PIC单片机的4*4键盘程序实例

<!--StartFragment-->;-------4*4键盘程序的使用--------
PC       EQU    2
STATUS   EQU    3
RA       EQU    5
RB       EQU    6
RC       EQU    7
BIJIAO   EQU    0F
JIANZHI  EQU    8
BUFFER   EQU    9
BUFFER1  EQU    0AH
BUFFER2  EQU    0BH
COUNTER  EQU    0CH
CON1     EQU    0DH
CON2     EQU    0EH
PIC57    EQU    7FFH
Z        EQU    2
;-----------------------------
         ORG    PIC57
         GOTO   MAIN
;-----------------------------
         ORG    0
;-----------------------------
;        延时子程序
;----------------------------
DELAY    MOVLW  D'100'
         MOVWF  CON1
L1       MOVLW  D'200'
         MOVWF  CON2
L2       DECFSZ CON2,1
         GOTO   L2
         DECFSZ CON1,1
         GOTO   L1
         RETLW  0        
;-----------------------------
;        4*4键盘扫描判断子程序
;-----------------------------
SCANKEY
         MOVLW  B'11101111'
         MOVWF  RB
         MOVF   RB,W
         ANDLW  B'00001111'
         MOVWF  BUFFER
         MOVLW  B'00001111'
         XORWF  BUFFER,W
         SKPNZ
         GOTO   XYB1
         MOVWF  BUFFER1
         MOVLW  1
         MOVWF  JIANZHI
         MOVF   RB,W
         MOVWF  BIJIAO
         GOTO   QJZ

XYB1     MOVLW  B'11011111'
         MOVWF  RB
         MOVF   RB,W
         ANDLW  B'00001111'
         MOVWF  BUFFER
         MOVLW  B'00001111'
         XORWF  BUFFER,W
         SKPNZ
         GOTO   XYB2
         MOVWF  BUFFER1
         MOVLW  5
         MOVWF  JIANZHI
         GOTO   QJZ

XYB2     MOVLW  B'10111111'
         MOVWF  RB
         MOVF   RB,W
         ANDLW  B'00001111'
         MOVWF  BUFFER
         MOVLW  B'00001111'
         XORWF  BUFFER,W