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TMS320F280025: epwm issue

Bright Zhu
Intellectual 260 points
Part Number: TMS320F280025


Dears

PWM is sent out using two ePWM modules ePWM1A and ePWM2A. The synchronization signal of ePWM2A is ePWM1A.PWM needs to update the three parameters of the TB module (CMA, PERIOD and PhaseShift) at regular intervals (CMA and Period update parameters are the same).

In the test, it was found that CMA and PERIOD were the values I needed, but the phase deviation produced serious deviation.

In the test, it is found that the operation order of the phase offset register has an impact on the results. However, after operating the PhaseShift register before and after updating the CMA or PERIOD, the results are not what I need.

In the fixed period, the phase deviation works normally. Why can't the phase deviation take effect when the PERIOD is changed?

  • 0
    TI__Genius 11076 points

    Hello,

    I have two immediate follow-up questions. First, are you utilizing immediate or shadow-load updates? If the latter, then all updates should happen simultaneously, assuming they're configured for the same update source. This means the order shouldn't matter.

    Second, please take a look at this thread. Is this applicable to your situation?

    Regards,

    Jason Osborn