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EEren's avatar
EEren
Icon for Occasional Contributor rankOccasional Contributor
7 years ago

MAX10 Signal propagation

I have a mux

F_LPTG_OUT(0) <= F_LPTG_IN(0) when (sel(0) = '1') else cpu_out(0);

What signal propagation time will be from the input to the output?

7 Replies

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

    basically, you have a mux which means there will be 3 input to one output. we calculate the delay base on register to register in time quest.

    You should be able to pull out the delay from the time quest for the delay that you have.​

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

    I go to Time Quest -> Custom Reports -> Report Path. Fill From and To.

    report_path -from [get_ports {F_LPTG_IN[0]}] -to [get_ports {F_LPTG_OUT

    [0]}] -npaths 1 -panel_name {Report Path} -multi_corner

    I get - Report Path: No paths were found

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

    OK. I did it. I got a delay from input to output 9.378 nanosec. It's awful. I need 2-3 nanosec. What can I use faster then mux?

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

    As mention, timequest report path from reg to reg. You need to see what reg to reg on the path that you interest and report from there. In the btw the register, you have to manually add in the delay to sum out the delay of your path.​

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

    I have fast switching signals. Maxsimum delay 3 nanosec. I got 9.378. What can I use to commutate inputs to output faster?

  • If you need it to be quicker, and that's the only way to design it, then you'll need a faster speed grade device or, more likely, a faster device family. MAX 10 isn't particularly fast.

    Where are these signals coming from? I'm assuming they're from device pins...

    Cheers,

    Alex

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

    If you are looking at a report from an input of the device all the way to an output, you're looking at the total delay through the entire device, so of course it might be large. Can you clarify exactly what reporting command you used that worked and also where the registers are in this design?