123 asm

单片机只是别人的东西

    ORG 0000H
 LJMP MAIN
    ORG 0003H
 LJMP INT0
    ORG 0050H
 PROC MAIN
 MAIN:
    MOV SP,#5FH
    SETB IT0
    CLR EX0
    SETB EA
    SETB P1.3
    CLR P1.3
    SETB P1.3
    MOV P0,#0C0H
    NOP
    NOP
    SETB EX0
    NOP
    MOV P0,#0FFH
    NOP
    NOP
    SJMP $
 END
 ORG 0300H
 PROC INT0
 INT0:
      PUSH PSW
      PUSH ACC
      MOV P0,#80H
      POP PSW
      RETI
 END