Datasheet

Break Module Registers
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor 295
21.5.4 SIM Break Flag Control Register
The SIM break flag control register (SBFCR) contains a bit that enables software to clear status bits while
the MCU is in a break state.
BCFE — Break Clear Flag Enable Bit
This read/write bit enables software to clear status bits by accessing status registers while the MCU is
in a break state. To clear status bits during the break state, the BCFE bit must be set.
1 = Status bits clearable during break
0 = Status bits not clearable during break
;
;
;
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 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: $FE03
Bit 7654321Bit 0
Read:
BCFE RRRRRRR
Write:
Reset: 0
R = Reserved
Figure 21-7. SIM Break Flag Control Register (SBFCR)