MC68HC908AB32 Datasheet, PDF (128/392 Pages) Motorola, Inc – HCMOS Microcontroller Unit

System Integration Module (SIM)
; 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.
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.
Address: $FE01
Bit 7
6
5
4
3
2
1
Bit 0
Read: POR
PIN
COP
ILOP
ILAD
0
LVI
0
Write:
Reset: 1
0
0
0
0
0
0
0
= Unimplemented
Figure 8-18. SIM Reset Status Register (SRSR)
POR — Power-On Reset Bit
1 = Last reset caused by POR circuit
0 = Read of SRSR
Technical Data
128
System Integration Module (SIM)
MC68HC908AB32 — Rev. 1.1
Freescale Semiconductor