Forum Discussion

VFres's avatar
VFres
Icon for New Contributor rankNew Contributor
6 years ago

Timequest for asynchronous design

​Hello,

Is it possible to use timequest to have information about delays inside an asynchronous design?

I would like to know the time between 2 nodes that are not linked by any clock. I have just combinatorial functions.

But if I try to use the report_path command:

report_path -from [x] -to [y]

I just receive:

Report Path: No paths were found

Thanks for help

4 Replies

  • sstrell's avatar
    sstrell
    Icon for Super Contributor rankSuper Contributor

    You don't mention what x and y are (ports, pins?) but the main command to use is report_timing. It should look something like this:

    report_timing -setup -from [get_[pins/ports] x] -to [get_[pins/ports] y]

    #iwork4intel

  • KhaiChein_Y_Intel's avatar
    KhaiChein_Y_Intel
    Icon for Regular Contributor rankRegular Contributor

    Hi,

    Does the design contain any registers? You can see the delay for a combinational logic between registers by reporting the timing between the registers. The Timing Analyzer recognizes and analyzes the following timing paths only.

    • Edge paths—connections from ports-to-pins, from pins-to-pins, and from pins-to-ports.
    • Clock paths—connections from device ports or internally generated clock pins to the clock pin of a register.
    • Data paths—connections from a port or the data output pin of a sequential element to a port or the data input pin of another sequential element.
    • Asynchronous paths—connections from a port or asynchronous pins of another sequential element such as an asynchronous reset or asynchronous clear.

    Thanks.

    Best regards,

    KhaiY

  • VFres's avatar
    VFres
    Icon for New Contributor rankNew Contributor

    ​Hi,

    Thank you for your answer.

    So if I don't have any register there is no way to know delays between luts?

    report_timing gives the same:

    "Report Timing: No setup paths were found"

    Best regards

  • skyjuice's avatar
    skyjuice
    Icon for Occasional Contributor rankOccasional Contributor

    report_path should be able to do what you want. Just make sure you use the correct filter as what sstrell mentioned