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pascalkuthe / OpenVAF

An innovative Verilog-A compiler
https://openvaf.semimod.de/
GNU General Public License v3.0
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Recording output variables during transient simulation #50

Closed bertgoz closed 1 year ago

bertgoz commented 1 year ago

Using ngspice-39 I am trying to save OPVARs during a transient simulation. When saving a vector of the right dimensions (same as simulation steps) is created but all its values are 0 except the first one.

Is it possible to save the value of OPVARs during all the steps of a transient simulation?

pascalkuthe commented 1 year ago

Thanks for reaching out.

This is not an issue with OpenVAF itself. The simulator can easily control when operating point variables are calculated by setting a simple variable. Currently our integration code in ngspice only enables operating point calculation during AC/DC analysis but not during tran (the first tran operating point counts as a DC simulation). Fixing this in ngspice would be quite trivial and only require:

Replacing

  if (is_init_smsig || is_sweep) {
    sim_info.flags |= CALC_OP;
  }

with

    sim_info.flags |= CALC_OP;

in osdiload.c. I am quite busy at the moment, could you submit an appropriate patch to ngspice @metroid120?

I am closing this issue here as no changes to OpenVAF itself are necessary, only ngspice itself needs to be adjusted.

metroid120 commented 1 year ago

Yes I will have a look, thanks for the hint.

metroid120 commented 1 year ago

I pushed a fix to branch "fix_calcop_transient" in Ngspice, it is working then.