02ok-鍵盤.txt

8051的鍵盤實習程式!可以透過鍵盤的按鍵來控制led

LED_PORT  REG    P2
KEY_PORT  REG    P1
          ORG    0H
          MOV     LED_PORT,#01010101B
$2:       ACALL    KEY_PRESS
          ACALL    SCAN_KEY
          ACALL    DISP_LED
          SJMP     $2
KEY_PRESS:
$1:       MOV     KEY_PORT,#00001111B
          MOV     A,KEY_PORT
          CJNE    A,#00001111B,$1
          RET
SCAN_KEY:
$3:       MOV     R5,#4
          MOV     A,#11101111B
$4:       MOV     KEY_PORT,A
          NOP
          CJNE    A,KEY_PORT,KEY_POS
          RL      A
          DJNZ    R5,$4
          SJMP    $3
KEY_POS:
          ACALL   DELAY0.1S
          MOV     A,KEY_PORT
          ACALL   LO_POS
          CJNE    R2,#4,$5
$6:       MOV     R3,#0FFH
          RET
$5:       MOV     A,R2
          MOV     R3,A
          MOV     A,KEY_PORT
          SWAP    A
          ACALL   LO_POS
          CJNE    R2,#04H,$9
          SJMP    $6
$9:       MOV     A,R2
          RL      A
          RL      A
          ADD     A,R3
          MOV     R3,A
          RET
DELAY0.1S:
         MOV      R1,#200
$7:
         MOV      R0,#250
$8:      DJNZ     R0,$8
         DJNZ     R1,$7
         RET
LO_POS:
         MOV    R2,#0
$10:     RRC    A
         JC     $11
         RET
$11      INC    R2
         CJNE   R2,#04H,$10
         RET
DISP_LED:
                CJNE    R3,#0FFH,$12
                RET
$12:            MOV     DPTR,#LED_TAB
                MOV     A,R3
                MOVC    A,@A+DPTR
                MOV     LED_PORT,A
                RET

LED_TAB:
        .DB 01111000B
        .DB 01110111B
        .DB 01110110B
        .DB 01110011B
        .DB 01111011B
        .DB 01111010B
        .DB 01111001B
        .DB 01110010B
        .DB 01111110B
        .DB 01111101B
        .DB 01111100B
        .DB 01110001B
        .DB 01111111B
        .DB 01110101B
        .DB 01110100B
        .DB 01110000B
        END