TMS320F28P650DK: Considerations when using software one-shot trip

Hi Wayne,

Yes you can use one-shot trip to set the trip event and then clear the flag to clear the action applied that's possible.

Although the TZFRC.OST will work only if EPWMCLKDIV is /1 as mentioned in thread here - https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1345272/tms320f28p650dk-unexpected-results-of-force-trip-action 

Other option is to use T1/T2 action events generated from the Digital compare submodule and take actions based on the events

Thanks

Hi Bhatt,

That explains it.

After setting EPWMCLKDIV = /1, we found our issue has been resolved.

ClkCfgRegs.PERCLKDIVSEL.bit.EPWMCLKDIV = 0; // EPWMCLK = 200MHz /1 of PLLSYSCLK

Questions:

1) On F2837x, where SYSCLK = 200 MHz and EPWM = 100 MHz max . Is there also such an issue? EPWMCLK cannot be set /1 there.

2) On F2838x, where SYSCLK = 200 MHz and EPWM = 200 MHz max. Is there also such an issue?

3) On F28P65x, where SYSCLK = 200 MHz and EPWM = 200 MHz max, have we documented this in errata or TRM note? This is critical because many users would just use EPWMx.TZFRC.OST without realizing this issue.

4) On F29H85x/P58x, where SYSCLK = 200 MHz and EPWM = 200 MHz max. Is there also such an issue?

Hi Bhatt,

For F28P65x/F2838x/F29H85x/P58x, the user can use this workaround by setting EPWMCLK /1 mode.

But for F2837x, which has /2 and should not be set as /1 because its EPWM is 100 MHz max there.

In this case, this workaround cannot be used on F2837x and the user cannot use TZFRC.OST there? Is it true?

The user can only use HW based trip method like CMPSS/GPIO.

Is my understanding correct?