Stats

  • Locked Locked
  • Replies 13
  • Subscribers 95
  • Views 59234
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Antenna Error in Calibre DRC but Passed antenna check in Encounter

mingfatty
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

  • Here is a link similar to your problem.

    /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.  

     

     

  • 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

  • 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. 

     

     

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.