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 timing critical design 

Last post Mon, Jan 7 2008 9:22 AM by archive. 2 replies.
Started by archive 07 Jan 2008 09:22 AM. Topic has 2 replies and 1181 views
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  • Mon, Jan 7 2008 9:22 AM

    • archive
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    timing critical design Reply

    Hi all, Currently iam handling timing critical design in which if setup is optimised hold comes into picture and vice versa Can anyone help me in solving this KVB


    Originally posted in cdnusers.org by viswanadhbabu
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  • Tue, Jan 8 2008 12:35 AM

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    RE: timing critical design Reply

    During Hold Optimization treat Setup nets as excluded

    Or you can do only HOLD optimization using selected-Terms.

    If you exclude setup nets and Select Only HOLD terms , If there is any common between hold and setup with be not optimized.

    Hope it helps !!

    FYI.

    Ex. optDesign -postCTS -excludeNets

    -Mohan


    Originally posted in cdnusers.org by mohanch007
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  • Fri, Jan 11 2008 11:59 AM

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    RE: timing critical design Reply

    Hi KVB,

    The situation you describe can be very tricky. Sometimes you need to fix these paths by hand, and look further back along the path to find a place to fix one (setup/hold) that doesn't break the other. If there really is no way to fix both, then you have to make some decisions. Can you live with the setup violation, as long as the hold is fixed? Most designers go this way (better to waive a few setups and have all the holds fixed, rather than the other way around). Also, maybe the hold margin is too aggressive and could be backed off a bit to make things easier. If doing OCV, make sure CPPR is turned on.

    - Kari


    Originally posted in cdnusers.org by Kari
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Started by archive at 07 Jan 2008 09:22 AM. Topic has 2 replies.