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 Antenna Error in Calibre DRC but Passed antenna check in Encounter 

Last post Mon, Mar 22 2010 8:07 PM by diablo. 13 replies.
Started by mingfatty 16 Mar 2010 01:14 PM. Topic has 13 replies and 6242 views
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  • Tue, Mar 16 2010 1:14 PM

    • mingfatty
    • Top 500 Contributor
    • Joined on Tue, Mar 16 2010
    • Posts 23
    • Points 385
    Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply
    Dear Experts, I am using encounter to do my place and route after having obtain the macro lef from the abstract generator, everything's going fine until i stream out my gds2 file and check the DRC using Calibre in virtuoso, where i am getting hundreds of antenna error out of the antenna check. I wonder how could this happened and not reported in encounter. i am desperately need this to be solved and proceed to the tape-out. FYI, i am using IBM 130nm technology, and i am using the technology lef that provided by foundry (i wonder do i need to change any of my lef file to suit the Calibre check). Please kindly help! Thank you! Regards, MF
    • Post Points: 20
  • Tue, Mar 16 2010 1:40 PM

    • Alex Soyer
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    • Sophia-Antipolis, Alpes-Maritimes
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hello,

    When you have generated your lef macro with Abstract generator did you extract teh antenna ?

    If the antenna information are not part of your abstracts the router could not check and calculate the antenna ratio and fix them.

    Thanks,

    Alex

    • Post Points: 20
  • Tue, Mar 16 2010 2:36 PM

    • mingfatty
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hi Alex,

    Thanks for the quick reply, actually i am able to put the antenna cell into my design during the place and route. and it is able to fix the antenna error in encounter as well, but the problem is that, when i stream out the design to do the calibre DRC check in virtuoso, hundreds of antenna error is reported, FYI following is the example of the macro lef i created,

     MACRO DL_XOR_NXOR2X1
      CLASS CORE ;
      ORIGIN 0 0 ;
      FOREIGN DL_XOR_NXOR2X1 0 0 ;
      SIZE 8 BY 4 ;
      SYMMETRY X Y ;
      SITE core ;
      PIN gnd!
        DIRECTION INOUT ;
        USE GROUND ;
        SHAPE ABUTMENT ;
        PORT
          LAYER M1 ;
            RECT 0.76 0 1.04 1.19 ;
            RECT 6.96 0 7.24 1.25 ;
            RECT 0 0 8 0.28 ;
        END
      END gnd!
      PIN vdd!
        DIRECTION INOUT ;
        USE POWER ;
        SHAPE ABUTMENT ;
        PORT
          LAYER M1 ;
            RECT 0.76 2.8 1.04 4 ;
            RECT 3.15 2.81 3.43 4 ;
            RECT 4.09 2.73 4.37 4 ;
            RECT 6.01 2.8 6.29 4 ;
            RECT 6.96 2.79 7.24 4 ;
            RECT 0 3.72 8 4 ;
        END
      END vdd!
      PIN nB
        DIRECTION INPUT ;
        USE SIGNAL ;
        ANTENNAMODEL OXIDE1 ;
          ANTENNAGATEAREA 0.2016 LAYER M1 ;
        PORT
          LAYER M1 ;
            RECT 1.98 1.69 2.28 1.99 ;
        END
      END nB
      PIN Q
        DIRECTION OUTPUT ;
        USE SIGNAL ;
        ANTENNADIFFAREA 0.2688 LAYER M1 ;
        PORT
          LAYER M1 ;
            RECT 7.44 0.97 7.88 1.25 ;
            RECT 7.72 0.97 7.88 3.03 ;
            RECT 7.44 2.73 7.88 3.03 ;
        END
      END Q
      PIN A
        DIRECTION INPUT ;
        USE SIGNAL ;
        ANTENNAMODEL OXIDE1 ;
          ANTENNAGATEAREA 0.2016 LAYER M1 ;
        PORT
          LAYER M1 ;
            RECT 3.82 1.69 4.31 1.99 ;
        END
      END A
      PIN nA
        DIRECTION INPUT ;
        USE SIGNAL ;
        ANTENNAMODEL OXIDE1 ;
          ANTENNAGATEAREA 0.2016 LAYER M1 ;
        PORT
          LAYER M1 ;
            RECT 1.36 3.24 1.66 3.54 ;
        END
      END nA
      PIN REQ
        DIRECTION OUTPUT ;
        USE SIGNAL ;
        ANTENNADIFFAREA 0 LAYER M1 ;
        ANTENNAMODEL OXIDE1 ;
          ANTENNAGATEAREA 0.2016 LAYER M1 ;
        PORT
          LAYER M1 ;
            RECT 1.15 2.01 1.45 2.31 ;
            RECT 6.64 2.01 6.94 2.31 ;
            RECT 1.15 2.15 6.94 2.31 ;
        END
      END REQ
      PIN B
        DIRECTION INPUT ;
        USE SIGNAL ;
        ANTENNAMODEL OXIDE1 ;
          ANTENNAGATEAREA 0.2016 LAYER M1 ;
        PORT
          LAYER M1 ;
            RECT 2.86 1.69 3.16 1.99 ;
            RECT 3.32 1.35 3.48 1.85 ;
            RECT 2.86 1.69 3.48 1.85 ;
            RECT 3.32 1.35 4.69 1.51 ;
            RECT 4.53 1.35 4.69 1.86 ;
            RECT 4.53 1.7 5.16 1.86 ;
            RECT 4.88 1.7 5.16 1.99 ;
        END
      END B
      PIN nQ
        DIRECTION OUTPUT ;
        USE SIGNAL ;
        ANTENNADIFFAREA 0.2688 LAYER M1 ;
        PORT
          LAYER M1 ;
            RECT 0.12 0.97 0.28 3.03 ;
            RECT 0.12 0.97 0.56 1.25 ;
            RECT 0.12 2.73 0.56 3.03 ;
        END
      END nQ
      OBS
        LAYER M1 ;
          RECT 2.67 0.97 2.95 1.25 ;
          RECT 0.77 1.35 2.83 1.51 ;
          RECT 2.67 0.97 2.83 1.51 ;
          RECT 0.63 1.46 0.93 1.76 ;
          RECT 0.77 1.35 0.93 2.64 ;
          RECT 0.77 2.48 2.35 2.64 ;
          RECT 2.19 2.48 2.35 3.03 ;
          RECT 1.24 2.48 1.4 3.03 ;
          RECT 1.24 2.8 1.52 3.03 ;
          RECT 2.19 2.74 2.47 3.03 ;
          RECT 1.83 0.65 3.63 0.81 ;
          RECT 3.47 0.65 3.63 1.19 ;
          RECT 1.83 0.65 1.99 1.19 ;
          RECT 1.31 0.97 1.99 1.19 ;
          RECT 3.47 0.97 3.75 1.19 ;
          RECT 2.79 2.47 3.79 2.63 ;
          RECT 3.63 2.47 3.79 3.03 ;
          RECT 1.7 2.8 1.98 3.03 ;
          RECT 2.67 2.75 2.95 3.03 ;
          RECT 3.63 2.73 3.91 3.03 ;
          RECT 1.82 2.8 1.98 3.36 ;
          RECT 2.79 2.47 2.95 3.36 ;
          RECT 1.82 3.2 2.95 3.36 ;
          RECT 4.57 2.73 4.85 3.03 ;
          RECT 5.53 2.8 5.81 3.03 ;
          RECT 4.69 2.73 4.85 3.47 ;
          RECT 5.53 2.8 5.69 3.47 ;
          RECT 4.69 3.31 5.69 3.47 ;
          RECT 4.37 0.65 6.17 0.81 ;
          RECT 6.01 0.65 6.17 1.19 ;
          RECT 4.37 0.65 4.53 1.19 ;
          RECT 4.25 0.97 4.53 1.19 ;
          RECT 6.01 0.97 6.29 1.19 ;
          RECT 5.53 0.97 5.81 1.19 ;
          RECT 6.47 0.97 6.75 1.25 ;
          RECT 5.65 0.97 5.81 1.51 ;
          RECT 6.47 0.97 6.63 1.51 ;
          RECT 5.65 1.35 6.63 1.51 ;
          RECT 4.73 0.97 5.12 1.19 ;
          RECT 4.96 0.97 5.12 1.54 ;
          RECT 4.96 1.38 5.49 1.54 ;
          RECT 5.33 1.38 5.49 1.83 ;
          RECT 5.33 1.67 7.26 1.83 ;
          RECT 7.1 2.11 7.4 2.41 ;
          RECT 7.1 1.67 7.26 2.63 ;
          RECT 5.17 2.47 7.26 2.63 ;
          RECT 5.17 2.47 5.33 3.03 ;
          RECT 5.05 2.8 5.33 3.03 ;
          RECT 6.49 2.47 6.77 3.03 ;
      END
    END DL_XOR_NXOR2X1

    I wonder whether this discrepancy is caused by the tech .lef where i use it directly as provided by the foundry. Thanks! Regards, MF

    • Post Points: 20
  • Tue, Mar 16 2010 3:29 PM

    • Alex Soyer
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hi,

    As you mentionned it could be duee to a mismatch between Virtuoso techfile and calibre techfile.

    Thanks,

    Alex

     

     

    • Post Points: 20
  • Tue, Mar 16 2010 3:44 PM

    • mingfatty
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    • Posts 23
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hi Alex,

    I think that is the case, i saw some of the similar error in google and mentioned something about "AntennaDiffSideAreaRatio PWL " in the tech lef need to be change, but i am not sure how to do that and i can't even find it in my tech lef.

    I think most important is i need to know why are there discrepancy between calibre and encounter antenna check at the first place.

    Thanks so much for the reply.

    Regards, MF

    • Post Points: 5
  • Wed, Mar 17 2010 8:42 AM

    • mingfatty
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    • Joined on Tue, Mar 16 2010
    • Posts 23
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply
    Please kindly help on this! thanks!
    • Post Points: 20
  • Wed, Mar 17 2010 1:11 PM

    • Quek
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hi MF

    My guess is that this might be due to your Encounter settings. It would be best if you can contact your local Cadence support and submit a testcase so that they can assist you in debugging this. If you would like to request for more help from our forums, perhaps you might want to post the same question in the digital implementation forum. Similar questions have been asked in that forum. When submitting the post, please indicate the version of Encounter which you are using and the relevant settings related to antenna fixing.

    linux>encounter -version

    Best regards
    Quek

    • Post Points: 35
  • Wed, Mar 17 2010 1:17 PM

    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    I'll move this question to the Digital Implementation Forum, so the complete history is preserved.

    Regards,

    Andrew.

     

    • Post Points: 5
  • Thu, Mar 18 2010 6:20 AM

    • mingfatty
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    • Joined on Tue, Mar 16 2010
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hi Quek,

    Thanks for the suggestion, i have actually submit the test case to Sourcelink but unfortunately i have not yet get the relevant reply even it already last for around 1 month plus, Due to the urgency of this case i hope that by all means i can get some clue how to solve my problem here. i am using the encounter 8.1 to do my place and route and stream-out the .gds for Calibre check in Virtuoso IC6.13.

    Thank you ,

    MF

    • Post Points: 20
  • Thu, Mar 18 2010 2:07 PM

    • Quek
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hi MF

    Your issue has already been highlighted to our office. My colleague supporting Encounter will go onsite to review this issue. I believe that she has already sent you an email for the earliest possible date of the onsite. We will do our best to resolve this as fast as possible. Sorry about the delays.

    Best regards
    Quek

    • Post Points: 20
  • Thu, Mar 18 2010 2:57 PM

    • mingfatty
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hi Quek,

    It's great to hear from your side, at least now i have some hope to settle the case before the tape-out. thanks again for your continuous support.

    Thanks again!

     MF

    • Post Points: 20
  • Fri, Mar 19 2010 11:39 PM

    • diablo
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Here is a link similar to your problem.

    http://www.cadence.com/Community/forums/p/11893/15690.aspx#15690

    In our case, we had to modify the LEF to match DRC deck to reduce the number of antenna violation in calibre. However, it didn't compleley  removed the antenna violations. We are able to bring down the violation to 10. Then you can use 

    attachDiode
    [-prefix prefix]
    -diodeCell diodeCellName
    -pin instName termName
    [-loc x y
    [-orient orient]]


    Adds an antenna diode to a post-routed design. EDI System places the diode as close as
    possible to the specified pin.

    Identify the nets that has antenna violation and manually attach the antenna diodes using "attachDiode" to the respective pin to clear the antenna violation in calibre.

    I hope this helps.  

     

     

    • Post Points: 20
  • Mon, Mar 22 2010 6:27 AM

    • mingfatty
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    Hi diablo,

    Can i know how to modify the LEF ruledeck according to calibre rule deck, i am sorry but i am quite new in this field. and i do not have the PWL value in my LEF but only one antenna ratio value (e.g. ANTENNAAREARATIO 148).

    Please kindly advise! Thank you!

    Regards,

    MF

    • Post Points: 20
  • Mon, Mar 22 2010 8:07 PM

    • diablo
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    Re: Antenna Error in Calibre DRC but Passed antenna check in Encounter Reply

    You should be able to modify the ANTENNAAREARATIO in LEF and route the design in encounter with this new ratio. Then try to check for antenna violation with calibre DRC. The number of antenna violations should be different from before.

    To understand how these ANTENNAAREARATIO are used to check for antenna violation and how to modify them, you can generate antenna report in encounter. Use this antenna report along with LEF/DEF Reference manual mentioned by Kari in my previous post to understand what values are calculated for ANTENNAAREARATIO by encounter and compare them with the one you have specified in LEF to flag antenna violations. 

     

     

    • Post Points: 5
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Started by mingfatty at 16 Mar 2010 01:14 PM. Topic has 13 replies.