fillNotch inserts are off grid in virtuoso

Discussion in 'Cadence' started by Nathaniel Gaskin, Apr 3, 2008.

  1. In Encounter, we verifyGeometry to find violations of spacing/width/
    etc ruls governed by the tech LEF.

    When we run the fillNotch command, nearly all of the added metal
    structures are placed off grid (see picture offgridfillNotch). The
    report file does not show off-grid locations, but the DEF file we
    write out at the end shows many special nets on the smaller grid. Our
    tech LEF specifies the following:



    UNITS

    DATABASE MICRONS 2000 ;

    END UNITS



    MANUFACTURINGGRID 0.0050 ;



    fillNotch places metal on a 0.0005 grid, and while it reduces
    violations shown in the verifyGeometry command it actually increases
    DRC violations in Calibre. When we write out a DEF file from
    Encounter to import into Virtuoso, the following message is printed
    out:



    Writing DEF file './output/pipeline_fill.def', current time is Thu
    Apr 3 08:25:33 2008 ...

    unitPerMicron=2000, dbgMicronPerDBU=0.000500, unitPerDBU=1.000000

    DEF file './output/pipeline_fill.def' is written, current time is Thu
    Apr 3 08:25:34 2008 ...



    Suggesting that Encounter uses the grid of 0.0005 for everything.
    However, all standard cells and all routed metal are placed on the
    correct 0.005 grid - only fillNotch generated metal is placed off-
    grid.


    Has anyone had this problem before?
     
    Nathaniel Gaskin, Apr 3, 2008
    #1
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