电表在不同供电模式下的安全过渡

ol byte to mark

mov dptr,#FUSE_TABLE
orl 0B2H,#01H ; set to flash write
movx @dptr,a ; write fuse table byte

jmp PASS

FAIL:
MOV DPTR,#20A9H ; WAKE address
MOV A,#0C1H ; SLEEP forces wake and fuse re-read
MOVX @DPTR,A

PASS: CLR A ; Select 0
MOV DPTR,#20FDH ; TRIMSEL address
MOVX @DPTR,A ; clear trim select register.

POP ACC
MOV R6,A ; Restore R7 in this register set
POP ACC
MOV R7,A ; Restore R7 in this register set
POP ACC
POP DPH
POP DPL
POP PSW ; Restore registers, so it's reentrant.
POP IEN0
RET

END
　　RTC例程

复位后，软件不应该马上调节时钟修正休眠模式下时差，而是首先计算需要消除的时间偏差，然会设置时钟进行补偿。