2 reset status register (rsr), Reset status register (rsr) – Freescale Semiconductor MC68HC08KH12 User Manual
Page 84
Advance Information
MC68HC(7)08KH12
—
Rev. 1.1
84
Freescale Semiconductor
7.8.2 Reset Status Register (RSR)
This register 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.
;
;
;
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,BSR, RETURN
;
;
See if wait mode or stop mode was exited
by break
TST
LOBYTE,SP
; If RETURNLO is not zero,
BNE
DOLO
; then just decrement low byte.
DEC
HIBYTE,SP
; Else deal with high byte, too.
DOLO
DEC
LOBYTE,SP
; Point to WAIT/STOP opcode.
RETURN
PULH
RTI
; Restore H register.
Address:
$FE01
Bit 7
6
5
4
3
2
1
Bit 0
Read:
POR
PIN
COP
ILOP
ILAD
USB
0
0
Write:
POR:
1
0
0
0
0
0
0
0
= Unimplemented
Figure 7-21. Reset Status Register (RSR)