Limitation of timer peried in HRPWM module

ashish ahir

I tried generating square wave of 20000Hz on f28335 delfino via built in HRPWM module using simulink. It is generating properly. When i reduce freqency to 50Hz ,it is showing error that timer peried has some limitation. How can i generate 50Hz square wave using PWM module in F28335?

over 8 years ago

0 MatthewPate over 8 years ago

TI__Guru 71785 points

Ashish,
At 50Hz, your period is 20ms. The HRPWM has avg step size of 150ps, but only contains 255 elements. I'm assuming the error is because we would need 133 million steps of HR to cover the 50Hz period and we only have 255. At 50Hz wave the normal PWM step resolution (16ns) should be sufficient for edge placement.
Matt

0 ashish ahir over 8 years ago in reply to MatthewPate

Expert 1020 points

thanks.
i changed time base clock prescaler devider to different value. now it is working fine.

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Limitation of timer peried in HRPWM module