Connector spec swathing.. to the Subcommittee meeting.

Chris..

I 've read ... reread... and reread Fred's message...
The only thing I see is references to providing a "full matrix"

Quoting the Fred's messages:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Why not give the full matrix and let the simulation SI tool decide which part
of the matrix to choose for simulation based on what pin and coupling is
desired."

"I'm not suggesting that you model the full connector if its large. Rather, if
you model only a portion then I prefer that you tell me that and give me that
answer rather than bogus something."

"If you feel that the connector is repetitive then put together the model such
that I get a full matrix type or sparse matrix."

" If you give me the full model I will then PICK the data I wish to simulate
from the full data you gave me. However giving me a swat
ensures that for some pins I will lose some coupling. It also ensures confusion
and abiguity."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To me this sounds like "No Swath..".

!!!!! I apologize to all if I incorrectly interpreted these statements and
wasted a lot of bandwidth describing the potential (maybe not apparent)
advantages of the swath concept!!!!

ALSO IMPORTANT:
Chris, Since your first message... I understood that you just want a defined
an algorithm for doing the swath...

In the "for what it is worth" category....
Right now, the specification is written such that a specific model could be a
"full matrix" OR "swath". .... (And for what it is worth... there is nothing
stating that a model must contain one or the other or both... nor is there
anything that states that a simulator needs to support one or the other or
both.).

I will make sure that our next IBIS Connector Model Subcommittee that we resolve
the issue of the "level of detail" that is needed for the swath algorithm.

I understand both sides of the argument on whether or not to include a specific
swath algorithm. I think some people want to leave the algorithm "more"
open... while others want the algorithm "more defined".
As such, I think our options are:

a) Keep the definition as it is... (i.e. OPEN)
b) Provide a "TYPICAL" algorithm
c) Provide a "RECOMMENDED" algorithm
d) provide a "SPECIFIC" algorithm
e) REMOVE swath.

I would guess that most of the people concerned want "c" or "d". I am happy
with a, b, c, or d.... but think "b or above" is a pretty good idea.
At this point, I think most of us believe that "e" is unacceptable.

I would encourage any one who really wants "d" to provide a "first pass" example
as soon as possible such that we can start the review and incorporation process.
 As I know the present keywords and methodology, I would be willing to commit
time to help with the development.

I can be contacted directly at:
630-527-4617
           .... for any further discussions.

_gus:

___________Reply Separator____________________
Subject: RE: Re[2]: Connector spec swathing
Author: "Chris Rokusek" <crokusek@innoveda.com>
Date: 6/16/00 9:58 AM

Gus,

(Hoping we are one step towards closure!!)

You wrote...

> The draw back to simulators... they need to bang out some code that
creates a
> matrix from a small matrix as limited by the keywords. From what I have
been
> told, this is not very difficult

This is the procedure I (and Fred?) are concerned about. It may not be
difficult but it sure seems ambiguous for cases not covered by Bob's
posting. If this mapping is described in detail or implemented within the
parser then I believe we will all be happy. The data files contain swaths
but we can query against a full matrix--which doesn't mean we're going to
SIMULATE the full matrix it just means we can reduce it to the pins we're
interested in. Fred is right--there is confusion between on this thread
between data presentation and simulation. Just because we want a full
matrix doesn't mean we're going to SIMULATE a full matrix.

Fred is also NOT saying "don't use the swath."

Perhaps the confusion is that you think we're saying that the Full Matrix
should be explicitly described in the file. No, we're saying USE the swath,
but define the expansion rigorously or build it into the parser. When we
say we want the Full Matrix, we're NOT saying it should be spelled out
explicitly in the file--we're saying we must be able to perform the swath
mapping correctly for all possible cases.

Chris Rokusek
Innoveda

> -----Original Message-----
> From: apanella@molex.com [mailto:apanella@molex.com]
> Sent: Friday, June 16, 2000 5:30 AM
> To: fred
> Cc: ibis@eda.org
> Subject: Re[2]: Connector spec swathing
>
>SNIP>
Received on Fri Jun 16 12:24:38 2000