Forum Post: RE: Cycle-by-Cycle PWM Trip with Comparator Outputs

Jon,

I believe that you have the XBAR configurations and Digital Compare configurations correct.  I do want you to know that the explanations and documentation for all these parts are being worked on.

I believe that your issue is purely in the Trip-Zone Submodule and how it connects to the digital compare module.

I think the main gotchas I see are below:
1) the TZCTL2.ETZE bit - if 0, the TZCTL register is used to configure the trip logic actions.  If 1, the TZCTLDCA, TZCTLDCB and TZCTL2 registers are used.
2) the default action for most unused TZCTL* actions is to push the PWM to Hi-Z.  I would explicitly configure all trips that you are not using to do nothing.
3) your CBC trip actions are not occurring because TZSEL.TDAEVT2 and DCBEVT2 are not set to 1.  This keeps it out of the CBC latch logic.
4) CBC and OSHT trips come via the TZA and TZB path.  The DCxEVTy.force paths will force the PWM signal only when the Digital Compare logic is active (ie won't latch at all).

I realize the above may not make sense alone.  I'm hoping that this + the attached pictures helps to clarify things.  In the picture, the highlighted are the paths/register bits that I believe to be active based on your code.

Please let me know if this helps.


Thank you,
Brett