• 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. Functional Verification
  3. forcing the creation of a vcd file

Stats

  • Locked Locked
  • Replies 14
  • Subscribers 67
  • Views 32016
  • 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

forcing the creation of a vcd file

freitas
freitas over 13 years ago

Hello,

How do I instruct simvision to force the creation of a vcd file?

I am trying to create tcl script to dump signals into a vcd file and then immediately post-process this very vcd.

These are the two lines I want to run in sequence from a ncsim tcl script : 

simvision -submit "database export $my_signals -format vcd -name my_vcd.vcd"

file copy my_vcd.vcd ${my_dir}/myvcd.vcd

The problem that I am experiencing is that simvision seems to postpone the creation of the vcd file. Therefore, at the moment the second line is executed the vcd file is not yet available.

I get the following error:

ncsim> *E,TCLERR: error copying "driver.vcd": no such file or directory

However, if I run the two lines separately (i.e., not in a script) it works.So It seems that I have to force the creation of the vcd, but I don't know how.

I would appreciate your help.

Thanks!

 

 

  • Cancel
Parents
  • StephenH
    StephenH over 13 years ago

    I expect the problem is that because the "simvision -submit" just passes the request to the simvision process, ncsim carries on executing Tcl commands before simvision even processes the request.

    How about getting SimVision to execute the file copy as well, as part of the same command?

    ncsim> simvision -submit "database export $my_signals -format vcd -name my_vcd.vcd ; file copy my_vcd ${my_dir}/myvcd.vcd"

    Alternatively, why not just set a probe straight into a VCD file?
    NCSim lets you open multiple waveform databases and set multiple probe commands, either into the same database or different ones.

    ncsim> database -open my_vcd -vcd -into ${my_dir}/myvcd.vcd 
    ncsim> probe -create -database my_vcd $my_signals

      

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Reply
  • StephenH
    StephenH over 13 years ago

    I expect the problem is that because the "simvision -submit" just passes the request to the simvision process, ncsim carries on executing Tcl commands before simvision even processes the request.

    How about getting SimVision to execute the file copy as well, as part of the same command?

    ncsim> simvision -submit "database export $my_signals -format vcd -name my_vcd.vcd ; file copy my_vcd ${my_dir}/myvcd.vcd"

    Alternatively, why not just set a probe straight into a VCD file?
    NCSim lets you open multiple waveform databases and set multiple probe commands, either into the same database or different ones.

    ncsim> database -open my_vcd -vcd -into ${my_dir}/myvcd.vcd 
    ncsim> probe -create -database my_vcd $my_signals

      

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Children
  • rkaur9
    rkaur9 over 3 years ago in reply to StephenH

    Hi Stephen,

     i tried above command but it gives error " my_dir not found"

     sim: *E,TCLERR: can't read "my_dir": no such variable.
    xcelium> xmsim: *E,TCLERR: can't read "my_signals": no such variable.

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
  • StephenH
    StephenH over 3 years ago in reply to rkaur9

    These would be variables that you've set in Tcl, if you don't set them, the tool can't read them!

    • Cancel
    • Vote Up +1 Vote Down
    • Cancel
  • rkaur9
    rkaur9 over 3 years ago in reply to StephenH

    Thanks for your response, i am trying to create vcd dump file and i have testbench.sv as top file

    how can i use it without setting variables

    tried this one also

    ncsim> database -open my_vcd -vcd -into myvcd.vcd 
    ncsim> probe -create -database my_vcd  testbench/*

    thnks

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
  • StephenH
    StephenH over 3 years ago in reply to rkaur9

    ncsim> database -open my_vcd -vcd -into myvcd.vcd 
    ncsim> probe -create -database my_vcd  [scope -tops] -depth all -all

    login to https://support.cadence.com/ and search for the "probe command syntax" for full details and examples.

    • Cancel
    • Vote Up +1 Vote Down
    • Cancel
  • rkaur9
    rkaur9 over 3 years ago in reply to StephenH

    Hi Stephen,

     Thanks a lot for the information, that works,

    thanks

    • 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