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PSoC 5, 3 & 1 MCU

Anonymous
Not applicable

I am trying to change the duty cycle of signal. if I set higher period for PWM component, i can acheive the duty cycle whereas I am not geeting the exact frequency. 

   

I am using Timer(tc) to input the PWM. 

   

How can I acheive the duty as well as correct frequency?

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2 Replies
JoMe_264151
Expert II

Use a PWM component and a clock. Set the period value so, that Clock / Period = desired frequency.

   

Now you may set in your program the compare-value with the appropiate API between 0 (0%) and the period value (100%).

   

This will keep the frequency of the PWM stable and only changes the duty-cycle.

   

 

   

Bob

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ETRO_SSN583
Esteemed Contributor

Note the update of the compare register is async, so you can short cycle

   

the current period duty cycle being output by PWM. To avoid this use an ISR on

   

the Tc output to do the update of compare register. Note this is not true for the

   

period register, it is updated at end of period with an internal reload of period register.

   

 

   

   

 

   

 

   

   

 

   

Regards, Dana.

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