                                             
IBIS Macromodel Task Group

Meeting date: 21 Aug 2012

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
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
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
Sigrity:                    * Brad Brim
                              Kumar Keshavan
                              Ken Willis
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

------------------------------------------------------------------------
Opens:

- Bob: Would like to address IBIS parser issues

--------------------------
Call for patent disclosure:

- None

-------------
Review of ARs:

- Walter email a list of package modeling features for voting
  - Done

- Arpad prepare example BIRD 125 IBIS file set
  - not done

- Bob to propose a simpler way for addressing the needs of parameter passing
  under [External Model] and [External Circuit]
  - not done

-------------
New Discussion:

Bob discussed AMI changes in the new IBIS parser:
- Bob: Initially there was a warning for parameter name collisions
  - It now checks for collisions only within each branch
  - The leaf check for Description has been fixed, allowing only one per branch
- Arpad: This Friday might be the big day for IBIS 5.1

Luis Armenta introduced himself:
- He is working on AMI models at ANSYS

Walter showed a presentation:
- Walter: This presentation has been sent out
  - It summarizes use of parameter trees and IBIS-ISS for various models
- Some slides are brief summaries
- slide 5:
  - Walter: This example explains the proposal for packages
- slide 6:
  - Walter: This tree shows a typical on-die model
    - There are 4 bump pads for power and ground
    - Power and signals could be merged together
- slide 7:
  - Walter: This package model tree looks similar to the on-die one
- slide 8:
  - Walter: This adds length modeling where that is known
- slide 9:
  - Walter: This package tree shows victims and aggressors for crosstalk
- slide 10:
  - Walter: Arpad asked for both package and on-die trees here
    - This makes the model understandable and easy for EDA tools to use
- slide 11:
  - Walter: [Path Description] can be converted programmatically to IBIS-ISS
- slide 12:
  - Walter: Here is a legacy EBD file
    - It has comments to show what things are
  - Arpad: Do the slashes precede comments?
  - Mike: They are for continuation, pipe characters for comments
  - Walter: I may have modified this
- slide 13:
  - Arpad: The red line doesn't say how the IBIS-ISS package is connected
  - Walter: Good point but we will not be pursuing that
- slide 15:
  - Walter: Gd and RS are critical, but EBD doesn't support them
- slide 16:
  - Walter: This replaces a path description
  - James: Is U1 a reference designator?
  - Walter: Yes, this EBD is for a DIMM board
  - Fangyi: Would this work without the pin order?
  - Walter: That could work
- slide 17:
  - Walter: EMD "module" is less constraining than EBD "board"
- slide 18:
  - Walter: This is the legacy EBD converted to EMD
    - The only new thing here is Diff_Pins
- slide 19:
  - Walter: Nothing is different for a connector
    - Defining the A and B sides may not be necessary
    - Vendors often give slice models from which all pins are derived
  - Fangyi: The unconnected pins are assumed to be open?
  - Walter: Or 50 ohms to ground, etc.
    - A typical method is to extract a smaller s4p
  - Fangyi: It still depends on what is assumed for the other ports
  - Walter: They are effectively open
  - Radek: That will not work
  - Arpad: Some models are not symmetric in each direction
  - Walter: The A and B signal names handle that
- slide 20:
  - Walter: Some of our existing BIRDs are gobbledygook
    - There is confusing baggage
- slide 21:
  - Walter: [External IBIS-ISS Model] is a simple way to handle it
    - Stimulus and other items are easily defined in tree format
  - Arpad: Stimulus is what the DtoA converters handle
    - This is a new keyword for something that exists
  - Walter: The Model_Ports syntax is very simple
- slide 22:
  - Walter: We should reject the listed BIRDs and create a new IBIS 6.0 EMD section
    - I will make this motion Friday at the Open Forum meeting
- slide 21:
  - Fangyi clarified how the TX Stimulus parameter works with the model ports
  - Walter: IBIS-ISS is invalid for most buffer models because it can't handle input and enable
    - PWLs or macros would have to be added, as in IBIS-BSS
    - Model_Ports is similar to Model Connection Protocol
  - James: How to tell which ports are connected to stimulus?
  - Walter: Drive is a reserved name for that
    - We might want to call that Stimulus
    - This attempts to not make too many changes
    - It will be a lot of work to write this BIRD, it should be a group effort
  - Fangyi: Coloring the reserved names may help avoid future questions
  - James asked about the format of the Tstonefile parameter
  - Walter: It goes into the AMI file to get the value
    - Some AMI models have many "knobs", and some change the Tstonefile
  - Radek: The right side model is used only with AMI models?
  - Walter: Values can be directly specified here
- slide 22:
  - Ambrish: This replaces all of the BIRDs proposed for rejection?
  - Walter: Yes, for example the package and on-die models replace [Circuit Call]
    - What I'm proposing requires only one new parser

AR: Walter send slides with modifications for posting

Bob: This Friday IBIS 5.1 is the priority
- There may not be much time for other items

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Next meeting: 28 Aug 2012 12:00pm PT

Next agenda:
1) Task list item discussions

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IBIS Interconnect SPICE Wish List:

1) Simulator directives
