keyboard.asm

PIC键盘小程序

;3*3键盘程序，使用C口作键盘扫描，7段数码管显示按键号
;63系列通用寄存器地址：20~7FH, A0~FFH

;未达到预期目的，只用个位数显示按键号时正常工作，增加按键号转换（用2位数显示）
;则提示“STACK OVERFLOW"--堆栈溢出.编译后机器码容量为1.3KB左右，未超过CALL跳转范围——1页（2K）

#include P16C63A.INC
KEYCODE EQU  H'0020'
KEYNUM  EQU  H'0021'
CC    EQU  H'0024'
TABADD EQU H'0025'
SW   EQU H'0026'
GW   EQU H'0027'
;PD   EQU H'0028'

ORG H'0000'
GOTO MAIN
ORG H'0010'

MAIN  MOVLW H'00'
      TRIS PORTA
      TRIS PORTB ;RB口全为输出，用作驱动7段数码管
      MOVWF KEYNUM
      MOVLW H'F0' 
      TRIS PORTC ;  设置RC低四位为输出，高四位为输入
      MOVLW TABLE
      MOVWF TABADD
      MOVLW H'0001'
;      MOVWF PD   ;用来判断按键号是否大于9

LOOP  
      CALL KEYSCAN
   ;   CALL JUDGE     ;判断是按键号是否大于9
   ;   XORLW H'0001'
   ;   BTFSS STATUS,Z
       CALL XIAO
   ;   GOTO DASHU
XS    CALL DISP_2
      GOTO LOOP    ;循环扫描、显示按键号

JUDGE     
      MOVLW H'0A'
      SUBWF KEYNUM,0
      BTFSC STATUS,0  ; C标志
   ;   RETLW 0  ;小于10
   ;   RETLW 1  ; 10以上的按键号
      GOTO XIAO
      GOTO DASHU

XIAO  MOVLW 0
      MOVWF SW
      MOVF KEYNUM,0
      MOVWF GW
      RETLW 0
     ; GOTO XS

DASHU  
      MOVLW H'01'
      MOVWF SW
      MOVLW H'0A'
      SUBWF KEYNUM,0
      MOVWF GW
      RETLW 0
     ; GOTO XS 

DISP_2
      MOVLW H'02'
      MOVWF PORTA
      MOVF SW,0
      CALL DISP
      CALL DELAY

      MOVLW H'01'
      MOVWF PORTA
      MOVF GW,0
      CALL DISP
      CALL DELAY
      RETLW 0

DELAY MOVLW 0
      MOVWF CC
LL    DECFSZ CC,1
      GOTO LL
      RETLW 0
   
DISP  ; MOVF KEYNUM,0                    ;输入W,输出W
      ADDWF TABADD,0 
      CALL CONV
      MOVWF PORTB
      RETLW 0
CONV  MOVWF PCL   ;取码，输入W（0～F），输出W
TABLE RETLW H'C0'
      RETLW H'F9'
      RETLW H'A4'
      RETLW H'B0'
      RETLW H'99'
      RETLW H'92'
      RETLW H'82'
      RETLW H'F8'
      RETLW H'80'
      RETLW H'90'
      RETLW H'88'
      RETLW H'83'
      RETLW H'C6' 
      RETLW H'A1'
      RETLW H'86'
      RETLW H'8E'    ;0~F 数码管代码
      RETLW H'C0'
      
KEYSCAN  MOVLW H'FE'  ;第一行置低（RC0输出0）
         MOVWF PORTC
         NOP
         MOVF PORTC,0 ;读RC各端口状态
         ANDLW H'F0' ;屏蔽低四位，只需要低四位来判断
         MOVWF KEYCODE ;保存端口状态
         MOVLW H'F0'
         SUBWF KEYCODE,0 ;与初值比较，看是否有键按下
         BTFSS STATUS,Z  ;有键按下（不等于初值，Z为零）则结束扫描
         GOTO  GETNUM1

         MOVLW H'FD'  ;第二行置低（RC1输出0）
         MOVWF PORTC
         NOP
         MOVF PORTC,0 ;读RC各端口值
         ANDLW H'F0' ;屏蔽低四位，只需要低四位来判断
         MOVWF KEYCODE ;保存端口状态
         MOVLW H'F0'
         SUBWF KEYCODE,0 ;与初值比较，看是否有键按下
         BTFSS STATUS,Z  ;有键按下（不等于初值，Z为零）则结束扫描
         GOTO  GETNUM2

         MOVLW H'FB'  ;第三行置低（RC2输出0）
         MOVWF PORTC
         NOP
         MOVF PORTC,0 ;读RC各端口值
         ANDLW H'F0' ;屏蔽低四位，只需要低四位来判断
         MOVWF KEYCODE ;保存端口状态
         MOVLW H'F0'
         SUBWF KEYCODE,0 ;与初值比较，看是否有键按下
         BTFSS STATUS,Z  ;有键按下（不等于初值，Z为零）则结束扫描
         GOTO  GETNUM3

         MOVLW H'F7'  ;第四行置低（RC3输出0）
         MOVWF PORTC
         NOP
         MOVF PORTC,0 ;读RC各端口值
         ANDLW H'F0' ;屏蔽低四位，只需要低四位来判断
         MOVWF KEYCODE ;保存端口状态
         MOVLW H'F0'
         SUBWF KEYCODE,0 ;与初值比较，看是否有键按下
         BTFSS STATUS,Z  ;有键按下（不等于初值，Z为零）则结束扫描
         GOTO  GETNUM4
FH       RETLW  0    ; 子程序返回

QUDOU    MOVF PORTC,0  ;去抖处理
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO QUDOU
         GOTO FH

GETNUM1  MOVLW H'E0'  ;1号键
         SUBWF KEYCODE,0 
         BTFSC STATUS,Z
         GOTO NUM1
         MOVLW H'D0'  ;2号键
         SUBWF KEYCODE,0 
         BTFSC STATUS,Z
         GOTO NUM2
         MOVLW H'B0'  ;3号键
         SUBWF KEYCODE,0 
         BTFSC STATUS,Z
         GOTO NUM3
         MOVLW H'70'  ;4号键
         SUBWF KEYCODE,0 
         BTFSC STATUS,Z
         GOTO NUM4         
         GOTO FH

GETNUM2  MOVLW H'E0'  ;5号键
         SUBWF KEYCODE,0 
         BTFSC STATUS,Z
         GOTO NUM5
         MOVLW H'D0'  ;6号键
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO NUM6 
         MOVLW H'B0'  ;7号键
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO NUM7 
         MOVLW H'70'  ;8号键
         SUBWF KEYCODE,0 
         BTFSC STATUS,Z
         GOTO NUM8
         GOTO FH

GETNUM3  MOVLW H'E0'  ;9号键
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO NUM9 
         MOVLW H'D0'  ;10号键
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO NUM10 
         MOVLW H'B0'  ;11号键
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO NUM11 
         MOVLW H'70'  ;12号键
         SUBWF KEYCODE,0 
         BTFSC STATUS,Z
         GOTO NUM12
         GOTO FH

GETNUM4  MOVLW H'E0'  ;13号键
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO NUM13 
         MOVLW H'D0'  ;14号键
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO NUM14 
         MOVLW H'B0'  ;15号键
         SUBWF KEYCODE,0
         BTFSC STATUS,Z
         GOTO NUM15 
         MOVLW H'70'  ;16号键
         SUBWF KEYCODE,0 
         BTFSC STATUS,Z
         GOTO NUM16
         GOTO FH

NUM1     MOVLW 1
         MOVWF KEYNUM
         GOTO QUDOU 
NUM2     MOVLW 2
         MOVWF KEYNUM
         GOTO QUDOU 
NUM3     MOVLW 3
         MOVWF KEYNUM
         GOTO QUDOU 
NUM4     MOVLW 4
         MOVWF KEYNUM
         GOTO QUDOU 
NUM5     MOVLW 5
         MOVWF KEYNUM
         GOTO QUDOU 
NUM6     MOVLW 6
         MOVWF KEYNUM
         GOTO QUDOU 
NUM7     MOVLW 7
         MOVWF KEYNUM
         GOTO QUDOU 
NUM8     MOVLW 8
         MOVWF KEYNUM
         GOTO QUDOU
NUM9     MOVLW 9
         MOVWF KEYNUM
         GOTO QUDOU 
NUM10     MOVLW H'000A'
         MOVWF KEYNUM
         GOTO QUDOU 
NUM11     MOVLW H'000B'
         MOVWF KEYNUM
         GOTO QUDOU 
NUM12     MOVLW H'000C'
         MOVWF KEYNUM
         GOTO QUDOU
NUM13     MOVLW H'000D'
         MOVWF KEYNUM
         GOTO QUDOU
NUM14     MOVLW H'000E'
         MOVWF KEYNUM
         GOTO QUDOU 
NUM15     MOVLW H'000F'
         MOVWF KEYNUM
         GOTO QUDOU 
NUM16     MOVLW H'0010'
         MOVWF KEYNUM
         GOTO QUDOU

  END