Subject: package and connector model questions

From: [email-masked]
Date: Thu, 23 Sep 1999 15:59:04 -0500

Hello ibis-users.  I am new to the discussion group -- joined the end of
July.  I have read through the Version 3.2 spec and the ibisConSpec
documents and I have 2 questions.

The first question has to do with Kellee's outstanding item below.  I.E.,
why not use the RLC matrix description in section 7 on package modeling?  I
am not sure why Connector modeling isn't (or couldn't be) a subset of the
package modeling spec.  After all, a package is a connector that connects
the silicon to a PCB....or socket, which is again another connector.  And
before someone comments "un-mated connector" I also wonder why I need the
model for an unmated connector or a package out of the socket, etc.

But there are some excellent modeling enhancements in the connector spec
such as Begin/End_Cn_Swath.  Great way to simplify what could be an
unnecessarily large matrix.  Can we put this in the package model section?
At least where possible, let's keep (or copy) everything that is or could be
the same.  And I also like the ability to name and therefore have more than
one RLC matrix.

Which brings me to my second (and more important to me) question.  As I read
section 7 of Ver 3.2, I can have only one RLC matrix set.  I can't put two
RLC sets in series.  Or, if I want to do distributed effects, I can do
sections (a wire bond section, a trace section, a via section, another trace
section, etc) but I can NOT have "trace to trace" coupling effects.  And I
can not connect several uncoupled sections to the single RLC matrix which
would at least give me some coupling.  Is this a correct statement of my
options?

I was hoping for the ability to connect more than one matrix in series.
And since the point of having a matrix is the coupling, I was also looking
for the typ, min, and max coupled matrix for L and C.

Is this too much for one message?

Thanks for your consideration and patience,
Aubrey Sparkman
Signal Integrity
[email-masked]
(512) 723-3592

-----Original Message-----
From: Kellee Crisafulli [mailto:[email-masked]]
Sent: Monday, August 23, 1999 12:56 PM
To: [email-masked]; Matthew Flora
Subject: Re: USB connector model 

Hi Ibisians, Matt,

  Matt thanks for giving the correct web address for the preliminary
connector specification.

FYI.. The only outstanding item in the connector specification is to agree
on the
wording of the RLC matrix description.  I have asked several industry
experts to
write it and have not received one from anyone yet.  If someone else out
their
would like to contribute a technically correct RLC matrix description that
would
allow someone "skilled in the art" to understand which type of RLC matrix
is being
used I am interested.  If I end up with more than one I would be extremely
happy.
It must have a simple included example of both a physical cross section and
the
resulting matrices.  Ideally it would explain things like what the diagonal
is and
why there are sometimes negative signs.
When we receive this and the connector sub-group reviews it and accepts it
I believe we are ready to give it to the IBIS group as a bird.

At 10:28 AM 8/23/99 -0700, you wrote:
>> Wilco Hamhuis writes:
>> > I have two short questions: Is IBIS capable of describing a (coupled)
>> > connector? Are there IBIS USB connector models available? I am
currently
>> > analysing a high speed board (app. 500 MHz) and I want to take the
effect
>of
>> > connectors into account.
>>
>>   There is an IBIS working group that has proposed an IBIS extension for
>> connectors that supports coupling, but it has not yet become
>> a part of the official standard.  If you are interested, a copy of the
>> proposal is on the Hyperlynx website at www.hyperlynx.com.  As for your
>> specific need, I am not aware of any IBIS USB connector models, but
others
>> may know of some.
>
>Actually, the proposed IBIS extension for connectors can best be found at:
>ftp://ftp.eda.org/pub/ibis/connector/
>
>Regards,
>Matthew Flora
>IBIS Open Forum Postmaster
>(425) 869-2320 PH
>(425) 881-1008 FAX
>[email-masked]
>HyperLynx, 14715 NE 95th Street, Redmond, WA 98052 USA
>

---

From: [email-masked]
Date: Thu, 23 Sep 1999 16:27:19 -0500

Aubrey,

There are rough drafts of this wording... created...  They are now under review.
 These descriptions are really to describe the format of the values in the
matrices (as related to the final simulation)

I would suggest a review of the samples may assist in understanding the
specification.  Most (all?) of the points you bring up are covered in the
specification...  however... to implement this... a rather complex format was
needed to be created.  I think the examples may be helpful in clearing up the
issues.

As an off note....  the IBISCnn specification is not a part of the general  IBIS
v3.2 spec....  maaybe the next one???

I'll try to address your specific questions now...

Re "unmated connector"
Need these to represent connectors that are not mated but are still on the bus. 
For instance, an empty PCI slot in a PC. 

Re: "Part of Package Modeling Spec..."
The package modeling spec does not have stubs, cascaded models, swath, other?? 
As such,  instead, maybe packages could be represented by the connector spec.

Re: "Trace to Trace Coupling Effects
The off diagonals of the matrices take care of the coupling.  The distributed
effects are handled by the "cascaded sections".  These cascaded sections also
allow the series connection of SLMs and MLMs in series or as stubs in the same
model.

The "Sections" area of the specification allows the installation of as many
matrices in a model as required....  These sections can then be hooked up in the
"Begin_Connector" area.  There are examples that contain multiple cascaded
sections.

Re: "Min / Max LC values"
These values are typically very tightly controlled in the final assembled
connector...  More variability in LC is always in the process where the
connector gets mounted to a board.  (Solder hole fill, board warp, connector
floating during a reflow, other..)

Best Regards,

Gus

[email-masked]

-----Original Message-----
From: [email-masked] 
Sent: Thursday, September 23, 1999 3:59 PM
To: [email-masked]; [email-masked]; [email-masked];
[email-masked]; [email-masked]
Subject: package and connector model questions

-----Original Message-----
From: Kellee Crisafulli [mailto:[email-masked]]
Sent: Monday, August 23, 1999 12:56 PM
To: [email-masked]; Matthew Flora
Subject: Re: USB connector model 

Hi Ibisians, Matt,

currently
effect
others