MC68HC08AS20 Datasheet, PDF (138/386 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

9.8.2 SIM Reset Status Register
This read-only register contains flags to show reset sources. A power-on
reset sets the POR flag and clears all other flags. Reset sources other
than power-on reset do not clear all other flags.
Reading the reset status register clears all reset flags. Reset service can
read the reset status register to clear the register after power-on reset
and to determine the source of any subsequent reset.
NOTE:
Only a read of the reset status register clears all reset flags. After
multiple resets from different sources without reading the register,
multiple flags remain set.
Address: $FE01
Bit 7
6
5
4
3
2
1
Bit 0
Read: POR
PIN
COP
ILOP
ILAD
0
LVI
0
Write:
Reset: 1
X
0
0
0
0
X
0
= Unimplemented X = Indeterminate
Figure 9-17. SIM Reset Status Register (SRSR)
POR — Power-On Reset Flag
1 = Power-on reset since last read of RSR
0 = Read of RSR since last power-on reset
PIN — External Reset Flag
1 = External reset since last read of RSR
0 = Power-on reset or read of RSR since last external reset
COP — COP Reset Flag
1 = COP reset since last read of RSR
0 = Power-on reset or read of RSR since last COP reset
ILOP — Illegal Opcode Reset Flag
1 = Illegal opcode reset since last read of RSR
0 = Power-on reset or read of RSR since last illegal opcode reset
Advance Information
138
MC68HC08AS20 —Rev. 4.1
Freescale Semiconductor