PIC 타이머0 를 활용한 버튼 빨리 누르기 게임

#include <xc.h>

#include <stdint.h>

#define _XTAL_FREQ 4000000

#define START   PORTBbits.RB1

#define SUCCESS PORTBbits.RB0

#define BUTTON  PORTBbits.RB2

#define MAXRT   200

#pragma config WDTE = OFF, PWRTE = OFF, CP = OFF, BOREN = OFF

void main() {

    uint8_t cnt_8ms;

    TRISB = 0b00000100;

    OPTION_REGbits.T0CS = 0;

    OPTION_REGbits.PSA  = 0;

    OPTION_REGbits.PS   = 4;

    while(1) {

        PORTB = 0;

        __delay_ms(2000);

        START = 1;

        cnt_8ms = 0;

        while(BUTTON == 1 && cnt_8ms < 1000/8) {

            TMR0 = 0;

            while(TMR0 < 8000/32);

            ++cnt_8ms;

        }

        if(cnt_8ms < MAXRT/8) SUCCESS = 1;

        __delay_ms(1000);

    }

}