Stats

  • Locked Locked
  • Replies 4
  • Subscribers 91
  • Views 18359
  • 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

How to obtain Congestion Statistics after Routing is complete?

Narasimhan
Hi, I am using SOC Encounter for the first time. I have done the placement and routing of a circuit using Encounter(with the help of a few tutorials). I want the congestion statistics of the design after the detailed routing is complete. On reading the User Guide, I understand that dumpCongestArea command gives the congestion statistics after the trial route or global route. I used the command after trial route to get the congestion statistics. It showed me negative values of remaining tracks. Then, I did detailed routing and used the dumpCongestArea command. The two files have the same data. But, if i try exporting the gds layout and do a post layout simulation on the circuit, it produces the correct output. Hence, I concluded that the circuit has been routed properly. So, there cannot be negative values of remaining tracks after detailed routing. Can someone explain me the procedure to get the congestion data of the design after detailed routing? Thank you. Lakshminarasimhan
Parents

  • Hi Narasimhan,

      Thanks for using Nanoroute!    The Nanoroute detail route search and repair iterations “repair” any over congestion by legalizing/detouring the routing.  

      If you stop after iteration zero, you will have a db with more congestion for your analysis:

      setNanoRouteMode drouteEndIteration 0 

    The database at this point will have spacing violations that are not repaired by the router.   

    By default, Nanoroute global route considers an area to be fully utilized when the track assignment in a gcell reaches 85% of the available tracks.     

    There is a hidden variable to adjust this metric:   

    setNanoRouteMode grouteCongThreshold    0.850000 (float, default setting)   

    You can use this variable to generate a global route that has more congestion.   

    To dump statistics on the NR congestion, use the following command:   

    dumpNanoCongestArea   

    You can use this command after global route finishes, and also after detail route. 

      You will notice a difference in the output if you allow detailRoute to clean up the violations in the design.

    Eric
Reply

  • Hi Narasimhan,

      Thanks for using Nanoroute!    The Nanoroute detail route search and repair iterations “repair” any over congestion by legalizing/detouring the routing.  

      If you stop after iteration zero, you will have a db with more congestion for your analysis:

      setNanoRouteMode drouteEndIteration 0 

    The database at this point will have spacing violations that are not repaired by the router.   

    By default, Nanoroute global route considers an area to be fully utilized when the track assignment in a gcell reaches 85% of the available tracks.     

    There is a hidden variable to adjust this metric:   

    setNanoRouteMode grouteCongThreshold    0.850000 (float, default setting)   

    You can use this variable to generate a global route that has more congestion.   

    To dump statistics on the NR congestion, use the following command:   

    dumpNanoCongestArea   

    You can use this command after global route finishes, and also after detail route. 

      You will notice a difference in the output if you allow detailRoute to clean up the violations in the design.

    Eric
Children
No Data

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.