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TMS320F28374D: how to sync CLA with ADC sampling and PWMs

Colombo Carlo
Mastermind 21560 points
Part Number: TMS320F28374D

HI everybody 

I have a PWM running ,  and in every period   I have   N  adc measures  ( up to 12  ) 

I use CLA  to do all calculation on ADC and then providing   results to C28x .

I would like to make everything synchronous   so to have ADC starting at  synched time to PWM and  CLA  calculations starting  synched  with ADC .

whihc is best way to make it happen  in HW ?  ideally I woudl like all this to happen in HW so no  SW needed 

best regards

Carlo

  • 0
    TI__Mastermind 24095 points

    Hi,

    You can either use ADC interrupt or EPWM interrupt to trigger CLA tasks.
    Upon completion of CLA task, CLA in turn can trigger interrupt to CPU upon task completion.

  • 0 in reply to Subrahmanya
    TI__Mastermind 21560 points

    Hi  

    please it is multiple ADC and multiple CLA to sync ( up to 12 in a PWM period ) .

    how can I make it easily in HW ?

    thank you 

    regards

    Carlo

  • 0 in reply to Colombo Carlo
    TI__Mastermind 24095 points

    Hi,

    You can use multiple ADCs and multiple channels in an ADC, but you can trigger CLA with the last conversion of the 12 conversions in a PWM period.
    Or you could use PWM interrupt to trigger CLA - this would occur once in PWM cycle and CLA can read all the 12 results and process them at once.
    Maybe there is something more to the question you are asking, can you be more specific what exactly is the issue you are facing with your implementation?

  • 0 in reply to Subrahmanya
    TI__Mastermind 21560 points

    Hi

                no  free PWMs  and all interrupts in use ...

                 ________                                  ________

    PWM  |                |______________|                |______________ |

    CLA     |__|__|__|__|__|__|__|__|__|__|__|__|__|__|__|__|

     

    CLA task is enabled by a timer 12x PWM frequency, but timer is shifting over PWM: is it possible to keep the TIMER(so ADC sampling) and PWM synced?

    thank you 

    best regards

    Carlo

  • 0 in reply to Colombo Carlo
    TI__Mastermind 24095 points

    Carlo,

    Colombo Carlo said:
    CLA task is enabled by a timer 12x PWM frequency, but timer is shifting over PWM: is it possible to keep the TIMER(so ADC sampling) and PWM synced?


    is this a variable frequency application? is that the reason timer is shifting over PWM?

    Is it possible to use multiple ADC SOCs (Channels) to do these 12 conversions in to 12 different SOCs/CHs?
    If so, you can use the last channel to trigger CLA.
    This is what i was mentioning above as well.