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TIMx_OCrefClear (stm32F30x)

Question asked by morgan.doug on Apr 19, 2016
Latest reply on Apr 21, 2016 by morgan.doug
Hello All:

I am tearing my hair out trying to get cycle-by-cycle PWM control working on the Stm32F303RE using the OCRrefClear signal from the comparators.  
PWM working on complimentary channels  (check).
COMP works fine (check).
Connection between the two?  None.  
I have tried this with several devices (303RE, 303R8),  timers (1, 8 , 15, 16, 17) and multiple randomly selected settings.   No joy -- comp output toggles happily, PWM is clean but no shut off using the OCrefClear output.

Has anyone got this to work with the 303?  Or is the OCrefClear some sort of mystical connection.

I am about to give up and try the BRK functions but the pinouts with OCrefClear suits my purposes better.   For one reason on the 303RE ST put the Timer15 output pin on the same pin as it's related COMP3 input, making the combination useless.

Is the BRK connection the only real working one for the F303?   Has anyone got the OCrefClear connection to work with Tim15/16/17? 


Note that this is more rhetorical remarks as I have moved on to using the BRK functions which work as documented.   
I would like to know if the OCrefClear in the reference manuals does actually function or is it some (mis-) information that needs to be removed?   The different part numbers for the F303 family are fairly confusing to begin with but information regarding features that don't appear to exist makes it more difficult to sort through..