• Skip to main content
  • Skip to search
  • Skip to footer
Cadence Home
  • This search text may be transcribed, used, stored, or accessed by our third-party service providers per our Cookie Policy and Privacy Policy.

  1. Community Forums
  2. Custom IC Design
  3. How to change analysis type in Ocean?

Stats

  • Locked Locked
  • Replies 2
  • Subscribers 125
  • Views 13685
  • 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 change analysis type in Ocean?

Honghao
Honghao over 12 years ago

Hi,

The subject may not reflect the issue I'm facing since I don't know how to describe it well in a short sentence. 

Here is a little background and the question that I have.

I'm using ocean script to run stability analysis over corners. When RC extracted netlist is being used, spectre has difficulties in finding DC operation solution. To deal with this issue, I run a transient first and then run stability analysis using the transient final state "spectre.fc" as the nodeset for stability analysis. 

The following is part of my script. My intention is to run transient analysis with one netlist where supply DC voltage is 0, and then run stability analysis with another netlist where DC voltage is back to normal. This part works fine.

My problem is that the second run in the for loop still does a transient analysis. That will take an extra five to ten minutes for nothing. I'm wondering if there is any way to eliminate the transient sim from the second run. Thank you in advance for your help! 

 

for(i 0 1

                if( i==0

                        then

                                desVar( "avdd" 0); Set variable avdd to 0 for transient analysis

                                analysis('tran ?anaName "tran"  ?stop "20u"  ?errpreset "conservative"

                                         ?write "spectre.ic"  ?writefinal "spectre.fc"  ?annotate "status"  ?finalTimeOp t

                                         ?maxiters "5"  ?threshold "0.0"  ?detail "node"  ?sort "name"  )

                        else

                                desVar( "avdd" Va); Set variable avdd to Va for stability analysis

                                analysis('stb ?anaName "stb"  ?start "1k"  ?stop "10G"

                                                ?probe "/Idiff"  ?usingProbeMode t

                                                ?stbProbeMode "differential"  ?readns "spectre.fc"

                                                ?oppoint "rawfile"  ?annotate "status")

                ); end if(i == 0)

 

                createNetlist(?recreateAll t)

                run()

        ); end for

 

 

 

  • Cancel
  • Andrew Beckett
    Andrew Beckett over 12 years ago

    You can use delete('analysis 'tran) to delete the transient analysis, or delete('analysis) to delete all analyses (I think, if my memory is correct).

    Andrew.

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
  • Honghao
    Honghao over 12 years ago
    Hi Andrew, Thank you so much for your help!! Save me at least a day or two if I could ever figure this out on my own. I have learned quite a lot from reading your posts. It's amazing that you pretty much carry out this forum alone and have helped so many people. Thank you again! Honghao
    • Cancel
    • Vote Up 0 Vote Down
    • Cancel

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.

© 2025 Cadence Design Systems, Inc. All Rights Reserved.

  • Terms of Use
  • Privacy
  • Cookie Policy
  • US Trademarks
  • Do Not Sell or Share My Personal Information