pwm.c (16F877A-Showtime)

//chen thu vien
#include"main.h"
void _SetDutyPWM1(unsigned int DutyCycle)
{
    PR2=99;
    CCPR1L=DutyCycle;
    CCP1X=T2CKPS1;
    CCP1Y=T2CKPS0;
}
void _SetUpPWM1(void)
{
    TRISC2=0;
    //cau hinh cho CCP1 o che do PWM
    CCP1M3=1;
    CCP1M2=1;
    CCP1M1=0;
    CCP1M0=0;
    TOUTPS3=0;
    TOUTPS2=0;
    TOUTPS1=0;
    TOUTPS0=0;
    TMR2ON=0;
    T2CKPS1=0;
    T2CKPS0=0;
    _SetDutyPWM1(0);
    TMR2ON=1;
}
void _SetDutyPWM2(unsigned int DutyCycle)
{
    PR2=99;
    CCPR2L=DutyCycle;
    CCP2X=T2CKPS1;
    CCP2Y=T2CKPS0;
}
void _SetUpPWM2(void)
{
    TRISC1=0;
    //cau hinh cho CCP2 o che do PWM
    CCP2M3=1;
    CCP2M2=1;
    CCP2M1=0;
    CCP2M0=0;
    TOUTPS3=0;
    TOUTPS2=0;
    TOUTPS1=0;
    TOUTPS0=0;
    TMR2ON=0;
    T2CKPS1=0;
    T2CKPS0=0;
    _SetDutyPWM2(0);
    TMR2ON=1;
}
/*
    Ap dung cong thuc chu ky PWM ta co:
    T(pwm)=[PR2+1]*4*(Tosc)*(TMR2 Prescale Value)
            =[PR2+1]*4*(1/Fosc)*(TMR2 Prescale Value)
    hay T(pwm)=[99+1]*4*(1/4)*1
                =100*10^(-6)=10^(-4)=10khz
    vay tan so de dieu khien dong co la 10(kHz)
*/