Datasheet
Table Of Contents
- List of Sections
- Table of Contents
- List of Figures
- List of Tables
- Section 1. General Description
- 1.1 Contents
- 1.2 Introduction
- 1.3 Features
- 1.4 MCU Block Diagram
- 1.5 Pin Assignments
- 1.6 Pin Functions
- 1.6.1 Power Supply Pins (Vdd and Vss)
- 1.6.2 Oscillator Pins (OSC1 and OSC2)
- 1.6.3 External Reset Pin (RST)
- 1.6.4 External Interrupt Pin (IRQ)
- 1.6.5 Analog Power Supply Pin (VDDA)
- 1.6.6 Analog Ground Pin (VSSA)
- 1.6.7 Analog Ground Pin (AVSS/VREFL)
- 1.6.8 ADC Voltage Reference Pin (VREFH)
- 1.6.9 Analog Supply Pin (VDDAREF)
- 1.6.10 External Filter Capacitor Pin (CGMXFC)
- 1.6.11 Port A Input/Output (I/O) Pins (PTA7-PTA0)
- 1.6.12 Port B I/O Pins (PTB7/ATD7-PTB0/ATD0)
- 1.6.13 Port C I/O Pins (PTC5-PTC0)
- 1.6.14 Port D I/O Pins (PTD7-PTD0)
- 1.6.15 Port E I/O Pins (PTE7/SPSCK-PTE0/TxD)
- 1.6.16 Port F I/O Pins (PTF7-PTF0/TACH2)
- 1.6.17 Port G I/O Pins (PTG2/KBD2-PTG0/KBD0)
- 1.6.18 Port H I/O Pins (PTH1/KBD4-PTH0/KBD3)
- 1.7 I/O Pin Summary
- 1.8 Signal Name Conventions
- 1.9 Clock Source Summary
- Section 2. Memory Map
- Section 3. Random-Access Memory (RAM)
- Section 4. FLASH Memory
- Section 5. EEPROM
- Section 6. Configuration Register (CONFIG)
- Section 7. Central Processor Unit (CPU)
- Section 8. System Integration Module (SIM)
- Section 9. Clock Generator Module (CGM)
- 9.1 Contents
- 9.2 Introduction
- 9.3 Features
- 9.4 Functional Description
- 9.5 I/O Signals
- 9.5.1 Crystal Amplifier Input Pin (OSC1)
- 9.5.2 Crystal Amplifier Output Pin (OSC2)
- 9.5.3 External Filter Capacitor Pin (CGMXFC)
- 9.5.4 PLL Analog Power Pin (VDDA)
- 9.5.5 Oscillator Enable Signal (SIMOSCEN)
- 9.5.6 Crystal Output Frequency Signal (CGMXCLK)
- 9.5.7 CGM Base Clock Output (CGMOUT)
- 9.5.8 CGM CPU Interrupt (CGMINT)
- 9.6 CGM Registers
- 9.7 Interrupts
- 9.8 Low-Power Modes
- 9.9 CGM During Break Interrupts
- 9.10 Acquisition/Lock Time Specifications
- Section 10. Monitor ROM (MON)
- Section 11. Timer Interface Module A (TIMA)
- Section 12. Timer Interface Module B (TIMB)
- Section 13. Programmable Interrupt Timer (PIT)
- Section 14. Analog-to-Digital Converter (ADC)
- Section 15. Serial Communications Interface Module (SCI)
- Section 16. Serial Peripheral Interface Module (SPI)
- 16.1 Contents
- 16.2 Introduction
- 16.3 Features
- 16.4 Pin Name Conventions and I/O Register Addresses
- 16.5 Functional Description
- 16.6 Transmission Formats
- 16.7 Queuing Transmission Data
- 16.8 Error Conditions
- 16.9 Interrupts
- 16.10 Resetting the SPI
- 16.11 Low-Power Modes
- 16.12 SPI During Break Interrupts
- 16.13 I/O Signals
- 16.14 I/O Registers
- Section 17. Input/Output (I/O) Ports
- Section 18. External Interrupt (IRQ)
- Section 19. Keyboard Interrupt Module (KBI)
- Section 20. Computer Operating Properly (COP)
- Section 21. Low-Voltage Inhibit (LVI)
- Section 22. Break Module (BRK)
- Section 23. Electrical Specifications
- 23.1 Contents
- 23.2 Introduction
- 23.3 Absolute Maximum Ratings
- 23.4 Functional Operating Range
- 23.5 Thermal Characteristics
- 23.6 5.0-V DC Electrical Characteristics
- 23.7 EEPROM and Memory Characteristics
- 23.8 5.0-V Control Timing
- 23.9 Timer Interface Module Characteristics
- 23.10 ADC Characteristics
- 23.11 SPI Characteristics
- 23.12 Clock Generation Module Characteristics
- 23.13 FLASH Memory Characteristics
- Section 24. Mechanical Specifications
- Section 25. Ordering Information
System Integration Module (SIM)
Technical Data MC68HC908AB32 — Rev. 1.1
128 System Integration Module (SIM) Freescale Semiconductor
8.8.2 SIM Reset Status Register
This register contains six flags that show the source of the last reset. The
SIM reset status register can be cleared by reading it. A power-on reset
sets the POR bit and clears all other bits in the register.
POR — Power-On Reset Bit
1 = Last reset caused by POR circuit
0 = Read of SRSR
;
;
;
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 STOP or WAIT mode was exited by
break.
TST LOBYTE,SP ; If RETURNLO is not 0,
BNE DOLO ; then just decrement low byte.
DEC HIBYTE,SP ; Else deal with high byte, too.
DOLO DEC LOBYTE,SP ; Point to STOP/WAIT opcode.
RETURN PULH
RTI
; Restore H register.
Address: $FE01
Bit 7654321Bit 0
Read: POR PIN COP ILOP ILAD 0 LVI 0
Write:
Reset:10000000
= Unimplemented
Figure 8-18. SIM Reset Status Register (SRSR)
