Re: snapshot/resimulate and hspice


To "'ng-spice-devel@ieee.ing.uniroma1.it'" <ng-spice-devel@ieee.ing.uniroma1.it>
From "Gillespie, Alan" <Alan.Gillespie@analog.com>
Date Wed, 4 Apr 2001 18:00:15 +0100
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>       well, in my experience, the number of iterations necessary
>       at each time point for time-point convergence is a function
>       of the circuit activity at each time point, and this effects
>       the total cpu time required at each time point.  otherwise,
>       each time point in a transient analysis would cost as much
>       cpu time as dc convergence.

Yeah, that's why I say it helps, but not as much as I think
Al reckons ACS should do in the same circumstances.

>       for transient analysis, commercial simulators like hspice
>       speed up significantly when a circuit is stable, and slow
>       down again when activity starts up again.  spice3 has this
>       behaviour as well, and infact, when it simulates something
>       correctly, usually is faster than hspice...

Interesting that you're using hspice. The reason I got into
this lark is 'cos I couldn't stand hspice. Spice3f4 seemed
to work much better if it worked, so I set about trying to
make it work in most cases. I ended up using my own version
of spice3f4 instead of hspice most of the time.

Have you tried ngspice yet ? I think rework 13 has got a few
obvious bugs, but rework 14 should be out soon. I have my own
version of spice3f4 which has a mos level 9 which is mos level
3 with some hspice parameters added. It's set up for win32,
rather than Linux, and it outputs pspice style .dat files.
I can it email to you if you're interested, but you need ESP
to know what parameters are included and how to use it ;-)

Paolo, is rework 14 coming soon ? I think I sent you my stuff
with level 9 MOS and level 2 BJT (dc current in the substrate
diode). Did that ever get in to ng-spice ?

Cheers,

Alan

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