s908qc16vdse Freescale Semiconductor, Inc, s908qc16vdse Datasheet - Page 167

• Manufacturer Part Number: s908qc16vdse
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

14.8.1 SIM Reset Status Register
The SRSR register contains flags that show the source of the last reset. The status register will
automatically clear after reading SRSR. A power-on reset sets the POR bit and clears all other bits in the
register. All other reset sources set the individual flag bits but do not clear the register. More than one
reset source can be flagged at any time depending on the conditions at the time of the internal or external
reset. For example, the POR and LVI bit can both be set if the power supply has a slow rise time.
POR — Power-On Reset Bit
PIN — External Reset Bit
COP — Computer Operating Properly Reset Bit
ILOP — Illegal Opcode Reset Bit
ILAD — Illegal Address Reset Bit (illegal attempt to fetch an opcode from an unimplemented
address)
MODRST — Monitor Mode Entry Module Reset bit
LVI — Low Voltage Inhibit Reset bit
Freescale Semiconductor
1 = Last reset caused by POR circuit
0 = Read of SRSR
1 = Last reset caused by external reset pin (RST)
0 = POR or read of SRSR
1 = Last reset caused by COP counter
0 = POR or read of SRSR
1 = Last reset caused by an illegal opcode
0 = POR or read of SRSR
1 = Last reset caused by an opcode fetch from an illegal address
0 = POR or read of SRSR
1 = Last reset caused by monitor mode entry when vector locations $FFFE and $FFFF are $FF after
0 = POR or read of SRSR
1 = Last reset caused by LVI circuit
0 = POR or read of SRSR
POR while IRQ ≠ V
Read:
Write:
POR:
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 4
POR
Bit 7
1
Figure 14-19. SIM Reset Status Register (SRSR)
= Unimplemented
TST
PIN
6
0
COP
5
0
ILOP
4
0
ILAD
3
0
MODRST
2
0
LVI
1
0
Bit 0
0
0
SIM Registers
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