Re: [ng-spice-devel] [ng-spice] ACS, model compiler, cross-post from gEDA list (fwd)
---"Al" == Al Davis <aldavis@ieee.org> writes:
Al> Mine doesn't do automatic differentiation.
That's unfortunate. Errors in derivatives are the one of the main
reasons for nonconvergence in SPICE, right in there with
discontinuities in the i-v and q-v characteristics. Automatic
differentiation at least gives a correct (almost always) set of
derivatives to start with.
Al> Fine, but it still doesn't handle the nuisance stuff, and translating
Al> existing models to Verilog-A probably won't happen. Mine is designed
Al> so that transating the existing models to it is equivalent to
Al> translating to a slightly different architecture. Then it opens up
Al> the ability for bigger architecture changes.
Translating most existing models to Verilog-A is fairly trivial; even
so, a production model will want some hand-tweaking to eliminate that
>3x penalty for automatic differentiation. But you're right, the
boilerplate for handling all the standard add-ons can get tedious. I'd
be curious to see how you've worked this out.
--Steve
Partial thread listing:
- Re: [ng-spice-devel] [ng-spice] ACS, model compiler, cross-post from gEDA list (fwd), (continued)
Models,
Alan Gillespie
personal note on ACS and NG-SPICE (fwd)
Paolo Nenzi