[ibis-macro] Minutes from the 24 Jul 2012 ibis-atm meeting
- From: Mike LaBonte <mike@xxxxxxxxxxx>
- To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
- Date: Tue, 24 Jul 2012 17:21:58 -0400
Minutes from the 24 Jul 2012 ibis-atm meeting are attached.
Mike
IBIS Macromodel Task Group
Meeting date: 24 July 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
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
LSI Logic: Wenyi Jin
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
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Opens:
- None
--------------------------
Call for patent disclosure:
- None
-------------
Review of ARs:
- Arpad: There was an AR from last week for me to create a bus package model
example
using BIRD 125
- Some complications have come up
- Bob to propose a simpler way for addressing the needs of parameter passing
under [External Model] and [External Circuit]
- not done
-------------
New Discussion:
Arpad: I would like o show a presentation about package modeling
- Walter: We should address the physics of the problem, not vendor specific
approaches.
- Arpad: We can combine that with what Michael M was presenting last week.
- Michael M: Ambrish had an unanswered question last week.
- Ambrish: It was about MCP.
- Michael M: We seem to be oriented toward pre-PCB analysis
- Some information may not be available at the time models are used.
- Not sure MCP adds the kind of value we are looking for.
Walter showed his previous email with additional comments:
- Walter: There was a question about package discretes
- IBIS-ISS can handle those as elements
- Walter explained the email he had sent to the list, with port counts
- John: The port counts seem small
- Walter: It is just an example
- No one so far disagrees with this
- Arpad: The pad and pin counts for power are different
- The word "resolution" is confusing here
- Subsets of these ports can be used
- Walter: It is impractical to create a subset that models the physics correctly
- No one creates full models at this level of detail though
- Questions:
- What can we do that allows users to make engineering decisions?
- Can VDD and VSS bumps be just two nodes?
- Users can can't control routing and bypass affecting above 10GHz
- Two nodes might be OK, except in advance power delivery cases
- Can a subset of the VDD/VSS pins be used?
- Is bump-buffer interconnect already in buffer models?
- For legacy IBIS this is C_comp
- For AMI this is already in on-die s-param models
- Michael M: What is the distinction between bump and buffer pads?
- Walter: 802.3 talks about test probes
- These are places specified there
- A t-coil is on-die interconnect between bump and buffer
- David: The bump is the point that contacts the package when the die is
correctly placed
- Michael M: On-die models are not universal
- Walter: Some do it
- Michael M: We tend to use non s-param models
- Walter: It will probably be IBIS-ISS regardless
- Arpad: What is the purpose of discussing these topologies?
- Walter: The die and package models are generated from different physical
databases
- Scott: It is reasonable to work with s800p models
- Walter: Packages can be much larger
- Scott: We partition by locality based on coupling
- Walter noted that Scott and Arpad disagree with his premise about whole
package models
- Walter discussed slices:
- Package model slices:
- Coupled and uncoupled
- Channel and power
- On-die model slices
- Channel and power
- Walter described types of models supplied by various (anonymous) vendors
- Walter: Vendor F is the one Scott spoke about
- This uses MCP
- Arpad: As long as subcircuits can have anything, this does not matter
- Walter: Crosstalk is not tied just to pins
- We should support the way vendors are currently modeling advanced cases
- Arpad: I have added to BIRD 125 but we are out of time to show it
- Michael M: Does the advanced model assume the layout is all there?
- Who is the audience?
- Scott: There is little coupling outside of each locality on a die
- On packages coupling extends further, even edge to edge
- Users of these are pushing the state of the art
- They will often extract quadrant package models themselves
- Single models can be extracted from those
- Walter: What does IBIS 6.0 need to support both vendors and users?
- Arpad might extend BIRD 125
- I will have my own proposal
- IBIS does not yet have:
- ISS
- bus level models
- generic models that can be assigned to pins with different lengths
- Michael M: This is similar to what I am asking for
- Other IC vendors should present their own needs
- Arpad: Do wee need anything else?
- Walter: We need to hear from other IC vendors
Arpad: We have no time for my presentation, but it is on the website
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Next meeting: 31 Jul 2012 12:00pm PT
Next agenda:
1) Task list item discussions
-------------
IBIS Interconnect SPICE Wish List:
1) Simulator directives
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- » [ibis-macro] Minutes from the 24 Jul 2012 ibis-atm meeting - Mike LaBonte
