pwm.rar_PIC24F pwm_pic24f

#include <p24F32KA302.h> /* Find the Period register value for a desired PWM frequency of 2 kHz, where Fosc = 16 MHz (16 MHz device clock rate) and a Timer3 prescaler setting of 1:1. Tcy = 2/Fosc = 125 ns PWM Period = 1/PWM Frequency = 1/2 kHz = 500 μs PWM Period = (PR2 + 1) * Tcy * (Timer 3 Prescale Value) *PWM周期计算公式 500 μs = (PR2 + 1) * 125 ns * 1 PR2 = 4000-1 */ void PWM_OUT(int Period,int rate); void IRA_38KHZ(int Period,int rate); void PWM_OUT(int Period,int rate) { OC1CON1 = 0;//It is a good practice to clear off the control bits initially OC1CON2 = 0; //PWM调试通过 OC1CON2bits.SYNCSEL = 0x1F; OC1CON2bits.OCTRIS = 0; OC1CON1bits.OCSIDL = 0;// Output capture will continue to operate in CPU Idle mode OC1CON1bits.OCTSEL = 1; //This selects the peripheral clock as the clock input to the OC1 //Select Timer3 as the clock input to the OC1 //111 = 系统时钟 //110 = 保留 //101 = 保留 //100 = Timer1 //011 = Timer5 //010 = Timer4 //001 = Timer3 //000 = Timer2 OC1CON1bits.OCM = 6 ; //110 = PWM模式：OCFA/B 禁用，当OCxTMR = 0 时输出设置为高电平，当OCxTMR = OCxR 时输出设 //置为低电平 T3CON = 0x00; //Stops any 16-bit Timer3 operation TMR3 = 0x00; //Clear contents of the timer3 register T3CONbits.TCKPS = 0; //11 = 1:256 //10 = 1:64 //01 = 1:8 //00 = 1:1 T3CONbits.TCS = 0; IFS0bits.T3IF = 0; //Clear the Timer3 interrupt status flag IEC0bits.T3IE = 0; //Enable Timer3 interrupts IEC0bits.OC1IE = 0; //Disable Compare 1 interrupts // / IFS0bits.OC1IF = 1; IFS0bits.OC1IF = 0; PR3 = Period; //Determine the period OC1R = rate; //Initial Compare Register1 duty cycle OC1RS = Period; //Initial Secondary Compare Register1 duty cycle T3CONbits.TON = 1; //Start Timer3 /* T3CON = 0x00; // 定时器3通过 //Stops any 16-bit Timer3 operation TMR3 = 0x00; //Clear contents of the timer3 register PR3 = 2999; //Determine the period T3CONbits.TCKPS = 0; //11 = 1:256 //10 = 1:64 //01 = 1:8 //00 = 1:1 T3CONbits.TCS = 0; IFS0bits.T3IF = 0; //Clear the Timer3 interrupt status flag IEC0bits.T3IE = 1; //Enable Timer3 interrupts T3CONbits.TON = 1; //Start Timer3 */ /* T1CON = 0; TMR1 = 0; //定时器1通过 PR1 = 1999; T1CONbits.TCKPS = 3;//T1CON=0x8030 1:256 定时时间=(FOSC/2)*256*DELAY T1CONbits.TCS = 0;//内部时钟FOSC/2 ///// T1CON=0x8030; IFS0bits.T1IF = 0; IEC0bits.T1IE = 1; ////_IPL=3; //置CPU优先级为3 IPC0bits.T1IP = 4; //置定时器1优先级为4 T1CONbits.TON = 1;*/ } void IRA_38KHZ(int Period,int rate) { OC3CON1 = 0;//It is a good practice to clear off the control bits initially OC3CON2 = 0; //PWM调试通过 OC3CON2bits.SYNCSEL = 0x1F; OC3CON2bits.OCTRIS = 0; OC3CON1bits.OCSIDL = 0;// Output capture will continue to operate in CPU Idle mode OC3CON1bits.OCTSEL = 1; //This selects the peripheral clock as the clock input to the OC1 //Select Timer3 as the clock input to the OC1 //111 = 系统时钟 //110 = 保留 //101 = 保留 //100 = Timer1 //011 = Timer5 //010 = Timer4 //001 = Timer3 //000 = Timer2 OC3CON1bits.OCM = 6 ; //110 = PWM模式：OCFA/B 禁用，当OCxTMR = 0 时输出设置为高电平，当OCxTMR = OCxR 时输出设 //置为低电平 T3CON = 0x00; //Stops any 16-bit Timer3 operation TMR3 = 0x00; //Clear contents of the timer3 register T3CONbits.TCKPS = 0; //11 = 1:256 //10 = 1:64 //01 = 1:8 //00 = 1:1 T3CONbits.TCS = 0; IFS0bits.T3IF = 0; //Clear the Timer3 interrupt status flag IEC0bits.T3IE = 0; //Enable Timer3 interrupts IEC1bits.OC3IE = 0; //Disable Compare 1 interrupts // / IFS0bits.OC1IF = 1; IFS1bits.OC3IF = 0; PR3 = Period; //Determine the period OC3R = rate; //Initial Compare Register1 duty cycle OC3RS = Period; //Initial Secondary Compare Register1 duty cycle T3CONbits.TON = 1; //Start Timer3 }