• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 82 subscribers
  • Views 469 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320F280039C: How to turn off on side of ePWMx output

Harley Sun
Prodigy 20 points

Part Number: TMS320F280039C

Tool/software:

Hi experts,


I want to turn off one side of ePWM output in a interrupt program while the other side is not affected.

e.g. ePWM1B is inverted from ePWM1A, I want to keep EPWM1B sent and not send EPWM1A for a while, and this operation have to be done in a interrupt, I already tried TZFRC with or without CBC&OSHT, the TZFRC with CBC or OSHT will shut both A&B output, the TZFRC without CBC and OSHT cannot hold the force signal for a while so the EPWM1A output will revitalize immediately, and I don't want to shut EPWM1A by GPIO control because it will conflict with other programs. Please give me some advice, thanks.

By the way, the signal controlled by OSHT has a very very uncanny wave ↓.

  • 0
    TI__Mastermind 27736 points

    Hi Harley,

    It looks like the TZCTL.TZA and TZCTL.TZB bits are set to high impedance. 

    You can set ePWM1B to low, and not affect ePWM1A based on the settings in the TZCTL register. Only will need to configure TZCTL.TZB and you can set TZCTL.TZA to do nothing.

    Best,

    Ryan Ma

  • 0 in reply to Ryan Ma
    Prodigy 20 points

    Hi Ryan, 

    Nice to see you again:)

    Unfortunately I can't use TZA since I have use other DC trip signals to realize some complicated logics, I think there is a necessary to know the internal circuit of TZCTL's logic if I want to add another trip logic.

    It would be very grateful if you can give some advice about it :}

  • 0 in reply to Harley Sun
    TI__Mastermind 27736 points

    Hi Harley,

    From the screenshots you have provided, PWMA seems to slope down when the blue rising edge occurs. This is mostly due to the TZA/TZB are set to high impedance. If you're not using TZA/TZB can you set those to "Do nothing, no action is taken on ePWMxA"? This will remove this falling slope.

    If you're using DC trip signals to realize some complicated logic, what are your settings for the TZCTL register?

     

    TZA, TZB, DCAEVT1/2, and DCABEVT1/2 can all be used together, thus setting each setting to a certain output that is other than high impedance will be necessary.

    Best,

    Ryan Ma