b7-4.asm

汇编语言的设计

   	ORG 	0000H
	LJMP	MAIN
        ORG 	0013H
        CLR 	TR1
        MOV 	A,TL1
        MOV 	DPL,A
        MOV 	A,TH1
        MOV 	DPH,A
	SETB	B.0
	RETI
MAIN:   ORG 	1000H
	CLR	B.0
        CLR 	A
	ORL 	P3,#08H
        MOV 	TH1,A
        MOV 	TL1,A
        ORL 	A,#90H
        MOV 	TMOD,A
L1:     JB 	P3.3,L1
L2:     JNB  	P3.3,L2
	MOV	TCON,#0F4H
	MOV	IE,#84H
L3:     JNB	B.0,L3
        CLR     EX1
L4:     SJMP	L4
          END