Stats

  • Locked Locked
  • Replies 3
  • Subscribers 125
  • Views 14934
  • 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

CCCS unusable in graphic schematic: Spectre Netlist Does Not Include gain parameter

msharma

Hi,

 

I am using IC616, and my circuit contains a CCCS from analogLib. However, the spectre circuit netlist does not contain the gain parameter of the CCCS. Thus the output current of my CCCS always comes 0. In the siminfo, gain is mapped to fgain:  "propMappin-> nil gain fgain propbe vref" "instParameters-> gain m" "otherParameters-> fgain vref".

Also, my analogLib is called NCSUAnalogLib because we use NCSU  CDK.

 

Best Regards,

Mohit

 

Parents

  • Mohit,

    I merged your two posts together as the forum guidelines tell you not to double post.

    The propMapping looks reasonable - the parameter on the instance is called fgain, but it should end up netlisted as gain. It seems your component is a cut-down version of what is in analogLib (probably based on an old version), so you could just use our analogLib rather than the NCSU version - add:

     analogLib       $(inst_root_with:tools/dfII/bin/virtuoso)/tools/dfII/etc/cdslib/artist/analogLib

    into your cds.lib

    However, I suspect the issue might just be that you don't have $CDS_Netlisting_Mode set. In the CIW, if you type:

    cdsGetNetlistMode()

    does it return "Digital" or "Analog"? If it is "Digital", then it will not take notice of default CDF values - and so it would omit the gain parameter (if you'd left the "Current Gain" at the default value). You can solve this by doing:

      setenv CDS_Netlisting_Mode Analog   # in csh

    or:

      export CDS_Netlisting_Mode=Analog   # in ksh or bash

    before starting virtuoso. You may need to do a Simulation->Netlist->Recreate to force it to re-netlist. 

    Regards,

    Andrew.

Reply

  • Mohit,

    I merged your two posts together as the forum guidelines tell you not to double post.

    The propMapping looks reasonable - the parameter on the instance is called fgain, but it should end up netlisted as gain. It seems your component is a cut-down version of what is in analogLib (probably based on an old version), so you could just use our analogLib rather than the NCSU version - add:

     analogLib       $(inst_root_with:tools/dfII/bin/virtuoso)/tools/dfII/etc/cdslib/artist/analogLib

    into your cds.lib

    However, I suspect the issue might just be that you don't have $CDS_Netlisting_Mode set. In the CIW, if you type:

    cdsGetNetlistMode()

    does it return "Digital" or "Analog"? If it is "Digital", then it will not take notice of default CDF values - and so it would omit the gain parameter (if you'd left the "Current Gain" at the default value). You can solve this by doing:

      setenv CDS_Netlisting_Mode Analog   # in csh

    or:

      export CDS_Netlisting_Mode=Analog   # in ksh or bash

    before starting virtuoso. You may need to do a Simulation->Netlist->Recreate to force it to re-netlist. 

    Regards,

    Andrew.

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.