Date: April 6, 1994
From: Will Hobbs (503) 696-4369, fax (503) 696-4210
Will_Hobbs@ccm2.jf.intel.com
XTG Modeling Manager, Intel Corp., Chairperson, IBIS Open Forum
Intel Corporation
5200 NE Elam Young Pkwy, Hillsboro, Oregon 97124 USA
and
Derrick Duehren (503) 696-4299, fax (503) 696-4904
Intel Program Manager
Subject: Minutes from IBIS Open Forum 4/1/94
To:
Anacad Steffen Rochel
Ansoft Henri Maramis
Atmel Corporation Dan Terry
Cadence Design Sandeep Khanna, Chris Reed,
Pawel Chadzynski, Kumar*
Contec Maah Sango*, Clark Cochran
Digital Equipment Corp. Barry Katz*
High Design Technology Michael Smith
HyperLynx Steve Kaufer, Kellee Crisafulli*
IBM Jay Diepenbrock
IBM-Motorola alliance Lynn Warriner, Hoa Quoc, John Burnett
Integrity Engineering Greg Doyle, Wayne Olhoft
Intel Corporation Stephen Peters*, Don Telian, Will Hobbs*
Arpad Muranyi*, D. Duehren, Lisa Huang*
Interconnectix, Inc. Bob Ross*
Intergraph Ian Dodd*, David Wiens
IntuSoft Charles Hymowitz
Logic Modeling Corp. Randy Harr
Mentor Graphics Greg Seltzer, Ravender Goyal
Meta-Software Mei Wong, Mei-Ling Wei
MicroSim Arthur Wong, Jerry Brown, Graham Bell
National Semiconductor Syed Huq
North Carolina State U. Paul Franzon, Michael Steer, Steve Lipa
Performance Signal Integrity Vivek Raghawan, Eric Bracken*
Quad Design Jon Powell*
Quantic Labs Mike Ventham, Zhen Mu
Racal-Redac John Berrie
Siemens Nixdorf Werner Rissiek, Olaf Rethmeier
Texas Instruments Bob Ward
Thomson-CSF/SCTF Jean Lebrun
Zeelan Technology Hiro Moriyasu, George Opsahl
CC:
Intel Corporation Randy Wilhelm, Jerry Budelman,
Intel IBIS team
In the list above, attendees at the 4/1/94 meeting are indicated by *
Upcoming Meetings: The room and bridge numbers for future IBIS
teleconferences are listed below:
Date Bridge Number Reservation #
4/15/94 (415) 904-8944, 721615
4/29/94 (415) 904-8944, 721618
5/13/94 (415) 904-8944, 721619
5/20/94 Face-to-face, editing committee
All meetings are 8:00 AM to 10:00 AM PST (16:00 to 18:00 UTC). We try
to have agendas out 7 days before each open forum and meeting minutes
out within 7 days after. When you call into the meeting, ask for the
IBIS Open Forum and give the bridge operator the reservation number.
PLEASE NOTE: Because of the current large number of open issues, we
decided at the 4/1 meeting to hold meetings on a bi-weekly basis until
ratification of IBIS 2.0 is achieved.
If you know of someone new who wants to join the e-mail reflector
(ibis@vhdl.org) send e-mail to ibis-request@vhdl.org.
------------------------------------------------------------------------
4/1/94 Meeting Agenda
----------------------
Check-in
Intros of new IBIS participants Hobbs
Review of 3/11/94 minutes Hobbs
Miscellany/Announcements Hobbs
Opens for new issues All
Press updates Hobbs/All
New Models Available All
IBIS 2.0 Ratification Hobbs
- DAC Conference 6/6 - 6/10
- Editing Committee
IBIS Cookbook Hobbs
Spice-to-IBIS Converter Lipa (NCSU)
Sign of Current checking Chrisafulli, All
BIRD 8, Spec. of V/I data monotonicity Crisafulli
BIRD 9, Other model types Ross
BIRD 10, Coupling Effects in Package Models Bracken
BIRD 2, VIH, VIL Thresholds for Inputs Powell
Egg 1, mutual pin coupling (ready to hatch?) Bracken
Simulation temperatures (new BIRD?) Warriner
Ramp measurement Reid, Ross, et. al.
Egg 2, ramp table? Hobbs
Canright paper Ward
Formal BNF notation (BIRD?) Reed, Harr
High freq. and EMI Goyal, et. al.
Phased turn-on/off of multiple devices Powell
Wrap-up, Next Meeting Plans Hobbs
1. Intros of new IBIS participants
New participants: None. In fact, due to the meeting taking place on
Good Friday, attendance was 30% lower than normal.
2. Review of 3/11 Minutes
There were no corrections made to last month's minutes.
3. Miscellany/Announcements
No new announcements.
4. Opens for new issues
Jon Powell has questions regarding a new model developed by Intel for
the Neptune 3.3v PCMC chip set which exhibits non-monotonic behavior
with the pulldown when the voltage goes below ground. Kellee also has a
customer that is using it and agrees that this is a probable problem.
We agreed to discuss this issue later in the meeting.
Kellee would also like to defer discussion of Bird 8 to a future meeting
in favor of the new BIRD 11, IBIS_CHK checks for table sign.
5. Press updates
There is an article on IBIS about to come out in EDA and ASIC magazine
and the March issue of Computer Design, on page 38, devotes a couple of
paragraphs to IBIS.
6. New Model Availability
New models: Intel's 486DX4 model is about to go on BBS. Expect it in
about a week. Arpad also has some new models that are ready for
posting.
AR, Stephen, Arpad, get models up on the vhdl.org BBS.
7. IBIS 2.0 Ratification: DAC Meeting, Editing Committee
Jon Powell proposed the meeting take place on Sunday, from 1-6, with
Monday as an overflow day. Jon could provide facilities that day.
Various members preferred not to meet on Sunday and Kumar offered for
Cadence to provide a room on any day, and needs the number of
participants. We tentatively set the meeting for 8-5 on Thursday, 6/9.
AR Will, send out notice, ask for RSVPs, for 6/9, 8-5. -- Done
Will suggested we convene an IBIS Birds of a Feather session to be held
through DAC. Bob Ward said that to do this only requires that 10 people
express interest and DAC will supply a time and a room. Bob was
volunteered to follow through on this.
AR, Bob Ward, get Birds of a Feather session on DAC agenda. Launch note
to reflector to get at least 10 replies from those interested in
attending. -- Done
Regarding the 5/20 editing get-together in Oregon, it was suggested we
divide up tasks into controversial/non-controversial topics and quickly
close on the non-controversial ones and tackle the remainder separately.
Possibly work in sub-groups.
8. IBIS Cookbook
Intel has completed its first revision of the internal IBIS Modeling
Cookbook, and has made its first pass at a "sanitized" version for use
by the forum. Will solicited volunteers to help get this in shape for
the forum, and the following individuals stepped forward: Jon Powell,
Bob Ross, Kellee Chrisafulli, Maah Saango, Barrie Katz, Arpad Muranyi,
Kumar and Eric Bracken.
AR Will, organize the review and editing effort for the cookbook. -- WIP
9. Spice to IBIS
Bob Ross has used sp2ibis with Pspice and provided some feedback to
Steve. Bob found some differences between Pspice results and Berkeley
Spice, gave Steve that feedback and another iteration is underway. Bob
judges the program usable, but more work is required. Barrie at DEC has
it and will be using it soon.
Jon Powell: How will it be used? If it is to be used primarily by IC
vendors, it does not have to be as clean; if its target is customers, it
must be cleaner. Kellee: IC vendors are #1, because they will have the
greatest impact. Bob Ross: But it will be public domain, so anyone can
use it. Jon is concerned if there is a minor bug that might create
major glitch, a model review would be required, so modeling and buffer
expertise would be required to be successful, or the evaluation of
Sp2ibis will have to be greater. Kellee: maybe we should ask Steve to
add something in the program's output to indicate need to correlate
resulting model against the original design (a disclaimer or caveat).
There was a short discussion about what to do about released IBIS models
that had erroneous behavior. Is there a way to resolve such issues?
Jon suggested that models should contain the originator's name, or some
way to get a message back to originator.
AR Jon, organize thoughts, post to reflector.
10. New Issue: Non-Monotonic Pull-Down Behavior
Re: pulldown on Neptune, Arpad on line. Jon feels the pulldown
transistor becomes linear, and doesn't believe the curve. Arpad had
dissected the design and checked the devices and verified the behavior
as reflected in the model.
AR Arpad, write up a discussion of this for the reflector.
Jon: if you are right, all the other IBIS models are wrong. Kellee:
The question is whether in the negative region is the diode carrying the
current or is the pulldown? Arpad: The models have not always been
correlated in that region. Earlier models are still useful, because
they are still more accurate in the forward biased diode regions than
many other spice models that are out there. Arpad would like to
continue this discussion in a forum where we can draw pictures, and
would like to add this discussion to the cookbook.
Jon: Quad does not model non-monotonic parts. The model that Arpad is
generating will not work in Quad tools. Arpad questions whether Jon can
use the data together-- the transistor is non-monotonic, but the diode
and the diode/transistor combination do not.
Maah: we're confusing 2 issues-- what does the data look like, and how
do we model it?
ARs, Arpad, post description of his findings that led him to the new
model data. Specify one particular model for everyone to look at.
psc_a2.ibs
11. BIRD 11, IBIS_CHK Changes
Kellee Crisafulli proposes three changes in this BIRD, each related to
the sign of VI table data, which has proven to be a common pitfall among
new modelers. First, the BIRD proposes adding a comment to the IBIS
specification discussing the sign of VI table data; second, add checking
to ibis_chk for the correct sign, using the algorithm tuned through
reflector feedback; and third, add a note to the ibis_chk source saying
a BIRD is required to change the source.
Proposed changes 1 and 3 appear OK to group, with the additional comment
that source licensees are free to modify their own source, but not to
post the result. Only the ibis_chk czar (Jon Powell) can post modified
versions of ibis_chk, and that requires a ratified BIRD to initiate.
Regarding change 2, there is controversy about the sign of the ECL
example. Kellee pulled the example out of the IBIS V1.1 spec, which was
a CMOS example, and indicated that if this was an ECL example then there
would be a sign error because for ECL pulldown, VI is Vcc-V per BIRD 4.
Kellee feels that right thing to do is to change the sign and use ECL
type data and present a correct ECL table, but doesn't have ECL data.
Kumar has ECL data which he offered to supply for inclusion in the BIRD.
AR Kumar, post ECL model to reflector, Kellee, use that data in the
BIRD.
AR Kellee, change the proposed ibis_chk notice to indicate that it is OK
to change your own source code, but not the global one without a
supporting BIRD.
12. Wrap-up
Because we ran out of time, and because a number of people did not
attend due to the meeting taking place on Good Friday, we decided to
convene on a bi-weekly basis until DAC so we could get 2.0 in shape.
Thus, next meeting will be on Bad Friday, 4/15. (For those non-U.S.
citizens reading this, April 15 is when Americans must pay their taxes.)
AR Will-- make meeting bi-weekly until DAC, post new bridge numbers. --
Done. Dates and numbers appear on the first page of these minutes.
Received on Wed Apr 6 13:33:12 1994
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