Virtuoso XL Update Device Correspondence

Discussion in 'Cadence' started by Erik Wanta, Oct 27, 2003.

  1. Erik Wanta

    Erik Wanta Guest

    Note: Use the Connectivity - Update - Device Correspondence command
    with designs that are not LVS correct and have been created using
    Virtuoso XL. Use the Create - Device Correspondence command for LVS
    correct designs that have not been created using Virtuoso XL.

    Does the Create Device Correspondence command use the LVS results at
    all? If so, does it use Diva or Assura results. One would think that
    there would be a way to use the LVS mappings to make the layout VXL
    compatible.
     
    Erik Wanta, Oct 27, 2003
    #1
  2. Erik Wanta

    Ethan Dawe Guest

    Hi Erik,

    All this allows you to do is to manually create a correspondence between a
    layout component and a schematic component for VXL. This will then allow you
    to use VXL to make updates/changes. It doesn't use the LVS data in either
    case.

    It's important to note that VXL can easily become confused with its
    connectivity and correspondence, especially if you break up devices into
    smaller pieces or accidently create a short. If the connectivity to a
    particular devices looks wrong, don't waste too much time with it. Either
    hook it as you think it should be and run LVS, or re-create the component
    from the linked schematic!

    Ethan
     
    Ethan Dawe, Oct 28, 2003
    #2
  3. Erik Wanta

    Erik Wanta Guest

    Ethan:
    We have a situation where we reuse old layouts that may or may not
    have been done with layoutXL. We really like layoutXL and would like
    to use it on the layout being reused. I would be nice if there was a
    way to make the layout XL compatible. I have found this to be
    difficult with create device correspondence and update device
    correspondence. One would think that the LVS device mappings could be
    used to rename the layout instance names and make the layoutXL
    compatible.
     
    Erik Wanta, Oct 28, 2003
    #3
  4. Erik,

    You might think that they could be used, but at the moment they can't. It's probably
    not as simple as it might at first seem, because most verification tools would work
    by identifying the polygons which form the devices, and finding the correspondence
    at that level - not by starting from any existing pcells and finding the correspondence
    there. In other words, they extract the devices and connectivity from the raw
    shapes, not the pcells - and so to get the devices mapped back into VXL, it
    would have to re-identify the components from which the shapes that the
    verification tool used to form the devices. Nothing impossible here, but it's not
    as straightforward as it might first seem - certainly not as simple as just
    taking the device mappings directly.

    Andew.
     
    Andrew Beckett, Oct 30, 2003
    #4
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