VXL shows incomplete nets : how to add connectivity to shapes

Discussion in 'Cadence' started by bu-bu, Jun 5, 2009.

  1. bu-bu

    bu-bu Guest

    Hello All,

    I have a question related to VXL and incomplete nets.

    My layout is LVS clean, but VXL is still showing incomplete nets. Some
    nets don't have the connectivity information when i "Q" on it.

    It's because sometimes, the connection is not made through the pin.
    The physical connection is done, but the shape does not have
    connectivity information because there are no contact with the pin.
    when i overlap the shape with the pin, the connectivity information is
    created.

    I would like to know how to add the connectivity to the shapes that
    don't have this information. it's important because i plan to create a
    LEF / DEF ...

    Moreover, when i "update components and nets", i have a strange
    warning in the CIW:
    *WARNING* Virtuoso XL autoPermutation: lxPerFindConnect: Unexpected
    type.

    Do you have some clue/ideas please ?

    Thanks and regards,

    bubu
     
    bu-bu, Jun 5, 2009
    #1
  2. bu-bu wrote, on 06/05/09 01:17:
    You should be able to set the extract depth to greater than 1 - this is on the
    XL options form.

    However... if you are trying to produce a DEF file, if you are not routing to
    the "hit point" (i.e. the pin) in the LEF, the chances are that the tool seeing
    the DEF file will not see it as properly connected either.

    The only record of that warning I saw was fixed a few years ago (around IC5141
    USR2). What subversion of IC are you using?

    Regards,

    Andrew.
     
    Andrew Beckett, Jun 8, 2009
    #2
  3. bu-bu

    bu-bu Guest

    Hello Andrew,

    Thanks a lot for your reply.

    Indeed, i have played with the extractStopLevel option of VXL (greater
    than 1 ) and VXL does the connectivity. But, as you said, my nets are
    not connected to the "hit points" :(

    So i have written a script to overlap the pin with the full metal.
    Hopefully, it will be ok.

    For the warning message (strange! ) i'm using IC5.1.41 usr6 Isr10.
    (the one that has been released in April i think)
    Looks like this warning is not killer : VXL shows the unconnected nets
    (but it's hard to say, because my design is a big one)

    Thanks and regards,

    bubu
     
    bu-bu, Jun 8, 2009
    #3
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