RE: [IBIS] AMS tastes great and leaves your teeth shiny white, too!

Arpad,

1) Geez, I'm really, really sorry.  I completely understand your position
and feelings, and you'll never hear me bring up the IBIS prayer again.   My
first point wasn't meant to be an allusion of any kind.  I was pointing out
that you've done as much work with AMS for SI as anyone, and if you're
convinced it has the capabilities to go forward, I'm inclined to agree.  I
was simply saying you're in the lead with modeling experience at this point
- nothing more.

2/3/4) It's a conundrum, isn't it?  We fix the present, we delay the future.
We focus on the future, we have trouble getting by in the present.  I don't
have the answer here; it's a balancing act we have to sound out as we go
forward.

I was intrigued by last night's discussion of EFGH sources.  I agree we
can't end up endorsing a specific SPICE version ... so the question is, is
there any set of sources we can reliably take as common?  Macromodeling
could still have value without controlled sources, but I'm inclined to agree
that it probably isn't worth the effort without them.  I think we need to
figure out whether there are a viable set of controlled sources we can rely
on or not, and go from there.

Going forward, I think we need to continue to look at the "big" picture in
modeling - the combination of language, model development tools,
documentation and EDA tool support.  As you point out, it does us little
good to define a standard if EDA vendors do what they want anyway.
Similarly, a great language and simulator does us little good if few people
can develop models for it.  It's taken quite a while to get IBIS in its
present state - if we're going to move toward AMS, we will repeatedly have
to ask ourselves the question "what does this mean to the average user?"

My apologies again for my inappropriate humor.  It was never meant to offend
- it was only meant to highlight your leadership in a lighthearted way.
Your contributions to SI are welcomed and sincerely appreciated, and I was
just trying to point that out.

Todd.

Todd Westerhoff
High Speed Design Group Manager
Cisco Systems
1414 Massachusetts Ave - Boxboro, MA - 01719
email:twesterh@cisco.com
ph: 978-936-2149
============================================

"Always do right.
 This will gratify some people and astonish the rest."

- Mark Twain


-----Original Message-----
From: owner-ibis@eda.org [mailto:owner-ibis@eda.org] On Behalf Of Muranyi,
Arpad
Sent: Monday, April 04, 2005 5:23 PM
To: ibis
Subject: RE: [IBIS] AMS tastes great and leaves your teeth shiny white, too!

Todd,

1)  Please don't start that again...  "if he says AMS is the future,
    it probably is".  In fact I would like to take this opportunity
    and publicly ask you not to make a habit of these kinds of
    allusions, and please stop that IBIS prayer "tradition" if
    possible...
    Not because I don't understand jokes, I could tolerate it once,
    but simply because I am a religious man and have a very difficult
    time with being elevated to levels (even in the form of a joke)
    where God alone deserves to be...  I hope you can relate to that.

2/3)  I agree completely.  I don't think that the macromodeling proposal
      is a bad idea.  I am just concerned that if this is made into a
      a standard, people will get too cozy in it to move on towards
      something better, or may divert the general direction for the
      long term solution.  Plus, there are a few of us who could already
      use that long term solution NOW.

4)  I agree with your observation in this too.  In fact I wonder some
    times what good is it to have the IBIS Open Forum if the major
    players pretty much do anything they want to do anyway?  Little
    active participation, out-of spec or partial spec implementations,
    etc...  I don't want to go too deep here, but I feel we are in
    different times from the way IBIS started...

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


-----Original Message-----
From: owner-ibis@eda.org [mailto:owner-ibis@eda.org] On Behalf Of Todd
Westerhoff (twesterh)
Sent: Monday, April 04, 2005 1:15 PM
To: 'ibis'
Subject: [IBIS] AMS tastes great and leaves your teeth shiny white, too!

Sorry, couldn't help myself ;-).

A few points I'm still stubbornly trying to make ....

1) The future of AMS

I have little doubt that Arpad can do great things with AMS models.  Heck,
if he says AMS is the future, it probably is.
Long term, I agree ... it's where we will probably end up

2) The practical issues with AMS

Unfortunately, it took us years to get vendors to create good IBIS 2.1
models - and there are a number that haven't figured that out, either.
Handing the modeling community a programming language is a non-solution.  We
need to create the modeling infrastructure that goes with it, both in terms
of constructing models (the "standard building blocks" Arpad mentioned) and
the processes that extract data the models use (in other words, s2ibis3 for
AMS).  Requiring model builders to hand craft models isn't going to get us
very far - we need the corresponding model development tools for AMS that we
had for IBIS.

AMS is a programming language.  Declaring AMS as the modeling language of
choice doesn't automatically get us good models any more than the definition
of C++ automatically resulted in superlative graphics programs.  C++ may
have been a key building block, but there was much, much more to it than
that.

We need to be realistic about the infrastructure required to put AMS "into
production" as a SI technology, and make sure that we can stay afloat from a
modeling perspective until we get there.

Which brings me to (you knew it was coming) ...

3) IBIS Macromodels

I don't see this as a long-term solution - I see it as a bridge technology.
I'm not sure why Donald's point of "we do everything with a B-element and
macromodeling" didn't resonate more than it did.  This isn't Cadence banging
on a proprietary drum, at least not in my view - it's saying that this
approach has worked for years, and still has some life left in it.  I think
it's the thing that can buy us time while we figure out what comes next.

4) EDA Vendors and IBIS Support

Arpad had a really good point earlier - why are people arguing about this
now, instead of when the BIRDs were passed?  Personally, I've seen that IBIS
support is no longer a competitive issue among EDA tools.  There was a time
when vendors rushed to support new IBIS standards for fear of losing sales.
I don't see that anymore - in fact, I see some vendors that can't articulate
which IBIS features their tool does or doesn't support.  That tells me
vendors don't see IBIS support as an issue, because customers don't see it
as an issue.

Todd.

Todd Westerhoff
High Speed Design Group Manager
Cisco Systems
1414 Massachusetts Ave - Boxboro, MA - 01719 email:twesterh@cisco.com
ph: 978-936-2149
============================================

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