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Any API in SKILL or other language to extract the connectivity from input.scs netlist or spectre results database?

marcelpreda

Hi,

The use case:
- we run a simulation
- some instance may be reported with problems (warnings in the spectre.out)
- we  extract those instances from spectre out, we know the hierarchical name  of the instance e.g. "I1.I_abc.M1"  (could be any type: M, R, C, D, X, ...) 

What we need:
For such instances a script to extract from input.scs (or from results database - in general psf/psfxl format) the pins of the instance, and where they are connected - the hierarchical name of the nets.
E.g. for an M  device like above ("I1.I_abc.M1") should be something like this:
g: I1.I_abc.net01
d: I1.I_abc.net02
s: vss
b: vss


Later we want to postprocess the waveforms , e.g. to analyze the V(g-s).
- Skill or any language is just fine.
- directly from input.scs or from results database (some spectre switches?? ) is also fine.

Thank you,

Marcel

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  • Andrew Beckett

    Marcel,

    You can get spectre to write out the mapping. It is not something you can get in a binary database, but if you add this entry on the Outputs->Save All form:

    which corresponds to:

    nodes info what=nodes where=file

    (you can specify the file of course; note that rawfile is not supported for this), then you get:

    *****************************
Terminal to node map `nodes':
*****************************


bsim4: I0.I0.M0 of g45n2svt
          d : I0.SP
          g : I0.I0.M0.n1
          s : I0.net12
          b : vssa!

bsim4: I0.I0.M1 of g45p2svt
          d : I0.net12
          g : I0.I0.M1.n1
          s : I0.SP
          b : vdda!

bsim4: I0.I0.M2 of g45p2svt
          d : I0.I0.net5
          g : I0.I0.M2.n1
          s : vdda!
          b : vdda!

bsim4: I0.I0.M3 of g45n2svt
          d : I0.I0.net5
          g : I0.I0.M3.n1
          s : vssa!
          b : vssa!

bsim4: I0.I1.M0 of g45n2svt
          d : I0.SN
          g : I0.I1.M0.n1
          s : I0.net11
          b : vssa!

bsim4: I0.I1.M1 of g45p2svt
          d : I0.net11
          g : I0.I1.M1.n1
          s : I0.SN
          b : vdda!

    That would be fairly easy to parse. The terminals info result contains the same info but the other way around - for each net it tells you the instances/terminals which are connected.

    The other way would be to take the instance name you've found, convert to a schematic name, traverse the hierarchy (potentially complicated if there's a config involved) find the instance and then find the instTerms and construct the hierarchical net names which are attached. That's a lot more work! 

    Andrew

  • marcelpreda
    in reply to Andrew Beckett

    Hi Andrew,

    Thanks a lot for fast reply.
    This  is exactly what we need.

    Regarding the other solution netlist_name -> schematic_name -> traverse_hier , this is what we actually have now.
    But, it is slow on big designs , and we faced the problems with the config views.

    Thank you,
    Marcel

Reply
  • marcelpreda
    in reply to Andrew Beckett

    Hi Andrew,

    Thanks a lot for fast reply.
    This  is exactly what we need.

    Regarding the other solution netlist_name -> schematic_name -> traverse_hier , this is what we actually have now.
    But, it is slow on big designs , and we faced the problems with the config views.

    Thank you,
    Marcel

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