1040641_20161109.asm

keybuf1 EQU 44h
keybuf2 EQU	45h
keycode EQU 46h
port4		EQU		0E8h
shift7LED	EQU		0FEh
dispBuf	EQU		40h

ORG 0000h			
			MOV a, #0FFh
			MOV port4, a		
			MOV 0A0h,a
			MOV 0B0h,a
			MOV keybuf1,#0FFh
			MOV keybuf2,#0FFh
			MOV keycode,#0
			MOV dispBuf, #1			
			MOV dispBuf+1, #2		
			MOV dispBuf+2, #3		
			MOV dispBuf+3, #4		

			MOV dptr, #led_table
reset:		MOV r0, #dispBuf			
			MOV a, #shift7LED		
loop:		MOV port4, A
			ACALL covled		
			ACALL getkeycode
			ACALL displaykeycode
			ACALL delay		
			INC r0				
			RL A				
			JB ACC.4, loop		
			SJMP reset

Delay:
			MOV r4, #1
delay0:	MOV r5, #2
delay1:	MOV r6, #100
delay2:	MOV r7, #100
delay3:	DJNZ r7, delay3
			DJNZ r6, delay2
			DJNZ r5, delay1
			DJNZ r4, delay0
			RET					


Covled:	PUSH 	0E0h		
			MOV		a, @R0		
			ANL		a, #0fh
			MOVC	a, @a+dptr
			MOV		p0, a
			POP		0E0h		
			RET


displaykeycode: 
push 0E0h
MOV a,keycode
MOV dispBuf,a			
MOV dispBuf+1,a		
MOV dispBuf+2, a		
MOV dispBuf+3, a		
POP 0E0h
RET

getkeycode:
push 0E0h
MOV a,0A0h
MOV keybuf1,a
MOV a,0B0h
MOV keybuf2,a
CJNE a,#0FFh,sub1
MOV r2,#0h
MOV a,keybuf1
back:jnb ACC.0,gotkeycode
INC r2
RR a
CJNE r2,#8h,back
POP 0E0h
RET

gotkeycode:MOV keycode,r2
exitkeycode:POP 0E0h
RET

sub1:
MOV r2,#8h
MOV a,keybuf2
loop1: jnb acc.0,gotkeycode
INC r2
RR a
CJNE r2 ,#16,loop1
POP 0E0h
RET

Led_table:
			DB	0c0h	
			DB	0F9h	
			DB	0A4h	
			DB	0B0h	
			DB	99h		
			DB	92h		
			DB	82h		
			DB	0D8h	
			DB	80h		
			DB	90h		
			DB	88h		
			DB	83h		
			DB	0C6h	
			DB	0A1h	
			DB	86h		
			DB	8Eh		
			END