extract and LVS my own device

Discussion in 'Cadence' started by Matthew E Rosenthal, Aug 6, 2003.

  1. Hi,
    I want to LVS a large layout that has several instances of an original
    device in it. I use a verilog-A model for the schematic and I really just
    want to check connectivity on the layout. I have written an extract rul
    file that is able to find my original device but When I try to LVS i get
    "net list match" regardless of whether or not my layout is correct. It
    does successfuly extract the device but it does not check that its
    terminal are connected correctly.
    What do i need to create or do to make sure the connectiviity is correct.
    I know i am creating the correct number of pins on the device because I no
    longer get an error about an incorrect number of pins.

    Your help is much appreciated

    Matthew E Rosenthal, Aug 6, 2003
  2. Matthew E Rosenthal

    S. Badel Guest

    i guess you should not write your own extract rules.
    what you can do is do a macro-mode extraction. this will extract
    any childs cells in your layout as "macro-cells".
    or you can tell the netlister to netlist your cell as a whole
    by creating an auLvs view for your cell.
    really, this is all a netlisting problem. check the netlist, find out
    what's wrong and then you will find how to tell the netlister
    to do what you want.

    i had this problem once and the easiest way i found was to make a
    copy of the layout. then i did flatten the whole layout except the cells
    i did want to have in my netlist. then i did a macro-mode extraction.

    maybe post the netlist and we can help

    S. Badel, Aug 6, 2003
  3. Matthew E Rosenthal

    Erik Wanta Guest

    As Stephane mentioned, you can use macro cell extraction in Diva to
    check for top level routing connectivity. If you are using Assura,
    look into the ?blackBoxCell option in the LVS options (Assura
    blackbox=Diva macrocell).
    Erik Wanta, Aug 6, 2003
  4. Stephane,

    Don't flatten any layout for that !

    There is a special feature which do this expansion for you
    during the macro-mode extraction :
    Add a property to each instance to be expanded :
    ivCellType = graphic

    If this instance is used several time across your design hierarchy
    and you need it to be always expanded, then you have to add this
    property inside the master cell by adding this property for the
    cellview (shift-q)

    The Cadence documentation is very clear about this and I recommend
    you to look at it.

    Kholdoun TORKI
    Kholdoun TORKI, Aug 6, 2003
  5. Matthew E Rosenthal

    S. Badel Guest

    ok that's very interesting.
    even though i did read the documentation i didn't
    see that.
    thanks for the trick.
    S. Badel, Aug 7, 2003
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