Unable to modify PWM duty cycle

tbiberdorf — Fri, 31 Jan 2020 18:40:34 GMT

I have a working TWR_K60D freeRTOS project.

I am confused as to why the FTM_UpdatePwmDutycycle() API call does not update the required FTM0-C2V registers unless I single step with the debugger. When I allow the code to run without stepping, it will not update the registers.

The code can be cloned from the following GitHub repository: GitHub - tsbiberdorf/freeRTOS_TwrK60D: freeRTOS project to run on TWR_K60D hardware with FTM0 PWM operation

The README file provides the h/w connections to the Tower Expansion board.

When I run the code and place a breakpoint on line 141 and 144 of FTM0Operation.c

at the same time I am monitoring the FTM0 registers.

When I hit the breakpoint on 141 the FTM0 registers provide this:

when I allow the code to continue to 144 the registers have not been updated:

Now if I reset the code and allow to run to breakpoint on 141, but single step through the FTM_UpdatePwmDutycycle() API, I find that the registers are updated.

Why does this not work when running? why does it only work when single step is happening? Is there a locking sequence that I'm missing?

Thanks

Re: Unable to modify PWM duty cycle

tbiberdorf — Thu, 06 Feb 2020 19:02:08 GMT

I added the API call FTM_SetDeadTimeEnable() and now the code is working as expected. Not sure why, but happy that its working.

topic Unable to modify PWM duty cycle in Kinetis Microcontrollers

Unable to modify PWM duty cycle

Re: Unable to modify PWM duty cycle