[ibis-macro] Minutes from the 05 Mar 2013 ibis-atm meeting

  • From: Mike LaBonte <mike@xxxxxxxxxxx>
  • To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
  • Date: Wed, 6 Mar 2013 14:46:39 -0500

Minutes from the 05 Mar 2013 ibis-atm meeting are attached.

IBIS Macromodel Task Group

Meeting date: 05 Mar 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 Raghat
                              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


- None

Call for patent disclosure:

- None

Review of ARs:

- Arpad try to apply BIRD 158 shortcut language to his BIRDs 116-118
  - In progress
  - Maybe we should schedule a vote for them

- Ambrish email reflector regarding BIRD 147 status
  - It is ready for posting

New Discussion:

- Michael M: Reviewed new EMD spec, now posted
  - No meeting this week
  - Expecting SI2 update for review next week

Walter showed a slide about conversions to s4p
- Walter: David Banas asked a question about conversions to s4p
  - In IBIS 6.0 David want to describe on-die interconnect as s4p
  - This is a surrogate model (someone from NCSU has call IBIS that)
  - The model in the top left takes a zero rise time stimulus
  - The diagram shows an equivalent RC circuit on the top right
  - The bottom left circuit can work correctly with a zero rise time
  - It has two s4ps, which can be combined into one on the bottom right
- Fangyi: How does the waveform shaping happen?
  - The transition from top right to lower left might not work
- Walter: It works like an op amp
  - I may not have the expertise to understand and explain it fully
- Fangyi: There might be a one to many correspondence for that filter
- Walter: The 1 to 2 insertion loss and the return loss at 2 are critical

- David: I have to trim V-T tables to achieve high bit rates
  - Can an s4p incorporate the behavior of that?
  - Brad Brim had raised concern about that
  - I was cautioned about lumping these things into one s4p
- Fangyi: I agree with that
  - This approximation is like a small signal analysis
  - The large signal operating point has to be chosen carefully
  - AMI is not always about linear
  - Superposition does not always hold, and it is more important than scaling
- Todd: Know where you are in the operating curve is important
  - Once you have the right point an extracted touchstone model can be 
- Walter: The operating point will not be at either steady state
- Radek: We are operating with a large swing, not a small signal
  - We are just basing an approximation on that point

- Dan: Doesn't using a short rise time require large bandwidth?
- Walter: Modeling the rise time requires NOT having full bandwidth
- Todd: The s4p needs to go high anyway, otherwise the simulator handles the 
- David: All that matters is that the remaining energy above some point is 
- Todd: Agree
- Dan: I get nervous relying on extrapolation
- Fangyi: We are modeling both the stimulus slope plus the RC delay
- Walter: The rise times do not amount to much above Nyquist

BIRD 147:
- Ambrish: Suggestions were made to add sections to the backchannel BIRD 147
- Please comment on it

AR: Mike post updated BIRD 147

BIRD 155:
- Arpad motioned to untable BIRD 155
- David seconded
- Fangyi showed New AMI API to Resolve Parameter Dependencies
- slide 5:
  - Fangyi: AMI_parameters_in is the input
    - AMI_parameters_out is the new output
- slides 9 & 10:
  - Fangyi described the flow
- slide 8:
   - Fangyi: A new Usage Dep would be used for returned items
- slide 11:
  - Fangyi: It easy easy to code FIR with this
- slide 12:
  - Fangyi: An auxiliary file could contain the dependency information

- Bob: This would have to be BIRD 155.1
- Radek: This could be used for Reserved_Parameters
- Fangyi: You might use different TStonefiles for different corners
- Arpad: I thought we would use dependency table parameter passing for
  [External Circuit] dependent parameters
  - Putting this in the DLL would take that feature away
- Walter: The impulse response might be gathered in a separate simulation
  - The advantages given here seem to be mostly for the model maker
  - We should see what model makers think
- Fangyi: This was proposed three years ago by IBM
- Walter: Adge concluded that the .ami was the best place to put the data
  - This is more complicated
- Radek: This is a simpler and more comprehensive solution
- Mike L: Is Usage Dep needed? Those models will be unusable in existing tools
- Radek: It will not be in the spec until 6.0 anyway
- Fangyi: A workaround is to simply not change Usage in .ami files

Next meeting: 12 Mar 2013 12:00pm PT

Next agenda:
1) Task list item discussions

IBIS Interconnect SPICE Wish List:

1) Simulator directives

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