LAUNCHXL-F28069M: A puzzle of EPWM Tripzone

Chen Yao

Prodigy 160 points

Part Number: LAUNCHXL-F28069M
Other Parts Discussed in Thread: CONTROLSUITE

Hello all,

I've met a weird problem when using Epwm Tripzone.

In my application, TZ1 is simply set to lock Epwm1&2 and Epwm1&2 is set output directly.

The phenomenon is:

If tripzone function is enabled, when first time power on, TZ will be trigged. Then if I manually reset the LAUNCHPAD, TZ will not be trigged and Epwm output normally.

If tripzone function is disabled, when firsttime power on, Epwm of course output normally.

Has anyone met the same problem? What is the problem probably located in? Is there any required sequence when initializing Epwm and TZ function?

Thanks a lot!

over 7 years ago

0 Gautam Iyer over 7 years ago

Guru 192875 points

Hi,

Did you try increasing the TZ pin qualification value to maximum? ie GPAQSELx=2 //6samples and
also, try increasing the TZ pin QUALPRDx to 0xFF.

Regards,
Gautam

0 Chen Yao over 7 years ago in reply to Gautam Iyer

Prodigy 160 points

YES， exactly set GPAQSELx=2 and QUALPRDx to 0xFF. And I've connect GPIO12(TZ1) directly to 3V3(High). The problem still exist.

0 Gautam Iyer over 7 years ago in reply to Chen Yao

Guru 192875 points

Initial power on is using a Power supply? Did you monitor the voltage level of same on DSO?

0 Chen Yao over 7 years ago in reply to Gautam Iyer

Prodigy 160 points

It is tested on the LAUNCHPAD. Power supply is the USB port from computer. A power supply is also tested. The results are same.
I've scoped on the TZ IO port and didn't capture any severe jitter.

If a manually reset is applied, it works correct. This is what puzzles me.

0 Cody Watkins over 7 years ago in reply to Chen Yao

TI__Mastermind 42195 points

Chen,
Run to the PWM initialization code and verify the pin voltage before configuring the TZ.

Are you sure that your code follows the same execution path when starting up and when resetting?

Is it possible that you trip isn't coming from the TZ1 input? Have you fully configured all options in the trip-zone(DCxEVTy, CBC trip, OSHT trip)?

Regards,
Cody

0 Chen Yao over 7 years ago in reply to Cody Watkins

Prodigy 160 points

TZ pin is connected to GND. Run in flash mode.
OSHT trip is configured and DC is disabled. TZ ISR is trigged at first time power on.

Now I change TZ mode to CBC. TZ ISR is still trigged at first time power on, then it works normally because of CBC mode.

0 Cody Watkins over 7 years ago in reply to Chen Yao

TI__Mastermind 42195 points

Chen,

Have you configured the GPIO setup before setting up the TZ module?

If you are still having issues try running the trip-zone example in controlSUITE. It can typically be found here after installing controlSUITE (C:\ti\controlSUITE\device_support\f2806x\v151\F2806x_examples_ccsv5\epwm_trip_zone)

Regards,
Cody

0 Cody Watkins over 7 years ago in reply to Cody Watkins

TI__Mastermind 42195 points

Has this been resolved?
If so please mark any helpful posts.

Regards,
Cody

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LAUNCHXL-F28069M: A puzzle of EPWM Tripzone