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 Encounter Export to Virtuoso (GDS/DEF or OA?) 

Last post Thu, Nov 21 2013 12:55 AM by Kabal. 5 replies.
Started by Kabal 19 Nov 2013 10:56 PM. Topic has 5 replies and 1292 views
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  • Tue, Nov 19 2013 10:56 PM

    • Kabal
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    Encounter Export to Virtuoso (GDS/DEF or OA?) Reply
    Hello,

     


    I have successfully implemented some small design with RTL Compiler, after that
    used the Encounter to produce the layout from synthesiz Verilog file. 

    Then I did Geometry and Connectivity checks, it all was fine. 

    Now I want to export the layout to Virtuoso for verification and integration in other modules, and here I have a huge problem.

    If I am correct there are two routes:
    1) Export DEF and GDS, then in Virtuoso Import them one after another
    2) Export OA and in Virtuoso Import OA

    #2 doesnt work for me, since during export from Encounter it wants streamMap file which I seem not to have for this kit 

    I tried #1, I export DEF file, then export the GDS file, but when I do streamIN in Virtuoso, some of the wires are not seen, and DRC gives me TONS of errors...

    One thing I noticed weird here is: when I export from Encounter GDS, and I dont have streamOut.map file, it creates it himself.
    But when I want to export OA, and do not have that file either, it complains that it cant find this file. Why?
     
    And in general, what is the best flow for export of Layout from Encounter to Virtuoso of version 6? (becuase I see some people suggest not to use GDS for version 6 but use OA) but again... OA doesnt want to export and I am not quite sure where to get the map file, the one which comes with kit is not being accepted by Encounter 
    • Post Points: 5
  • Wed, Nov 20 2013 10:35 AM

    • Kabal
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    Re: Encounter Export to Virtuoso (GDS/DEF or OA?) Reply

    ok, after more tries and experementation I managed to get the layout generated with right traces/layers after importing DEF file.

    However; All the cells used to construct my design are in abstract layer, if I go ahead and manually change each cell to layout type it appears properly in layout mode. However there are tons of cells, I am not sure how to convert now freshly imported layout of design from DEF so that each cell is in layout mode and not abstract mode?

    (choosing List view to layout during DEF import does not work, because for some reason all cells are shifted badly within design)

    any ideas? 

    • Post Points: 20
  • Wed, Nov 20 2013 11:01 AM

    • Kari
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    Re: Encounter Export to Virtuoso (GDS/DEF or OA?) Reply

    The method I always use is to export GDS from EDI. (You don't need GDS and DEF, just GDS). You can easily create the Encounter stream map file yourself. Sounds like you have the template to start with, just make sure it includes everything you need. The format is well documented in the EDI docs.

    You can output a merged GDS, which will include the full layouts of your std cells, IP, etc if you point to the GDS files of those in the streamOut command, and then stream that in to a clean Virtuoso library. Or you can output an un-merged GDS and read it into a Virtuoso session where you are pointing to the already-existing layout libraries. Sounds like that's the missing piece in what you tried so far, since you only had abstracts. 

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  • Wed, Nov 20 2013 6:59 PM

    • Kabal
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    Re: Encounter Export to Virtuoso (GDS/DEF or OA?) Reply

    That looks like a messier approach especially with a picky kit I have. Anyhow, here is how I finally made it to work:

    1) Create a fresh new library in Virtuoso, and reference the technology library to it.

    2) Stream In the GDS files of standard cells provided inside a Kit

    3) Import LEF files provided within a Kit with "Layout" shown in a view parameter

    4) Produce DEF file in Encounter

    5) Import the DEF file produced in Encounter in Virtuoso to the created library with view and View List both set to "Layout"

     This worked, and no manual messing with layer maps (I assume because you read LEFs already inside newly created library) 

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  • Wed, Nov 20 2013 9:21 PM

    • Kabal
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    Re: Encounter Export to Virtuoso (GDS/DEF or OA?) Reply

    and well, what you wrote in first paragraph doesnt work since in my case it messes up coordinates & layers. Which is why I was looking for another solution. And when I do things the way you described in second paragraph same things happen, for some reason when I open design in Virtuoso Layout, I see all cells are shifted. And by the way I also see that no power/other connections are made on different metal layers.

    And now about my previous solution, it kind of works, however I noticed that during LEF import with layout option, the diagonal layout connections are messed up sometimes and have some square areas added to them. So I am still trying to make it all work in a right way.

    I am really not sure now why during the LEF import with Layout view the 45deg connections are "spoiled" 

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  • Thu, Nov 21 2013 12:55 AM

    • Kabal
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    Re: Encounter Export to Virtuoso (GDS/DEF or OA?) Reply

    So, my flow was not quite right, even though seemed to work, but then created those M1 malforming errors during export. Now I managed to finally get it working in a different way, which is something like what you mentioned.

    1) create new library in virtuoso

    2) Import only Layer info from corresponding LEF file (i.e. not cell info)

    3) Go to Encounter, supply it with the MAP file which came later with Kit, and at the same time provide as a merged file GDS file which also came with standard cell libraries. Indicate top level cell.

    4) got o virtuoso, streamIN the produced GDS file into library created before.

     Now I see its working, and metals do not get malformed. 

    • Post Points: 5
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Started by Kabal at 19 Nov 2013 10:56 PM. Topic has 5 replies.