Sim Reset Status Register - Freescale Semiconductor MC68HC908MR16 Datasheet

System Integration Module (SIM)
SBSW can be read within the break state SWI routine. The user can modify the return address on the
stack by subtracting one from it.

14.7.2 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.
Address: $FE01
Read:
Write:
Reset:
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
LVI — Low-Voltage Inhibit Reset Bit
1 = Last reset caused by the LVI circuit
0 = POR or read of SRSR
192
BIt 7 6 5
POR PIN COP
R R R
1 0 0
R = Reserved
Figure 14-15. SIM Reset Status Register (SRSR)
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
4 3 2
ILOP ILAD MENRST
R R R
0 0 0
1 Bit 0
LVI 0
R R
0 0
Freescale Semiconductor