eCAP module accessing for 28335 dsp

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Submitted by balaji5291 on Thu, 01/12/2012 - 20:48 



hi, i have been using the embedded controls developer for TMS320F 28335.It has been a very helpful tool for operating our motor. i wish to determine the on time of a square wave.i used the eCAP module but how to view the output of the timestamp registers? i used the scope in vissim,but it does not show any output..any help on this will be appreciated.

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2016

    Submitted by Anders89 on Fri, 01/13/2012 - 05:07.

    Set 'Max Events' to 2
    Set event 1 to trigger on rising edge and check 'reset counter on capture event'
    Set event 2 to trigger on falling edge
    Output pin 2 will result in the on time when you compile the diagram.
    If you still have problems, attach your diagram to this post

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2016

    Submitted by balaji5291 on Fri, 01/13/2012 - 11:53.

    i understand the instructions..but how to view the output from eCAP second port? i am unable to view the time in a 2d plot or in a display...and should hexadecimal conversions be done?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2016

    Submitted by Anders89 on Fri, 01/13/2012 - 20:54.

    Yes, either a plot or display will work. The output from the pin is a 32 bit integer representing the number of system clocks between event 1 and event 2. So if the duty cycle doesn't change, then you will get a constant number. The maximum will be just under the PWM period (at 100% duty cycle there is no falling edge to trigger the capture), the minimum will be 1 (at 0 there is no falling edge either)