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How to flatten layout cells and preserve pin names when pin names from different cells are the same

twen

I am using virtuoso version 6.1.6-64b 12/07/2015 20:18 (sjfbm186) .

Suppose I have a top level cell T, and T contains two cells A and B, and there are a pin called P in both A and B. When I flatten cells A and B by gui (Preserve pins, preserve ROD Objects) to by foreach(s list(dbA dbB) dbFlattenInst(s 1 t t t t t t t)), the pin P in cell A is brought up into cell T without any problem. However, the label on pin P in cell B is renamed to something like dbNet032. I see this can be useful in certain cases, but it is not what I want.

Is there anyway that I can flatten A and B and brought up the pin P to cell T and keep both pins' label as it was?

Thanks in advance,

TJ

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  • Quek

    Hi TJ

    After flattening 2 instances I1 and I2, you should have the following 2 pins at the top level:

    pinName : I1|pinP
    terminalName: pinP

    pinName : I2||pinP
    terminalName: dbNet1
    (IC617 will name it as "I2|pinP")

    The following warning will also be shown in CIW:
    *WARNING* (DB-270000): dbCreateTerm: Terminal with name 'pinP' already exists

    Suppose Virtuoso preserves the terminal name for inst2, we would have the following situation:

    pinName : I2||pinP
    terminalName: pinP

    In terms of pin connectivity model, this would mean that pins "I1|pinP" and "I2|pinP" are strongly connected under the terminal "pinP". By setting the terminal name as "dbNet1", the 2 pins would not be related to each other.

    If creating strongly connected pins is really what you need, you will have to use a SKILL script to post process the flattened results so that the terminal names are the same.

    Best regards
    Quek

Reply
  • Quek

    Hi TJ

    After flattening 2 instances I1 and I2, you should have the following 2 pins at the top level:

    pinName : I1|pinP
    terminalName: pinP

    pinName : I2||pinP
    terminalName: dbNet1
    (IC617 will name it as "I2|pinP")

    The following warning will also be shown in CIW:
    *WARNING* (DB-270000): dbCreateTerm: Terminal with name 'pinP' already exists

    Suppose Virtuoso preserves the terminal name for inst2, we would have the following situation:

    pinName : I2||pinP
    terminalName: pinP

    In terms of pin connectivity model, this would mean that pins "I1|pinP" and "I2|pinP" are strongly connected under the terminal "pinP". By setting the terminal name as "dbNet1", the 2 pins would not be related to each other.

    If creating strongly connected pins is really what you need, you will have to use a SKILL script to post process the flattened results so that the terminal names are the same.

    Best regards
    Quek

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