• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 83 subscribers
  • Views 631 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.

TMS320F280049C: How long is the interrupt latency

Rayna Wang
Expert 3680 points

Part Number: TMS320F280049C

Hi Expert,

In F280049 TRM, the minimum interrupt latency is 14 SYSCLK cycles, however there's no information show the latency range or how to calculate this time.

Could you know about how to predict the interrupt latency time? Thanks!

Best Regards

Rayna

  • 0
    TI__Mastermind 19795 points

    Hi Rayna,

    Thanks for your question! The interrupt latency time can definitely range quite a bit depending on items such as wait states and others. To get started on understanding what makes up the minimum latency range, the TMS320F28004x Microcontroller Workshop PDF (linked here) provides a brief overview of what makes up the minimum cycle time on page 4 - 21 (slide titled "Interrupt Latency").

    There is also additional information provided in section 5.9.7.1 "External Interrupt (XINT) Electrical Data and Timing" of the device datasheet (linked here) in the case where external interrupts are involved.

    Let me know if this helps answer your question! If so, please click the green Verified Answer button.

    Regards,

    Vince

  • 0 in reply to Vince
    TI__Expert 3680 points

    Hi Vince,

    Thanks for your reply.

    By the way, could you tell me how to test the interrupt latency with high accuracy? Thanks!

    Best Regards

    Rayna

  • 0 in reply to Rayna Wang
    TI__Mastermind 19795 points

    Hi Rayna,

    While testing the interrupt latency externally is possible (input interrupt using an external trigger, output to pin when input interrupt occurs in ISR, measure both using a scope/measurement tool), having sufficient accuracy externally from a scope or other measurement tool can be difficult. Additionally, by setting up the system in such a way (so that it generates an output to be measured), you are adding additional interrupt delays that would not be there if the interrupt was fully internal or only on the input side

    Because of this, I would first suggest looking through the following thread which provides some great resources that can help more directly estimate the interrupt latency.

    https://e2e.ti.com/support/microcontrollers/c2000/f/171/p/651440/2393071

    Let me know if this answers your question!

    Regards,

    Vince