Advance Information MC68HC908MR16/MC68HC908MR32 — Rev. 4.0
106 System Integration Module (SIM) MOTOROLA
System Integration Module (SIM)
7.8.2 SIM Reset Status Register
The SIM reset status register (SRSR) 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.
POR — Power-On Reset Bit
1 = Last reset caused by POR circuit
0 = Read of SRSR
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
MENRST — Forced Monitor Mode Entry Reset Bit
1 = Last reset caused by the MENRST circuit
0 = POR or read of SRSR
Address: $FE01
BIt 7654321Bit 0
Read: POR PIN COP ILOP ILAD MENRST LVI 0
Write:RRRRRRRR
Reset:10000000
R= Reserved
Figure 7-15. SIM Reset Status Register (SRSR)