Subject: re: needed for IBIS V3.1

From: "fabrizio zanella" <fabrizio=[email-masked]>
Date: Fri, 6 Jun 97 15:24:03 EDT

Hans, you say that IBIS models are easier to work with than HSPICE models.  
What tool do you use to run the IBIS models?  I use HSPICE, it's an 
accurate tool and up until now 90% of the device models provided, ASICs and 
discrete transistors, have been in HSPICE format.
Now some of our suppliers are starting to create IBIS models and a couple 
have said they are switching exclusively to IBIS format for all their 
future ASIC and transistor models.
My question is, does anyone have a translator from IBIS to HSPICE or 
Berkeley or PSPICE format?  If not, how have other SPICE users handled the 
problem of running IBIS models?
Thank you,
 Fabrizio Zanella
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Original Text
From: Hans M Hilbig <[email-masked]>, on 6/6/97 11:31 AM:
To: <[email-masked]>, "Steve Kaufer" <[email-masked]>

Steve,
I fully subscribe the statements of your msg about the example files. 
Having
started with IBIS in my group early this year, we are still relativly new 
to
IBIS and can remember well the pitfalls we were trapping into. We had two 
major
reasons to generate IBIS models: Our customers like it and it's (still)
relativly easy to construct and to tweak (compared to H-SPICE). Personally 
I'm
concerned that IBIS will become so blown up in the future that the latter
reason will go away. Adding more bells and whistles does not necessarily 
mean
better 'accuracy', particularly if you don't have real (accurate) data to 
feed
the bells and whistles. Pls remember that our customers want us to supply 
IBIS
models early in the development stages, mostly at that time when the design
(and its simulation) is not completed yet. The more estimates and 
judgements we
add, the higher the chance that the model does not reflect the silicon that
comes out later.

Regards,
Hans M Hilbig
**************************************************************
EMSLP New Products Characterization Texas Instruments Freising
Phone:  +49-8161-804126  FAX:+49-8161-804909
e-mail: [email-masked]

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Original text

From: Steve Kaufer <[email-masked]>, on 6/6/97 9:25 AM:
Mini-topic for the upcoming IBIS Summit meeting at DAC:

I believe it's important for V3.1 of the specification to include several
simple, clear example files, e.g., a simple IC using a minimum of
constructs, a more-complex IC using a few "extra" features like waveform
tables, a network-packaged passive device, and a bus switch.

Why? Because lacking these, the specification is so intimidating to
newcomers that many are being scared off, to the detriment of the entire
standard. Remember V1.x? It was a relatively quick, easily comprehended
"read." What we have now is richer and more powerful, but also 
exponentially
more confusing. Some of us on the committee are probably "velocitized" to
the point where we're not aware of the problem's gravity.

From recent conversations with IBIS "newbies" (and this includes
semiconductor-vendor personnel, unfortunately), I think it works like this:

1. Reads IBIS spec (or part of it).
2. Wants to kill self.
3. Hears about Spice-to-IBIS, and thinks "that's my only hope!"
4. Then the real trouble begins...

Personally, I'd like to see the opening page of the spec state clearly that
about 85% of modeling applications can use about 25% of the specification's
constructs, and point straight to the example models. Also good would be a
designation of some kind delineating between "basic" and "luxury" 
constructs.

I'd be interested in hearing opinions about this at the Summit...

Regards,

Steve Kaufer,
HyperLynx

---

From: Hans M Hilbig <[email-masked]>
Date: Mon, 9 Jun 1997 09:00:37 -0700

Fabrizio,
I'm comming from the bench measurement side, not from the Design or Simulation
side. Thus it was easier for us to 'close the loop' with IBIS: take
measurements of the device - generate the IBIS model - add the bench board
parasitics - feed both into an IBIS simulator - and see how well this matches
to what you have measured. On those parts where we didn't have silicon we used
the SPICE outputs from our Designers, generated IBIS models and verified them
by running the IBIS simulator with the known parasitics of the bench board
added.
Best regards,
Hans
*************************************************
EMSLP Characterization Texas Instruments Freising
Phone:  +49-8161-804126  FAX:+49-8161-804909
e-mail: [email-masked]

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Original text

From: "fabrizio zanella" <fabrizio=[email-masked]>,
on 6/6/97 3:24 PM:

Steve,

feed

Regards,
Hans M Hilbig

------------------
Original text

Regards,

Steve Kaufer,
HyperLynx