[ibis-quality] Re: Minutes, IBIS Quality Teleconference, July 12, 2005
- From: "Mike LaBonte (milabont)" <milabont@xxxxxxxxx>
- To: <ibis-quality@xxxxxxxxxxxxx>
- Date: Tue, 12 Jul 2005 17:30:20 -0400
I think the common notion that differential termination can be viewed
such that the "center" of the terminator resistor is fixed at the common
mode voltage is a reasonable approximation, if the termination is to be
built into each buffer individually. I think [Series Pin Mapping] is
better, but sometimes you have to carefully de-embed the built-in
termination when extracting. Parts with external terminator power can
also use [Series Pin Mapping], although I am not aware of how well
various simulators will handle this.
The topic of on-die termination came up in the IQ phone call today.
Although there seems to be no clear policy on how to model every type of
termination in IBIS, we at least agreed that IBIS files should document
the approaches taken within. It wouldn't hurt for the IQ document to
recommend approaches for the cut-and-dried cases, like single-ended
static termination. If anyone has best-practice recommendations on how
to do dynamic termination and differential, that would help.
Mike
-----Original Message-----
From: ibis-quality-bounce@xxxxxxxxxxxxx
[mailto:ibis-quality-bounce@xxxxxxxxxxxxx] On Behalf Of Tom Dagostino
Sent: Tuesday, July 12, 2005 4:52 PM
To: ibis-quality@xxxxxxxxxxxxx
Subject: [ibis-quality] Re: Minutes, IBIS Quality Teleconference, July
12, 2005
What happens if your on die termination is a differential termination or
has one end open so the use can tie it to the voltage of their choice?
You cannot put these in clamp tables. See the ON Semi part NBSG53A as
an example.
Tom Dagostino
Teraspeed(R) Labs
13610 SW Harness Lane
Beaverton, OR 97008
503-430-1065
tom@xxxxxxxxxxxxx
www.teraspeed.com
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
401-284-1827
-----Original Message-----
From: ibis-quality-bounce@xxxxxxxxxxxxx
[mailto:ibis-quality-bounce@xxxxxxxxxxxxx]On Behalf Of Robert Haller
Sent: Tuesday, July 12, 2005 1:32 PM
To: ibis-quality@xxxxxxxxxxxxx
Subject: [ibis-quality] Minutes, IBIS Quality Teleconference, July 12,
2005
Minutes, IBIS Quality Committee
July 12, 2005
11-12 AM EST (8-9 AM PST)
Phone: 408-902-7868 or 866-902-7868
Meeting access: Meeting ID: 42477825
ROLL CALL
Adam Tambone
Barry Katz
Benny Lazer
Benjamin P Silva
*Bob Ross
Brian Arsenault
*Eckhard Lenski
Eric Brock
Gregory R Edlund
Hazem Hegazy
John Figueroa
John Angulo
Katja Koller
Kevin Fisher
*Kim Helliwell
Lance Wang
Lynne Green
*Mike Labonte
Peter LaFlamme
*Robert Haller
Roy Leventhal
Sherif Hammad
Todd Westerhoff
Tom Dagostino
Kazuyoshi Shoji
Sadahiro Nonoyama
Everyone in attendance marked by *
NOTE: "AR" = Action Required.
-----------------------MINUTES --------------------------- Bob Haller
conducted the meeting.
- Review of minutes for June 7, 2005
Minutes approved with no changes
- Announcements - EIA Call for Patent Disclosure:
No company declared a patent
- AR Review
AR: Mike to rewrite wording of 4.3.4 these are not consistent - Done
- Opens for new items
Eckhard requested discussion on DDR2 ODT - We have described the
on-die-termination as follows:
4.3.14 {LEVEL 1} On-die termination modeling documented
Any IBIS models with on-die termination should be labeled as such
using comment lines. On die termination should be modeled in [Power
Clamp] and/or [GND Clamp] tables. Document the method used to embed
the termination into the clamps.
But what happens, when we have an on-die-termination, which can be
non-driving /driving only ?? ( e.g. DDR2 with ODT ) Eckhard thinks we
need a submodel, because if you put it in the clamps, it will always be
there.
Reviewed wording - it is appropriate for Static always present
terminations.
but dynamic termination
might be better served by Sub model. Unfortuntley some simulators do
not properly support submodel
The team agreed that we need to add the static always present wording,
and additionally caution/documentation may be required for dynamic
termination.
- Review of draft parser bug report
- Choose representative warning candidate for parser bug report
Preliminary list of IBIS parser cautions, draft parser bug report
http://www.sisoft.com/ibis-quality/docs/caution.txt
http://www.sisoft.com/ibis-quality/docs/bugxx_caution.txt
Proposal to submit overshoot (4.2.13). This may be controversial because
a lot of IBIS models do not have Overshoot specified, but most data
sheets do have it specified (maby it should be a warning?).
Alternate proposal was to submit 4.2.3 vinl and vinh enclose Vmeas This
is a good representative check for the caution and consensus by team to
use that as 1st caution submission.
reviewed wording of bugxx_caution.txt - minor editorial changes
recommended Goal is to submit parser bug for representative caution to
IBIS open forum, then prioritize and submit high priority ones. We will
have to create test case ibis files for each submission
AR: Bob H. to update wording ot 4.3.13 (ODT)
AR: Bob H. to update Bugxx_caution.txt
AR: Bob H to provide Mike generic .ibs file for test case
AR: Mike to generate test case .ibs
Next meeting:
August 2, 2005
11-12 AM EST (8-9 AM PST)
Phone: 408-902-7868 or 866-902-7868
Meeting access: 42477825
Meeting ended at 12:00 PM Eastern Time.
--
Robert J. Haller (rhaller@xxxxxxxxxx)
Principal Consultant
Signal Integrity Software Inc.
6 Clock Tower Place, Suite 250
Maynard, MA 01754
Phone: (978) 461-0449, ext 15
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