prg.asm

利用不同的按键实现7段数码显示不同的字符

NAME ROWSCAN                          ;反转法

KEY_ROW1	equ	0EFh
KEY_ROW2	equ	0DFh
KEY_ROW3	equ	0BFh
KEY_ROW4	equ	07Fh

ORG 0000H
				ljmp START
ORG 0100H		
START:			mov R0,#00 			 ;行号
				mov R1,#00			 ;列号

				;读列号
				mov p1,#0FH
				nop
				mov A,p1
				anl A,#0Fh
c1:				cjne A,#0EH, c2
				mov R1,#1
				jmp row
c2:				cjne A,#0DH, c3
				mov R1,#2
				jmp row
c3:				cjne A,#0BH, c4
				mov R1,#3
				jmp row
c4:				cjne A,#07H, START
				mov R1,#4

				;读行号
row:			mov p1,#0F0H
				nop
				mov A,p1
				anl A,#0F0H
row1:			cjne A,#0E0H, row2
				mov R0,#1
				jmp count
row2:			cjne A,#0D0H, row3
				mov R0,#2
				jmp count
row3:			cjne A,#0B0H, row4
				mov R0,#3
				jmp count
row4:			cjne A,#070H, START
				mov R0,#4

				;(R0 - 1) * 4 + (R1 - 1)
count:			dec R0
				dec R1
				mov A,R0
				mov B,#4
				mul AB
				add A,R1
	
ksnew:			mov DPTR,#keycodes						
				movc A,@A+DPTR			
				mov P0,A
				nop
				nop
							
ksend:			ljmp START

keycodes:		db 	3FH,06H,5BH,4FH
				db	66H,6DH,7DH,07H
				db	7FH,6FH,77H,7CH
				db	39H,5EH,79H,71H

				END