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Flex Timer use with Comparators

Question asked by ivekengineer on Oct 11, 2012
Latest reply on Feb 12, 2013 by Adrian Sanchez Cano

I want to implement a current controlled chopper using the internal comparator and FlexTimer module for stepper motor control.

 

I'll explain a simplified version of what I need in order to keep the response focused.


I need two independent PWM channels operating 99% duty cycle.  When an internal comparator output goes active, I need the PWM channel to go to the inactive state for the remainder of the present period, returning to the active state at the zero point.  I initially thought I could do this by using the Fault signals - however, upon closer inspection it appears that any enabled fault condition will affect both channels. Do I understand this correctly?  Is there a way for each channel to be affected by a specific fault signal independently?

 

If I can't use fault signals, is there some sort of synchronization method I can use?  Perhaps using the comparator outputs as hardware triggers to affect a change of the output mask, and then calling an ISR before the zero point in order to restore the output mask synchronously at the zero point?  However, I would prefer a hardware solution to this instead of using ISRs.

 

 

 

 

 


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