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Altera_Forum's avatar
Altera_Forum
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10 years ago

TimeQuest Timing Analyzer

First of all, sorry for my poor English, I'm from China.

I use the set_net_delay command to specify the delay between a source and destination points.

This is the command: "set_net_delay -from [get_pins {u6|out~57_I|combout}] -max -to [get_pins {u6|out~59_I|datad}] 0.5".

But the delay between "u6|out~57_I|combout" and "u6|out~59_I|datad" more than 0.5ns, and it is 1.622ns. What should I do to let this command work?

http://www.alteraforum.com/forum/attachment.php?attachmentid=10720&stc=1

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    One reason that I could think of is probably the minimum delay achievable by Quartus II is 1.622ns. So, even though you set to 0.5ns, Quartus II cannot achieve your intended delay. You may try to set to a value larger than 1.622ns to see what will be the change just to verify this hypothesis.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    --- Quote Start ---

    One reason that I could think of is probably the minimum delay achievable by Quartus II is 1.622ns. So, even though you set to 0.5ns, Quartus II cannot achieve your intended delay. You may try to set to a value larger than 1.622ns to see what will be the change just to verify this hypothesis.

    --- Quote End ---

    I set the value to 1.7ns, but the delay turn into 1.564ns. Do you have any other ideas?

    Thank you.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    --- Quote Start ---

    Could you upload project?

    --- Quote End ---

    I checked the report of TQ, and found that the commands I specified were ignored.