[ibis-macro] Minutes from the 5 Feb 2013 ibis-atm meeting

  • From: Mike LaBonte <mike@xxxxxxxxxxx>
  • To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
  • Date: Thu, 7 Feb 2013 14:46:36 -0500

Minutes from the 5 Feb 2013 ibis-atm meeting are attached.

IBIS Macromodel Task Group

Meeting date: 05 Feb 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


- Arpad: We need to introduce Walter's recent BIRD

- Walter: It would be useful to review Arpad's excellent DesignCon

Call for patent disclosure:

- None

Review of ARs:

- None

New Discussion:

Interconnect Task Group report:
- Michael M: On Jan 23 we discussed summit material and David Banas' survey

Analog modeling plan:
- Arpad: After the end of the summit we discussed the SiSoft/Agilent press 
  - The authors were given an unofficial AR to propose the method they are using
  - Hopefully this will be discussed soon
- Walter: I have vacation, it will be ready in 2 weeks
- Arpad: It seems the idea of two parallel approaches is bottoming out
  - The BIRDs I like would allow IBIS modeling as well as AMI
  - The approaches have some overlap
- Walter: IBIS-ISS would allow legacy IBIS broadband models
  - The idea here is to represent on-die interconnect as broadband
  - Non-AMI solutions would best target non-LTI using legacy buffers
- Arpad: We could review the BIRDs involved
  - The Cadence BIRD 145 also allows broadband models
  - A slide set should be made
  - We should set aside time for long term overhaul of keywords like [Model]

Arpad show the presentation "What's Wrong with IBIS?":
- slide 2:
  - Arpad: We must decide whether to tweak or leave behind.
    - The legacy syntax is unappealing
    - This might involve many IBIS feature changes
  - Walter: EMD is not a leave behind approach
    - It addresses all industry interconnect needs
    - IBIS has various interconnect solutions, which would not be touched
    - The final problem is on-die interconnect, which EMD can address
    - Modifications for pre and post layout might be needed
    - The existing models can be unaffected
    - Only minor tweaks to IBIS are needed
- slide 3:
  - Arpad: We both have content related issues, but also usage issues
    - Stacked die support is a problem, we have no [Die] keyword
    - IBIS [Pin] is targeted for post-layout
  - Walter: Disagree, a stacked die should go in EMD, not IBIS

- Arpad: I had some syntax examples, but it was too long for the summit
  - We should have a planned effort to clean up the IBIS specification
- Radek: That would be good, a review of the IBIS specification structure
- Bob: This sets a new direction, seeming to abandon [External Model] and
  [External Circuit]
- Arpad: Yes, I am thinking about a new model keyword, object oriented
  - It should not be layered the way we have it now, where one language
    calls another
- Radek: Those do not seem to be popular
- Michael M: There may be interest in tying IBIS to HDL languages
- Arpad: IBIS-ISS is universally accepted, but BIRD 116 is not well received
  - A new keyword may solve that
- Walter: ISS is for interconnect, [External Model] is not
  - An IBIS-BSS might work
- Arpad: We chose an LTI subset of HSPICE, but not excluding other possibilities
- Walter: IBIS-ISS was created after we decided EMD needed it
- Bob: We could use any SPICE brand as a superset
  - The idea was to connect any kind of buffer to pins
  - As it stands EDA vendors are getting around the problem with proprietary
- Arpad: We must decide if a new meeting is needed for an overhaul, or use
  this one
  - We still have BIRDs to work on
- Michael M: The people will be the same anyway
  - A combined meeting would be best, this one
- Arpad: The Advanced Technology meeting would be best for futures work

David: Can we agree to decide on BIRDs 116 and 122 in two weeks?
- Arpad: Yes, and next week we can discuss redrivers
- Radek: Fangyi may not be here next week
- Walter: A repeater can a redriver or a retimer
  - Fangyi's flows are nearly identical for a retimer
- Arpad: Can Walter speak for BIRD 131?
- Ambrish: There is nothing in the AMI file for what happens between RX and TX
- Walter: SiSoft believe both Init and GetWave flows should be supported
  - Some support this and others produce separate models
  - With a repeater there can be more flows to support, without rules
    requiring specific support
- Ambrish: I would like to see a case that is a problem
- Radek: Fangyi would rather not combine BIRDs 131 and 156
- Arpad: Fangyi's BIRD is only for redrivers
- Michael M: BIRD 156 needs to be relabeled
  - There has to be a flow to describe how data gets from the RX to TX side
  - Only BIRD 131 has the keyword to say the RX and TX are connected
- Ambrish: Fangyi believes [Repeater Pin] changes traditional IBIS waveforms
- Michael M: We could say repeater has to have an AMI model
  - Otherwise we would have to be clever
  - This is just like [Series Switch], it might be put in there
- Bob: It might be [AMI Repeater]
- Michael M: Only if [Series Switch] is not adequate
- Walter: Retimers want to use multiple ways to generate the TX side impulse
  - Redrivers have no digital stimulus, how to generate the impulse response?
- Arpad: Do we need two BIRDs?
- Walter: The repeater BIRD should stay the same
  - I could create a new BIRD for retimers
- Ambrish: I would prefer to add to BIRD 156 instead of having 3 BIRDs
- Walter: I will add it only if Fangyi and I can't agree

Arpad: If Fangyi is not here next week can we discuss backchannel?
- Ambrish: Not sure we will be ready to discuss BIRD 147
- Radek: We could discuss BIRD 155
- Arpad: We will plan to discuss BIRD 155

AR: Ambrish email reflector regarding BIRD 147 status

Next meeting: 12 Feb 2013 12:00pm PT

Next agenda:
1) Task list item discussions

IBIS Interconnect SPICE Wish List:

1) Simulator directives

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