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How to size transistors using SKILL

KrishnaPraveen

Hi!

 I wanted to know how one can size a transistor schematic using SKILL.

 I am using these commands but I want to know how I can size the transistors, I read the CDSDOC but could not figure out:

windowID = dbOpenCellViewByType("test_schematic" "skillSchematic" "schematic" "schematic" "w")

masterID = dbOpenCellViewByType("analogLib" "nmos4" "symbol")

dbCreateInst(windowID masterID "I0" 1:1 "R0" 1)

These commands creates an nmos in the schematic view but I want to be able to size it.

 I tried doing this which I read in some code (though it does not make sense to me) :

windowID~>w="10u"

windowID~>l="130u"

 I think I am doing something fundamentally wrong.

I want to be able to size the transistors as I place them in the shematic.

 Any help is highly appreciated.

 

Thank You.

Krishna

 

  

Parents

  • The only reason this could happen is if the parameters are not actually called w and l that are displayed in the CDF. If the property names match (and are of the correct type), then the CDF for an instance ALWAYS uses the instance property to override the CDF default.

    Sometimes there are "CDF Callbacks" which are used to derive one CDF parameter from another whenever you  modify the value of one parameter. You might have (say) "wf" from which "w" is computed (or something similar). For more information see my Cadence Online Support note The Dangers of CDF Callbacks together with How to call CDF callbacks procedurally from SKILL?

    Regards,

    Andrew.

Reply

  • The only reason this could happen is if the parameters are not actually called w and l that are displayed in the CDF. If the property names match (and are of the correct type), then the CDF for an instance ALWAYS uses the instance property to override the CDF default.

    Sometimes there are "CDF Callbacks" which are used to derive one CDF parameter from another whenever you  modify the value of one parameter. You might have (say) "wf" from which "w" is computed (or something similar). For more information see my Cadence Online Support note The Dangers of CDF Callbacks together with How to call CDF callbacks procedurally from SKILL?

    Regards,

    Andrew.

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