IBIS Macromodel Task Group

Meeting date: 17 September 2013

Members (asterisk for those attending):
Agilent:                      Fangyi Rao
                            * Radek Biernacki
Altera:                     * David Banas
                              Julia Liu
                              Hazlina Ramly
Andrew Joy Consulting:        Andy Joy
ANSYS:                        Samuel Mertens
                            * Dan Dvorscak
                              Curtis Clark
                              Steve Pytel
                              Luis Armenta
Arrow Electronics:            Ian Dodd
Cadence Design Systems:       Terry Jernberg
                              Ambrish Varma
                              Feras Al-Hawari
                            * Brad Brim
                              Kumar Keshavan
                              Ken Willis
Cavium Networks:              Johann Nittmann
Celsionix:                    Kellee Crisafulli
Cisco Systems:                Ashwin Vasudevan
                              Syed Huq
Ericsson:                     Anders Ekholm
IBM:                          Greg Edlund
Intel:                        Michael Mirmak
Maxim Integrated Products:    Mahbubul Bari
                              Hassan Rafat
                              Ron Olisar
Mentor Graphics:            * John Angulo
                              Zhen Mu
                            * Arpad Muranyi
                              Vladimir Dmitriev-Zdorov
Micron Technology:          * Randy Wolff
                            * Justin Butterfield
NetLogic Microsystems:        Ryan Couts
Nokia-Siemens Networks:       Eckhard Lenski
QLogic Corp.                  James Zhou
SiSoft:                     * Walter Katz
                            * Todd Westerhoff
                              Doug Burns
                            * Mike LaBonte
Snowbush IP:                  Marcus Van Ierssel
ST Micro:                     Syed Sadeghi
Teraspeed Consulting Group:   Scott McMorrow
                            * Bob Ross
TI:                           Casey Morrison
                              Alfred Chong
Vitesse Semiconductor:        Eric Sweetman
Xilinx:                       Mustansir Fanaswalla
                              Ray Anderson

The meeting was led by Arpad Muranyi

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Opens:

- Bob asked to give a brief BIRD 155 update.

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Call for patent disclosure:

- None

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Review of ARs:

- Arpad submit BIRD 155.1 draft 7 to open forum
  - Done.
  - Recommendation also made to reject BIRD 150.

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New Discussion:


BIRD 155.2 update:
Bob said he has been working with Radek to make some clean ups. All
"DLL" have been changed to "executable model" for OS independence. A
motion to vote will be made, as well as a motion to reject BIRD 150.

Interconnect update:
Arpad said interconnect meeting attendance has been low, and it was
decided to suspend the meetings until further notice. Related discussion
will take place in the ATM meetings.


Package Modeling Decisions:

Arpad showed and narrated a presentation. This contained a single
slide overview of BIRD 125, BIRD 145, and EMD, plus a conclusion slide.
Arpad noted that BIRD 125 lacks support for stacked die.  BIRD 145 was
deemed a quick, small specification change, and with "poetic license"
could be used for package modeling. There was no recommendation however
to do this.  Arpad suggested that EMD might take over the role of defining
the component from .ibs files, and it would require more work on the
details.  On the conclusion slide Arpad stated that it would not be good
to have two approaches in IBIS.

Walter made some clarifications regarding EMD, which stands for Electrical
Module Description. He called it a replacement for the EBD Path syntax,
using subcircuits. It is not intended as a package model syntax, but
rather for modules with multiple components. His proposal for IBIS
package models is different, and is based on data the industry has available.

Walter showed a Package Model Requirement Survey slide from months ago.
Arpad asked what Walter's package proposal would be, if not EMD.  Walter
clarified how EMD would not be good for package models, and he described
the requirements for different package model types.  David added that
another type used is an s2p that adds a crosstalk path.  Walter wondered
if this should be added to the list of types.  Slide 12 compared an
"EMD-like" solution to BIRD 125. He said that the EMD-like proposal would
work a dn that this probably could not be done using BIRD 145.

John asked if the tool/user would have to make guided aggressor
assignments. Walter said that the EDA tool would use coupling information
to determine this. John asked if Touchstone 2 sparse format would help
to represent coupling, where it could slide around and map to a larger
s-param model. Walter said the sparse format can reduce file size, but
it would be used to represent an s156p in s20p portions, for example.
John said a script would be required. Brad said some tool would have to
know how to create a coupled s156p from smaller pieces, progressing from
uncoupled s2ps to coupled s6ps. Both known and unknown aggressors would
be involved. John noted that the package model alone can not be used to
choose all of the aggressors because it does not know enough about the
board.  Walter suggested that at times an s156p would be needed, but
vendors might be hesitant to produce those. Users would have to use
their influence.

Brad noted that Scott McMorrow had said that unknown aggressors are
not helpful, and that about 10 known aggressors are needed. He suggested
that Scott and Walter only disagreed on the number of aggressors. Radek
disagreed, saying that there can be indirect coupling, and that this
is hard to predict by approximation. Brad agreed that building a model
from smaller pieces constitutes an approximation. Walter said the
suggested models would be difficult to produce using BIRD 125. Brad
asked if Walter's idea would support 10 aggressor models. Walter said
it would. Brad asked if having unknown or "maximum" aggressors would
be useful, and how.  Walter said an s156p could have maximum aggressors
throughout, and that multiple package models for different purposes could
be included. Brad asked how the tool would arrange s6p models to create
larger models, the problem being unknown aggressors. Bob said Scott
recommended using the s156p to determine the strong coupling areas.
Arpad believed that this "building block" approach could be used with
BIRD 125.

AR: Arpad send Package Modeling Decisions presentation to Mike for posting

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IBIS Interconnect SPICE Wish List:

1) Simulator directives
