ORG 0000H
        LJMP MAIN
        ORG 0003H
        LJMP INT0ADD
        ORG 0100H
MAIN:
        MOV P1,#0ffH
        setb IT0        
        mov IE,#81H 
        mov DPTR,#0fffbH
        mov A,#0fbH
        movx @DPTR,A
        /*MOV P0,#0fbH
        clr p3.6
        setb P3.6*/
        SJMP $      
INT0ADD:
        CLR EX0
        mov P0,#0ffh
        movx A,@DPTR
        mov P1,A
        mov A,#0fbh
        movx @DPTR,A 
        /*clr p3.7
        MOV A,p0
        setb p3.7
        MOV P0,#0fbH
        clr p3.6
        setb P3.6
        MOV P1,A*/       
        SETB EX0
        RETI
END