微處理器 - Microchip PIC12F1822 - Assembly - Button

TRISA(方向設定)、PORTA(I/O資料)


提升電阻設定



main.s

    list p=12f1822, r=hex
    #include <p12f1822.inc>
    __config _CONFIG1, _FOSC_INTOSC & _WDTE_OFF & _MCLRE_OFF
    __config _CONFIG2, _LVP_OFF
 
    org 0x0000
    goto start
   
    org 0x0100
start:
    banksel TRISA
    bcf TRISA, 0
    bsf TRISA, 3

    banksel OPTION_REG
    bcf OPTION_REG, 7

    banksel WPUA
    bsf WPUA, 3

    banksel PORTA
    bsf PORTA, 0

loop:
    banksel PORTA
    btfss PORTA, 3
    bcf PORTA, 0
    btfsc PORTA, 3
    bsf PORTA, 0
    goto loop
    end

編譯

$ gpasm main.s

完成