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TMS320F280025: Using Multiple Compare Values for PWM Control Strategy with TMS320F280025

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Prodigy 10 points

Part Number: TMS320F280025

I am currently working with the TMS320F280025 chip and need to implement a PWM control strategy that utilizes four compare values. At present, it seems that only CMPA and CMPB can set up the Action Qualifier output to alter the output square-wave voltage polarity. I am looking for a way to also use CMPC and CMPD to trigger changes in the output square-wave voltage polarity. Is there any method or alternative approach that allows the use of all four compare values to modify the output square-wave voltage polarity?

Thank you for your assistance!

  • 0
    TI__Mastermind 19616 points

    Hi,

    There are only CMPA and CMPB values that you can use for action qualifier events, CMPC and CMPD cant be used as action qualifiers

    You can optionally use T1,T2 or software forced events as action qualifiers

  • 0
    Intellectual 450 points

    What do you need the 4 CMP for?

    I always try to set up the PWMs symmetrically with an up-down count so that I have two CMPs. So once when the counter increments and once when it decrements. Together with PRD and ZRO, this has always been enough for me, except once.
    Where it wasn't enough, I had an internal PWM in parallel (not connected to GPIO), which only controls an interrupt in which I change the outputs of the actual PWM on the software side. This is not perfect in terms of timing, but it is feasible.

    But it's all a question of what you want to do with the PWM? Then we can see how it can be implemented.

    Best regards
    Leon