这个很简单

;********************************************************************************

;*  标题:  伟纳电子ME300B单片机开发系统演示程序 - 矩阵键盘数码管显示键值        *

;*  文件:  WL031.asm                                                            *

;*  日期:  2005-3-20                                                            *

;*  版本:  1.0                                                                  *

;*  作者:  gguoqing                                                             *

;*  邮箱:  gguoqing.com                                                  *

;*  网站： http://www.willar.com                                                *

;********************************************************************************

;*  描述:                                                                       *

;*         矩阵键盘数码管显示键值                                               *

;*                                                                              *

;*         矩阵键盘定义：                                                       *

;*         P1.0-P1.3为列线,P1.4-P1.7为行线                                      *

;*                                                                              *

;*                                                                              *

;********************************************************************************

;* 【版权】 Copyright(C)伟纳电子 www.willar.com  All Rights Reserved            *

;* 【声明】 此程序仅用于学习与参考，引用请注明版权和作者信息！                  *

;********************************************************************************

RELAY  EQU  P1.3

BEEP   EQU  P3.7

;------------------------------------------------------

ORG  0000H

JMP  MAIN

;------------------------------------------------------

MAIN:      MOV  SP,#60H

MOV  30H,#00H

LOOP1:

CALL  KEY_IN

CALL  KEY_PLAER

JMP  LOOP1

;-----------------------------------------------------

KEY_IN:    MOV  P1,#0F0H          ;置列线为0，行线为1

MOV  A,P1

ANL  A,#0F0H

MOV  B,A

MOV  P1,#0FH           ;置列线为1，行线为0

MOV  A,P1

ANL  A,#0FH

ORL  A,B               ;高四位与低四位重新组合

CJNE  A,#0FFH,KEY_IN1  ;0FFH为末按键

RET

KEY_IN1:   MOV  B,A

MOV  DPTR,#KEYTABLE

MOV  R3,#0FFH           ;

KEY_IN2:   INC  R3

MOV  A,R3

MOVC  A,+DPTR

CJNE  A,B,KEY_IN3

MOV  A,R3             ;找到，取顺序码

MOV  30H,A

CALL  BEEP_BL

RET

KEY_IN3:   CJNE  A,#0FFH,KEY_IN2  ;末完，继续查

RET                    ;0FFH为结束码

;----------------------------------------------

;蜂鸣器响一声子程序

;----------------------------------------------

BEEP_BL:

MOV  R6,#100

BL1:     CALL  DEX1

CPL  BEEP

DJNZ  R6,BL1

MOV  R5,#25

CALL  DELAY

RET

DEX1:     MOV  R7,#180

DEX2:     NOP

DJNZ  R7,DEX2

RET

DELAY:                    ;延时R5×10MS

MOV  R6,#50

DELAY1:    MOV  R7,#100

DJNZ  R7,  R6,DELAY1

DJNZ  R5,DELAY

RET

;-----------------------------------------------------

KEYTABLE:

DB  0EEH,0EDH,0EBH,0E7H,0DEH  ;0,1,2,3,4,  顺序码

DB  0DDH,0DBH,0D7H,0BEH,0BDH  ;5,6,7,8,9,

DB  0BBH,0B7H,07EH,07DH,07BH  ;A,B,C,D,E,

DB  077H,0FFH                 ;F      0FF为结束码

;-----------------------------------------------------

;键值显示子程序

;使用一个数码管显示

;-----------------------------------------------------

KEY_PLAER:

MOV  A,30H

MOV  DPTR,#TAB      ;取段码表地址

MOVC  A,+DPTR     ;查显示数据对应段码

MOV  P0,A           ;段码放入P0口

CLR  P2.7           ;第一个数码管亮

RET

;-----------------------------------------------------

TAB:

DB  0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H

DB  80H,90H,88h,83h,0c6h,0a1h,86h,8eh

;-----------------------------------------------------

END