10.1.3 8279键盘接口.txt

里面有好多的原码,大家都来下载.用asm编写的

START:
MOV	DPTR,# 7FFFH					
MOV 	A,#0Dl H						
MOVX	DPTR,A
WAIT:
MOVX 	A,＠DPTR					
JB 		ACC. 7,WAIT				
MOV 	A,#2AH					
MOVX	DPTR,A
MOV 	A,#00H						
MOVX	DPTR,A
MOV 	R0,#30H						
MOV 	R7,#08H						
MOV 	A,#90H						
MOVX 	@DPTR,A
MOV 	DPTR,#7FFEH					
LOOP1:
MOV 	A,R0							
MOVX	＠DPTR，A
INC 		R0
DJNZ 	R7,LOOPl
MOV 	R0,#40H					
MOV 	R7,#10H
LOOP2:
MOV 	DPTR,#7FFFH					
LOOP3:
MOVX 	A,@DPTR						
ANL 	A,#OFH						
JZ 		LOOP3					
MOV 	A,#40H						
MOVX 	DPTR,A
MOV 	DPTR,#7FFEH					
MOVX 	A,DPTR
ANL 	A,#3FH						
MOV	＠R0,A						
INC 		R0
DJNZ 	R7,LOOP2
HERE:
SJMP 	HERE						
RET