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cb2oa, missing vias

stuso

 Hi guys, when i translate from 5141 to OA i have some missing vias in my IC6 layout. Our PDK providers have the same process in 5141 and OA so we have only converted the design libs.

Looking at my PDK providers OA techlib it looks more complex regards via definitions, compared to 5141. In the OA techfile i see a standard vias & viaSpecs definition. I tried to manually edit the tech file and put my missing via definitions into these 2 sections but i noticed when i import this hacked OA techfile and dump it back out again that the viaSpec part has reverted to default...i.e my edits are gone, but the standardVias i added are still there. Crucially however when i open the layout with my new hached techfile attached to the lib the vias are still missing. any advice greatly appreciated, if this is a complex process i'll log an SR.

Thanks

Stu

 

 

 

 

 

  • Just looking at the techfile i see there are a load of "validVia" sections for each "constraint" group. I guess that if i work out which is my default constraint group that i can simply add my new vias to its validVias list.

  •  Hi,

    you should file a SR for this since we would need to look at the cdb and the oa techfile.
    Just by adding vias to the validVia section will not help you to bring them back into the
    translated layout.
    Your cdb2oa should have created a log which should have more informations about
    problems found in the translation process. If vias can't be mapped from cdb to oa you
    should see that reported in that log.

     Marc

  •  Hi Marc, yes i think an SR is required.

    i looked in the log and i cannot see any specific mention of vias or the specific vias which are missing. In the OA layout the missing vias are represented by marker layers with the name of said via shown in text as well. Does this suggest that cdb2oa has no issues translating these vias BUT that my OA techfile simply does not define these vias. For example in a similar situation i had some custom multipart paths (MPP) which were missing but to get them back all i had to do was modify my MPP code very slightly then re-load it in IC6 and they re-appeared.

    Thanks for your help.

    Stu

     

     

  •  Hi Stu,

    that really depends on the type of via you are using. Sounds like a custom via in your case which is
    missed in your target oa techlib. Is the via in question missed or does it just have a new/different name
    in the OA kit? Maybe you could try a via mapping with cdb2oa (check the docu).

    But to be save hand it over to support. I've done some cdb2oa calls and vias usually causing most of
    the trouble.

    Kind regards,
    Marc

  • Hi Marc, i made a little progress since my last post, this time as you just mentioned, i put the vias in the "custom via" section and when i opened up the offending cell the vias were in the layout, so good news...or so i thought. Inadvertently i've broken something else as now some unrelated metal and vias are broken when i run DRC (though visually in layout they appear to be ok, very strange).

    I logged an SR anyway & sent cadence the cdb2oa log file. 

    Thanks

    Stu

     

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