Stats

  • Locked Locked
  • Replies 2
  • Subscribers 143
  • Views 13932
  • 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

Unable to open nodeset file Warning

Eshar

I have noticed that in my SP simulations the following warning occurs when a DC operating point simulation doesn't precede it:

WARNING (CMI-2015): Unable to open nodeset file `spectre.dc'. No such file or directory.

 

 Could someone please clarify what the function of the spectre.dc file in performing a SP simulation? Also, why is this a warning instead of an error?

 

Thanks for the help. 


  • Most likely you have the readns parameter on one of the analyses (for example the sp analysis) set to "spectre.dc". This tells whichever analysis it is to try to read the nodeset file as a hint for the DC algorithm that precedes the analysis (pretty much every analysis requires a DC operating point to start from, including an S-parameter analysis). If the file is missing, it will solve the DC operating point as usual - the file is just a hint.

    The reason why it's not an error is that quite often you do things like this:

    dc dc readns="spectre.dc" write="spectre.dc"

    Which means the first time it will give you a warning, then write the DC operating point at the end of the simulation. The second run, the file will exist, and it will use that as a starting point. We try to make it not too critical if the file doesn't exist - since it is a hint.

    If you really want it to error out, you can do that by adding this option into your netlist:

    increaseSeverity options warning_change_severity=error warning_id=[CMI-2015]

    And then it will fail:

     Error found by spectre during DC solution estimation, during DC analysis `dc'.
        ERROR (CMI-2015): Unable to open nodeset file `spectre.dc'.
            No such file or directory.

    Regards,

    Andrew.

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.