ex4-1.asm

《增强型8051单片机实用开发技术》例程代码

SIGN	EQU		50H
		ORG		0000H
		LJMP	MAIN
		ORG    	0100H
MAIN:	CJNE   	R0,#37,NOTEQ  	 ;R0中数与37数比较，不相等则转NOTEQ
		MOV   	SIGN,#00H        ;若比较相等,则SIGN←0
		LJMP  	ENDME
NOTEQ:	JC    	NEG              ;两数不相等,若R0＜37则转NEG
		MOV   	SIGN,#01H        ;R0＞37时,SIGN←+1
		LJMP   	ENDME
NEG:  	MOV   	SIGN,#0FFH       ;R0＜37时,SIGN←-1（以补码形式给出）
ENDME:	NOP
		END