1 Reply Latest reply on Mar 15, 2012 2:09 PM by chris_balcom

    missing ports on LVS

    ogouveia

      Hi,

       

      I'm using calibre to perform LVS. The schematic and layout were generated with virtuoso. I always get problems with ports.

      See, below, the LVS report.

      Thanks.

       

      LAYOUT NAME                                               SOURCE NAME

      Discrepancy #1 in inv                                                                          

       

       

       

       

      ** missing port **                                        VDD! on net: vdd!

       

       

      Discrepancy #2 in inv                                                                          

       

       

       

       

      ** missing port **                                        GND! on net: gnd!

       

       

      Discrepancy #3 in inv                                                                          

       

       

       

       

      ** missing port **                                        in! on net: in!

       

       

      Discrepancy #4 in inv                                                                          

       

       

       

       

      ** missing port **                                        out! on net: out!

        • 1. Re: missing ports on LVS
          chris_balcom

          It looks like the ports are missing from the layout side. For the layout ports to exist, text labels are usually required in the layout database, and corresponding statements in the rulefile are needed too. For instance, if your text in the layout is on layer 123 for metal 2 ports and net names, you might have something like this in your rule file:

           

          TEXT LAYER 123  // for net names

          PORT LAYER TEXT 123  // for existence of top level ports

           

          If you search in your transcript (log file) you should see sections in there relating to text objects for net names, and also ports, for instance:

           

          --------------------------------------------------------------------------------
          -----               TEXT OBJECTS FOR CONNECTIVITY EXTRACTION               -----
          --------------------------------------------------------------------------------

          VSS (-78,-136) 4 topcell                VSS (-78,-96) 4 topcell
          VSS (-78,-56) 4 topcell                 VSS (-78,-16) 4 topcell

           

           

          --------------------------------------------------------------------------------
          -----                                PORTS                                 -----
          --------------------------------------------------------------------------------

          VSS (27,83.5) 4 cell0                   IN_0 (30.5,99.5) 2 cell0
          VSS (42,61.5) 4 cell0                   IN_1 (45.5,77.5) 2 cell0
          VSS (57,39.5) 4 cell0                   IN_2 (60.5,55.5) 2 cell0