Re[2]: dual curve issue for input pad

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Weber,

It is true that we do not have something like that in IBIS, but I am currently
working on BIRD 45 in which we are addressing this kind of needs. Could you
please give me a beter description of these I-V curves so I could consider these
when I write the BIRD?

Thanks,

Arpad Muranyi
==============================================================================

Weber Chuang wrote:

> I am currently involved in the design of a I/O pad and building
IBIS
> for it, but I am facing some troubles, my I/O
> pad has dual I/V curves while in input mode, that is, the I/V curves
for
> rising input and falling input are
> different. IBIS seems to not supporting this kind of design, and
s2ibis2
> will not generate correct model for this. Is
> there any workaround? Any comment is welcome.

Are you talking about a hysteresis-like feedback characteristic, such as
a bus-hold circuit?

If so, IBIS doesn't do it. Both because it doesn't handle input I/V
curves that change, and because bus-hold input curves are non-monotonic
which can create problems for the simulator.

(Someone correct me if I'm wrong or if version 3 changes this.)

Regards,
Andy Ingraham

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Date: Wed, 18 Feb 1998 11:41:51 -0500
Subject: RE: dual curve issue for input pad
To: "'ibis@eda.org'" <ibis@eda.org>,
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From: Andrew Ingraham <Andrew.Ingraham@digital.com>
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