only can be applied in internal communications, but can
also be used as a typical command reception serial bus for factory setup
and alignment purposes. It also provides the flexibility of hooking
additional devices to an existing system for future expansion without
adding extra hardware.
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Technical Data
Multi-Master IIC Interface (MMIIC)
179
Multi-Master IIC Interface (MMIIC)
This Multi-master IIC module uses the IICSCL clock line and the IICSDA
data line to communicate with external DDC host or IIC interface. These
two pins are shared with port pins PTD5 and PTD6 respectively. The
outputs of IICSDA and IICSCL pins are open-drain type — no clamping
diode is connected between the pin and internal VDD. The maximum
data rate typically is 750k-bps. The maximum communication length and
the number of devices that can be connected are limited by a maximum
bus capacitance of 400pF.
14.3 Features
•
Compatibility with multi-master IIC bus standard
•
Software controllable acknowledge bit generation
•
Interrupt driven byte by byte data transfer
•
Calling address identification interrupt
•
Auto detection of R/W bit and switching of transmit or receive
mode
•
Detection of START, repeated START, and STOP signals
•
Auto generation of START and STOP condition in master mode
•
Arbitration loss detection and No-ACK awareness in master mode
•
8 selectable baud rate master clocks
•
Automatic recognition of the received acknowledge bit
14.4 I/O Pins
The MMIIC module uses two I/O pins, shared with standard port I/O pins.
The full name of the MMIIC I/O pins are listed in Table 14-1. The generic
pin name appear in the text that follows.
Table 14-1. Pin Name Conventions
MMIIC
Generic Pin Names:
Full MCU Pin Names:
Pin Selected for
IIC Function By:
SDA
PTD6/IICSDA
IICDATE bit in PDCR ($0049)
SCL
PTD5/IICSCL
IICSCLE bit in PDCR ($0049)
Technical Data
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MOTOROLA
Multi-Master IIC Interface (MMIIC)
Registers
Table 14-2. MMIIC I/O Register Summary
Addr.
Register Name
$004E
$004F
Reset:
4
3
2
1
Bit 0
MMALIF
MMNAKIF
MMBB
MMAST
MMRW
MMBR2
MMBR1
MMBR0
0
0
0
0
0
0
0
0
MMAD7
MMAD6
MMAD5
MMAD4
MMAD3
MMAD2
MMAD1
MMEXTAD
1
0
1
0
0
0
0
0
0
0
0
0
0
MMEN
MMIEN
0
0
0
0
0
Read:
Write:
Reset:
Read:
Multi-Master IIC
Control Register
(MMCR)
MMTXAK
Write:
Reset:
Read: MMRXIF
Multi-Master IIC
Status Register
(MMSR)
$004D
5
Write:
Multi-Master IIC
Address Register
(MMADR)
$004C
6
Read:
Multi-Master IIC
$004A Master Control Register
(MIMCR)
$004B
Bit 7
0
0
0
MMTXIF MMATCH MMSRW MMRXAK
0
MMTXBE MMRXBF
Write:
0
0
Reset:
0
0
0
0
1
0
1
0
MMTD7
MMTD6
MMTD5
MMTD4
MMTD3
MMTD2
MMTD1
MMTD0
1
1
1
1
1
1
1
1
MMRD6
MMRD5
MMRD4
MMRD3
MMRD2
MMRD1
MMRD0
0
0
0
0
0
0
0
Read:
Multi-Master IIC
Data Transmit Register
(MMDTR)
Write:
Reset:
Read: MMRD7
Multi-Master IIC
Data Receive Register
(MMDRR)
Write:
Reset:
0
= Unimplemented
14.5 Registers
Six registers are associated with the Multi-master IIC module, they
outlined in the following sections.
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Multi-Master IIC Interface (MMIIC)
14.5.1 Multi-Master IIC Address Register (MMADR)
Address:
$004B
Bit 7
6
5
4
3
2
1
Bit 0
MMAD7
MMAD6
MMAD5
MMAD4
MMAD3
MMAD2
MMAD1
MMEXTAD
1
0
1
0
0
0
0
0
Read:
Write:
Reset:
Figure 14-1. Multi-Master IIC Address Register (MMADR)
MMAD[7:1] — Multi-Master Address
These 7 bits can be the MMIIC interface’s own specific slave address
in slave mode or the calling address when in master mode. Reset sets
a default value of $A0.
MMEXTAD — Multi-Master Expanded Address
This bit is set to expand the calling address of the MMIIC in slave
mode. When set, the MMIIC will acknowledge the general call
address $00 and the matched 4-bit MSB address, MMAD[7:4].
For example, when MMAD[7:1] = $A1 and MMEXTAD = 1, the MMIIC
calling address is $A0, and it will acknowledge calling addresses $00
and $A0 to $AF.
Reset clears this bit.
1 = MMIIC calling address is $MMAD[7:4]0
MMIIC respond address is $00, and $MMAD[7:4]0 to
$MMAD[7:4]F
0 = MMIIC address id $MMAD[7:1]
Technical Data
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Multi-Master IIC Interface (MMIIC)
MOTOROLA
Multi-Master IIC Interface (MMIIC)
Registers
14.5.2 Multi-Master IIC Control Register (MMCR)
Address:
$004C
Bit 7
6
MMEN
MMIEN
0
0
Read:
5
4
0
0
3
2
1
Bit 0
0
0
0
0
0
0
MMTXAK
Write:
Reset:
0
0
0
= Unimplemented
Figure 14-2. Multi-Master IIC Control Register (MMCR)
MMEN — Multi-Master IIC Enable
This bit is set to enable the Multi-master IIC module. When
MMEN = 0, module is disabled and all flags will restore to its poweron default states. Reset clears this bit.
1 = MMIIC module enabled
0 = MMIIC module disabled
MMIEN — Multi-Master IIC Interrupt Enable
When this bit is set, the MMTXIF, MMRXIF, MMALIF, and MMNAKIF
flags are enabled to generate an interrupt request to the CPU. When
MMIEN is cleared, the these flags are prevented from generating an
interrupt request. Reset clears this bit.
1 = MMTXIF, MMRXIF, MMALIF, and/or MMNAKIF bit set will
generate interrupt request to CPU
0 = MMTXIF, MMRXIF, MMALIF, and/or MMNAKIF bit set will not
generate interrupt request to CPU
MMTXAK — Transmit Acknowledge Enable
This bit is set to disable the MMIIC from sending out an acknowledge
signal to the bus at the 9th clock bit after receiving 8 data bits. When
MMTXAK is cleared, an acknowledge signal will be sent at the 9th
clock bit. Reset clears this bit.
1 = MMIIC does not send acknowledge signals at 9th clock bit
0 = MMIIC sends acknowledge signal at 9th clock bit
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Multi-Master IIC Interface (MMIIC)
14.5.3 Multi-Master IIC Master Control Register (MIMCR)
Address:
$004A
Bit 7
6
5
4
3
2
1
Bit 0
MMALIF
MMNAKIF
MMBB
MMAST
MMRW
MMBR2
MMBR1
MMBR0
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 14-3. Multi-Master IIC Master Control Register (MIMCR)
MMALIF — Multi-Master Arbitration Lost Interrupt Flag
The flag is set when software attempt to set MMAST but the MMBB
has been set by detecting the start condition on the lines or when the
MMIIC is transmitting a "1" to SDA line but detected a "0" from SDA
line in master mode – an arbitration loss. This bit generates an
interrupt request to the CPU if the MMIEN bit in MMCR is also set.
This bit is cleared by writing "0" to it or by reset.
1 = Lost arbitration in master mode
0 = No arbitration lost
MMNAKIF — No Acknowledge Interrupt Flag
The flag is only set in master mode (MMAST = 1) when there is no
acknowledge bit detected after one data byte or calling address is
transferred. This flag also clears MMAST. MMNAKIF generates an
interrupt request to CPU if the MMIEN bit in MMCR is also set. This
bit is cleared by writing "0" to it or by reset.
1 = No acknowledge bit detected
0 = Acknowledge bit detected
MMBB — Bus Busy Flag
This flag is set after a start condition is detected (bus busy), and is
cleared when a stop condition (bus idle) is detected or the MMIIC is
disabled. Reset clears this bit.
1 = Start condition detected
0 = Stop condition detected or MMIIC is disabled
Technical Data
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Multi-Master IIC Interface (MMIIC)
MOTOROLA
Multi-Master IIC Interface (MMIIC)
Registers
MMAST — Master Control Bit
This bit is set to initiate a master mode transfer. In master mode, the
module generates a start condition to the SDA and SCL lines,
followed by sending the calling address stored in MMADR.
When the MMAST bit is cleared by MMNAKIF set (no acknowledge)
or by software, the module generates the stop condition to the lines
after the current byte is transmitted.
If an arbitration loss occurs (MMALIF = 1), the module reverts to slave
mode by clearing MMAST, and releasing SDA and SCL lines
immediately.
This bit is cleared by writing "0" to it or by reset.
1 = Master mode operation
0 = Slave mode operation
MMRW — Master Read/Write
This bit will be transmitted out as bit 0 of the calling address when the
module sets the MMAST bit to enter master mode. The MMRW bit
determines the transfer direction of the data bytes that follows. When
it is "1", the module is in master receive mode. When it is "0", the
module is in master transmit mode. Reset clears this bit.
1 = Master mode receive
0 = Master mode transmit
MMBR2–MMBR0 — Baud Rate Select
These three bits select one of eight clock rates as the master clock
when the module is in master mode.
Since this master clock is derived the CPU bus clock, the user
program should not execute the WAIT instruction when the MMIIC
module in master mode. This will cause the SDA and SCL lines to
hang, as the WAIT instruction places the MCU in WAIT mode, with
CPU clock is halted. These bits are cleared upon reset. (See Table
14-3 . Baud Rate Select.)
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Multi-Master IIC Interface (MMIIC)
Table 14-3. Baud Rate Select
MMBR2
MMBR1
MMBR0
Baud Rate
0
0
0
750k
0
0
1
375k
0
1
0
187.5k
0
1
1
93.75k
1
0
0
46.875k
1
0
1
23.437k
1
1
0
11.719k
1
1
1
5.859k
NOTE:
CPU bus clock is external clock ÷ 4 = 6MHz
14.5.4 Multi-Master IIC Status Register (MMSR)
Address:
$004D
Bit 7
Read: MMRXIF
6
5
4
3
MMTXIF MMATCH MMSRW MMRXAK
Write:
0
0
Reset:
0
0
0
0
1
2
0
0
1
Bit 0
MMTXBE MMRXBF
1
0
= Unimplemented
Figure 14-4. Multi-Master IIC Status Register (MMSR)
MMRXIF — Multi-Master IIC Receive Interrupt Flag
This flag is set after the data receive register (MMDRR) is loaded with
a new received data. Once the MMDRR is loaded with received data,
no more received data can be loaded to the MMDRR register until the
CPU reads the data from the MMDRR to clear MMRXBF flag.
MMRXIF generates an interrupt request to CPU if the MMIEN bit in
MMCR is also set. This bit is cleared by writing "0" to it or by reset; or
when the MMEN = 0.
1 = New data in data receive register (MMDRR)
0 = No data received
Technical Data
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MOTOROLA
Multi-Master IIC Interface (MMIIC)
Registers
MMTXIF — Multi-Master Transmit Interrupt Flag
This flag is set when data in the data transmit register (MMDTR) is
downloaded to the output circuit, and that new data can be written to
the MMDTR. MMTXIF generates an interrupt request to CPU if the
MMIEN bit in MMCR is also set. This bit is cleared by writing "0" to it
or when the MMEN = 0.
1 = Data transfer completed
0 = Data transfer in progress
MMATCH — Multi-Master Address Match
This flag is set when the received data in the data receive register
(MMDRR) is an calling address which matches with the address or its
extended addresses (MMEXTAD=1) specified in the MMADR
register.
1 = Received address matches MMADR
0 = Received address does not match
MMSRW — Multi-Master Slave Read/Write
This bit indicates the data direction when the module is in slave mode.
It is updated after the calling address is received from a master
device. MMSRW = 1 when the calling master is reading data from the
module (slave transmit mode). MMSRW = 0 when the master is
writing data to the module (receive mode).
1 = Slave mode transmit
0 = Slave mode receive
MMRXAK — Multi-Master Receive Acknowledge
When this bit is cleared, it indicates an acknowledge signal has been
received after the completion of 8 data bits transmission on the bus.
When MMRXAK is set, it indicates no acknowledge signal has been
detected at the 9th clock; the module will release the SDA line for the
master to generate "stop" or "repeated start" condition. Reset sets this
bit.
1 = No acknowledge signal received at 9th clock bit
0 = Acknowledge signal received at 9th clock bit
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Multi-Master IIC Interface (MMIIC)
MMTXBE — Multi-Master Transmit Buffer Empty
This flag indicates the status of the data transmit register (MMDTR).
When the CPU writes the data to the MMDTR, the MMTXBE flag will
be cleared. MMTXBE is set when MMDTR is emptied by a transfer of
its data to the output circuit. Reset sets this bit.
1 = Data transmit register empty
0 = Data transmit register full
MMRXBF — Multi-Master Receive Buffer Full
This flag indicates the status of the data receive register (MMDRR).
When the CPU reads the data from the MMDRR, the MMRXBF flag
will be cleared. MMRXBF is set when MMDRR is full by a transfer of
data from the input circuit to the MMDRR. Reset clears this bit.
1 = Data receive register full
0 = Data receive register empty
14.5.5 Multi-Master IIC Data Transmit Register (MMDTR)
Address:
$004E
Bit 7
6
5
4
3
2
1
Bit 0
MMTD7
MMTD6
MMTD5
MMTD4
MMTD3
MMTD2
MMTD1
MMTD0
1
1
1
1
1
1
1
1
Read:
Write:
Reset:
Figure 14-5. Multi-Master IIC Data Transmit Register (MMDTR)
When the MMIIC module is enabled, MMEN = 1, data written into this
register depends on whether module is in master or slave mode.
In slave mode, the data in MMDTR will be transferred to the output circuit
when:
•
the module detects a matched calling address (MMATCH = 1),
with the calling master requesting data (MMSRW = 1); or
•
the previous data in the output circuit has be transmitted and the
receiving master returns an acknowledge bit, indicated by a
received acknowledge bit (MMRXAK = 0).
Technical Data
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MOTOROLA
Multi-Master IIC Interface (MMIIC)
Registers
If the calling master does not return an acknowledge bit (MMRXAK = 1),
the module will release the SDA line for master to generate a "stop" or
"repeated start" condition. The data in the MMDTR will not be transferred
to the output circuit until the next calling from a master. The transmit
buffer empty flag remains cleared (MMTXBE = 0).
In master mode, the data in MMDTR will be transferred to the output
circuit when:
•
the module receives an acknowledge bit (MMRXAK = 0), after
setting master transmit mode (MMRW = 0), and the calling
address has been transmitted; or
•
the previous data in the output circuit has be transmitted and the
receiving slave returns an acknowledge bit, indicated by a
received acknowledge bit (MMRXAK = 0).
If the slave does not return an acknowledge bit (MMRXAK = 1), the
master will generate a "stop" or "repeated start" condition. The data in
the MMDTR will not be transferred to the output circuit. The transmit
buffer empty flag remains cleared (MMTXBE = 0).
The sequence of events for slave transmit and master transmit are
illustrated in Figure 14-7.
14.5.6 Multi-Master IIC Data Receive Register (MMDRR)
Address:
$004F
Bit 7
Read: MMRD7
6
5
4
3
2
1
Bit 0
MMRD6
MMRD5
MMRD4
MMRD3
MMRD2
MMRD1
MMRD0
0
0
0
0
0
0
0
Write:
Reset:
0
= Unimplemented
Figure 14-6. Multi-Master IIC Data Receive Register (MMDRR)
When the MMIIC module is enabled, MMEN = 1, data in this read-only
register depends on whether module is in master or slave mode.
In slave mode, the data in MMDRR is:
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Multi-Master IIC Interface (MMIIC)
•
the calling address from the master when the address match flag
is set (MMATCH = 1); or
•
the last data received when MMATCH = 0.
In master mode, the data in the MMDRR is:
•
the last data received.
When the MMDRR is read by the CPU, the receive buffer full flag is
cleared (MMRXBF = 0), and the next received data is loaded to the
MMDRR. Each time when new data is loaded to the MMDRR, the
MMRXIF interrupt flag is set, indicating that new data is available in
MMDRR.
The sequence of events for slave receive and master receive are
illustrated in Figure 14-7.
14.6 Programming Considerations
When the MMIIC module detects an arbitration loss in master mode, it
will release both SDA and SCL lines immediately. But if there are no
further STOP conditions detected, the module will hang up. Therefore, it
is recommended to have time-out software to recover from such ill
condition. The software can start the time-out counter by looking at the
MMBB (Bus Busy) flag in the MIMCR and reset the counter on the
completion of one byte transmission. If a time-out occur, software can
clear the MMEN bit (disable MMIIC module) to release the bus, and
hence clearing the MMBB flag. This is the only way to clear the MMBB
flag by software if the module hangs up due to a no STOP condition
received. The MMIIC can resume operation again by setting the MMEN
bit.
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MOTOROLA
Multi-Master IIC Interface (MMIIC)
Programming Considerations
(a) Master Transmit Mode
START
Address
MMTXBE=0
MMRW=0
MMAST=1
Data1 → MMDTR
0
ACK
TX Data1
ACK
MMTXBE=1
MMTXIF=1
Data3 → MMDTR
MMTXBE=1
MMTXIF=1
Data2 → MMDTR
TX DataN
NAK
STOP
MMTXBE=1 MMNAKIF=1
MMTXIF=1 MMAST=0
DataN+2 → MMDTR MMTXBE=0
(b) Master Receive Mode
START
Address
1
ACK
RX Data1
ACK
Data1 → MMDRR
MMRXIF=1
MMRXBF=1
MMRXBF=0
MMRW=1
MMAST=1
MMTXBE=0
(dummy data → MMDTR)
RX DataN
NAK
STOP
DataN → MMDRR MMNAKIF=1
MMRXIF=1 MMAST=0
MMRXBF=1
(c) Slave Transmit Mode
START
Address
MMTXBE=1
MMRXBF=0
1
ACK
TX Data1
MMRXIF=1
MMRXBF=1
MMATCH=1
MMSRW=1
Data1 → MMDTR
ACK
MMTXBE=1
MMTXIF=1
Data2 → MMDTR
TX DataN
NAK
STOP
MMTXBE=1 MMNAKIF=1
MMTXIF=1 MMTXBE=0
DataN+2 → MMDTR
(d) Slave Receive Mode
START
Address
MMTXBE=0
MMRXBF=0
0
ACK
MMRXIF=1
MMRXBF=1
MMATCH=1
MMSRW=0
RX Data1
ACK
Data1 → MMDRR
MMRXIF=1
MMRXBF=1
RX DataN
NAK
STOP
DataN → MMDRR
MMRXIF=1
MMRXBF=1
KEY: shaded data packets indicate a transmit by the MCU’s MMIIC module
Figure 14-7. Data Transfer Sequences for Master/Slave Transmit/Receive Modes
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Technical Data
Multi-Master IIC Interface (MMIIC)
191
Multi-Master IIC Interface (MMIIC)
Technical Data
192
MC68HC908BD48 — Rev. 1.0
Multi-Master IIC Interface (MMIIC)
MOTOROLA
Technical Data — MC68HC908BD48
Section 15. DDC12AB Interface
15.1 Contents
15.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
15.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
15.4
I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
15.5
DDC Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
15.6 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
15.6.1 DDC Address Register (DADR) . . . . . . . . . . . . . . . . . . . . . 196
15.6.2 DDC2 Address Register (D2ADR) . . . . . . . . . . . . . . . . . . . 197
15.6.3 DDC Control Register (DCR) . . . . . . . . . . . . . . . . . . . . . . . 198
15.6.4 DDC Master Control Register (DMCR) . . . . . . . . . . . . . . . 199
15.6.5 DDC Status Register (DSR) . . . . . . . . . . . . . . . . . . . . . . . . 202
15.6.6 DDC Data Transmit Register (DDTR) . . . . . . . . . . . . . . . . 204
15.6.7 DDC Data Receive Register (DDRR). . . . . . . . . . . . . . . . . 205
15.7
Programming Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 206
15.2 Introduction
This DDC12AB Interface module is used by the digital monitor to show
its identification information to the video controller. It contains DDC1
hardware and a two-wire, bidirectional serial bus which is fully
compatible with multi-master IIC bus protocol to support DDC2AB
interface.
This module not only can be applied in internal communications, but can
also be used as a typical command reception serial bus for factory setup
and alignment purposes. It also provides the flexibility of hooking
additional devices to an existing system for future expansion without
adding extra hardware.
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Technical Data
DDC12AB Interface
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DDC12AB Interface
This DDC12AB module uses the DDCSCL clock line and the DDCSDA
data line to communicate with external DDC host or IIC interface. These
two pins are shared with port pins PTD3 and PTD2 respectively. The
outputs of DDCSDA and DDCSCL pins are open-drain type — no
clamping diode is connected between the pin and internal VDD. The
maximum data rate typically is 100k-bps. The maximum communication
length and the number of devices that can be connected are limited by
a maximum bus capacitance of 400pF.
15.3 Features
•
DDC1 hardware
•
Compatibility with multi-master IIC bus standard
•
Software controllable acknowledge bit generation
•
Interrupt driven byte by byte data transfer
•
Calling address identification interrupt
•
Auto detection of R/W bit and switching of transmit or receive
mode
•
Detection of START, repeated START, and STOP signals
•
Auto generation of START and STOP condition in master mode
•
Arbitration loss detection and No-ACK awareness in master mode
•
8 selectable baud rate master clocks
•
Automatic recognition of the received acknowledge bit
15.4 I/O Pins
The DDC12AB module uses two I/O pins, shared with standard port I/O
pins. The full name of the DDC12AB I/O pins are listed in Table 15-1.
The generic pin name appear in the text that follows.
Table 15-1. Pin Name Conventions
DDC12AB
Generic Pin Names:
Full MCU Pin Names:
Pin Selected for
DDC Function By:
SDA
PTD2/DDCSDA
DDCDATE bit in PDCR ($0049)
SCL
PTD3/DDCSCL
DDCSCLE bit in PDCR ($0049)
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DDC12AB Interface
MOTOROLA
DDC12AB Interface
I/O Pins
Table 15-2. DDC I/O Register Summary
Addr.
Register Name
$0016
DDC Master Control
Register
(DMCR)
Bit 7
6
5
4
3
2
1
Bit 0
ALIF
NAKIF
BB
MAST
MRW
BR2
BR1
BR0
0
0
0
0
0
0
0
0
DAD7
DAD6
DAD5
DAD4
DAD3
DAD2
DAD1
EXTAD
1
0
1
0
0
0
0
0
0
0
DEN
DIEN
TXAK
SCLIEN
DDC1EN
Reset:
0
0
0
0
0
0
0
0
Read:
RXIF
TXIF
MATCH
SRW
RXAK
SCLIF
TXBE
RXBF
Write:
0
0
Reset:
0
0
0
0
1
0
1
0
DTD7
DTD6
DTD5
DTD4
DTD3
DTD2
DTD1
DTD0
Reset:
1
1
1
1
1
1
1
1
Read:
DRD7
DRD6
DRD5
DRD4
DRD3
DRD2
DRD1
DRD0
0
0
0
0
0
0
0
0
D2AD7
D2AD6
D2AD5
D2AD4
D2AD3
D2AD2
D2AD1
0
0
0
0
0
0
0
Read:
Write:
Reset:
Read:
$0017
DDC Address Register
(DADR)
Write:
Reset:
DDC
Control Register
(DCR)
$0018
DDC
Status Register
(DSR)
$0019
$001A
$001B
DDC
Data Transmit Register
(DDTR)
DDC
Data Receive Register
(DDRR)
Read:
0
Write:
0
Read:
Write:
Write:
Reset:
Read:
DDC2 Address Register
$001C
(D2ADR)
0
Write:
Reset:
0
= Unimplemented
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Technical Data
DDC12AB Interface
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DDC12AB Interface
15.5 DDC Protocols
In DDC1 protocol communication, the module is in transmit mode. The
data written to the transmit register is continuously clocked out to the
SDA line by the rising edge of the Vsync input signal. During DDC1
communication, a falling transition on the SCL line can be detected to
generate an interrupt to the CPU for mode switching.
In DDC2AB protocol communication, the module can be either in
transmit mode or in receive mode, controlled by the calling master.
In DDC2 protocol communication, the module will act as a standard IIC
module, able to act as a master or a slave device.
15.6 Registers
Seven registers are associated with the DDC module, they outlined in
the following sections.
15.6.1 DDC Address Register (DADR)
Address:
$0017
Bit 7
6
5
4
3
2
1
Bit 0
DAD7
DAD6
DAD5
DAD4
DAD3
DAD2
DAD1
EXTAD
1
0
1
0
0
0
0
0
Read:
Write:
Reset:
Figure 15-1. DDC Address Register (DADR)
DAD[7:1] — DDC Address
These 7 bits can be the DDC2 interface’s own specific slave address
in slave mode or the calling address when in master mode. Reset sets
a default value of $A0.
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DDC12AB Interface
MOTOROLA
DDC12AB Interface
Registers
EXTAD — DDC Expanded Address
This bit is set to expand the calling address of the DDC in slave mode.
When set, the DDC will acknowledge the general call address $00
and the matched 4-bit MSB address, DAD[7:4].
For example, when DAD[7:1] = $A1 and EXTAD = 1, the DDC calling
address is $A0, and it will acknowledge calling addresses $00 and
$A0 to $AF.
Reset clears this bit.
1 = DDC calling address is $DAD[7:4]0
DDC respond address is $00, and $DAD[7:4]0 to $DAD[7:4]F
0 = DDC address id $DAD[7:1]
15.6.2 DDC2 Address Register (D2ADR)
Address:
$001C
Bit 7
6
5
4
3
2
1
D2AD7
D2AD6
D2AD5
D2AD4
D2AD3
D2AD2
D2AD1
0
0
0
0
0
0
0
Read:
Bit 0
0
Write:
Reset:
0
Figure 15-2. DDC2 Address Register (D2ADR)
D2AD[7:1] — DDC2 Address
These 7 bits represent the second slave address for the DDC2BI
protocol. D2AD[7:1] should be set to the same value as DAD[7:1] in
DADR if user application do not use DDC2BI. Reset clears all bits this
register.
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Technical Data
DDC12AB Interface
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DDC12AB Interface
15.6.3 DDC Control Register (DCR)
Address:
$0018
Bit 7
6
DEN
DIEN
0
0
Read:
5
4
0
0
3
2
1
Bit 0
TXAK
SCLIEN
DDC1EN
0
0
0
0
Write:
Reset:
0
0
0
= Unimplemented
Figure 15-3. DDC Control Register (DCR)
DEN — DDC Enable
This bit is set to enable the DDC module. When DEN = 0, module is
disabled and all flags will restore to its power-on default states. Reset
clears this bit.
1 = DDC module enabled
0 = DDC module disabled
DIEN — DDC Interrupt Enable
When this bit is set, the TXIF, RXIF, ALIF, and NAKIF flags are
enabled to generate an interrupt request to the CPU. When DIEN is
cleared, the these flags are prevented from generating an interrupt
request. Reset clears this bit.
1 = TXIF, RXIF, ALIF, and/or NAKIF bit set will generate interrupt
request to CPU
0 = TXIF, RXIF, ALIF, and/or NAKIF bit set will not generate
interrupt request to CPU
TXAK — Transmit Acknowledge Enable
This bit is set to disable the DDC from sending out an acknowledge
signal to the bus at the 9th clock bit after receiving 8 data bits. When
TXAK is cleared, an acknowledge signal will be sent at the 9th clock
bit. Reset clears this bit.
1 = DDC does not send acknowledge signals at 9th clock bit
0 = DDC sends acknowledge signal at 9th clock bit
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DDC12AB Interface
MOTOROLA
DDC12AB Interface
Registers
SCLIEN — SCL Interrupt Enable
When this bit is set, the SCLIF flag is enabled to generate an interrupt
request to the CPU. When SCLIEN is cleared, SCLIF is prevented
from generating an interrupt request. Reset clears this bit.
1 = SCLIF bit set will generate interrupt request to CPU
0 = SCLIF bit set will not generate interrupt request to CPU
DDC1EN — DDC1 Protocol Enable
This bit is set to enable DDC1 protocol. The DDC1 protocol will use
the Vsync input (from sync processor) as the master clock input to the
DDC module. Vsync rising-edge will continuously clock out the data
to the output circuit. No calling address comparison is performed. The
SRW bit in DDC status register (DSR) will always read as "1". Reset
clears this bit.
1 = DDC1 protocol enabled
0 = DDC1 protocol disabled
15.6.4 DDC Master Control Register (DMCR)
Address:
$0016
Bit 7
6
5
4
3
2
1
Bit 0
ALIF
NAKIF
BB
MAST
MRW
BR2
BR1
BR0
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 15-4. DDC Master Control Register (DMCR)
ALIF — DDC Arbitration Lost Interrupt Flag
The flag is set when software attempt to set MAST but the BB has
been set by detecting the start condition on the lines or when the DDC
is transmitting a "1" to SDA line but detected a "0" from SDA line in
master mode – an arbitration loss. This bit generates an interrupt
request to the CPU if the DIEN bit in DCR is also set. This bit is
cleared by writing "0" to it or by reset.
1 = Lost arbitration in master mode
0 = No arbitration lost
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DDC12AB Interface
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DDC12AB Interface
NAKIF — No Acknowledge Interrupt Flag
The flag is only set in master mode (MAST = 1) when there is no
acknowledge bit detected after one data byte or calling address is
transferred. This flag also clears MAST. NAKIF generates an interrupt
request to CPU if the DIEN bit in DCR is also set. This bit is cleared
by writing "0" to it or by reset.
1 = No acknowledge bit detected
0 = Acknowledge bit detected
BB — Bus Busy Flag
This flag is set after a start condition is detected (bus busy), and is
cleared when a stop condition (bus idle) is detected or the DDC is
disabled. Reset clears this bit.
1 = Start condition detected
0 = Stop condition detected or DDC is disabled
MAST — Master Control Bit
This bit is set to initiate a master mode transfer. In master mode, the
module generates a start condition to the SDA and SCL lines,
followed by sending the calling address stored in DADR.
When the MAST bit is cleared by NAKIF set (no acknowledge) or by
software, the module generates the stop condition to the lines after
the current byte is transmitted.
If an arbitration loss occurs (ALIF = 1), the module reverts to slave
mode by clearing MAST, and releasing SDA and SCL lines
immediately.
This bit is cleared by writing "0" to it or by reset.
1 = Master mode operation
0 = Slave mode operation
MRW — Master Read/Write
This bit will be transmitted out as bit 0 of the calling address when the
module sets the MAST bit to enter master mode. The MRW bit
determines the transfer direction of the data bytes that follows. When
it is "1", the module is in master receive mode. When it is "0", the
module is in master transmit mode. Reset clears this bit.
1 = Master mode receive
0 = Master mode transmit
Technical Data
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DDC12AB Interface
MOTOROLA
DDC12AB Interface
Registers
BR2–BR0 — Baud Rate Select
These three bits select one of eight clock rates as the master clock
when the module is in master mode.
Since this master clock is derived the CPU bus clock, the user
program should not execute the WAIT instruction when the DDC
module in master mode. This will cause the SDA and SCL lines to
hang, as the WAIT instruction places the MCU in WAIT mode, with
CPU clock is halted. These bits are cleared upon reset. (See Table
15-3 . Baud Rate Select.)
Table 15-3. Baud Rate Select
BR2
BR1
BR0
Baud Rate
0
0
0
100k
0
0
1
50k
0
1
0
25k
0
1
1
12.5k
1
0
0
6.25k
1
0
1
3.125k
1
1
0
1.56k
1
1
1
0.78k
NOTE:
CPU bus clock is external clock ÷ 4 = 6MHz
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Technical Data
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DDC12AB Interface
15.6.5 DDC Status Register (DSR)
Address:
$0019
Bit 7
6
5
4
3
2
1
Bit 0
Read:
RXIF
TXIF
MATCH
SRW
RXAK
SCLIF
TXBE
RXBF
Write:
0
0
Reset:
0
0
1
0
0
0
0
1
0
= Unimplemented
Figure 15-5. DDC Status Register (DSR)
RXIF — DDC Receive Interrupt Flag
This flag is set after the data receive register (DDRR) is loaded with a
new received data. Once the DDRR is loaded with received data, no
more received data can be loaded to the DDRR register until the CPU
reads the data from the DDRR to clear RXBF flag. RXIF generates an
interrupt request to CPU if the DIEN bit in DCR is also set. This bit is
cleared by writing "0" to it or by reset; or when the DEN = 0.
1 = New data in data receive register (DDRR)
0 = No data received
TXIF — DDC Transmit Interrupt Flag
This flag is set when data in the data transmit register (DDTR) is
downloaded to the output circuit, and that new data can be written to
the DDTR. TXIF generates an interrupt request to CPU if the DIEN bit
in DCR is also set. This bit is cleared by writing "0" to it or when the
DEN = 0.
1 = Data transfer completed
0 = Data transfer in progress
MATCH — DDC Address Match
This flag is set when the received data in the data receive register
(DDRR) is an calling address which matches with the address or its
extended addresses (EXTAD=1) specified in the DADR register.
1 = Received address matches DADR
0 = Received address does not match
Technical Data
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DDC12AB Interface
MOTOROLA
DDC12AB Interface
Registers
SRW — DDC Slave Read/Write
This bit indicates the data direction when the module is in slave mode.
It is updated after the calling address is received from a master
device. SRW = 1 when the calling master is reading data from the
module (slave transmit mode). SRW = 0 when the master is writing
data to the module (receive mode).
1 = Slave mode transmit
0 = Slave mode receive
RXAK — DDC Receive Acknowledge
When this bit is cleared, it indicates an acknowledge signal has been
received after the completion of 8 data bits transmission on the bus.
When RXAK is set, it indicates no acknowledge signal has been
detected at the 9th clock; the module will release the SDA line for the
master to generate "stop" or "repeated start" condition. Reset sets this
bit.
1 = No acknowledge signal received at 9th clock bit
0 = Acknowledge signal received at 9th clock bit
SCLIF — SCL Interrupt Flag
This flag is set when a falling edge is detected on the SCL line, only if
DDC1EN bit is set. SCLIF generates an interrupt request to CPU if the
SCLIEN bit in DCR is also set. SCLIF is cleared by writing "0" to it or
when the DCC1EN = 0, or DEN = 0. Reset clears this bit.
1 = Falling edge detected on SCL line
0 = No falling edge detected on SCL line
TXBE — DDC Transmit Buffer Empty
This flag indicates the status of the data transmit register (DDTR).
When the CPU writes the data to the DDTR, the TXBE flag will be
cleared. TXBE is set when DDTR is emptied by a transfer of its data
to the output circuit. Reset sets this bit.
1 = Data transmit register empty
0 = Data transmit register full
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DDC12AB Interface
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DDC12AB Interface
RXBF — DDC Receive Buffer Full
This flag indicates the status of the data receive register (DDRR).
When the CPU reads the data from the DDRR, the RXBF flag will be
cleared. RXBF is set when DDRR is full by a transfer of data from the
input circuit to the DDRR. Reset clears this bit.
1 = Data receive register full
0 = Data receive register empty
15.6.6 DDC Data Transmit Register (DDTR)
Address:
$001A
Bit 7
6
5
4
3
2
1
Bit 0
DTD7
DTD6
DTD5
DTD4
DTD3
DTD2
DTD1
DTD0
1
1
1
1
1
1
1
1
Read:
Write:
Reset:
Figure 15-6. DDC Data Transmit Register (DDTR)
When the DDC module is enabled, DEN = 1, data written into this
register depends on whether module is in master or slave mode.
In slave mode, the data in DDTR will be transferred to the output circuit
when:
•
the module detects a matched calling address (MATCH = 1), with
the calling master requesting data (SRW = 1); or
•
the previous data in the output circuit has be transmitted and the
receiving master returns an acknowledge bit, indicated by a
received acknowledge bit (RXAK = 0).
If the calling master does not return an acknowledge bit (RXAK = 1), the
module will release the SDA line for master to generate a "stop" or
"repeated start" condition. The data in the DDTR will not be transferred
to the output circuit until the next calling from a master. The transmit
buffer empty flag remains cleared (TXBE = 0).
In master mode, the data in DDTR will be transferred to the output circuit
when:
Technical Data
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DDC12AB Interface
MOTOROLA
DDC12AB Interface
Registers
•
the module receives an acknowledge bit (RXAK = 0), after
setting master transmit mode (MRW = 0), and the calling address
has been transmitted; or
•
the previous data in the output circuit has be transmitted and the
receiving slave returns an acknowledge bit, indicated by a
received acknowledge bit (RXAK = 0).
If the slave does not return an acknowledge bit (RXAK = 1), the master
will generate a "stop" or "repeated start" condition. The data in the DDTR
will not be transferred to the output circuit. The transmit buffer empty flag
remains cleared (TXBE = 0).
The sequence of events for slave transmit and master transmit are
illustrated in Figure 15-8.
15.6.7 DDC Data Receive Register (DDRR)
Address:
Read:
$001B
Bit 7
6
5
4
3
2
1
Bit 0
DRD7
DRD6
DRD5
DRD4
DRD3
DRD2
DRD1
DRD0
0
0
0
0
0
0
0
0
Write:
Reset:
= Unimplemented
Figure 15-7. DDC Data Receive Register (DDRR)
When the DDC module is enabled, DEN = 1, data in this read-only
register depends on whether module is in master or slave mode.
In slave mode, the data in DDRR is:
•
the calling address from the master when the address match flag
is set (MATCH = 1); or
•
the last data received when MATCH = 0.
In master mode, the data in the DDRR is:
•
the last data received.
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DDC12AB Interface
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DDC12AB Interface
When the DDRR is read by the CPU, the receive buffer full flag is cleared
(RXBF = 0), and the next received data is loaded to the DDRR. Each
time when new data is loaded to the DDRR, the RXIF interrupt flag is set,
indicating that new data is available in DDRR.
The sequence of events for slave receive and master receive are
illustrated in Figure 15-8.
15.7 Programming Considerations
When the DDC module detects an arbitration loss in master mode, it will
release both SDA and SCL lines immediately. But if there are no further
STOP conditions detected, the module will hang up. Therefore, it is
recommended to have time-out software to recover from such ill
condition. The software can start the time-out counter by looking at the
BB (Bus Busy) flag in the DMCR and reset the counter on the completion
of one byte transmission. If a time-out occur, software can clear the DEN
bit (disable DDC module) to release the bus, and hence clearing the BB
flag. This is the only way to clear the BB flag by software if the module
hangs up due to a no STOP condition received. The DDC can resume
operation again by setting the DEN bit.
Technical Data
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MOTOROLA
DDC12AB Interface
Programming Considerations
(a) Master Transmit Mode
START
Address
TXBE=0
MRW=0
MAST=1
Data1 → DDTR
0
TX Data1
ACK
ACK
TXBE=1
TXIF=1
Data3 → DDTR
TXBE=1
TXIF=1
Data2 → DDTR
TX DataN
NAK
STOP
TXBE=1 NAKIF=1
TXIF=1 MAST=0
DataN+2 → DDTR TXBE=0
(b) Master Receive Mode
START
Address
1
RX Data1
ACK
ACK
Data1 → DDRR
RXIF=1
RXBF=1
RXBF=0
MRW=1
MAST=1
TXBE=0
(dummy data → DDTR)
RX DataN
NAK
STOP
NAKIF=1
DataN → DDRR
RXIF=1 MAST=0
RXBF=1
(c) Slave Transmit Mode
START
Address
TXBE=1
RXBF=0
1
TX Data1
ACK
RXIF=1
RXBF=1
MATCH=1
SRW=1
Data1 → DDTR
ACK
TXBE=1
TXIF=1
Data2 → DDTR
TX DataN
NAK
STOP
TXBE=1 NAKIF=1
TXIF=1 TXBE=0
DataN+2 → DDTR
(d) Slave Receive Mode
START
Address
TXBE=0
RXBF=0
0
ACK
RXIF=1
RXBF=1
MATCH=1
SRW=0
RX Data1
ACK
Data1 → DDRR
RXIF=1
RXBF=1
RX DataN
NAK
STOP
DataN → DDRR
RXIF=1
RXBF=1
KEY: shaded data packets indicate a transmit by the MCU’s DDC module
Figure 15-8. Data Transfer Sequences for Master/Slave Transmit/Receive Modes
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
DDC12AB Interface
207
DDC12AB Interface
Technical Data
208
MC68HC908BD48 — Rev. 1.0
DDC12AB Interface
MOTOROLA
Technical Data — MC68HC908BD48
Section 16. Sync Processor
16.1 Contents
16.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
16.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
16.4
I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
16.5 Functional Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
16.5.1 Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
16.5.1.1
Hsync Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . 214
16.5.1.2
Vsync Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . 214
16.5.1.3
Composite Sync Polarity Detection . . . . . . . . . . . . . . . . 214
16.5.2 Sync Signal Counters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
16.5.3 Polarity Controlled HSYNCO and VSYNCO Outputs. . . . . 215
16.5.4 Clamp Pulse Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
16.5.5 Low Vertical Frequency Detect . . . . . . . . . . . . . . . . . . . . . 217
16.6 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
16.6.1 Sync Processor Control & Status Register (SPCSR). . . . . 217
16.6.2 Sync Processor Input/Output Control Register (SPIOCR) . 219
16.6.3 Vertical Frequency Registers (VFRs). . . . . . . . . . . . . . . . . 221
16.6.4 Hsync Frequency Registers (HFRs). . . . . . . . . . . . . . . . . . 223
16.6.5 Sync Processor Control Register 1 (SPCR1). . . . . . . . . . . 225
16.6.6 H&V Sync Output Control Register (HVOCR) . . . . . . . . . . 226
16.7
System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
16.2 Introduction
The Sync Processor is designed to detect and process sync signals
inside a digital monitor system — from separated Hsync and Vsync
inputs, or from composite sync inputs such as Sync-On-Green (SOG).
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
209
Sync Processor
After detection and the necessary polarity correction and/or sync
separation, the corrected sync signals are sent out. The MCU can also
send commands to other monitor circuitry, such as for the geometry
correction and OSD, using the DDC12AB and/or the IIC communication
channels.
The block diagram of the Sync Processor is shown in Figure 16-1.
NOTE:
All quoted timings in this section assume an internal bus frequency of
6MHz.
Technical Data
210
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
Features
16.3 Features
Features of the Sync Processor include the following:
•
Polarity detector
•
Horizontal frequency counter
•
Vertical frequency counter
•
Low vertical frequency indicator (40.7Hz)
•
Polarity controlled HSYNCO and VSYNCO outputs:
– From separate Hsync and Vsync
– From composite sync on HSYNC or SOG input pin
– From internal selectable free running Hsync and Vsync pulses
•
CLAMP pulse output to the external pre-amp chip
•
Internal schmitt trigger on HSYNC, VSYNC, and SOG input pins
to improve noise immunity
16.4 I/O Pins
The Sync Processor uses six I/O pins, with four pins shared with
standard port I/O pins. The full name of the Sync Processor I/O pins are
listed in Table 16-1. The generic pin name appear in the text that
follows.
Table 16-1. Pin Name Conventions
Sync Processor
Generic Pin Names:
Full MCU Pin Names:
Pin Selected for
Sync Processor Function By:
HSYNC
HSYNC
—
VSYNC
VSYNC
—
SOG
PTE0/SOG/TCH0
SOGE bit in CONFIG1 ($001D)
HSYNCO
PTE1/HSYNCO
HSYNCOE bit in CONFIG 1 ($001D)
VSYNCO
PTE2/VSYNCO
VSYNCOE bit in CONFIG 1 ($001D)
CLAMP
PTD4/CLAMP
CLAMPE bit in PDCR ($0049)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
211
Sync Processor
Table 16-2. Sync Processor I/O Register Summary
Addr.
Register Name
$0040 Sync Processor Control
and Status Register
(SPCSR)
$0041 Vertical Frequency High
Register
(VFHR)
$0042 Vertical Frequency Low
Register
(VFLR)
$0043
$0044
$0045
Hsync Frequency High
Register
(HFHR)
Hsync Frequency Low
Register
(HFLR)
Sync Processor I/O
Control Register
(SPIOCR)
$0046 Sync Processor Control
Register 1
(SPCR1)
$0047
H&V Sync Output
Control Register
(HVOCR)
Bit 7
6
VSIE
VEDGE
Read:
5
3
2
COMP
VINVO
HINVO
VSIF
Write:
1
Bit 0
VPOL
HPOL
0
Reset:
0
0
0
0
0
0
0
0
Read:
VOF
0
0
VF12
VF11
VF10
VF9
VF8
CPW1
CPW0
Write:
Reset:
0
0
0
0
0
0
0
0
Read:
VF7
VF6
VF5
VF4
VF3
VF2
VF1
VF0
Reset:
0
0
0
0
0
0
0
0
Read:
HFH7
HFH6
HFH5
HFH4
HFH3
HFH2
HFH1
HFH0
Reset:
0
0
0
0
0
0
0
0
Read:
HOVER
0
0
HFL4
HFL3
HFL2
HFL1
HFL0
0
0
0
0
0
0
0
0
COINV
R
BPOR
SOUT
0
0
0
0
0
0
HPS1
HPS0
R
R
ATPOL
FSHF
0
0
0
0
0
0
0
0
0
0
0
Write:
Write:
Write:
Reset:
Read: VSYNCS HSYNCS
SOGSEL CLAMPOE
Write:
Reset:
0
Read:
0
LVSIF
LVSIE
Write:
Reset:
0
0
Read:
R
HVOCR2 HVOCR1 HVOCR0
Write:
Reset:
0
0
0
= Unimplemented
Technical Data
212
4
0
0
R
0
0
0
= Reserved
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
Functional Blocks
16.5 Functional Blocks
EXTRACTED
VSYNC
SVF
A1
VSYNCO
B S
B S
VSYNC
VINVO
A1
SOUT
COMP
VSIF
POLARITY DETECT
VPOL
VSIE
EDGE DETECT
ONE SHOT
VEDGE
VFLR
INTERNAL
BUS CLOCK
(6MHz)
(125kHz)
÷ 48
VFHR
VOF
13-BIT COUNTER
OVERFLOW DETECT
$C00 DETECT
TO INTERRUPT
LOGIC
LVSIF
LVSIE
ONE SHOT
HFLR
CLK32/32.768
A1
HSYNC
HFHR
13-BIT COUNTER
HOVER
OVERFLOW DETECT
B S
SOG
SOGSEL
POLARITY DETECT
VPOL
A1
B S
HPOL
COMP
EXTRACTED VSYNC
VSYNC EXTRACTOR
BPOR
SVF
2µs
H/V SYNC
PULSE GENERATOR
HVOCR[2:0]
B
SHF
COINV
CLAMP
PULSE GENERATOR
CLAMP
A1 S
SOUT
HINVO
HSYNCO
Figure 16-1. Sync Processor Block Diagram
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
213
Sync Processor
16.5.1 Polarity Detection
16.5.1.1 Hsync Polarity Detection
The Hsync polarity detection circuit measures the length of high and low
period of the HSYNC input. If the length of high is longer than L and the
length of low is shorter than S, the HPOL bit will be "0", indicating a
negative polarity HSYNC input. If the length of low is longer than L and
the length of high is shorter than S, the HPOL bit will be "1", indicating a
positive polarity HSYNC input. The table below shows three possible
cases for HSYNC polarity detection — the conditions are selected by the
HPS[1:0] bits in the Sync Processor Control Register 1 (SPCR1).
Polarity Detection Pulse Width
SPCR1 ($0046)
Long is greater than (L)
Short is less than (S)
HPS1
HPS0
7µs
6µs
0
0
3.5µs
3µs
1
X
14µs
12µs
0
1
16.5.1.2 Vsync Polarity Detection
The Vsync polarity detection circuit performs a similar function as for
Hsync. If the length of high is longer than 4ms and the length of low is
shorter than 2ms, the VPOL bit will be "0", indicating a negative polarity
VSYNC input. If the length of low is longer than 4ms and the length of
high is shorter than 2ms, the VPOL bit will be "1", indicating a positive
polarity VSYNC input.
16.5.1.3 Composite Sync Polarity Detection
When a composite sync signal is the input (COMP = 1 for composite
sync processing), the HPOL bit = VPOL bit, and the polarity is detected
using the VSYNC polarity detection criteria described in section
16.5.1.2.
Technical Data
214
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
Functional Blocks
16.5.2 Sync Signal Counters
There are two counters: a 13-bit horizontal frequency counter to count
the number of horizontal sync pulses within a 32ms or 8ms period; and
a 13-bit vertical frequency counter to count the number of system clock
cycles between two vertical sync pulses. These two data can be read by
the CPU to check the signal frequencies and to determine the video
mode.
The 13-bit vertical frequency register encompasses vertical frequency
range from approximately 15Hz to 128kHz. Due to the asynchronous
timing between the incoming VSYNC signal and internal system clock,
there will be ±1 count error on reading the Vertical Frequency
Registers (VFRs) for the same vertical frequency.
The horizontal counter counts the pulses on HSYNC pin input, and is
uploaded to the Hsync Frequency Registers (HFRs) every 32.768ms
or 8.192ms.
16.5.3 Polarity Controlled HSYNCO and VSYNCO Outputs
The processed sync signals are output on HSYNCO and VSYNCO when
the corresponding bits in Configuration Register 0 ($001D) are set. The
signal to these output pins depend on SOUT and COMP bits (see Table
16-3), with polarity controlled by ATPOL, HINVO, and VINVO bits as
shown in Table 16-4.
Table 16-3. Sync Output Control
Sync Outputs:
VSYNCO and HSYNCO
SOUT
COMP
1
X
Free-running pulse with negative polarity
0
0
Sync outputs follow sync inputs VSYNC and HSYNC
respectively, with polarity correction shown in Table 16-4.
0
1
HSYNCO follows the composite sync input and VSYNCO
is the extracted Vsync (3 to 14µs delay to composite input),
with polarity correction shown in Table 16-4.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
215
Sync Processor
Table 16-4. Sync Output Polarity
ATPOL
SOUT
VINVO
or
HINVO
X
1
X
Free-running pulse with negative polarity
0
0
0
Same polarity as sync input
0
0
1
Inverted polarity of sync input
1
0
0
Negative polarity sync output
1
0
1
Positive polarity sync output
Sync Outputs:
VSYNCO/HSYNCO
When the SOUT bit is set, the HSYNCO output is a free-running pulse
with 2µs width. Both HSYNCO and VSYNCO outputs are negative
polarity, with frequencies selected by the H & V Sync Output Control
Register (HVOCR).
16.5.4 Clamp Pulse Output
When the CLAMPOE bit in SPIOCR is set to "1", a clamp signal is output
on the CLAMP pin. This clamp pulse is triggered either on the leading
edge or the trailing edge of HSYNC, controlled by BPOR bit, with the
polarity controlled by the COINV bit. See Figure 16-2 . Clamp Pulse
Output Timing.
HSYNC
(HPOL = 1)
CLAMP
(BPOR = 0)
Pulse width = 0.33~2.1µs
CLAMP
(BPOR = 1)
Pulse width = 0.33~2.1µs
HSYNC
(HPOL = 0)
CLAMP
(BPOR = 0)
Pulse width = 0.33~2.1µs
CLAMP
(BPOR = 1)
Pulse width = 0.33~2.1µs
Figure 16-2. Clamp Pulse Output Timing
Technical Data
216
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
Registers
16.5.5 Low Vertical Frequency Detect
Logic monitors the value of the Vsync Frequency Register (VFR), and
sets the low vertical frequency flag (LVSIF) when the value of VFR is
higher than $C00 (frequency below 40.7Hz). LVSIF bit can generate an
interrupt request to the CPU when the LVSIE bit is set and I-bit in the
Condition Code Register is "0". The LVSIF bit can help the system to
detect video off mode fast.
16.6 Registers
Eight registers are associated with the Sync Processor, they outlined in
the following sections.
16.6.1 Sync Processor Control & Status Register (SPCSR)
Address:
$0040
Bit 7
6
VSIE
VEDGE
Read:
4
3
2
COMP
VINVO
HINVO
0
0
0
VSIF
Write:
Reset:
5
1
Bit 0
VPOL
HPOL
0
0
0
0
0
0
= Unimplemented
Figure 16-3. Sync Processor Control & Status Register (SPCSR)
VSIE — VSync Interrupt Enable
When this bit is set, the VSIF flag is enabled to generate an interrupt
request to the CPU. When VSIE is cleared, the VSIF flag is prevented
from generating an interrupt request to the CPU. Reset clears this bit.
1 = VSIF bit set will generate interrupt request to CPU
0 = VSIF bit set does not generate interrupt request to CPU
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
217
Sync Processor
VEDGE — VSync Interrupt Edge Select
This bit specifies the triggering edge of Vsync interrupt. When it is "0",
the rising edge of internal Vsync signal which is either from the
VSYNC pin or extracted from the composite input signal will set VSIF
flag. When it is "1", the falling edge of internal Vsync signal will set
VSIF flag. Reset clears this bit.
1 = VSIF bit will be set by rising edge of Vsync
0 = VSIF bit will be set by falling edge of Vsync
VSIF — VSync Interrupt Flag
This flag is only set by the specified edge of the internal Vsync signal,
which is either from the VSYNC input pin or extracted from the
composite sync input signal. The triggering edge is specified by the
VEDGE bit. VSIF generates an interrupt request to the CPU if the
VSIE bit is also set. This bit is cleared by writing a "0" to it or by a reset.
1 = A valid edge is detected on the Vsync
0 = No valid Vsync is detected
COMP — Composite Sync Input Enable
This bit is set to enable the separator circuit which extracts the Vsync
pulse from the composite sync input on HSYNC or SOG pin (select by
SOGSEL bit). The extracted Vsync signal is used as it were from the
VSYNC input. Reset clears this bit.
1 = Composite Sync Input Enabled
0 = Composite Sync Input Disabled
VINVO — VSYNCO Signal Polarity
This bit, together with the ATPOL bit in SPCR1 controls the output
polarity of the VSYNCO signal (see Table 16-5).
HINVO — HSYNCO Signal Polarity
This bit, together with the ATPOL bit in SPCR1 controls the output
polarity of the HSYNCO signal (see Table 16-5).
Technical Data
218
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
Registers
Table 16-5. ATPOL, VINVO, and HINVO setting
Sync Outputs:
VSYNCO/HSYNCO
ATPOL
VINVO / HINVO
0
0
Same polarity as sync input
0
1
Inverted polarity of sync input
1
0
Negative polarity sync output
1
1
Positive polarity sync output
VPOL — Vsync Input Polarity
This bit indicates the polarity of the VSYNC input, or the extracted
Vsync from a composite sync input (COMP=1). Reset clears this bit.
1 = Vsync is positive polarity
0 = Vsync is negative polarity
HPOL — Hsync Input Polarity
This bit indicates the polarity of the HSYNC input. This bit equals the
VPOL bit when the COMP bit is set. Reset clears this bit.
1 = Hsync is positive polarity
0 = Hsync is negative polarity
16.6.2 Sync Processor Input/Output Control Register (SPIOCR)
Address:
$0045
Bit 7
6
5
4
COINV
R
0
0
3
2
1
Bit 0
BPOR
SOUT
0
0
Read: VSYNCS HSYNCS
SOGSEL CLAMPOE
Write:
Reset:
0
0
= Unimplemented
0
R
0
= Reserved
Figure 16-4. Sync Processor Input/Output Control Register (SPIOCR)
VSYNCS — VSYNC Input State
This read-only bit reflects the logical state of the VSYNC input.
HSYNCS — HSYNC Input State
This read-only bit reflects the logical state of the HSYNC input.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
219
Sync Processor
COINV — Clamp Output Invert
This bit is set to invert the clamp pulse output to negative. Reset
clears this bit.
1 = clamp output is set for negative pulses
0 = clamp output is set for positive pulses
SOGSEL — SOG Select
This bit selects either the HSYNC pin or SOG pin as the composite
sync signal input pin. Reset clears this bit.
1 = SOG pin is used as the composite sync input
0 = HSYNC pin is used as the composite sync input
CLAMPOE — Clamp Output Enable
This bit is set to enable the clamp pulse output circuitry. Reset clears
this bit.
1 = Clamp pulse circuit enabled
0 = Clamp pulse circuit disabled
BPOR — Back Porch
This bit defines the triggering edge of the clamp pulse output relative
to the HSYNC input. Reset clears this bit.
1 = Clamp pulse is generated on the trailing edge of HSYNC
0 = Clamp pulse is generated on the leading edge of HSYNC
SOUT — Sync Output Enable
This bit will select the output signals for the VSYNCO and HSYNCO
pins. Reset clears this bit.
1 = VSYNCO and HSYNCO outputs are internally generated
free-running sync pulses with frequencies determined by
HVCOR[2:0] bits in HVCOR.
0 = VSYNCO and HSYNCO outputs are processed VSYNC and
HSYNC inputs respectively
Technical Data
220
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
Registers
16.6.3 Vertical Frequency Registers (VFRs)
This register pair contains the 13-bit vertical frequency count value, an
overflow bit, and the clamp pulse width selection bits.
Address:
Read:
$0041
Bit 7
6
5
4
3
2
1
Bit 0
VOF
0
0
VF12
VF11
VF10
VF9
VF8
CPW1
CPW0
0
0
0
0
0
0
0
Write:
Reset:
0
Figure 16-5. Vertical Frequency High Register
Address:
Read:
$0042
Bit 7
6
5
4
3
2
1
Bit 0
VF7
VF6
VF5
VF4
VF3
VF2
VF1
VF0
0
0
0
0
0
0
0
0
Write:
Reset:
= Unimplemented
Figure 16-6. Vertical Frequency Low Register
VF[12:0] — Vertical Frame Frequency\
This read-only 13-bit contains information of the vertical frame
frequency. An internal 13-bit counter counts the number of 8µs
periods between two Vsync pulses. The most significant 5 bits of the
counted value is transferred to the high byte register, and the least
significant 8 bits is transferred to an intermediate buffer. When the
high byte register is read, the 8-bit counted value stored in the
intermediate buffer will be uploaded to the low byte register.
Therefore, user program must read the high byte register first, then
low byte register in order to get the complete counted value of one
vertical frame. If the counter overflows, the overflow flag, VOF, will be
set, indicating the counter value stored in the VFRs is meaningless.
The data corresponds to the period of one vertical frame. This register
can be read to determine if the frame frequency is valid, and to
determine the video mode.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
221
Sync Processor
The frame frequency is calculated by:
1
Vertical Frame Frequency = --------------------------------------------------VFR ± 1 × 48 × t CYC
1
= -------------------------------------VFR ± 1 × 8µ s
for internal bus clock of 6 MHz
Table 16-6 shows examples for the Vertical Frequency Register, all VFR
numbers are in hexadecimal.
Table 16-6. Sample Vertical Frame Frequencies
VFR
Max Freq.
Min Freq.
VFR
Max Freq.
Min Freq.
$02A0
186.20 Hz
185.70 Hz
$0780
65.10 Hz
65.00 Hz
$03C0
130.34 Hz
130.07 Hz
$0823
60.04 Hz
59.98 Hz
$03C1
130.21 Hz
129.94 Hz
$0824
60.01 Hz
59.95 Hz
$03C2
130.07 Hz
129.80 Hz
$0825
59.98 Hz
59.92 Hz
$04E2
100.08 Hz
99.92 Hz
$09C4
50.02 Hz
49.98 Hz
$04E3
100.00 Hz
99.84 Hz
$09C5
50.00 Hz
49.96 Hz
$04E4
99.92 Hz
99.76 Hz
$09C6
49.98 Hz
49.94 Hz
$06F9
70.07 Hz
69.99 Hz
$1FFD
15.266 Hz
15.262 Hz
$06FA
70.03 Hz
69.95 Hz
$1FFE
15.264 Hz
15.260 Hz
$06FB
69.99 Hz
69.91 Hz
$1FFF
15.262 Hz
15.258 Hz
VOF — Vertical Frequency Counter Overflow
This read-only bit is set when an overflow has occurred on the 13-bit
vertical frequency counter. Reset clears this bit, and will be updated
every vertical frame.
An overflow occurs when the period of Vsync frame exceeds
64.768ms (a vertical frame frequency lower than 15.258Hz).
1 = A vertical frequency counter overflow has occurred
0 = No vertical frequency counter overflow has occurred
Technical Data
222
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
Registers
CPW[1:0] — Clamp Pulse Width
The CPW1 and CPW0 bits are used to select the output clamp pulse
width. Reset clears these bits, selecting a default clamp pulse width
between 0.33µs and 0.375µs. These bits always read as Zeros.
Table 16-7. Clamp Pulse Width
CPW1
CPW0
Clamp Pulse Width
0
0
0.33µs to 0.375µs
0
1
0.5µs to 0.542µs
1
0
0.75µs to 0.792µs
1
1
2µs to 2.042µs
16.6.4 Hsync Frequency Registers (HFRs)
This register pair contains the 13-bit Hsync frequency count value and
an overflow bit.
Address:
Read:
$0043
Bit 7
6
5
4
3
2
1
Bit 0
HFH7
HFH6
HFH5
HFH4
HFH3
HFH2
HFH1
HFH0
0
0
0
0
0
0
0
0
Write:
Reset:
Figure 16-7. Hsync Frequency High Register
Address:
Read:
$0044
Bit 7
6
5
4
3
2
1
Bit 0
HOVER
0
0
HFL4
HFL3
HFL2
HFL1
HFL0
0
0
0
0
0
0
0
0
Write:
Reset:
= Unimplemented
Figure 16-8. Hsync Frequency Low Register
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
223
Sync Processor
HFH[7:0], HFL[4:0] — Horizontal Line Frequency
This read-only 13-bit contains the number of horizontal lines in a
32ms window. An internal 13-bit counter counts the Hsync pulses
within a 32ms window in every 32.768ms period. If the FSHF bit in
SPCR1 is set, only the most 11-bits (HFH[7:0] & HFL[4:2]) will be
updated by the counter. Thus, providing a Hsync pulse count in a 8ms
window in every 8.192ms.
The most significant 8 bits of counted value is transferred to the high
byte register, and the least significant 5 bits is transferred to an
intermediate buffer. When the high byte register is read, the 5-bit
counted value stored in the intermediate buffer will be uploaded to the
low byte register. Therefore, user the program must read the high byte
register first then low byte register in order to get the complete
counted value of Hsync pulses. If the counter overflows, the overflow
flag, HOVER, will be set, indicating the number of Hsync pulses in
32ms are more than 8191 (213 –1), i.e. a Hsync frequency greater
than 256kHz.
For the 32ms window, the HFHR and HFLR are such that the
frequency step unit in the 5-bit of HFLR is 0.03125kHz, and the step
unit in the 8-bit HFHR is 1kHz. Therefore, the Hsync frequency can
be easily calculated by:
Hsync Frequency = [HFH + (HFL × 0.03125)]kHz
where: HFH is the value of HFH[7:0]
HFL is the value of HFL[4:0]
HOVER — Hsync Frequency Counter Overflow
This read-only bit is set when an overflow has occurred on the 13-bit
Hsync frequency counter. Reset clears this bit, and will be updated
every count period.
An overflow occurs when the number Hsync pulses exceed 8191, a
Hsync frequency greater than 256kHz.
1 = A Hsync frequency counter overflow has occurred
0 = No Hsync frequency counter overflow has occurred
Technical Data
224
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
Registers
16.6.5 Sync Processor Control Register 1 (SPCR1)
Address:
$0046
Bit 7
Read:
6
4
3
2
1
Bit 0
HPS1
HPS0
R
R
ATPOL
FSHF
0
0
0
0
0
0
LVSIF
LVSIE
Write:
Reset:
5
0
0
0
= Unimplemented
R
= Reserved
Figure 16-9. Sync Processor Control Register 1 (SPCR1)
LVSIE — Low VSync Interrupt Enable
When this bit is set, the LVSIF flag is enabled to generate an interrupt
request to the CPU. When LVSIE is cleared, the LVSIF flag is
prevented from generating an interrupt request to the CPU. Reset
clears this bit.
1 = Low Vsync interrupt enabled
0 = Low Vsync interrupt disabled
LVSIF — Low VSync Interrupt Flag
This read-only bit is set when the value of VFR is higher than $C00
(vertical frame frequency below 40.7Hz). LVSIF generates an
interrupt request to the CPU if the LVSIE is also set. This bit is cleared
by writing a "0" to it or reset.
1 = Vertical frequency is below 40.7Hz
0 = Vertical frequency is higher than 40.7Hz
HPS[1:0] — HSYNC input Detection Pulse Width
These two bits control the detection pulse width of HSYNC input.
Reset clears these two bits, setting a default middle frequency of
HSYNC input.
Table 16-8. HSYNC Polarity Detection Pulse Width
HPS1
HPS0
Polarity Detection Pulse Width
0
0
Long > 7µs and Short < 6µs
1
X
Long > 3.5µs and Short < 3µs
0
1
Long > 14µs and Short < 12µs
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
225
Sync Processor
ATPOL — Auto Polarity
This bit, together with the VINVO or HINVO bits in SPCSR controls
the output polarity of the VSYNCO or HSYNCO signals respectively.
Reset clears this bit (see Table 16-9).
Table 16-9. ATPOL, VINVO, and HINVO setting
Sync Outputs:
VSYNCO/HSYNCO
ATPOL
VINVO / HINVO
0
0
Same polarity as sync input
0
1
Inverted polarity of sync input
1
0
Negative polarity sync output
1
1
Positive polarity sync output
FSHF — Fast Horizontal Frequency Count
This bit is set to shorten the measurement cycle of the horizontal
frequency. If it is set, only HFH[7:0] and HFL[4:2] will be updated by
the Hsync counter, providing a count in a 8ms window in every
8.192ms, with HFL[1:0] reading as zeros. Therefore, user can
determine the horizontal frequency change within 8.192ms to protect
critical circuitry. Reset clears this bit.
1 = Number of Hsync pulses is counted in an 8ms window
0 = Number of Hsync pulses is counted in a 32ms window
16.6.6 H&V Sync Output Control Register (HVOCR)
Address:
$0047
Bit 7
Read:
6
5
4
3
0
0
0
0
R
2
1
Bit 0
HVOCR2 HVOCR1 HVOCR0
Write:
Reset:
0
0
0
= Unimplemented
0
0
R
0
0
0
= Reserved
Figure 16-10. H&V Sync Output Control Register (HVOCR)
Technical Data
226
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Sync Processor
System Operation
HVOCR[2:0] — H&V Output Select Bits
These three bits select the frequencies of the internal generated
free-running sync pulses for output to HSYNCO and VSYNCO pins,
when the SOUT bit is set in the SPIOCR. Reset clears these bits,
setting a default horizontal frequency of 31.25kHz and a vertical
frequency of 60Hz, a video mode of 640×480.
Table 16-10. Free-Running HSYNC and VSYNC Options
HSYNCO
VSYNCO
HVOCR
Video Mode
Pulse width
Frequency
Pulse width
Frequency
000
Negative 2µs
31.25kHz
Negative 192µs
59.98 Hz
640 × 480
001
Negative 2µs
43.48kHz
Negative 138µs
84.92 Hz
640 × 480
010
Negative 2µs
48.78kHz
Negative 123µs
60.00 Hz
1024 × 768
011
Negative 2µs
54.05kHz
Negative 111µs
84.98 Hz
800 × 600
100
Negative 2µs
60.61kHz
Negative 99µs
75.01 Hz
1024 × 768
101
Negative 2µs
80.00kHz
Negative 75µs
74.98 Hz
1280 × 1024
110
Negative 2µs
90.91kHz
Negative 66µs
84.96 Hz
1280 × 1024
111
Negative 2µs
105.26kHz
Negative 57µs
85.02 Hz
1600 × 1200
16.7 System Operation
This Sync Processor is designed to assist in determining the video mode
of incoming HSYNC and VSYNC of various frequencies and polarities,
and DPMS modes. In the DPMS standard, a no sync pulses definition
can be detected when the value of the Hsync Frequency Register (the
number of Hsync pulses) is less than one or when the VOF bit is set.
Since the Hsync Frequency Register is updated repeatedly in every
32.768ms, and a valid Vsync must have a frequency greater than
40.7Hz, a valid Vsync pulse will arrive within the 32.768ms window.
Therefore, the user should read the Hsync Frequency Register every
32.768ms to determine the presence of Hsync and/or Vsync pulses.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Sync Processor
227
Sync Processor
Technical Data
228
MC68HC908BD48 — Rev. 1.0
Sync Processor
MOTOROLA
Technical Data — MC68HC908BD48
Section 17. Input/Output (I/O) Ports
17.1 Contents
17.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
17.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
17.3.1 Port A Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
17.3.2 Data Direction Register A . . . . . . . . . . . . . . . . . . . . . . . . . 234
17.3.3 Port A Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
17.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
17.4.1 Port B Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
17.4.2 Data Direction Register B . . . . . . . . . . . . . . . . . . . . . . . . . 237
17.4.3 Port B Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
17.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
17.5.1 Port C Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
17.5.2 Data Direction Register C . . . . . . . . . . . . . . . . . . . . . . . . . 240
17.5.3 Port C Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
17.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
17.6.1 Port D Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
17.6.2 Data Direction Register D. . . . . . . . . . . . . . . . . . . . . . . . . . 243
17.6.3 Port D Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
17.7 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
17.7.1 Port E Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
17.7.2 Data Direction Register E. . . . . . . . . . . . . . . . . . . . . . . . . . 248
17.7.3 Port E Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
17.2 Introduction
Thirty-two (32) bidirectional input-output (I/O) pins form four parallel
ports. All I/O pins are programmable as inputs or outputs.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Input/Output (I/O) Ports
229
Input/Output (I/O) Ports
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.
Table 17-1. I/O Port Register Summary
Addr.
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
PTA7
PTA6
PTA5
PTA4
PTA3
PTA2
PTA1
PTA0
PTB2
PTB1
PTB0
PTC2
PTC1
PTC0
PTD2
PTD1
PTD0
Read:
$0000
Port A Data Register
Write:
(PTA)
Reset:
Unaffected by reset
Read:
$0001
Port B Data Register
Write:
(PTB)
Reset:
Read:
$0002
PTB6
PTB5
PTB4
PTB3
Unaffected by reset
0
0
PTC5
Port C Data Register
Write:
(PTC)
Reset:
Read:
$0003
PTB7
PTC4
PTC3
Unaffected by reset
0
PTD6
Port D Data Register
Write:
(PTD)
Reset:
PTD5
PTD4
PTD3
Unaffected by reset
Read:
$0004
DDRA7
Data Direction Register A
Write:
(DDRA)
Reset:
0
DDRA6
DDRA5
DDRA4
DDRA3
DDRA2
DDRA1
DDRA0
0
0
0
0
0
0
0
DDRB6
DDRB5
DDRB4
DDRB3
DDRB2
DDRB1
DDRB0
0
0
0
0
0
0
0
DDRC5
DDRC4
DDRC3
DDRC2
DDRC1
DDRC0
0
0
0
0
0
0
Read:
$0005
DDRB7
Data Direction Register B
Write:
(DDRB)
Reset:
0
Read:
$0006
Data Direction Register C
Write:
(DDRC)
Reset:
0
0
0
0
= Unimplemented
Technical Data
230
MC68HC908BD48 — Rev. 1.0
Input/Output (I/O) Ports
MOTOROLA
Input/Output (I/O) Ports
Introduction
Table 17-1. I/O Port Register Summary (Continued)
Addr.
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Data Direction Register D
$0007
Write:
(DDRD)
Reset:
0
DDRD6
DDRD5
DDRD4
DDRD3
DDRD2
DDRD1
DDRD0
0
0
0
0
0
0
0
0
Read:
Port E Data Register
Write:
(PTE)
Reset:
0
0
0
0
0
PTE2
PTE1
PTE0
Read:
Data Direction Register E
$0009
Write:
(DDRE)
Reset:
0
DDRE2
DDRE1
DDRE0
$0008
$001D
$0028
$0049
$0059
Unaffected by reset
0
0
0
Read:
Port D Configuration
Write:
Register (PDCR)
Reset:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PWM6E
PWM5E
PWM4E
PWM3E
PWM2E
PWM1E
PWM0E
0
0
0
0
0
0
0
IICDATE
IICSCLE
0
0
Read:
HSYNCOE VSYNCOE
Configuration Register 0
Write:
(CONFIG0)
Reset:
0
0
Read:
PWM7E
PWM Control Register 1
Write:
(PWMCR1)
Reset:
0
0
SOGE
0
0
CLAMPE DDCSCLE DDCDATE USBD–E
0
0
0
Read:
PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E
PWM Control Register 2
Write:
(PWMCR2)
Reset:
0
0
0
0
0
0
USBD+E
0
0
PWM9E
PWM8E
0
0
= Unimplemented
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Input/Output (I/O) Ports
231
Input/Output (I/O) Ports
Table 17-2. Port Control Register Bits Summary
Port
A
B
C
D
E
Module Control
Bit
DDR
0
DDRA0
PWM8E
PTA0/PWM8
1
DDRA1
PWM9E
PTA1/PWM9
2
DDRA2
PWM10E
PTA2/PWM10
3
DDRA3
PWM11E
PTA3/PWM11
4
DDRA4
PWM12E
PTA4/PWM12
5
DDRA5
PWM13E
PTA5/PWM13
6
DDRA6
PWM14E
PTA6/PWM14
7
DDRA7
PWM15E
PTA7/PWM15
0
DDRB0
PWM0E
PTB0/PWM0
1
DDRB1
PWM1E
PTB1/PWM1
2
DDRB2
PWM2E
PTB2/PWM2
3
DDRB3
PWM3E
PTB3/PWM3
4
DDRB4
PWM4E
PTB4/PWM4
5
DDRB5
PWM5E
PTB5/PWM5
6
DDRB6
PWM6E
PTB6/PWM6
7
DDRB7
PWM7E
PTB7/PWM7
0
DDRC0
PTC0/ADC0
1
DDRC1
PTC1/ADC1
2
DDRC2
3
DDRC3
4
DDRC4
PTC4/ADC4
5
DDRC5
PTC5/ADC5
0
DDRD0
1
DDRD1
2
DDRD2
3
DDRD3
4
DDRD4
5
DDRD5
6
DDRD6
0
DDRE0
1
DDRE1
2
DDRE2
Module
PWM
PWM
ADC
Register
PWMCR2
$0059
PWMCR1
$0028
ADSCR
$005D
USB
DDC12AB
PDCR
$0049
SYNC
MMIIC
SYNC/TIM
SYNC
CONFIG0
$001D
Technical Data
232
Control Bit
ADCH[4:0]
Pin
PTC2/ADC2
PTC3/ADC3/
D+E
PTD0/D+
D–E
PTD1/D–
DDCDATE
PTD2/DDCSDA
DDCSCLE
PTD3/DDCSCL
CLAMPE
PTD4/CLAMP
IICSCLE
PTD5/IICSCL
IICDATE
PTD6/IICSDA
SOGE
PTE0/SOG/TCH0
HSYNCOE
PTE1/HSYNCO
VSYNCOE
PTE2/VSYNCO
MC68HC908BD48 — Rev. 1.0
Input/Output (I/O) Ports
MOTOROLA
Input/Output (I/O) Ports
Port A
17.3 Port A
Port A is an 8-bit special-function port that shares all eight of its pins with
the pulse width modulator (PWM).
17.3.1 Port A Data Register
The port A data register (PTA) contains a data latch for each of the eight
port A pins.
Address:
$0000
Bit 7
6
5
4
3
2
1
Bit 0
PTA7
PTA6
PTA5
PTA4
PTA3
PTA2
PTA1
PTA0
PWM10
PWM9
PWM8
Read:
Write:
Reset:
Alternate
Function:
Unaffected by reset
PWM15
PWM14
PWM13
PWM12
PWM11
Figure 17-1. Port A Data Register (PTA)
PTA7–PTA0 — 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.
PWM15–PWM8 — PWM Outputs 15–8
The PWM output enable bits PWM15E–PWM8E, in PWM control
register 2 (PWMCR2) enable port A pins as PWM output pins. (See
17.3.3 Port A Options.)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Input/Output (I/O) Ports
233
Input/Output (I/O) Ports
17.3.2 Data Direction Register A
Data direction register A (DDRA) 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
6
5
4
3
2
1
Bit 0
DDRA7
DDRA6
DDRA5
DDRA4
DDRA3
DDRA2
DDRA1
DDRA0
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 17-2. Data Direction Register A (DDRA)
DDRA7–DDRA0 — Data Direction Register A Bits
These read/write bits control port A data direction. Reset clears
DDRA7–DDRA0, 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 17-3 shows the port A I/O logic.
INTERNAL DATA BUS
READ DDRA ($0004)
WRITE DDRA ($0004)
RESET
DDRAx
WRITE PTA ($0000)
PTAx
PTAx
READ PTA ($0000)
Figure 17-3. Port A I/O Circuit
Technical Data
234
MC68HC908BD48 — Rev. 1.0
Input/Output (I/O) Ports
MOTOROLA
Input/Output (I/O) Ports
Port A
When bit DDRAx is a logic 1, reading address $0000 reads the PTAx
data latch. When bit 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 17-3 summarizes
the operation of the port A pins.
Table 17-3. Port A Pin Functions
PTAPUE Bit
DDRA Bit
PTA Bit
Accesses
to DDRA
I/O Pin Mode
Accesses to PTA
Read/Write
Read
Write
0
0
X(1)
Input, Hi-Z(2)
DDRA7–DDRA0
Pin
PTA7–PTA0(3)
X
1
X
Output
DDRA7–DDRA0
PTA7–PTA0
PTA7–PTA0
NOTES:
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
17.3.3 Port A Options
The PWM control register 2 (PWMCR2) selects the port A pins for PWM
function or as standard I/O function. See 11.4.2 PWM Control
Registers 1 and 2 (PWMCR1:PWMCR2).
Address:
$0059
Bit 7
6
5
4
3
2
1
Bit 0
PWM9E
PWM8E
0
0
Read:
PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E
Write:
Reset:
0
0
0
0
0
0
Figure 17-4. PWM Control Register 1 (PWMCR1)
PWM15E–PWM8E — PWM Output Enable 15–8
Setting a bit to "1" will configure the corresponding PTAx/PWMx pin
for PWM output function. Reset clears these bits.
1 = PTAx/PWMx pin configured as PWMx output pin
0 = PTAx/PWMx pin configured as standard I/O pin
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Input/Output (I/O) Ports
235
Input/Output (I/O) Ports
17.4 Port B
Port B is an 8-bit special-function port that shares all eight of its pins with
the pulse width modulator (PWM).
NOTE:
Port pins PTB7–PTB2 are not available in a 28-pin dual in-line package.
17.4.1 Port B Data Register
The port B data register (PTB) contains a data latch for each of the eight
port pins.
Address:
$0001
Bit 7
6
5
4
3
2
1
Bit 0
PTB7
PTB6
PTB5
PTB4
PTB3
PTB2
PTB1
PTB0
PWM2
PWM1
PWM0
Read:
Write:
Reset:
Alternate
Function:
Unaffected by reset
PWM7
PWM6
PWM5
PWM4
PWM3
Figure 17-5. Port B Data Register (PTB)
PTB7–PTB0 — 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.
PWM7–PWM0 — PWM Outputs 7–0
The PWM output enable bits PWM7E–PWM0E, in PWM control
register 1 (PWMCR1) enable port B pins as PWM output pins. (See
17.4.3 Port B Options.)
Technical Data
236
MC68HC908BD48 — Rev. 1.0
Input/Output (I/O) Ports
MOTOROLA
Input/Output (I/O) Ports
Port B
17.4.2 Data Direction Register B
Data direction register B (DDRB) 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
6
5
4
3
2
1
Bit 0
DDRB7
DDRB6
DDRB5
DDRB4
DDRB3
DDRB2
DDRB1
DDRB0
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 17-6. Data Direction Register B (DDRB)
DDRB7–DDRB0 — Data Direction Register B Bits
These read/write bits control port B data direction. Reset clears
DDRB7–DDRB0], 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.
NOTE:
For those devices packaged in a 28-pin dual in-line package, set
DDRB7–DDRB2 to a 1 to configure PTB7–PTB2 as outputs.
Figure 17-7 shows the port B I/O logic.
INTERNAL DATA BUS
READ DDRB ($0005)
WRITE DDRB ($0005)
RESET
DDRBx
WRITE PTB ($0001)
PTBx
PTBx
READ PTB ($0001)
Figure 17-7. Port B I/O Circuit
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Input/Output (I/O) Ports
When bit DDRBx is a logic 1, reading address $0001 reads the PTBx
data latch. When bit 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 17-4 summarizes
the operation of the port B pins.
Table 17-4. Port B Pin Functions
DDRB Bit
PTB Bit
Accesses
to DDRB
I/O Pin Mode
Accesses to PTB
Read/Write
Read
Write
0
X(1)
Input, Hi-Z(2)
DDRB7–DDRB0
Pin
PTB7–PTB0(3)
1
X
Output
DDRB7–DDRB0
PTB7–PTB0
PTB7–PTB0
Notes:
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
17.4.3 Port B Options
The PWM control register 1 (PWMCR1) selects the port B pins for PWM
function or as standard I/O function. See 11.4.2 PWM Control
Registers 1 and 2 (PWMCR1:PWMCR2).
Address:
$0028
Bit 7
6
5
4
3
2
1
Bit 0
PWM7E
PWM6E
PWM5E
PWM4E
PWM3E
PWM2E
PWM1E
PWM0E
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 17-8. PWM Control Register 1 (PWMCR1)
PWM7E–PWM0E — PWM Output Enable 7–0
Setting a bit to "1" will configure the corresponding PTBx/PWMx pin
for PWM output function. Reset clears these bits.
1 = PTBx/PWMx pin configured as PWMx output pin
0 = PTBx/PWMx pin configured as standard I/O pin
Technical Data
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Port C
17.5 Port C
Port C is an 6-bit special-function port that shares all six of its pins with
the analog-to-digital converter (ADC) module.
NOTE:
Port pin PTC5 is not available in a 28-pin dual in-line package.
17.5.1 Port C Data Register
The port C data register (PTC) contains a data latch for each of the
seven port C pins.
NOTE:
Bit 5 of PTC are not available in a 28-pin dual in-line package.
Address:
Read:
$0002
Bit 7
6
0
0
5
4
3
2
1
Bit 0
PTC5
PTC4
PTC3
PTC2
PTC1
PTC0
ADC2
ADC1
ADC0
Write:
Reset:
Alternate
Function:
Unaffected by reset
ADC5
ADC4
ADC3
= Unimplemented
Figure 17-9. Port C Data Register (PTC)
PTC5–PTC0 — 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.
ADC5–ADC0 — Analog-to-Digital Input Bits
ADC5–ADC0 are pins used for the input channels to the analog-todigital converter module. The channel select bits in the ADC Status
and Control Register define which port C 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.
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NOTE:
Care must be taken when reading port C while applying analog voltages
to ADC5–ADC0 pins. If the appropriate ADC channel is not enabled,
excessive current drain may occur if analog voltages are applied to the
PTCx/ADCx pin, while PTC is read as a digital input. Those ports not
selected as analog input channels are considered digital I/O ports.
17.5.2 Data Direction Register C
Data direction register C (DDRC) 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:
6
5
4
3
2
1
Bit 0
DDRC6
DDRC5
DDRC4
DDRC3
DDRC2
DDRC1
DDRC0
0
0
0
0
0
0
0
0
Write:
Reset:
0
= Unimplemented
Figure 17-10. Data Direction Register C (DDRC)
DDRC6–DDRC0 — Data Direction Register C Bits
These read/write bits control port C data direction. Reset clears
DDRC6–DDRC0, 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 17-11 shows the port C I/O logic.
NOTE:
For those devices packaged in a 28-pin dual in-line package, set DDRC5
to a 1 to configure PTC5 as output.
Technical Data
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Input/Output (I/O) Ports
Port C
READ DDRC ($0006)
INTERNAL DATA BUS
WRITE DDRC ($0006)
RESET
DDRCx
WRITE PTC ($0002)
PTCx
PTCx
READ PTC ($0002)
Figure 17-11. Port C I/O Circuit
When bit DDRCx is a logic 1, reading address $0002 reads the PTCx
data latch. When bit 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 17-5 summarizes
the operation of the port C pins.
Table 17-5. Port C Pin Functions
Accesses to DDRC
PTCPUE Bit
DDRC Bit
PTC Bit
Accesses to PTC
I/O Pin Mode
Read/Write
Read
Write
0
0
X
Input, Hi-Z(2)
DDRC6–DDRC0
Pin
PTC6–PTC0(3)
X
1
X
Output
DDRC6–DDRC0
PTC6–PTC0
PTC6–PTC0
Notes:
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
17.5.3 Port C Options
The ADCH4–ADCH0 bits in the ADC Status and Control Register
(ADSCR) defines which PTCx/ADCx pin is 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. See 12.8.1 ADC Status and Control
Register.
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Input/Output (I/O) Ports
17.6 Port D
Port D is an 7-bit special-function port that shares two of its pins with the
multi-master IIC (MMIIC) module, one of its pins with the sync processor,
two of its pins with the DDC12AB module, and two of its pins with the
USB module.
NOTE:
Port pins PTD6–PTD4 and PTD1–PTD0 are not available in a 28-pin
dual in-line package. PTD1–PTD0 are 3.3V pins.
17.6.1 Port D Data Register
The port D data register (PTD) contains a data latch for each of the eight
port D pins.
Address:
$0003
Bit 7
Read:
6
5
4
3
2
1
Bit 0
PTD6
PTD5
PTD4
PTD3
PTD2
PTD1
PTD0
D–
D+
0
Write:
Reset:
Alternate
Function:
Unaffected by reset
IICSDA
IICSCL
CLAMP
DDCSCL DDCSDA
= Unimplemented
Figure 17-12. Port D Data Register (PTD)
PTD6–PTD0 — 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.
IICSDA, IICSCL — Multi-master IIC Data and Clock pins
The PTD6/IICSDA and PTD5/IICSCL pins are multi-master IIC data
and clock pins. When the IICDATE and IICSCLE bits in the port D
configuration register (PDCR) is clear, the PTD6/IICSDA and
PTD5/IICSCL pins are available for general-purpose I/O. See 17.6.3
Port D Options.
Technical Data
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Port D
CLAMP — Sync Processor Clamp pulse output pin
The PTD4/CLAMP pin is the sync processor clamp pulse output pin.
When the CLAMPE bit in the port D configuration register (PDCR) is
clear, the PTD4/CLAMP pin is available for general-purpose I/O. See
17.6.3 Port D Options.
DDCSCL, DDCSDA — DDC12AB Data and Clock pins
The PTD3/DDCSCL and PTD2/DDCSDA pins are DDC12AB clock
and data pins respectively. When the DDCSCLE and DDCDATE bits
in the port D configuration register (PDCR) is clear, the
PTD3/DDCSCL and PTD2/DDCSDA pins are available for generalpurpose I/O. See 17.6.3 Port D Options.
D–, D+ — USB I/O pins
The PTD1/D– and PTD0/D+ pins are the USB port pins. When the
USBD–E and USBD+E bits in the port D configuration register (PDCR)
is clear, the PTD1/D– and PTD0/D+ pins are available for generalpurpose I/O. See 17.6.3 Port D Options.
17.6.2 Data Direction Register D
Data direction register D (DDRD) 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:
6
5
4
3
2
1
Bit 0
DDRD6
DDRD5
DDRD4
DDRD3
DDRD2
DDRD1
DDRD0
0
0
0
0
0
0
0
0
Write:
Reset:
0
Figure 17-13. Data Direction Register D (DDRD)
DDRD6–DDRD0 — Data Direction Register D Bits
These read/write bits control port D data direction. Reset clears
DDRD6–DDRD0, configuring all port D pins as inputs.
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Input/Output (I/O) Ports
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.
NOTE:
For those devices packaged in a 28-pin dual in-line package, set
DDRD6, 5, 4, 1 and 0 to a 1 to configure PTD6, 5, 4, 1 and 0 as outputs.
Figure 17-14 shows the port D I/O logic.
READ DDRD ($0007)
INTERNAL DATA BUS
WRITE DDRD ($0007)
RESET
DDRDx
WRITE PTD ($0003)
PTDx
PTDx
READ PTD ($0003)
Figure 17-14. Port D I/O Circuit
When bit DDRDx is a logic 1, reading address $0003 reads the PTDx
data latch. When bit 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 17-6 summarizes
the operation of the port D pins.
Table 17-6. Port D Pin Functions
Accesses to DDRD
PTDPUE Bit
DDRD Bit
PTD Bit
Accesses to PTD
I/O Pin Mode
Read/Write
Read
Write
0
0
X
Input, Hi-Z(2)
DDRD7–DDRD0
Pin
PTD7–PTD0(3)
X
1
X
Output
DDRD7–DDRD0
PTD7–PTD0
PTD7–PTD0
Notes:
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
Technical Data
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Port D
17.6.3 Port D Options
The port D configuration register (PDCR) selects the port D pins for
module function or as standard I/O function.
Address:
$0049
Bit 7
Read:
6
5
IICDATE
IICSCLE
0
0
4
3
2
1
Bit 0
0
CLAMPE DDCSCLE DDCDATE USBD–E
USBD+E
Write:
Reset:
0
0
0
0
0
0
= Unimplemented
Figure 17-15. Port D Configuration Register (PDCR)
IICDATE — MMIIC Data Pin Enable
This bit is set to configure the PTD6/IICSDA pin for IICSDA function.
Reset clears this bit.
1 = PTD6/IICSDA pin configured as IICSDA pin
0 = PTD6/IICSDA pin configured as standard I/O pin
IICSCLE — MMIIC Clock Pin Enable
This bit is set to configure the PTD5/IICSCL pin for IICSCL function.
Reset clears this bit.
1 = PTD5/IICSCL pin configured as IICSCL pin
0 = PTD5/IICSCL pin configured as standard I/O pin
CLAMP — CLAMP Pin Enable
This bit is set to configure the PTD4/CLAMP pin for sync processor
clamp pulse output. Reset clears this bit.
1 = PTD4/CLAMP pin configured as CLAMP pin
0 = PTD4/CLAMP pin configured as standard I/O pin
DDCSCLE — DDC Clock Pin Enable
This bit is set to configure the PTD3/DDCSCL pin for DDCSCL
function. Reset clears this bit.
1 = PTD3/DDCSCL pin configured as DDCSCL pin
0 = PTD3/DDCSCL pin configured as standard I/O port
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Input/Output (I/O) Ports
DDCDATE — DDC Data Pin Enable
This bit is set to configure the PTD2/DDCSDA pin for DDCSDA
function. Reset clears this bit.
1 = PTD2/DDCSDA pin configured as DDCSDA pin
0 = PTD2/DDCSDA pin configured as standard I/O port
USBD–E — USB D– Pin Enable
This bit is set to configure the PTD1/D– pin for D– function. Reset
clears this bit.
1 = PTD1/D– pin configured as D– pin
0 = PTD1/D– pin configured as standard I/O port
USBD+E — USB D+ Pin Enable
This bit is set to configure the PTD0/D+ pin for D+ function. Reset
clears this bit.
1 = PTD0/D+ pin configured as D+ pin
0 = PTD0/D+ pin configured as standard I/O port
Technical Data
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Port E
17.7 Port E
Port E is a 3-bit special-function port that shares all of its pins with the
sync processor.
NOTE:
Port pin PTE0 is not available in a 28-pin dual in-line package.
17.7.1 Port E Data Register
The port E data register contains a data latch for each of the two port E
pins.
Address:
Read:
$0008
Bit 7
6
5
4
3
0
0
0
0
0
2
1
Bit 0
PTE2
PTE1
PTE0
Write:
Reset:
Unaffected by reset
Alternate
Function:
VSYNCO HSYNCO
SOG or
TCH0
= Unimplemented
Figure 17-16. Port E Data Register (PTE)
PTE2 and PTE0 — Port E Data Bits
PTE2–PTE0 are read/write, software programmable bits. Data
direction of each port E pin is under the control of the corresponding
bit in data direction register E.
VSYNCO — Vsync Output
The PTE2/VSYNCO pin is the Vsync output from the sync processor.
When the VSYNCOE is clear, the PTE2/VSYNCO pin is available for
general-purpose I/O. See 17.7.3 Port E Options.
HSYNC — Hsync Output
The PTE1/HSYNCO pin is the Hsync output from the sync processor.
When the HSYNCOE is clear, the PTE1/HSYNCO pin is available for
general-purpose I/O. See 17.7.3 Port E Options.
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Input/Output (I/O) Ports
SOG/TCH0 — SOG Output or TCH0 Input
The PTE0/SOG/TCH0 pin is the SOG input for the sync processor or
the input capture of the TIM channel 0. See 17.7.3 Port E Options.
17.7.2 Data Direction Register E
Data direction register E (DDRE) 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:
Read:
$000C
Bit 7
6
5
4
3
0
0
0
0
0
2
1
Bit 0
DDRE2
DDRE1
DDRE0
0
0
0
Write:
Reset:
0
0
0
0
0
= Unimplemented
Figure 17-17. Data Direction Register E (DDRE)
DDRE2–DDRE0 — Data Direction Register E Bits
These read/write bits control port E data direction. Reset clears
DDRE2–DDRE0, 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.
NOTE:
For those devices packaged in a 28-pin dual in-line package, set DDRE0
to a 1 to configure PTE0 as an output.
Figure 17-18 shows the port E I/O logic.
Technical Data
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MOTOROLA
Input/Output (I/O) Ports
Port E
INTERNAL DATA BUS
READ DDRE ($0009)
WRITE DDRE ($0009)
RESET
DDREx
WRITE PTE ($0008)
PTEx
PTEx
READ PTE ($0008)
Figure 17-18. Port E I/O Circuit
When bit DDREx is a logic 1, reading address $0008 reads the PTEx
data latch. When bit 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 17-7 summarizes
the operation of the port E pins.
Table 17-7. Port E Pin Functions
Accesses to DDRE
DDRE Bit
PTE Bit
Accesses to PTE
I/O Pin Mode
Read/Write
Read
Write
0
X(1)
Input, Hi-Z(2)
DDRE1–DDRE0
Pin
PTE1–PTE0(3)
1
X
Output
DDRE1–DDRE0]
PTE1–PTE0
PTE1–PTE0
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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Input/Output (I/O) Ports
17.7.3 Port E Options
The configuration register 0 (CONFIG0) selects the port E pins for
module function or as standard I/O function.
Address:
$001D
Bit 7
6
5
Read:
HSYNCOE VSYNCOE
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
0
0
SOGE
Write:
Reset:
0
0
0
= Unimplemented
Figure 17-19. Configuration Register 0 (CONFIG0)
HSYNCOE — VSYNCO Enable
This bit is set to configure the PTE1/HSYNCO pin for HSYNCO output
function. Reset clears this bit.
1 = PTE1/HSYNCO pin configured as HSYNCO pin
0 = PTE1/HSYNCO pin configured as standard I/O pin
VSYNCOE — VSYNCO Enable
This bit is set to configure the PTE2/VSYNCO pin for VSYNCO output
function. Reset clears this bit.
1 = PTE2/VSYNCO pin configured as VSYNCO pin
0 = PTE2/VSYNCO pin configured as standard I/O pin
SOGE — SOG Enable
This bit is set to configure the PTE0/SOG/TCH0 pin for SOG output
function. Reset clears this bit.
1 = PTE0/SOG/TCH0 pin configured as SOG pin
0 = PTE0/SOG/TCH0 pin configured as standard I/O or TCH0 pin.
TCH0 function is configured by ELS0B and ELS0A bits in
TSC0 (bits 3 and 2 in $0010).
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MOTOROLA
Technical Data — MC68HC908BD48
Section 18. External Interrupt (IRQ)
18.1 Contents
18.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
18.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
18.4
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
18.5
IRQ Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
18.6
IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . 255
18.7
IRQ Status and Control Register . . . . . . . . . . . . . . . . . . . . . . 255
18.2 Introduction
The IRQ (external interrupt) module provides a maskable interrupt input.
18.3 Features
Features of the IRQ module include:
•
A dedicated external interrupt pin (IRQ)
•
IRQ interrupt control bits
•
Hysteresis buffer
•
Programmable edge-only or edge and level interrupt sensitivity
•
Automatic interrupt acknowledge
•
Internal pullup resistor
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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 latch that caused the vector
fetch.
•
Software clear — Software can clear an interrupt latch by writing
to the appropriate acknowledge bit in the interrupt status and
control register (INTSCR). Writing a logic 1 to the ACK bit clears
the IRQ latch.
•
Reset — A reset automatically clears the interrupt latch.
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 INTSCR controls the triggering sensitivity
of the IRQ pin.
When an interrupt pin is edge-triggered only, the interrupt remains set
until a vector fetch, software clear, or reset occurs.
When an interrupt pin is both falling-edge and low-level-triggered, the
interrupt 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 INTSCR mask all external interrupt
requests. A latched interrupt request is not presented to the interrupt
priority logic unless the IMASK bit is clear.
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External Interrupt (IRQ)
MOTOROLA
External Interrupt (IRQ)
Functional Description
NOTE:
The interrupt mask (I) in the condition code register (CCR) masks all
interrupt requests, including external interrupt requests.
INTERNAL ADDRESS BUS
ACK
RESET
TO CPU FOR
BIL/BIH
INSTRUCTIONS
VECTOR
FETCH
DECODER
VDD
INTERNAL
PULLUP
DEVICE
VDD
IRQF
D
IRQ
CLR
Q
SYNCHRONIZER
CK
IRQ
INTERRUPT
REQUEST
IRQ
FF
IMASK
MODE
TO MODE
SELECT
LOGIC
HIGH
VOLTAGE
DETECT
Figure 18-1. IRQ Module Block Diagram
Table 18-1. IRQ I/O Register Summary
Addr.
$001E
Register Name
Read:
IRQ Status and Control
Write:
Register (INTSCR)
Reset:
Bit 7
6
5
4
3
2
0
0
0
0
IRQF
0
ACK
0
0
0
0
0
0
1
Bit 0
IMASK
MODE
0
0
= Unimplemented
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External Interrupt (IRQ)
18.5 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:
•
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 (INTSCR).
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 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.
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 INTSCR 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.
Technical Data
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External Interrupt (IRQ)
MOTOROLA
External Interrupt (IRQ)
IRQ Module During Break Interrupts
NOTE:
When using the level-sensitive interrupt trigger, avoid false interrupts by
masking interrupt requests in the interrupt routine.
18.6 IRQ Module During Break Interrupts
The BCFE bit in the SIM break flag control register (SBFCR) enables
software to clear the latch during the break state. See Section 20. Break
Module (BRK).
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.
To protect CPU interrupt flags 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 interrupt flags.
18.7 IRQ Status and Control Register
The IRQ status and control register (INTSCR) controls and monitors
operation of the IRQ module. The INTSCR:
•
Shows the state of the IRQ flag
•
Clears the IRQ latch
•
Masks IRQ interrupt request
•
Controls triggering sensitivity of the IRQ interrupt pin
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Technical Data
External Interrupt (IRQ)
255
External Interrupt (IRQ)
Address:
$001E
Bit 7
6
5
4
Read:
3
2
IRQF
0
Write:
Reset:
1
Bit 0
IMASK
MODE
0
0
ACK
0
0
0
0
0
0
= Unimplemented
Figure 18-2. IRQ Status and Control Register (INTSCR)
IRQF — IRQ Flag Bit
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
Technical Data
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External Interrupt (IRQ)
MOTOROLA
Technical Data — MC68HC908BD48
Section 19. Computer Operating Properly (COP)
19.1 Contents
19.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
19.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
19.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.1 OSCXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.2 STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.3 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.4 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
19.4.5 Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
19.4.6 Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
19.4.7 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
19.4.8 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . 260
19.5
COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
19.6
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
19.7
Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
19.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
19.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
19.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
19.9
COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . 262
19.2 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
through the COPD bit in the CONFIG register.
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Technical Data
Computer Operating Properly (COP)
257
Computer Operating Properly (COP)
19.3 Functional Description
Figure 19-1 shows the structure of the COP module.
RESET CIRCUIT
RESET STATUS REGISTER
COP TIMEOUT
CLEAR STAGES 5–12
STOP INSTRUCTION
INTERNAL RESET SOURCES
RESET VECTOR FETCH
CLEAR ALL STAGES
12-BIT COP PRESCALER
OSCXCLK
COPCTL WRITE
COP CLOCK
COP MODULE
6-BIT COP COUNTER
COPEN (FROM SIM)
COP DISABLE
(COPD FROM CONFIG1)
RESET
COPCTL WRITE
CLEAR
COP COUNTER
COP RATE SEL
(COPRS FROM CONFIG1)
Figure 19-1. 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
OSCXCLK cycles, depending on the state of the COP rate select bit,
COPRS, in configuration register 1. With a 218 – 24 OSCXCLK cycle
overflow option, a 6MHz crystal gives a COP timeout period of
43.688ms. 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
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Computer Operating Properly (COP)
MOTOROLA
Computer Operating Properly (COP)
I/O Signals
A COP reset pulls the RST pin low for 32 OSCXCLK 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 IRQ1 is held
at VTST. During the break state, VTST on the RST pin disables the COP.
NOTE:
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.
19.4 I/O Signals
The following paragraphs describe the signals shown in Figure 19-1.
19.4.1 OSCXCLK
OSCXCLK is the crystal oscillator output signal. OSCXCLK frequency is
equal to the crystal frequency.
19.4.2 STOP Instruction
The STOP instruction clears the COP prescaler.
19.4.3 COPCTL Write
Writing any value to the COP control register (COPCTL) (see 19.5 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.
19.4.4 Power-On Reset
The power-on reset (POR) circuit clears the COP prescaler 4096
OSCXCLK cycles after power-up.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Computer Operating Properly (COP)
259
Computer Operating Properly (COP)
19.4.5 Internal Reset
An internal reset clears the COP prescaler and the COP counter.
19.4.6 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.
19.4.7 COPD (COP Disable)
The COPD signal reflects the state of the COP disable bit (COPD) in the
configuration register 1 (see Figure 19-2).
19.4.8 COPRS (COP Rate Select)
The COPRS signal reflects the state of the COP rate select bit (COPRS)
in the configuration register 1(see Figure 19-2).
Address:
Read:
$001F
Bit 7
6
5
4
0
0
0
0
3
2
1
Bit 0
SSREC
COPRS
STOP
COPD
0
0
0
0
Write:
Reset:
0
0
0
0
= Unimplemented
Figure 19-2. Configuration Register 1 (CONFIG1)
COPRS — COP Rate Select Bit
COPRS selects the COP timeout period. Reset clears COPRS.
1 = COP timeout period = 213 – 24 OSCXCLK cycles
0 = COP timeout period = 218 – 24 OSCXCLK cycles
COPD — COP Disable Bit
COPD disables the COP module.
1 = COP module disabled
0 = COP module enabled
Technical Data
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Computer Operating Properly (COP)
MOTOROLA
Computer Operating Properly (COP)
COP Control Register
19.5 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
Read:
Low byte of reset vector
Write:
Clear COP counter
Reset:
Unaffected by reset
2
1
Bit 0
Figure 19-3. COP Control Register (COPCTL)
19.6 Interrupts
The COP does not generate CPU interrupt requests.
19.7 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.
19.8 Low-Power Modes
The WAIT and STOP instructions put the MCU in low powerconsumption standby modes.
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Technical Data
Computer Operating Properly (COP)
261
Computer Operating Properly (COP)
19.8.1 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.
19.8.2 Stop Mode
Stop mode turns off the OSCXCLK 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 configuration register has the STOP
instruction is disabled, execution of a STOP instruction results in an
illegal opcode reset.
19.9 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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Computer Operating Properly (COP)
MOTOROLA
Technical Data — MC68HC908BD48
Section 20. Break Module (BRK)
20.1 Contents
20.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
20.3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
20.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
20.4.1 Flag Protection During Break Interrupts . . . . . . . . . . . . . . . 266
20.4.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 266
20.4.3 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . 266
20.4.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 266
20.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
20.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
20.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
20.6 Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
20.6.1 Break Status and Control Register. . . . . . . . . . . . . . . . . . . 267
20.6.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 268
20.6.3 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 268
20.6.4 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 270
20.2 Introduction
This section describes the break module. 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
Break Module (BRK)
263
Break Module (BRK)
20.3 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
20.4 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 20-1 shows the structure of the break module.
Technical Data
264
MC68HC908BD48 — Rev. 1.0
Break Module (BRK)
MOTOROLA
Break Module (BRK)
Functional Description
IAB15–IAB8
BREAK ADDRESS REGISTER HIGH
8-BIT COMPARATOR
IAB15–IAB0
BREAK
CONTROL
8-BIT COMPARATOR
BREAK ADDRESS REGISTER LOW
IAB7–IAB0
Figure 20-1. Break Module Block Diagram
Table 20-1. Break Module I/O Register Summary
Addr.
Register Name
Read:
SIM Break Status Register
$FE00
Write:
(SBSR)
Reset:
$FE03
$FE0C
$FE0D
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:
Read:
Break Status and Control
$FE0E
Write:
Register (BRKSCR)
Reset:
Note: Writing a logic 0 clears SBSW.
Bit 7
6
5
4
3
2
R
R
R
R
R
R
0
0
0
0
0
0
0
0
BCFE
R
R
R
R
R
R
R
Bit 15
14
13
12
11
10
9
Bit 8
0
0
0
0
0
0
0
0
Bit 7
6
5
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
BRKE
BRKA
0
0
0
0
0
0
0
0
0
0
0
0
0
0
SBSW
Note
Bit 0
R
0
= Unimplemented
MC68HC908BD48 — Rev. 1.0
MOTOROLA
1
R
= Reserved
Technical Data
Break Module (BRK)
265
Break Module (BRK)
20.4.1 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.
20.4.2 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)
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.
20.4.3 TIM During Break Interrupts
A break interrupt stops the timer counters.
20.4.4 COP During Break Interrupts
The COP is disabled during a break interrupt when VTST is present on
the RST pin.
20.5 Low-Power Modes
The WAIT and STOP instructions put the MCU in low powerconsumption standby modes.
20.5.1 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 7. System Integration Module (SIM)). Clear the
SBSW bit by writing logic 0 to it.
Technical Data
266
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MOTOROLA
Break Module (BRK)
Break Module Registers
20.5.2 Stop Mode
A break interrupt causes exit from stop mode and sets the SBSW bit in
the break status register.
20.6 Break Module Registers
These registers control and monitor operation of the break module:
•
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)
20.6.1 Break Status and Control Register
The break status and control register (BRKSCR) contains break module
enable and status bits.
Address:
$FE0E
Bit 7
6
BRKE
BRKA
0
0
Read:
5
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
0
0
0
0
Write:
Reset:
= Unimplemented
Figure 20-2. 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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Technical Data
Break Module (BRK)
267
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
20.6.2 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
6
5
4
3
2
1
Bit 0
Bit 15
14
13
12
11
10
9
Bit 8
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 20-3. Break Address Register High (BRKH)
Address:
$FE0D
Bit 7
6
5
4
3
2
1
Bit 0
Bit 7
6
5
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
Read:
Write:
Reset:
Figure 20-4. Break Address Register Low (BRKL)
20.6.3 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
268
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Break Module (BRK)
MOTOROLA
Break Module (BRK)
Break Module Registers
Address:
$FE00
Bit 7
6
5
4
3
2
R
R
R
R
R
R
Read:
Bit 0
SBSW
Write:
Reset:
1
R
Note
0
0
Note: Writing a logic 0 clears SBSW.
0
0
R
= Reserved
0
0
0
0
Figure 20-5. SIM Break Status Register (SBSR)
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
EQU
5
LOBYTE
EQU
6
;
If not SBSW, do RTI
BRCLR
SBSW,SBSR, RETURN
; See if wait mode or stop mode was exited by
; break.
TST
LOBYTE,SP
;If RETURNLO is not zero,
BNE
DOLO
;then just decrement low byte.
DEC
HIBYTE,SP
;Else deal with high byte, too.
DOLO
DEC
LOBYTE,SP
;Point to WAIT/STOP opcode.
RETURN
PULH
RTI
;Restore H register.
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Technical Data
Break Module (BRK)
269
Break Module (BRK)
20.6.4 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
6
5
4
3
2
1
Bit 0
BCFE
R
R
R
R
R
R
R
Read:
Write:
Reset:
0
R
= Reserved
Figure 20-6. 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
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MOTOROLA
Technical Data — MC68HC908BD48
Section 21. Electrical Specifications
21.1 Contents
21.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
21.3
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 272
21.4
Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . 273
21.5
Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
21.6
DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 274
21.7
Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
21.8
Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
21.9
ADC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
21.10 USB DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . 277
21.11 USB Low Speed Source Electrical Characteristics. . . . . . . . . 278
21.12 Timer Interface Module Characteristics . . . . . . . . . . . . . . . . . 278
21.13 DDC12AB/MMIIC Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
21.13.1 DDC12AB/MMIIC Interface Input Signal Timing . . . . . . . . 279
21.13.2 DDC12AB/MMIIC Interface Output Signal Timing . . . . . . . 279
21.14 Sync Processor Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
21.15 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
21.2 Introduction
This section contains electrical and timing specifications.
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Technical Data
Electrical Specifications
271
Electrical Specifications
21.3 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 21.6 DC Electrical Characteristics for guaranteed
operating conditions.
Characteristic
Symbol
Value
Unit
Supply Voltage
VDD
–0.3 to +5.5
V
Input Voltage
VIN
VSS –0.3 to VDD +0.3
V
I
±25
mA
Storage Temperature
TSTG
–55 to +150
°C
Maximum Current Out of VSS
IMVSS
100
mA
Maximum Current Into VDD
IMVDD
100
mA
Maximum Current Per Pin
Excluding VDD and VSS
NOTE:
1. Voltages referenced to VSS.
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
272
MC68HC908BD48 — Rev. 1.0
Electrical Specifications
MOTOROLA
Electrical Specifications
Functional Operating Range
21.4 Functional Operating Range
Characteristic
Symbol
Value
Unit
TA
0 to 85
°C
VDD
4.5 to 5.5
V
Symbol
Value
Unit
Thermal Resistance
QFP (44 Pins)
SDIP (42 Pins)
PDIP (28 Pins)
θJA
95
60
70
°C/W
I/O Pin Power Dissipation
PI/O
User Determined
W
Power Dissipation(1)
PD
PD = (IDD × VDD) + PI/O =
K/(TJ + 273 °C)
W
Constant(2)
K
PD × (TA + 273 °C)
+ PD2 × θJA
W/°C
Average Junction Temperature
TJ
TA + (PD × θJA)
°C
TJM
100
°C
Operating Temperature Range
Operating Voltage Range
21.5 Thermal Characteristics
Characteristic
Maximum Junction Temperature
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.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Electrical Specifications
273
Electrical Specifications
21.6 DC Electrical Characteristics
Symbol
Min
Typ(2)
Max
Unit
Output High Voltage
(ILOAD = –2.0mA) All I/O Pins
VOH
VDD – 0.8
—
—
V
Output Low Voltage
(ILOAD = 1.6mA) All I/O Pins
VOL
—
—
0.4
V
Input High Voltage
All ports, IRQ, RST, OSC1
VIH
0.7 × VDD
—
VDD
V
Input Low Voltage
All ports, IRQ, RST, OSC1
VIL
VSS
—
0.2 × VDD
V
VDD Supply Current
Run, USB active
Run, USB suspended(3)
Wait (4)
Stop(5) 0°C to 85°C
IDD
—
—
—
—
10
8
4
2
15
12
8
5
mA
mA
mA
mA
I/O Ports Hi-Z Leakage Current
IIL
—
—
±10
µA
Input Current
IIN
—
—
±1
µA
Capacitance
Ports (as Input or Output)
COUT
CIN
—
—
—
—
12
8
pF
POR ReArm Voltage(6)
VPOR
0
—
100
mV
RPOR
0.035
—
—
V/ms
Monitor Mode Entry Voltage
VTST
VDD + 2.5
9
V
Pull-up Resistor
RST, IRQ
RPU
20
45
65
kΩ
Low-Voltage Inhibit, trip falling voltage
VTRIPF
3.5
3.8
4.5
V
Low-Voltage Inhibit, trip rising voltage
VTRIPR
3.5
4.0
4.5
V
VHYS
—
200
—
mV
Characteristic
POR Rise Time Ramp
Rate(7)
Low-Voltage Inhibit Reset/Recover Hysteresis
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. All inputs 0.2 V from rail. No dc loads. Less than 100 pF on
all outputs. CL = 15 pF on OSC2. All ports configured as inputs. OSC2 capacitance linearly affects run I DD. Measured with all modules
enabled.
4. Wait IDD measured using external square wave clock source (f OSCXCLK = 24MHz); all inputs 0.2 V from rail; no dc loads; less than 100
pF on all outputs. CL = 15pF on OSC2; USB in suspend mode, 15 KΩ ± 5% termination resistors on D+ and D– pins; all ports configured as inputs; OSC2 capacitance linearly affects wait I DD.
5. STOP IDD measured with USB in suspend mode, OSC1 grounded, 1.5 KΩ ± 1% pull-up resistor on D+ pin and 15 KΩ ± 1% pull-down
resistors on D+ and D– pins, no port pins sourcing current.
6. Maximum is highest voltage that POR is guaranteed.
7. If minimum VDD is not reached before the internal POR reset is released, RST must be driven low externally until minimum V DD is
reached.
Technical Data
274
MC68HC908BD48 — Rev. 1.0
Electrical Specifications
MOTOROLA
Electrical Specifications
Control Timing
21.7 Control Timing
Characteristic
Symbol
Min
Max
Unit
Internal Operating Frequency(2)
fOP
—
6
MHz
RST Input Pulse Width Low(3)
tIRL
50
—
ns
NOTES:
1. VDD = 4.5 to 5.5 Vdc, VSS = 0 Vdc; timing shown with respect to 20% VDD and 70% VDD, unless otherwise noted.
2. Some modules may require a minimum frequency greater than dc for proper operation; see appropriate table for this
information.
3. Minimum pulse width reset is guaranteed to be recognized. It is possible for a smaller pulse width to cause a reset.
21.8 Oscillator Characteristics
Characteristic
Symbol
Min
Typ
Max
Unit
Crystal Frequency(1)
fOSCXCLK
—
24
—
MHz
External Clock
Reference Frequency(1), (2)
fOSCXCLK
dc
—
24
MHz
Crystal Load Capacitance(3)
CL
—
15
—
pF
Capacitance(3)
C1
—
2 × CL
—
Crystal Tuning Capacitance(3)
C2
—
2 × CL
—
Feedback Bias Resistor
RB
—
10
—
Series Resistor(3), (4)
RS
—
—
—
Crystal Fixed
MΩ
NOTES:
1. The sync processor module is designed to function at fOSCXCLK = 24MHz. The values given here are oscillator specifications.
2. No more than 10% duty cycle deviation from 50%
3. Consult crystal vendor data sheet
4. Not Required for high frequency crystals
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Electrical Specifications
275
Electrical Specifications
21.9 ADC Characteristics
Characteristic(1)
Symbol
Min
Max
Unit
Supply voltage
VDDAD
4.5
(VDD
min)
5.5
(VDD
max)
V
Input voltages
VADIN
0
------ VDD
2
3
V
Resolution
BAD
8
8
Bits
Absolute accuracy
(VSS = 0 V, VDD = 5 V ± 10%)
AAD
—
±2
LSB
Includes quantization
ADC internal clock
fADIC
0.375
6
MHz
tAIC = 1/fADIC, tested
only at 1.5 MHz
Conversion range
RAD
VSS
------ VDD
V
Power-up time
tADPU
16
Conversion time
tADC
12
13
tAIC cycles
Sample time(2)
tADS
4
—
tAIC
cycles
Zero input reading(3)
ZADI
00
02
Hex
Full-scale reading(3)
FADI
FD
FF
Hex
Input capacitance
CADI
—
8
pF
—
—
±1
µA
Input leakage(4)
Port C
2
3
Comments
tAIC cycles
Not tested
NOTES:
1. VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted.
2. Source impedances greater than 10 kΩ 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.
Technical Data
276
MC68HC908BD48 — Rev. 1.0
Electrical Specifications
MOTOROLA
Input Voltage, ADIN
Electrical Specifications
USB DC Electrical Characteristics
3.5
3.4
3.3
3.2
3.1
3
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
VDD = 5V @ 25°C, ADC Clock = 1.5MHz
Offset is typically 22mV
Steps
Figure 21-1. ADC Input Voltage vs. Step Readings
21.10 USB DC Electrical Characteristics
Characteristic
Symbol
Conditions
Min
Hi-Z State Data Line Leakage
ILO
0V<VIN <3.3V
–10
Differential Input Sensitivity
VDI
|(D+)–(D–)|
0.2
Differential Common Mode Range
VCM
Includes VDI range
0.8
2.5
V
Single Ended Receiver Threshold
VSE
0.8
2.0
V
Static Output Low
VOL
RL of 1.5k to 3.6V
0.3
V
Static Output High
VOH
RL of 15k to GND
2.8
3.6
V
VREGOUT
IL= 4 mA
3.0
3.6
V
Regulator Supply Voltage (2), (3)
Typ
Max
Unit
+10
µA
V
3.3
NOTES:
1. VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted.
2. Transceiver pullup resistor of 1.5KΩ ± 5% between VDD3 and D– and 15KΩ ± 5% to ground termination resistors on
D+ and D–.
3. No external current draw besides the USB required external resistors should be connected to the VDD3 pin.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Electrical Specifications
277
Electrical Specifications
21.11 USB Low Speed Source Electrical Characteristics
Characteristic
Symbol
Transition time:
Rise Time
TR
Fall Time
TF
Rise/Fall Time Matching
TRFM
Output Signal Crossover Voltage
VCRS
Low Speed Data Rate
TDRATE
Source Differential Driver Jitter
To Next Transition
For Paired Transitions
TUDJ1
TUDJ2
Receiver Data Jitter Tolerance
To Next Transition
For Paired Transitions
TDJR1
TDJR2
Conditions
(Notes 1,2,3)
Min
Typ
Max
75
—
75
—
—
300
—
300
80
—
120
%
1.3
—
2.0
V
1.4775
676.8
1.500
666.0
1.5225
656.8
Mbs
ns
25
10
ns
ns
Notes 4, 5, 8
CL=50pF
CL =350pF
CL =50pF
CL =350pF
TR/TF
1.5Mbs±1.5%
CL =350pF
Notes 6, 7
—
—
–25
–10
CL =350pF
Note 7
Unit
ns
–75
–45
—
—
75
45
ns
ns
Source EOP Width
TEOPT
Note 7
1.25
—
1.50
µs
Differential to EOP Transition
Skew
TDEOP
Note 7
–40
—
100
ns
TEOPR1
TEOPR2
Note 7
330
675
—
—
—
—
ns
ns
Receiver EOP Width
Must Reject as EOP
Must Accept
NOTES:
1. All voltages measured from local ground, unless otherwise specified.
2. All timings use a capacitive load of 50pF, unless otherwise specified.
3. Low speed timings have a 1.5kΩ pull-up to 2.8V on the D– data line.
4. Measured from 10% to 90% of the data signal.
5. The rising and falling edges should be smoothly transitioning (monotonic).
6. Timing differences between the differential data signals.
7. Measured at crossover point of differential data signals.
8. Capacitive loading includes 50pF of tester capacitance.
21.12 Timer Interface Module Characteristics
Characteristic
Input Capture Pulse Width
Input Clock Pulse Width
Symbol
Min
Max
Unit
tTIH, tTIL
125
—
ns
tTCH, tTCL
(1/fOP) + 5
—
ns
Technical Data
278
MC68HC908BD48 — Rev. 1.0
Electrical Specifications
MOTOROLA
Electrical Specifications
DDC12AB/MMIIC Timing
21.13 DDC12AB/MMIIC Timing
SDA
SCL
tHD.STA
tLOW
tHIGH
tSU.DAT
tHD.DAT
tSU.STA
tSU.STO
21.13.1 DDC12AB/MMIIC Interface Input Signal Timing
Characteristic
Symbol
Min
Max
Unit
tHD.STA
2
—
tCYC
Clock low period
tLOW
4
—
tCYC
Clock high period
tHIGH
4
—
tCYC
Data set-up time
tSU.DAT
250
—
ns
Data hold time
tHD.DAT
0
—
ns
START condition set-up time
(for repeated START condition only)
tSU.STA
2
—
tCYC
STOP condition set-up time
tSU.STO
2
—
tCYC
START condition hold time
NOTES:
1. VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc; timing shown with respect to 20% VDD and 70% VDD, unless otherwise noted.
21.13.2 DDC12AB/MMIIC Interface Output Signal Timing
Characteristic
Symbol
Min
Max
Unit
SDA/SCL rise time(2)
tR
—
1
µs
SDA/SCL fall time
tF
—
300
ns
Data set-up time
tSU.DAT
tLOW
—
ns
Data hold time
tHD.DAT
0
—
ns
NOTES:
1. VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc; timing shown with respect to 20% VDD and 70% VDD, unless otherwise noted.
2. With 200pF loading on the SDA/SCL pins.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Electrical Specifications
279
Electrical Specifications
21.14 Sync Processor Timing
Characteristic
Symbol
Min
Max
Unit
VSYNC input sync pulse
tVI.SP
8
2048
µs
HSYNC input sync pulse
tHI.SP
0.1
6
µs
VSYNC to VSYNCO delay (8pF loading)
tVVd
30
40
µs
HSYNC to HSYNCO delay (8pF loading)
tHHd
30
40
µs
NOTES:
1. VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc; timing shown with respect to 20% VDD and 70% VDD, unless otherwise noted.
Technical Data
280
MC68HC908BD48 — Rev. 1.0
Electrical Specifications
MOTOROLA
Electrical Specifications
Memory Characteristics
21.15 Memory Characteristics
Characteristic
Symbol
Min
Max
Unit
VRDR
2
—
V
—
1
—
MHz
FLASH read bus clock frequency
fRead(1)
32k
8.4M
Hz
FLASH page erase time
tErase(2)
2
—
ms
FLASH mass erase time
tMErase(3)
4
—
ms
FLASH PGM/ERASE to HVEN set up time
tnvs
5
—
µs
FLASH high-voltage hold time
tnvh
5
—
µs
FLASH high-voltage hold time (mass erase)
tnvhl
100
—
µs
FLASH program hold time
tpgs
10
—
µs
FLASH program time
tPROG
20
40
µs
FLASH return to read time
trcv(4)
1
—
µs
FLASH cumulative program hv period
tHV(5)
—
4
ms
FLASH row erase endurance(6)
—
10k
—
Cycles
FLASH row program endurance(7)
—
10k
—
Cycles
—
10
—
Years
RAM data retention voltage
FLASH program bus clock frequency
FLASH data
retention time(8)
Notes:
1. fRead is defined as the frequency range for which the FLASH memory can be read.
2. If the page erase time is longer than tErase (Min), there is no erase-disturb, but it reduces the endurance of
the FLASH memory.
3. If the mass erase time is longer than tMErase (Min), there is no erase-disturb, but it reduces the endurance of
the FLASH memory.
4. trcv is defined as the time it needs before the FLASH can be read after turning off the high voltage charge
pump, by clearing HVEN to logic 0.
5. tHV is defined as the cumulative high voltage programming time to the same row before next erase.
tHV must satisfy this condition: tnvs + tnvh + tpgs + (tPROG × 64) ≤ tHV max.
6. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at
least this many erase / program cycles.
7. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at
least this many erase / program cycles.
8. The FLASH is guaranteed to retain data over the entire operating temperature range for at least the minimum
time specified.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Electrical Specifications
281
Electrical Specifications
Technical Data
282
MC68HC908BD48 — Rev. 1.0
Electrical Specifications
MOTOROLA
Technical Data — MC68HC908BD48
Section 22. Mechanical Specifications
22.1 Contents
22.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
22.3
28-Pin Plastic Dual In-Line Package (PDIP). . . . . . . . . . . . . . 284
22.4
42-Pin Shrink Dual in-Line Package (SDIP) . . . . . . . . . . . . . . 284
22.5
44-Pin Plastic Quad Flat Pack (QFP) . . . . . . . . . . . . . . . . . . . 285
22.2 Introduction
This section gives the dimensions for:
•
28-pin plastic dual in-line package (case 710-02)
•
42-pin shrink dual in-line package (case 858-01)
•
44-pin plastic quad flat pack (case 824E-02)
The following figures show the latest package drawings 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
•
Motorola Mfax
– Phone 602-244-6609
– EMAIL [email protected]
•
Worldwide Web (wwweb) at http://motorola.com/sps
Follow Mfax or Worldwide Web on-line instructions to retrieve the current
mechanical specifications.
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Mechanical Specifications
283
Mechanical Specifications
22.3 28-Pin Plastic Dual In-Line Package (PDIP)
28
NOTES:
1. POSITIONAL TOLERANCE OF LEADS (D), SHALL
BE WITHIN 0.25 (0.010) AT MAXIMUM MATERIAL
CONDITION, IN RELATION TO SEATING PLANE
AND EACH OTHER.
2. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.
3. DIMENSION B DOES NOT INCLUDE MOLD FLASH.
15
B
DIM
A
B
C
D
F
G
H
J
K
L
M
N
14
1
L
C
A
N
G
H
F
D
M
K
J
SEATING
PLANE
MILLIMETERS
MIN
MAX
36.45
37.21
13.72
14.22
3.94
5.08
0.36
0.56
1.02
1.52
2.54 BSC
1.65
2.16
0.20
0.38
2.92
3.43
15.24 BSC
0°
15°
0.51
1.02
INCHES
MIN
MAX
1.435
1.465
0.540
0.560
0.155
0.200
0.014
0.022
0.040
0.060
0.100 BSC
0.065
0.085
0.008
0.015
0.115
0.135
0.600 BSC
0°
15°
0.020
0.040
Figure 22-1. 28-Pin PDIP (Case 710)
22.4 42-Pin Shrink Dual in-Line Package (SDIP)
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION L TO CENTER OF LEAD WHEN
FORMED PARALLEL.
4. DIMENSIONS A AND B DO NOT INCLUDE MOLD
FLASH. MAXIMUM MOLD FLASH 0.25 (0.010).
–A–
42
22
–B–
1
21
DIM
A
B
C
D
F
G
H
J
K
L
M
N
L
H
C
–T–
SEATING
PLANE
0.25 (0.010)
N
G
F
D 42 PL
K
M
T A
S
M
J 42 PL
0.25 (0.010)
M
T B
INCHES
MIN
MAX
1.435
1.465
0.540
0.560
0.155
0.200
0.014
0.022
0.032
0.046
0.070 BSC
0.300 BSC
0.008
0.015
0.115
0.135
0.600 BSC
0°
15°
0.020
0.040
MILLIMETERS
MIN
MAX
36.45
37.21
13.72
14.22
3.94
5.08
0.36
0.56
0.81
1.17
1.778 BSC
7.62 BSC
0.20
0.38
2.92
3.43
15.24 BSC
0°
15°
0.51
1.02
S
Figure 22-2. 42-Pin SDIP (Case 858)
Technical Data
284
MC68HC908BD48 — Rev. 1.0
Mechanical Specifications
MOTOROLA
Mechanical Specifications
44-Pin Plastic Quad Flat Pack (QFP)
22.5 44-Pin Plastic Quad Flat Pack (QFP)
S
0.20 (0.008) M T L-M S N S
-L-, -M-, -N-
A
0.20 (0.008) M H L-M S N S
0.05 (0.002) L-M
PIN 1
IDENT
J1
44
33
-M-
VIEW Y
11
40X
V
0.20 (0.008) M T L-M S N S
-L-
0.05 (0.002) N
J1
B
0.20 (0.008) M H L-M S N S
1
G
G
34
VIEW Y
3 PL
BASE METAL
J
B1
D
0.20 (0.008) M T L-M S N S
23
12
F
PLATING
22
SECTION J1-J1
44 PL
NOTES:
-N-
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 -L-, -M- AND -N- TO BE DETERMINED AT
DATUM PLANE -H-.
5. DIMENSIONS S AND V TO BE DETERMINED AT
SEATING PLANE -T-.
M
VIEW P
C E
-H-
DATUM
PLANE
0.01 (0.004)
W
Y
-T-
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. DAMBAR PROTRUSION SHALL NOT
CAUSE THE D DIMENSION TO EXCEED 0.530
(0.021).
q1
R
DATUM
PLANE
-H-
R
K
A1
R1
R2
q2
C1
VIEW P
DIM
A
B
C
D
E
F
G
J
K
M
S
V
W
Y
A1
B1
C1
R1
R2
q1
q2
MILLIMETERS
MIN
MAX
9.90
10.10
9.90
10.10
2.00
2.21
0.30
0.45
2.00
2.10
0.30
0.40
0.80 BSC
0.13
0.23
0.65
0.95
10°
5°
12.95
13.45
12.95
13.45
0.000
0.210
10°
5°
0.450 REF
0.130
0.170
1.600 REF
0.130
0.300
0.130
0.300
10°
5°
7°
0°
INCHES
MIN
MAX
0.390 0.398
0.390 0.398
0.079 0.087
0.0118 0.0177
0.079 0.083
0.012 0.016
0.031 BSC
0.005 0.009
0.026 0.037
5°
10°
0.510 0.530
0.510 0.530
0.000 0.008
5°
10°
0.018 REF
0.005 0.007
0.063 REF
0.005 0.012
0.005 0.012
5°
10°
0°
7°
Figure 22-3. 44-Pin QFP (Case 824E)
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Mechanical Specifications
285
Mechanical Specifications
Technical Data
286
MC68HC908BD48 — Rev. 1.0
Mechanical Specifications
MOTOROLA
Technical Data — MC68HC908BD48
Section 23. Ordering Information
23.1 Contents
23.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
23.3
MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
23.2 Introduction
This section contains ordering numbers for the MC68HC908BD48.
23.3 MC Order Numbers
Table 23-1. MC Order Numbers
MC order number(1)
Operating
temperature range
MC68HC908BD48IB
0 °C to +85 °C
MC68HC908BD48IFB
0 °C to +85 °C
Notes:
1. P = Plastic dual in-line package
B = Shrink dual in-line package
FB = Plastic quad flat pack
I = Operating temperature range: 0 °C to +85 °C
MC68HC908BD48 — Rev. 1.0
MOTOROLA
Technical Data
Ordering Information
287
Ordering Information
Technical Data
288
MC68HC908BD48 — Rev. 1.0
Ordering Information
MOTOROLA
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