November 5, 1993

November 5, 1993
From: Cathy Lundberg (503) 696-4620, fax (503) 696-4904
                Will Hobbs (503) 696-4369, fax (503) 696-4210
Subject: Minutes from IBIS Open Forum 10/29/93
To:

Anacad Petra Osterman
AnSoft Henri Maramis
Cadence Design Sandeep Khanna, Chris Reed, Pawel Chadzynski, Kumar*
Contec Maah Sango*, Clark Cochran
High Design Technology Michael Smith
HyperLynx Steve Kaufer, Kellee Crisafulli
Integrity Engineering Greg Doyle, Wayne Olhoft
Intel Corporation Stephen Peters*, Gary Saunders, Jim Alexander, Don
Telian,
                        Arpad Muranyi*, Donna Rendon, Will Hobbs*,
                        Cathy Lundberg*
Interconnectix, Inc. Bob Ross*
Intergraph Ian Dodd
IntuSoft Charles Hymowitz
Logic Modeling Corp. Randy Harr*
Mentor Graphics Greg Seltzer, Ravender Goyal
Meta-Software Stephen Fenstermaker
MicroSim Arthur Wong*, Meeling Wei, Jerry Brown, Graham Bell
North Carolina State University Paul Franzon
PC Ware Paul Munsey
Performance Signal Integrity Vivek Raghawan, Eric Bracken*
Quad-Design Jon Powell*
Quantic Labs Mike Ventham*, Zhen Mu
Siemens Nixdorf Werner Rissiek*
Texas Instruments Bob Ward*
Thomson-CSF/SCTF Jean Lebrun
Zeelan Technology Hiro Moriyasu, George Opsahl*, Samie Samaan, Tay Wu

Cc: Intel Corporation Randy Wilhelm, Jerry Budelman, Intel IBIS team

In the list above, attendees at the 10/29 meeting are indicated by *

Future meetings: Face to face IBIS Summit, Santa Clara, CA: Nov. 12, 1993,
                  8:00-5:00 PST
                  Phone number: (916)356-9999. Reservation Number: 130639

Please note: If you know of someone new who wants to join the email reflector
(ibis@lmc.com), or have updates to your email address, email to
ibis-request@vhdl.org.

10/29 Meeting Agenda:

9:00 Check-in
9:05 Introductions of new IBIS members
9:10 10/1 Minutes Review, Opens for New Issues Will Hobbs
9:15 Press Release, Trademark issue Randy Harr, Will Hobbs
9:25 Summit Planning
                Attendees
                Presenters
                Discussion Chairs, Topics
9:40 SCVs Will Hobbs, All
9:45 BBS Updates Siuki Chan, Randy Harr
9:50 BIRDS
                ECL, BIRD #1 Stephen Peters
                VIH, VIL Input Threshold, Bird #2 Jon Powell
10:20 10/1 Opens
                #6 Open Side (shelved) Kellee Crisafulli
                #7 .pkg Eric Bracken
                #8 Thresholds for Timing Jon Powell
                #9 Monotonicity Kellee Crisafulli, Arpad
                                                        Muranyi
10:50 Wrap-Up
        Action Items
        Next Meeting Plans

Minutes
I. Open Issues:

Atmel called, they will be doing IBIS models.
Motorola will do IBIS models of the PowerPC. They may attend the summit.

No corrections to minutes.

Paul Munsey has not been paid by one company. The group agreed that a check
should be issued to Paul by Will from the IBIS account.

AR: Will - issue check to Paul Munsey from the IBIS account. Update: waiting on
final confirmation of facts.

Changes to coding style would make 2.0 easier to use, and easier to write
translators. Jon would like people to talk to Paul about it.

We'll send out directions to get to the summit to reflector by next Monday. A
map will also be sent with the faxed minutes.

AR: Cathy - send directions to get to the summit to the reflector. DONE
AR: Cathy - fax map to Bob Ward. DONE

II. Press Release:

Texas Instruments didn't get deleted from the copy and TI did appear in a couple
of places as supporting the IBIS standard. The final release went out without
Randy's review. Key editors were called about the mistake and corrected copies
were faxed to several places. No backlash is expected at TI.

We have a letter on letterhead from every company but Intel authorizing the
press release.

The IBIS Overview document that will be sent out on request by Karen Kirkpatrick
at Cadence has not been sent to her yet; It has been reviewed by various Intel
people and Jon Powell and still needs some revision. It is a nice overview, but
gets too specific in some areas. For example, some simulator vendors have
varying support for the ability to accurately model traces, so the document
should give transmission line values instead of trace lengths, etc. Subsequent
to the meeting, we learned that Cadence has received a few requests yet as far
as we know. Robin (Intel's tech writer working on the document) is making final
revisions. She will finish shortly and we will submit it to vhdl.org and fax it
to our standard fax list.

The press release got low coverage because of the HyperLynx press release that
went out earlier. Also, the press release was just on white paper, not on slick
letterhead with a packet. The next time we issue a press release we should have
each company generate their own press release which we can then assemble
together to send out. We need to make sure we time it right and release the
information at the same time.

We have some potential logos to use for IBIS. The results of the trademark
search are in a 50 page document that Logic Modeling has - any paying IBIS
member can get it from them.

III. Summit planning:

A session led by Kumar of Cadence and Eric Bracken (now Vivek Reghawan) of
Performance Signal Integrity will discuss modeling simultaneous switching /
ground bounce, which drivers talk to which pins, different supplies powering
different pins, representing Vcc pins shared by buffers, timing and noise
implications and dual supply components.

AR: Kumar - let Will or Cathy know your topic of discussion by 11/5.

Other potential sessions:

Data measurement and derivation methods - how semiconductor vendors derive data.
 Other semiconductor vendors have rise times characterized differently than
Intel does. It would be nice to have Intel, Motorola and Texas Instruments talk
about this.

In order for IBIS to be useful, semiconductor vendors need to get involved.
Will is inviting some companies to the summit. Others should do the same.

We would like to see foils ahead of time so we can have copies prepared. We
will also send out copies afterward as necessary.

November 12 IBIS conference agenda
8:00 - 5:00 SC4-150

Note: Intel will provide coffee and lunch.

8:00 All Assemble, get aquainted, have
                                                coffee
8:20 Will Hobbs Intel IC vendor view of IBIS
8:45 Randy Harr LMC Die 0.9 bare die spec work with
                                                National
9:15 Bob Ross Interconnectix Measurement and Extraction of
                                                buffer data
9:45 Break
10:05 Jon Powell Quad-Design Slew Controlled Devices
10:25 Arpad Muranyi Intel V/I/T
10:40 Panel Handling Dynamic
                                                Characterization of Buffers
12:00 Lunch
1:00 Kumar Cadence Implementation of IBIS models
                                                using current controlled voltage
                                                sources
1:20 Vivek Raghawan Performance Package Parameters
                        Signal Integrity
1:40 Panel Package Parameters
2:10 Panel SSO: Sharing of Vcc and Ground
2:45 Break
3:05 BIRD discussion, voting
4:00 Open issues, action item review, summary

BIRDs

BIRD #1
We discussed ICs in which diodes and buffer transistors are referenced to
different voltage rails. Stephen Peters proposed that he add support for
multiple voltage rails to BIRD#1. Because of the other issues that came up with
diodes on ECL parts and requirements for mixed supply parts, he decided to
rewrite the BIRD#1 to include voltage rail statements, put it out as BIRD#3, to
substitute for BIRD#1, and close BIRD#1. Since the meeting, Stephen concluded
that it was easier to revise and close BIRD#1, replaced by BIRD#3, dealing with
ECL alone. He has also created BIRD#4 to address multiple rails.

On the subject that Bob Ross brought up during the previous meeting regarding
diodes on ECL parts, the clamp diodes on ECL parts are strictly for ESD
protection and don't affect the signals in normal operating conditions. The
signal swings in ECL are so small that the ESD diode should never be forward
biased. If the diodes are turned on, the part is far beyond operating ranges.
With the new voltage rail support in BIRD#4, the user would be able to specify
the ESD diodes.

Kumar discussed Cadence's approach to multiple rails. In their table called VI,
they use a keyword, "vreference" that specifies the Vcc used for that curve.
Kumar says that this approach is very simple and works.

AR: Kumar write up example and send to reflector. - Done.

BIRD#2

Bird 2 - there are many unresolved issues regarding input thresholds. There was
a discussion on what the real trip point should be for logic devices and how we
might handle non-logic devices such as resistor packs.

AR- Jon Powell post BIRD#2 to reflector Friday afternoon. DONE

We engaged in a discussion on monotonic behavior. There are two aspects to be
dealt with. 1) How should we deal with output buffers that exhibit
non-monotonic behavior (and in what situations does this occur), and 2) Must
data be entered in the IBIS file monotonically?

1) Non-monotonic buffer behavior: Arpad asked, "Do we require monotonic
behavior in curves?" If this is a requirement, the parser must check for
monotonicity.

Jon Powell said that customers want to model non-monotonic parts. Non-monotonic
behavior can result from slow feedback designed to prevent parts from melting;
thus is is more of a DC phenomenon than an AC phenomenon. Does this pose a
convergence problem for some simulators? Is a DC representation of the curve
acceptable for some devices? Due to DC current limiting, DC measurements may
imply non-monotonic behavior that would never actually occur under real
switching conditions. How do we measure in an AC manner instead of DC manner?

Behavior that is nonmonotonic due to feedback goes into the controlled slew rate
discussion, modeling the dynamic characteristics of device. For IBIS to be
useful, it must deal with negative resistance regions.

2) Monotonic data entry: We felt that in IBIS tables, voltage values should be
monotonically rising or falling, but that current values may change. The
parser should check whether the data is good, but it shouldn't restrict the type
of data. A BIRD against the parser should be written at some point to add
checks for this in rev 2.0. No specific AR owner was identified.
Received on Mon Nov 8 16:48:51 1993