TMS320F280049C: EPWM6A remains high for about 1 second when debugging is attempted in running code.

Nikhil Thakkar

I have configured EPWM6A to generate 10 KHz duty at 50% duty cycle. When I try to debug the code while the hardware is running, the epwm is remaining high for almost 1 second and this damages the switch. I am not able to figure out the reason why this is happening. I am attaching the code as well as the DSO screenshot which shows the problem. Kindly help me resolve the issue or guide me where I am making a mistake.

EPWM6A_OldCompiler.zip

I have tried with 2 different versions of compiler also but I am not able to figure out the issue.

over 2 years ago

0 Luke Jones over 2 years ago

TI__Mastermind 28580 points

Hi Nikhil,

To clarify, does this issue occur every time your code begins executing, or only when you hit a breakpoint in your code. If it always occurs on startup, try adding a delay between the end of your EPWM initialization and when you enable TBCLKSYNC. If it happens only when you hit a breakpoint, this is due to the FREE_SOFT bits. You should set these to 11 or 10 if you want the PWM to continue it's normal behavior even when you have hit a breakpoint in your code.

Thank you,

Luke

0 Nikhil Thakkar over 2 years ago in reply to Luke Jones

Prodigy 30 points

Hi Luke,

This issue happens only when I am debugging the code using xds110 emulator. So, as soon as debug session begins, after some time it makes the epwm 6A pin high. Where can the FREE_SOFT bits be set ? Are they part of some specific register ?

I will try out the delay approach you have proposed. Any specific minimal value of delay that should be used ?

regards,

Nikhil

0 Luke Jones over 2 years ago in reply to Nikhil Thakkar

TI__Mastermind 28580 points

Hi Nikhil,

I would recommend a delay of 1000 us. Another user encountered a similar issue here:

https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1283765/tms320f280034-behaviour-of-pwm-pins-during-start-up

Let me know if this resolves your issue.

Thank you,

Luke

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F280049C: EPWM6A remains high for about 1 second when debugging is attempted in running code.