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Encounter different row sizes (is it possible?)

Thodoros

 Hello,

 I have three (3)  kind of cells:

 1. the ones that are placed at the bottom of the design

2. the ones placed in the middle

3. and the ones placed at top.

 

These three kind of cells have different height but their vdd - gnd rails can overlap.

Is it possible to use encounter to place these cells?

For example I could have one site only for the bottom cells , one site for the middle many cells and one site only for the top cells.

 

Thanks for your help,

It will help me build a special design.

Regards,

Thodoros.

 

  • Thodoros:
    PlaceDesign is easy , optDesign and CTS are really limited without a multy voltage dot.CommonPowerFormat control file

    Most of the floorplan / power grid commands have -area options.
    createRow addstripe addWellTap addEndCap etc. etc
    You are probably best off to K.I.S.S. and make isolated cell islands that are almost totally self contained.
    Totally benign island boundaries with left, right, top and bot welltaps / endcaps
    If your netlist is logically partitioned into type1 type2 and type3 modules, you can easily fence in the islands for placement.

    Complex optDesign without a .cpf control file is next to impossible, ie how to limit type1 optDesign added buffer to type1 islands.
    You could possibly avoid the "added cell type"  problem  altogether with optDesign resize only.
    But next, CTS is going to have the same problem without a .cpf file, which clock buffer in which island?

    If you pursue this layout without a .cpf ,   I can see hours of interactive eco command in your future.

    Shawn

  • Thodoros:
    I thought about the optDesign issues some more and there are a couple of possible solutions.
    You could optDesign each cell island separately, ie. dont_touch, dont_use type 2&3 , then optDesign will work on type1 only.
    Or if you create a level of hierarchy out of  the islands. then you could work on the 3 blocks individually.
    Shawn

  • Shawn, thanks for your help. I will try to find a solution on this using your guidance.

    Will let you know how I managed it later on..

    Thodoros

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