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Timing ECO steps

ErezBS

Hi,

In my design (post route) i need to do some timing optimization eco.

mainly upsize some cells.

I will appriciate if you can write down the steps i need to do in order to do so.

I am guessing its: upsizing the cell, run incremental placement, run incremental routing? (what are the commands)

Thanks! 

 

  • The flow is:

    1. ecoChangeCell to resize the cell. This will automically run refinePlace to legalize the placement.

    2. Run ecoRoute to perform incremental routing

    Hope this helps,

    Brian

  • I have a problem similar to the OP.
    A fourth party signoff tool is reporting a few hundred  SI victim nets  that need a source drive strength boost .
    I can dbGet the driver instName and cell type easily enough with ...........................
    set netName <SI victim net> ; set inst [dbGet [dbGet -p [dbGet -p top.nets.name $netName].allTerms.isOutput 1].inst] ; Puts "Net: $netName, inst: [dbGet $inst.name], cell: [dbGet $inst.cell.name]" ;

    Unfortunately ecoChangeCell -inst <instname> -upsize  is simply switching VT's to a faster cell and not necessarily increasing the overall drive strength. ( possibly to maintain same footprint??? )
    The simple but tedious solution would be to ecoChangeCell -inst <instname> -cell <masterCellName+nextDrive>.
    But I did not want to have to manually look up and enter a few hundred  <masterCellName+nextDrive>.

    Does anyone know how to  [dbGet $inst.cell.name+nextDrive] ?????

    Shawn


    Note: i find the following the fastest for a ton of ecoChangeCell instructions.............................

    setEcoMode -refinePlace false
    setEcoMode -updateTiming false
    setEcoMode -honorFixedStatus false
    setEcoMode -batchMode true

    ecoChangeCell -upsize -inst AB_sequencer_inst/AB_SEQUENCER_SW_REGS_inst/FE_OFCC318979_sequence_memory_943 ;

    setEcoMode -batchMode false
    setEcoMode -reset
    refinePlace -wireLenOptEffort none -preserveRouting true -rmAffectedRouting false

    addFiller
    routeDesign

     

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