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cdb to oa conversion VIA missing

Simon87
Hi Folks:
Problem description: After doing CDB to OpenAccess translation on a design from IC5 to IC6, the VIAs in all layouts are missing, even I selected the “Detect vias automatically” and “Map via parameters” in Set library options. 
Environment: 
Cadence Virtuoso 6.1.6
IBM_PDK cmrf8sf V1.8.0.4DM
I know in CDB vias are like cellviews and could be placed as instances, and differs from that defined in OA, which are not instances. So anyone please tell me how to migrate them correctly? 
Thank you so much for your time.
Simon 

  •  Hi Simon,

     could you please check the cdb2oa conversion log and post the warning/error messages you probably find there regarding the vias?
    There is a summary for every warning/error type at the end of the log, no need for the whole file. This will save us from guessing around.

     Kind regards,

    Marc

  • Thanks Marc, actually there are some warnings concerning the vias in cdbwoa log as posted below. Does it mean vias (contacts) could never be converted? I also tried gds file streaming in, and each via is created as a instance in IC6, not standard via.

    WARNING (CDBOA-518): Any instance of the VDM2_M3 device in the CDB design
                         library will not be translated as a via in the OpenAccess
                         design library and will not work as expected. This is
                         because the CDB technology library that was translated to
                         the OpenAccess technology library is different from the
                         current CDB technology library. The device definition in
                         the current CDB technology library is not present in the
                         OpenAccess technology library.

    WARNING (CDBOA-518): Any instance of the VDM1_M2 device in the CDB design
                         library will not be translated as a via in the OpenAccess
                         design library and will not work as expected. This is
                         because the CDB technology library that was translated to
                         the OpenAccess technology library is different from the
                         current CDB technology library. The device definition in
                         the current CDB technology library is not present in the

                         OpenAccess technology library. 

  • Hi Simon,

    like the warning message says..there is a difference in the technology libraries which makes the automatic
    via mapping impossible. cdb2oa is comparing the source-cdb and target-oa technology libraries and tries
    to do the mapping. In some cases this fails since the oa technology was not directly translated from the cdb
    source but "hand written" or other wise generated ( which is ok to do, btw).

    Without having the data it is hard to say why the mapping is failing, it realy depends on how the vias are defined/named
    between cdb and oa. Could you please check the "Virtuoso Design Environment Adoption Guide"  where you can
    find a chapter about via mapping  "Conversion of Technology File devices Class".

    Kind regards,

    Marc

  • Hi Marc,

    Sorry I could not find the document "Virtuoso Design Environment Adoption Guide" you mentioned. Could you please tell me how I can get a copy of that? Thank you.

    Regards,

    Simon 

  • Hi Simon,

     if you can't find it in the documentation ( cdnshelp ) it is available as pdf here:

    <IC6 Install Path>/doc/dfoaAdopt/dfoaAdopt.pdf

     Kind regards,

    Marc

  •  You may also want add the flag -keepdevicemasters to your cdb2oa run, it will keep the cellViews from the vias and symbol pins. That will help with the initial translation and you can clean it up after it is translated if necessary (Always run DRC and LVS after translation)

    Ted

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