DIN		EQU		P3.0
CLK		EQU		P3.1
DBUF	EQU		30H
TEMP 	EQU     40H
		ORG		00H
		MOV		30H,#16			;數(shù)碼管顯示初始化
MAIN:	ACALL	DISP			;顯示
		ACALL	KEY				;計(jì)算鍵值
		AJMP	MAIN
KEY: 							;計(jì)算鍵碼子程序
		MOV 	P1,#0FFH    	;讀數(shù)前先寫1       
		MOV		A,P1               
		CJNE	A,#0FFH,K00 	;判斷是否有鍵按下   
		AJMP	KEY                     
K00:	ACALL	DELAY                  
		MOV		A,P1
		CJNE	A,#0FFH,K01 	;消除按鍵抖動(dòng)    
		AJMP	KEY
K01:	MOV		R3,#8              
		MOV 	R2,#0                  
		MOV 	B,A                   
		MOV		DPTR,#K0TAB		;查表比較,計(jì)算鍵值
K02: 	MOV 	A,R2
		MOVC 	A,@A+DPTR             
		CJNE 	A,B,K04               
K03: 	MOV		A,P1                     
		CJNE  	A,#0FFH,K03     ;等待按鍵抬起    
		ACALL  	DELAY                   
		MOV  	A,R2                    
		RET
K04:	INC 	R2              
		DJNZ	R3,K02
		MOV 	A,#0FFH     
		AJMP 	KEY
K0TAB:	DB  	0FEH,0FDH,0FBH,0F7H       
		DB  	0EFH,0DFH,0BFH,07FH
DISP: 					  		;數(shù)碼顯示子程序
		MOV   	DBUF,A			;鍵值存入緩存
		MOV   	R0,#DBUF
		MOV   	R1,#TEMP

DP10:	MOV   	DPTR,#SEGTAB
		MOV   	A,@R0
		MOVC  	A,@A+DPTR		;根據(jù)鍵值查表取段碼
		MOV   	@R1,A			;暫存段碼
		MOV     R0,#TEMP

DP12:	MOV   	R2,#8			;設(shè)置移位次數(shù)
		MOV   	A,@R0
DP13: 	RLC    	A				;段碼移位輸出
		MOV   	DIN,C
		CLR    	CLK				;輸出移位脈沖
		SETB   	CLK
		DJNZ   	R2,DP13
		RET
SEGTAB: DB  	3FH,06H,5BH,4FH,66H         
        DB  	6DH,7DH,07H,7FH,6FH
		               
DELAY:  MOV     R4,#02H                
AA1:    MOV     R5,#0F8H
AA:     DJNZ 	R5,AA
		DJNZ	R4,AA1
		RET
		END