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 tip of the week: improve run time during initial placement 

Last post Tue, Dec 5 2006 1:50 AM by archive. 4 replies.
Started by archive 05 Dec 2006 01:50 AM. Topic has 4 replies and 1636 views
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  • Tue, Dec 5 2006 1:50 AM

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    tip of the week: improve run time during initial placement Reply

    You can cut your run time by up to 3x (for 500k instances) by not doing scan recordering during placeDesign.  You can do the following
    .
    . SETUP UP YOUR SCAN IN & SCAN OUT
    .
    setPlaceMode -noReorderScan -modulePlan
    placeDesign -with_your_own_option
    scanReorder
    optDesign -preCts

    With the above flow, the run time is reduced at the same time congestion & timing do not get worst.

    li siang



    Originally posted in cdnusers.org by lisiang
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  • Sun, Dec 31 2006 8:32 PM

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    RE: tip of the week: improve run time during initial placement Reply

    Hi Li Siang,

    I tried out your suggestion, but does not see improvement. The design is bigger than 500K during placeDesign. Maybe I am using scandef. There are many scan chaisn due to the use of scan compressor. I think it is a easier flow to use scandef than to define scan-in and scan-out in Encounter especially with scan compressor the scan-ins and scan-outs are at defined at hier ports.

    Do you have any idea why disable scan reordering can make placeDesign with modulePlan run faster?

    Regards,
    Eng Han


    Originally posted in cdnusers.org by EngHan
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  • Mon, Jan 1 2007 12:00 PM

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    RE: tip of the week: improve run time during initial placement Reply

    i assumed you are using -inPlaceOpt with -modulePlan.

    -modulePlan wil run placement multi-time with the -inPlaceOpt to improve timing. Each re-placement will cause a scan recordering. Thus turning off the scan recordering will save some run time. If you design is not timing critical, then the re-placement might not happen and you might not see the run time saving.

    li siang


    Originally posted in cdnusers.org by lisiang
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  • Tue, Jan 2 2007 10:23 AM

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    RE: tip of the week: improve run time during initial placement Reply

    Hi Li Siang,

    I am not using "-inPlaceOpt" with -modulePlan. I using optDesign after placeDesign. This is the reason why I don't see improvement in runtime.

    In your experience, do you prefer to use "-inplaceOpt"? Somehow it appear to me that running in two steps give better result.
    Regards,
    Eng Han


    Originally posted in cdnusers.org by EngHan
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  • Tue, Jan 2 2007 10:48 AM

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    RE: tip of the week: improve run time during initial placement Reply

    it is design dependent. In general -inPlaceOpt with -modulePlan works pretty well due to the replacement & re-opt. In some of the block i did, i found the following woked better (gave better timing)

    placeDesing -modulePlan
    optDesign -preCts
    placeDesign -incr
    optDesign -preCts

    li siang


    Originally posted in cdnusers.org by lisiang
    • Post Points: 0
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Started by archive at 05 Dec 2006 01:50 AM. Topic has 4 replies.