Re: [IBIS-Users] ODT topics

From: Andrew Ingraham <a.ingraham_at_.....>
Date: Fri Apr 01 2005 - 19:51:06 PST
> "My question would be: what are simulators (e.g. HSPICE) really doing with
> IBIS models ...

> The clamp I-V tables are always present in the simulation, and
> the pullup and pulldown I-V tables are switched on/off as the
> buffer is driving high/low.  The end result is that the currents
> of the pullup or pulldown I-V tables are added together with
> the clamps.

Well actually, ...

Sorry to nit-pick, but in HSPICE the clamps are not necessarily always
there.  The end-user who puts an IBIS model in his simulation needs to make
sure to include ALL the optional element nodes.  If he leaves the optional
nodes out, HSPICE has this nasty feature (it is really intended as a
feature, not a bug) that the clamp I-V tables are omitted.

Once those nodes are included in the netlist, then Arpad's statement above
is correct.

Regards,
Andy


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Received on Fri Apr 1 19:51:15 2005

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