• Skip to main content
  • Skip to search
  • Skip to footer
Cadence Home
  • This search text may be transcribed, used, stored, or accessed by our third-party service providers per our Cookie Policy and Privacy Policy.

  1. Community Forums
  2. Digital Implementation
  3. Bob, How can I constrain optDesign -hold to add buffers...

Stats

  • Locked Locked
  • Replies 5
  • Subscribers 91
  • Views 2107
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Bob, How can I constrain optDesign -hold to add buffers on end points only?

eminemshow
eminemshow over 15 years ago

Bob,

Things are like this, I am now at the final stage of timing closure, since functional timing is clean and test timing is ongoing. There is not enough time to config a MMMC environment. After investigation, I found that if I can add all the hold buffers at SI pin of DFF at scan shift mode, then functional timing would be un-touched (as you know, at Q pin of DFF, things would be dangerous......). So I want to ask whether I can control optDesign to make end-point only buffer insertion when fixing hold.

Thanks.

  • Cancel
Parents
  • BobD
    BobD over 15 years ago

    I should have been clear with the "USEMINSPACING OBS" parameter suggestion.  I was thinking that there might be a "USEMINSPACING OBS" statement present in your tech.lef which was instructing the tool to use min spacing next to obstructions.  Since it wasn't present previously, this is not what's causing the tool to think it's safe to go in spacing next to obstractions.  It must be something else, but I can't think of anything else to ask you to look for.

    If possible I'd suggest you file a service request so you can submit a testcase for us to look at.

    Thanks,
    Bob

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Reply
  • BobD
    BobD over 15 years ago

    I should have been clear with the "USEMINSPACING OBS" parameter suggestion.  I was thinking that there might be a "USEMINSPACING OBS" statement present in your tech.lef which was instructing the tool to use min spacing next to obstructions.  Since it wasn't present previously, this is not what's causing the tool to think it's safe to go in spacing next to obstractions.  It must be something else, but I can't think of anything else to ask you to look for.

    If possible I'd suggest you file a service request so you can submit a testcase for us to look at.

    Thanks,
    Bob

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Children
No Data

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.

© 2025 Cadence Design Systems, Inc. All Rights Reserved.

  • Terms of Use
  • Privacy
  • Cookie Policy
  • US Trademarks
  • Do Not Sell or Share My Personal Information