Subject: Re: needed for IBIS V3.1

From: Arpad Muranyi <[email-masked]>
Date: Fri, 06 Jun 97 07:55:00 PDT

Text item: 

Steve,

Regarding the issue of "basic" and "luxury" items in IBIS, a very simple way to 
determine what is basic is to look at the criteria whether the item is required 
or not.  You will find that most items are optional.

Arpad
===============================================================================

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

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Subject: needed for IBIS V3.1
From: Steve Kaufer <[email-masked]>
To: [email-masked]
Date: Thu, 5 Jun 1997 18:41:07 -0700 (PDT)
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From: [email-masked] ( Bob Ross)
Date: Fri, 6 Jun 97 10:08 PDT

Steve:

We will put this discussion topic on the meeting Agenda.  Thank you for
proposing it.  I am also concerned about the amount of material in IBIS
and the fact that the fundamental aspects of IBIS are no longer apparent.
The new features in IBIS are all justified, based on real device modeling
issues.  However, most IBIS models will still need to follow only the
guidelines and convensions of IBIS Versions 1.1 and 2.1.  Having a set
of examples is an excellent starting point to illustrate both the
recommended fundamental aspects of IBIS models which apply to most
situations, and also to illustrate the new functionality.

I am also interested in ideas on how we can organize IBIS in a clearer
manner.

Bob Ross
Interconnectix

---

From: Unger Bernhard <[email-masked]>
Date: Mon, 9 Jun 1997 18:59:51 +-200

Fabrizio,
we have developed an IBIS to HSPICE converter to generate HSPICE behavioral models.
The bases are IBIS 2.1 models. The static and dynamic driver characteristics fit very well
with the transistor based HSPICE simulations.

Best regards
Bernhard

************************************************************************************
#  Dr. Bernhard Unger                                                                                                   
#  Siemens AG                                                                                                                 
#  Dept. ANL A45 AM                                                                                                     
#  Otto-Hahn-Ring 6                 Tel.        +49-89-636-47404                                       
#  D-81730 Munich                  Fax.       +49-89-636-44595                                       
#  Germany                             E-Mail    [email-masked]                                                                                        
************************************************************************************

----------
Von: 	fabrizio zanella[SMTP:fabrizio=[email-masked]]
Gesendet: 	Freitag, 6. Juni 1997 21:24
An: 	[email-masked]
Betreff: 	re: needed for IBIS V3.1

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
			                          _/ _/  email: 
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4645
      _/        _/_/ _/_/  _/        _/          Fax: (508) 435-8949
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                                                Hopkinton, MA 01748-9103
-------------
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]

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

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

"read." What we have now is richer and more powerful, but also 
exponentially

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.

Regards,

Steve Kaufer,

HyperLynx