Riad KACED wrote, on 04/28/08 22:55:
> Hi Again,
>
> Cadence do***entation :
> VirtuosoŽ Spectre Circuit Simulator User Guide
> UNIX> acroread $CDSHOME/doc/sklanguser/sklanguser.pdf
> Chaper 5: Parameter Specification and Modeling Features
>
> Well : 1G = 1e+9, 1M=1e+6.
> Do mind the case with spectre : 1M=1e+6 but 1m=1e-3 (mili).
> NO SPACE between the NUMBER and the Scale factor.
>
> But if your value got changed, means that you've reached the max value
> and a callback runs to adjust this value. A good PDK comes with popup
> windows that informs designers about any change made by the callback.
> You should not see this with the ideal res in the AnalogLib (I didn't
> test).
>
> Bye, Riad.
Actually a good PDK should NOT produce popup windows, as this makes it
very hard
to procedurally call the callbacks - in the event you have to do this (and
my
feelings on CDF callbacks are well known, but range checking is a
reasonable
usage).
That said, most PDKs would normally give a message in the CIW if they
constrained the value of a component.
Having a 1Gohm real resistor on a chip is not terribly likely, so I'm
presuming
this is not intended to be a physical component. If so, you're better off
using
res from analogLib for such non-physical components, as that's a primitive
resistor in spectre, which doesn't have such limitations.
Regards,
Andrew.
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