51单片机键盘汇编程序

KEYVAL EQU 30H
KEYSCAN EQU 31H
KEYTM EQU 32H
KEYSEL:
MOV KEYVAL,#0
MOV KEYSCAN,#0EFH
LCALL GETKEY
MOV A,KEYTM
JZ KEYS1
MOV KEYVAL,A
SJMP KEYRTN
KEYS1:
MOV KEYSCAN,#0DFH
LCALL GETKEY
MOV A,KEYTM
JZ KEYS2
CLR C
ADD A,#4
MOV KEYVAL,A
SJMP KEYRTN
KEYS2:
MOV KEYSCAN,#0BFH
LCALL GETKEY
MOV A,KEYTM
JZ KEYS3
CLR C
ADD A,#8
MOV KEYVAL,A
SJMP KEYRTN
KEYS3:
MOV KEYSCAN,#7FH
LCALL GETKEY
MOV A,KEYTM
JZ KEYRTN
CLR C
ADD A,#12
MOV KEYVAL,A
KEYRTN:
RET

;--------------------
GETKEY:
MOV KEYTM,#0
MOV A,KEYSCAN
MOV P3,A
NOP
MOV A,P3
ANL A,#0FH
XRL A,#0FH
JZ NOKEY
MOV R2,#10
LCALL DELAY
MOV A,P3
ANL A,#0FH
XRL A,#0FH
JZ NOKEY
MOV A,P3
ANL A,#0FH
MOV R7,A
SF:
MOV A,P3
ANL A,#0FH
XRL A,#0FH
JNZ SF
MOV A,R7
CJNE A,#0EH,NK1
MOV KEYTM,#1
SJMP NOKEY
NK1:
CJNE A,#0DH,NK2
MOV KEYTM,#2
SJMP NOKEY
NK2:
CJNE A,#0BH,NK3
MOV KEYTM,#3
SJMP NOKEY
NK3:
CJNE A,#07H,NOKEY
MOV KEYTM,#4
NOKEY: RET

可以帮你写的