Re: IBIS modeling questions

Greg:

Here are some brief responses to your questions.

(1) Arpad covered that one well.

(2) We seem to be having a problem in compiling a Windows verion
of s2ibis2 which seems difficult to resolve, so I cannot give a date
or committment.

(3) I do not know of any theory of operation of behavioral models
(even from CAE vendors), but many vendors use IBIS models or
translated versions for simulation with excellent results and
correlation with Spice Models. So while vendors are not
necessarily open about all the details of their internal
algorithms, the fundamental IBIS architecture gives
enough detail for using IBIS models in simulation. IBIS
models work well in tranmission line simulations.

(4) There was extensive discussion regarding an IBIS USERS group
last February and March. There was agreement of the need, but
we got bogged down in what specific from it should take. After
discussing this with Will Hobbs, I intend to set up a users mail
group reflector. This may take several days or a week. This
will be announced on the IBIS and SI reflectors, and people can join
at that time. We can elaborate elsewhere on what the scope and
rules should be, but this is basically an unmoderated group
focused on user questions and applying IBIS models. We will
archive all of the mail.

Bob Ross
Interconnectix, Inc.

> Date: Thu, 9 Nov 95 13:01:50 -0600

> To: ibis@vhdl.org
> From: grege@chensys.com (Greg Edlund)
> Subject: IBIS modeling questions
> Status: R

> Anybody care to take a stab at these?

> 1. I was discussing IBIS model support with one of
> our IC vendors, and they raised a concern about
> ESD diode SPICE models not being accurate at
> -5 V and + 10 V. Any clues about how to get
> around this without setting up a test lab? Why
> do you need such a wide range in the first place,
> since nobody operates out there?

> 2. When will s2ibis 2.0 be available on Windows?
> Actually, I'd be happy with DOS, but that's
> probably not in the plan...

> 3. Has anybody written a "theory of operations"
> paper on behavioral simulators? For instance, if
> I have a simple behavioral driver model (no ESD
> diodes, no package) driving a 50 Ohm transmission
> line terminated at the far end into 50 Ohms, how
> do I calculate the current and voltage vs. time at
> the output of the driver? At the far end? This
> must be an easy problem to solve. I'd like to
> write a little C program to do this so I can better
> understand IBIS and critically compare it to SPICE.
> (For the sake of accuracy in system design issues,
> not so I can write another simulator!)

> 4. Has anybody thought about organizing an IBIS
> users group and mailing list?

> Thanks in advance,

> --
> Greg Edlund +----+----+
> Circuits and Modeling | | |
> Chen Systems Corp. < | )
> 1414 W. Hamilton Ave. > ----- )
> Eau Claire, WI 54701 < ----- )
> voice (715) 833-7067 > | )
> FAX (715) 833-7096 | | |
> email grege@chensys.com +----+----+
Received on Thu Nov 9 14:51:26 1995