• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 82 subscribers
  • Views 529 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CCS/TMS320F28379D: EXTSYNCIN1 Trigger Edge

Qingxuan Ma
Prodigy 150 points
Part Number: TMS320F28379D


Tool/software: Code Composer Studio

Hello,

    I am using EXTSYNCIN1 to synchronize my EPWM. The operating principle is listed below:

    1 Connect Gpio4 with Gpio22 using wires
    2 Configure Gpio22 as input signal for Input5 of Xbar
    3 EXTSYNCIN1 selected as SYNC signal for EPWM4
    4 Using CCS to command GPIO4 to give a pulse signal
    5 EPWM4 synchronized after pulse rising edge of Gpio4 is detected.
What I want to do now is to make EPWM4 synchronized on the falling edge of pulse signal. I could not find registers dealing with this function in 28379D manual. Is it possible to do that ? Or EXTSYNCINx could be only trigger on rising edge? Thanks!
  • 0
    TI__Genius 15260 points

    Hi Qingxuan Ma,

    The synchronization is fixed at active low. What you can do is use the GPIO inversion registers to make this work. Take a look at the GPAINV (pg 939) register in the TRM here:

    www.ti.com/.../spruhm8g.pdf

    Just a side note, there's nothing wrong with the way you are doing this now, but you can simplify it by eliminating GPIO4 and only using GPIO22. Just set GPIO22 to an output and toggle it directly. The Input X-Bar will always read the input buffer of the pin regardless of what mode it is in.

    Regards,
    Kris