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Disconnected vias from planes - different problem

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Hi all

I've possibly found a new serious problem with shapes.  I can't find the
exact problem in the archives, so I thought I'd throw it to you all
before I submit it as a bug.

We have a board with several negative shapes.  Upon sliding a via, all
the shapes that either are in contact with that via or void around that
via, immediately become 'out of date'.   It happens randomly.

Eg, it could be a GND via I am sliding, but all negative shapes around
that via effectively disappear, leaving only its outline.  This leaves
thousands of unconnected vias, ie unconnected nets.

That's not the problem.  The real issue is that any stitching vias on
these shapes are now disassociated with any signal.  Updating shapes
will NOT work.  The stitching vias now have a dummy net, and will stay
that way.  (By stitching vias, I mean only those from shape-to-shape.)

Funnily, if you catch it soon enough, an undo will rectify it!

We're using 15.5.1, latest ISR, etc. We also really need to keep
negative shapes, due to the size of the designs.

Any clues?  Has this been reported before?

Cheers,
Richard


Originally posted in cdnusers.org by Richard Moffat

  • Richard,

        I have had this problem before on older releases but I seem to remember it hapened also with other operations such as move.  Since I started using dynamic shapes for all my shapes I have not seen it. Are your negative shapes dynamic or static. Either way it still sounds like a bug to me.

    Carl


    Originally posted in cdnusers.org by CTMusetti

  • Richard,

    I use stitching vias all the time and yes I have seen the issue where the vias become disconnected from the associated net.
    After much stress, I decided to generate a small shape inside the via boundary which is attached to GND then copy the via/shape around the design. Cadence added the "Retain Net of Vias" checkbox to the Copy command which seems to leave the via associated to the net but in some cases it loses its association. Whatever we do it will be a Band-Aid.

    If this issue has not been reported before maybe it should.. I would certainly jump on board to support the PCR by adding my company to the list.

    Mike Catrambone
    UTStarcom, Inc.


    Originally posted in cdnusers.org by mcatramb91

  • Richard,

    Please do contact customer support and let them troubleshoot the issue with you.  This is the recommendation to me from a couple of Cadence engineers.

    Linda


    Originally posted in cdnusers.org by lindam

  • Hi

    This was addressed in the latest hotfix, and it seems to have been fixed.

    (To my own understanding and trialing, it was related to the Esc key being aliased to the Oops function; I'll explain no further.)

    Thank you to the people in Cadence.

    Cheers,
    Richard


    Originally posted in cdnusers.org by Richard Moffat
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