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  2. Custom IC SKILL
  3. Auto contact SKILL function

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Auto contact SKILL function

Yaosan
Yaosan over 15 years ago

Can someone please point me to the SKILL function used to invoke the auto contact feature (i.e. create via -> auto) in Virtuoso? I would like to use this function to automatically insert vias instead of doing it by manually clicking where I want the auto via to appear.

If there is no such public SKILL function available (any idea why?), can someone please suggest how should I go about coding such a function myself. I'm thinking of using dbLayerAnd, dbGetOverlap etc. to find the intersection area, but I'm not sure if I can traverse the hierarchy and get the shapes and net underneath the intersection area.

Any feedback will be greatly appreciated! Thanks!
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  • skillUser
    skillUser over 15 years ago

     Hi Yaosan,

    First, I will assume that you are talking about version IC61x, since the menu you described was "Create Via" and not Create Contact. In IC61 (based on the Open Access database), vias are objects as opposed to instances (as they were in IC5141 and earlier), so you would use the dbCreateVia() SKILL function to create the via.  Yes, you would probably want to use the dbGetOverlaps() function to find the appropriate overlapping connectivity layers, perhaps in conjunction with the techFindViaSpec() function to find the via definitions that could be used.  I'm not sure if there are any solutions, but you might search for leCreateContact() and the dbCreateVia() functions as starting points.

    I hope that this helps you.

    Regards,

    Lawrence.

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  • skillUser
    skillUser over 15 years ago

    Hi again Yaosan,

    I just searched and found Solution 11185634

    Additionally there is a solution which uses dbGetOverlaps which may help: Solution 11304230

    Hopefully this will help you.

    Regards,

    Lawrence.

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  • Yaosan
    Yaosan over 15 years ago

    Thanks Lawrence, that certainly helps a lot! The first solution uses leLayerAnd which only works with shapes within the same level. Thankfully, the 2nd solution you pointed out should allow me to traverse the hierarchy and bring some of the shapes to top level for manipulation. I'll give them a try later on and report if I have any success with it.

    Thank you!

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  • Yaosan
    Yaosan over 15 years ago

    btw, I think the 2nd solution are only able to bring bBox to the top level, not the actual shapes. Is flattening the design my only option to bring the actual shape to top level? And if I do flatten, the net info will be lost, no?

     Well, I'm not sure if this can done, but I'll see how far I can get...

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  • skillUser
    skillUser over 15 years ago

    Hi Yaosan,

    Yes, the code just transforms the bounding box, not the shapes themselves. If I have understood your problem correctly, you are wanting to create a via at the intersection of two appropriately overlapping shapes in the layout, whether these shapes are present at level 0, or at other levels.  Perhaps I am oversimplifying this, but I would have thought that the layers and the dimensions of the overlap is what is important (and not the net information?).  You might be able to copy the shapes or Yank and Paste the section of interest to a "scratch" cellview, i.e. one that is in virtual memory only and not save-able, for further processing.  By the way, in addition to the leLayer.* SKILL functions, there are also dbLayer.* functions, such as dbLayerAnd() which accept shapes for their input, this might be very useful to you.

    Regards,

    Lawrence.

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  • Yaosan
    Yaosan over 15 years ago

    Hi Lawrence,

    Yes, you are right about the requirement to drop vias between 2 overlapping shapes, I do not need to know the net in order for the vias to be created. However, I would like to automate some of the via dropping without user manually clicking on those intersecting areas, and only through net connectivity will the code be able to know where to drop these vias.

    Of course, making a simplified via dropping function that traverse hierarchy is the first step i.e. ignore net connectivity. After that I'll see if I can extend this function to account for net connectivity.

    Thanks for your feedback, working in "scratch" cellview is definitely the way to go if I do flatten or yank the design.

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