[SI-LIST] Re: IBIS Models

Hello Rajesh,

I volunteer my time to the IBIS Committee to help them as IBIS librarian.
This means that every few months I check and fix broken links, etc., on the
IBIS model page at:

http://www.eigroup.org/ibis/

where you will find links to IBIS resources including Atmel, Motorola,
Phillips, STMicroelectronics and Intersil.

I do not provide individual help on finding specific IBIS models except in a
very general way, particularly since being retired from 3Com and having no
acess to the resources I built up there.

But, I will tell you what I used to do. Particularly, since I get inquiries
such as yours from time-to-time and need to re-iteriate my role.

First, I would go to the above links and search the supplier's web sites and
download the models from there. In some cases you'll have to jump over new
breaucratic hurdles put in your way by the supplier. For example, Fairchild
used to post their models directly on the web. Now, you have to request
them, which means you may see a time delay and get a follow-up sales call.
Also, many suppliers make IBIS models available only privately, with
customers, non-disclosure agreements, etc.

Second, if the model isn't on the website, contact the supplier directly and
request the model file. If you have a local sales rep who will help, all the
better. If your Purchasing Department can apply some muscle, better still.
But, be prepared to wait. Sometimes, for a long time. Sometimes, for
forever. Especially now in hard times and reduced staff.

Third, I would use various approaches like using generic models, default
models in the software supplier's library, and inference to similar models.
The more critical the circuit, the less meaningful the simulation results
from playing such games. If you find it necessary to hire a modeling service
it will be expensive. The trick will be convincing your management that it
is money well spent (which it is) on any kind of critical circuit.

Whatever models you get, be prepared that most of them will have mistakes
ranging from minor to major. I presented papers 4 years ago indicating IBIS
models fail passing a parser 70% of the time as first received. I confirmed
my initial results on over 800 IBIS files from across the industry. Since
then, several others have reported nearly identical results. There are about
half a dozen semiconductor suppliers who are notable exceptions to this.They
provide IBIS models that are correct, per standard nearly all the time, as
first received. You can learn how to fix about half the problems yourself.
About half the remaining problems will be fixed by the suppliers in a time
frame ranging from weeks to years. Supplier response time followed an
identical curve when I worked in component reliability a long time ago.

My earliest indications about SPICE model file availability and quality is
that it is worse than the above. There is, after all, no standard for SPICE
and there are many flavors of SPICE. Population statistics similar to IBIS's
typ-min-max are very rare in SPICE. But, my sample size of SPICE models is
much smaller.

The IBIS Committee is hard at work on making their Golden Parser even
stronger in screening for mistakes with the resources they have at their
disposal. They have a sub-committee on quality putting together an IBIS file
checklist for folks like you. It is available at:

http://www.sisoft.com/ibis-quality/


Best Regards and Happy Hunting,

Roy


  -----Original Message-----
  From: Rajesh-Reliant [mailto:rajesh@xxxxxxxxxxxxxxx]
  Sent: Friday, January 31, 2003 3:41 AM
  To: roy.leventhal@xxxxxxxx
  Subject: IBIS Models


  Hi Roy,

  Kindly suggest where can we get the IBIS Models of the following IC's.

  (1)  MC68020RC25E , 114pin PGA(COM).Make Mot/eqv.

  (2)  MC68882RC25A 68pinPGA(COM). Make Mot/eqv

  (3)  AT28C010(E)-12PC , 32PIN DIPMake ATMEL/eqv.

  (4)  SC28L92A1B , 44PIN PQFP (IND).Make Phillips/eqv.

  (5)  M68AF511AL55MC1 , 32PIN SO (COM).Make ST micro/eqv.

  (6)  CP82C55A , 40PIN DIPMake Intersil/eqv.

  (7)  CP82C54(8MHZ) , 24PIN DIPMake Intersil/eqv.

  Thanks and Best Regards

  Rajesh
  ----------------------------------------------
  Rajesh Sharma
  Senior SI Engineer
  Reliant-EDS,
  4/1,Vittal Villa Apartment,
  14th A Main,
  HAL II Stage,
  Bangalore-56008

  Tel No: 91-80-5217110
  E Mail: rajesh@xxxxxxxxxxxxxxx


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