7按键扫描 .asm

本原码是51单片机的实验原程序

;=================================================
; 按键扫描           
;=================================================
;
;	zsMCU51实验板配套学习例程
;
;	中山单片机学习网	智佳科技
;
;	作者：逸风	QQ:105558851
;
;	http://www.zsmcu.com
;	E-mail:[e-mail]
;=================================================
ORG 0000H 
LJMP START;转入主程序
ORG 0010H 
START:

MAIN:

	MOV	A,#00000011B
	ORL	A,P3
	CPL	A
	JZ		MAIN
	LCALL	DELAY10MS	;去抖动
	MOV	A,#00000011B
	ORL	A,P3
	CPL	A
	JZ		MAIN

	JB		ACC.2,KEY_SW1
	JB		ACC.3,KEY_SW2
	JB		ACC.4,KEY_SW3
	JB		ACC.5,KEY_SW4
	JB		ACC.6,KEY_SW5
	JB		ACC.7,KEY_SW6
	LJMP	MAIN
KEY_SW1:
	CPL	P1.0
	AJMP	KEY_END
KEY_SW2:
	CPL	P1.1
	AJMP	KEY_END
KEY_SW3:
	CPL	P1.2
	AJMP	KEY_END
KEY_SW4:
	CPL	P1.3
	AJMP	KEY_END
KEY_SW5:
	CPL	P1.4
	AJMP	KEY_END
KEY_SW6:	
	CPL	P1.5
	AJMP	KEY_END


KEY_END:
	MOV	A,#00000011B
	ORL	A,P3
	CPL	A
	JNZ	KEY_END
	LJMP	MAIN



DELAY10MS: 
	MOV R4,#20
DELAY10MSA:
	MOV R5,#247
	DJNZ R5,$
	DJNZ R4,DELAY10MSA
RET
END