How to Create a dummy two-terminal

Discussion in 'Cadence' started by tagger, Oct 26, 2005.

  1. tagger

    tagger Guest

    All,

    The below was from a previous post,
    I would like info on how to create the dummy device ?

    Regards
    Herman

    Create a dummy two-terminal device like a capacitor using an enclosing
    prBoundary shape as the recognition shape.



    area1=measureParameter( area (boundary_layer over dens_layer))
    area2=measureParameter( area boundary_layer )
    ratio=calculateParameter( area1 / area2 )
    saveParameter( ratio "density )
    saveRecognition( boundary_layer "prBoundary" )
     
    tagger, Oct 26, 2005
    #1
  2. I think you need 3 layers ....


    <ramble mode on >

    The device recognition layer must be different from both conductors

    (even if it is identical ... )
    I find myself generating a copy of every conductor in my design to do this
    kind of measurement.

    ( mostly for custom voltage/area/perimeter/density based antenna rules
    about 15 years ago when we called
    them "process induced charging failures" and I asked for the capability
    .... )

    I think it is a stupid limitation that a recognition layer can not be a
    conductor, but the answer I got from R&D
    many years ago is "no one else does this, why do you want to? It is hard to
    code so go away ... "

    Since I discovered the trick of self-OR-ing the conductor twice
    poly_rec = geomOr( "poly" )
    poly = geomOr( "poly" )
    and only using poly in the connect statements and poly_rec in the device
    recognition statements

    (repeated for each conductor that you want to make also into a device. Note
    that this defeats how PRE works since the entire layer is covered by a
    "device interface" )

    conductor ( don't use self and! ) I went away, but still think it is a
    silly solution.

    ( many esoteric comments here are my recollections of the poor documentation
    on how conductors (and pins and nets) fail in degenerate cases
    that I seem to generate. )

    <ramble mode off >
    And all of my comments are very dated. This stuff may all work now, ( I
    doubt it ! )

    -- Gerry

    This was a hot topic for a while until I sat down with several cadence
    people who explained how nets and pins and netnames
    worked inside the database ( EdK & JimH & JohnR & ... )

    You only need two layers on a 1 terminal device ( that is what I do on my
    "substrate" device, because I netlist out the
    global net "gnd!" another terminal but only extract 1 terminal ....
     
    Gerry Vandevalk, Oct 31, 2005
    #2
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