456.asm

proteus的一个小定时计时

        ORG     00H
        AJMP    MAIN
        ORG     03H
  AJMP  SUB1
        ORG     0030H
MAIN:
        MOV     IE,#10000001B  
        MOV     TCON,#00000001B 
        MOV     SP,#20H
START:
        MOV     A,#0FEH
ROTATE:
        RR      A
        MOV     P0,A
        ACALL   DELAY
        AJMP    ROTATE
DELAY:
        MOV     R3,#00H
DEL:
        MOV     R4,#00H
        DJNZ    R4,$
        DJNZ    R3,DEL
        RET
SUB1:
        PUSH    PSW
PUSH A
        SETB    RS0   
        CLR     RS1
        MOV     R0,#09H
LOOP:
        MOV     A,#0H
        MOV     P0,A
        ACALL   DELAY
 MOV     A,#0FFH
        MOV     P0,A
        ACALL   DELAY
        DJNZ    R0,LOOP
POP A
        POP     PSW
        RETI
        END