b4-1.asm

汇编语言的设计

	ORG	0000H
	LJMP	MAIN
	ORG	1000H
MAIN:   MOV 	R2,#70H
        MOV 	R3,#71H
L2:     ACALL 	L1
        INC 	R2
        INC 	R3
        CJNE 	R3,#80H,L2
L3:     SJMP 	L3
        NOP
L1:     MOV 	A,R2
        MOV 	R0,A
        MOV 	A,R3
        MOV 	R1,A
        MOV 	A,@R0
L5:     CLR 	C
        SUBB 	A,@R1
        MOV 	A,@R0
        JC 	L4
        XCH 	A,@R1
        MOV 	@R0,A
L4:     INC 	R1
        CJNE 	R1,#80H,L5
        MOV 	@R0,A
        RET
        END