关于矩阵键盘的问题，求给位高手给我解答下问题所在。。

做了一个矩阵键盘程序，要求是当按下对应的键时数码管显示对应的数值0到F，问题在按下按键时数码管无反应

               ORG 0000H
               AJMP MAIN
               NOP

MAIN:          LCALL KEY
               LCALL DIS
               AJMP MAIN

KEY:          LCALL KEYY //调扫描键盘
               JNZ KEY1       //有键按下转KEY1
               LCALL DEL
               AJMP MAIN
KEY1:          LCALL DEL  //去抖
               LCALL KEYY //再检测
               JZ MAIN       //无键按下转回主程序
KEY0:          JNZ KEY0       //等待释放按键
               CPL A
               MOV R3,A
               LCALL KEY2
KEYY:          MOV P1,#0FH
               MOV A,P1
               MOV 30H,A
               MOV P1,#0F0H
               MOV A,P1
               MOV 31H,A
               ANL 30H,#0FH
               MOV A,30H
               ANL 31H,#0F0H
               ADD A,31H
               CPL A
               RET
KEY2:          CJNE R3,#0EEH,KEY3
               MOV R2,#00H
               AJMP DIS
KEY3:          CJNE R3,#0EDH,KEY4
               MOV R2,#01H
               AJMP DIS
KEY4:          CJNE R3,#0EBH,KEY5
               MOV R2,#02H
               AJMP DIS
KEY5:          CJNE R3,#0E7H,KEY6
               MOV R2,#03H
               AJMP DIS
KEY6:          CJNE R3,#0DEH,KEY7
               MOV R2,#04H
               AJMP DIS
KEY7:          CJNE R3,#0DEH,KEY8
               MOV R2,#05H
               AJMP DIS
KEY8:          CJNE R3,#0DEH,KEY9
               MOV R2,#06H
               AJMP DIS
KEY18:          AJMP MAIN
KEY9:          CJNE R3,#0DEH,KEY10
               MOV R2,#07H
               AJMP DIS
KEY10:          CJNE R3,#0DEH,KEY11
               MOV R2,#08H
               AJMP DIS
KEY11:          CJNE R3,#0DEH,KEY12
               MOV R2,#09H
               AJMP DIS
KEY12:          CJNE R3,#0DEH,KEY13
               MOV R2,#0AH
               AJMP DIS
KEY13:          CJNE R3,#0DEH,KEY14
               MOV R2,#0BH
               AJMP DIS
KEY14:          CJNE R3,#0DEH,KEY15
               MOV R2,#0CH
               AJMP DIS
KEY15:          CJNE R3,#0DEH,KEY16
               MOV R2,#0DH
               AJMP DIS
KEY16:          CJNE R3,#0DEH,KEY17
               MOV R2,#0EH
               AJMP DIS
KEY17:          CJNE R3,#0DEH,KEY18
               MOV R2,#0FH
               AJMP DIS
DIS:          MOV A,R2
               MOV DPTR,#DUAN
               MOVC A,@A+DPTR
         MOV P0,A
               SETB P2.3
               CLR P2.3
               MOV P0,#0FEH
               SETB P2.2
               LCALL DEL
               CLR P2.2
               RET
DEL:          MOV R7,#50
DEL2:          MOV R6,#100
               DJNZ R6,$
               DJNZ R7,DEL2
               RET

DUAN: DB 3Fh,06h,5Bh,4Fh,66h,6Dh,7Dh,07h,7Fh,6Fh,77h,7Ch,39h,5Eh,79h,71h
               END