[PIC] PWM USING PIC 16f887

[incognito007]

/*
   Frequency 8Mhz
 */
 
 
void main()
{    
     PORTC=0;    //Clearing output port
     TRISC=0x00; //Initialising C port as output
     T2CON=0;    //Prescaler for timer (1:1) Timer2 off
     CCP1CON=12;  //Initialising ADC
     TMR2ON_BIT=1; // Turning On timer 2
      PR2=199;     //  Setting Time period/Frequency
     CCPR1L=80;  //  Setting Duty Cycle
}

Will this code generate 10 MHz

 

[ZASto]

You can not genarate frequencies that are higher than osc/4

 

[amayilsamy]

First thing your oscillator frequency is only 8 MHz, How can you generate 10 MHz

 

[incognito007]

[
/*
Crystal Frequency 8Mhz

*/

void main()
{
     PORTC=0;    //Clearing output port

     TRISC=0x00; //Initialising C port as output

     T2CON=0;    //Prescaler for timer (1:1) Timer2 off

     CCP1CON=12;  //Initialising ADC

     TMR2ON_BIT=1; // Turning On timer 2

      PR2=199;     //  Setting Time period/Frequency

      while(1)
      {
        CCPR1L=99;  //  Setting Duty Cycle

      }
]

SORRY I want frequency of 10 KHz.This code is working in PROTEUS.
My question is ,when I remove the while loop and write CCPR1L=99; outside, the code is not working.
Why is it so

 

[paulfjujo]

hello,


i didn't check your code, but you must have an infinite loop at the end of you code
else program stop..

void main()
{
     PORTC=0;    //Clearing output port

     TRISC=0x00; //Initialising C port as output

     T2CON=0;    //Prescaler for timer (1:1) Timer2 off

     CCP1CON=12;  //Initialising ADC

     TMR2ON_BIT=1; // Turning On timer 2

      PR2=199;     //  Setting Time period/Frequency

  
        CCPR1L=99;  //  Setting Duty Cycle

         while(1);
      }

 

[incognito007]

Yes that for loop is loading the CCPR1L register infinitely.
Is it required to load the CCPR1L register with duty cycle bit every time a pulse is produced.