IBIS Macromodel Task Group

Meeting date: 21 September 2010

Members (asterisk for those attending):
  Adge Hawes, IBM
* Ambrish Varma, Cadence Design Systems
* Anders Ekholm, Ericsson
* Arpad Muranyi, Mentor Graphics Corp.
  Barry Katz, SiSoft
* Bob Ross, Teraspeed Consulting Group
  Brad Brim, Sigrity
  Brad Griffin, Cadence Design Systems
  Chris Herrick, Ansoft
  Chris McGrath, Synopsys
  Danil Kirsanov, Ansoft
  David Banas, Xilinx
  Deepak Ramaswany, Ansoft
  Donald Telian, consultant
  Doug White, Cisco Systems
  Eckhard Lenski, Nokia-Siemens Networks
  Eckhard Miersch, Sigrity
  Essaid Bensoudane, ST Microelectronics
Y Fangyi Rao, Agilent
  Ganesh Narayanaswamy, ST Micro
  Gang Kang, Sigrity
  Hemant Shah, Cadence Design Systems
  Ian Dodd, consultant
  Jerry Chuang, Xilinx
  Joe Abler, IBM
* John Angulo, Mentor Graphics
  John Shields, Mentor Graphics
  Ken Willis, Sigrity
  Kellee Crisafulli, Celsionix
  Kumar Keshavan, Sigrity
  Lance Wang, Cadence Design Systems
  Luis Boluna, Cisco Systems
* Michael Mirmak, Intel Corp.
* Mike LaBonte, Cisco Systems
  Mike Steinberger, SiSoft
  Mustansir Fanaswalla, Xilinx
  Patrick O'Halloran, Tiburon Design Automation
  Paul Fernando, NCSU
  Pavani Jella, TI
  Radek Biernacki, Agilent (EESof)
* Randy Wolff, Micron Technology
  Ray Komow, Cadence Design Systems
  Richard Mellitz, Intel
  Richard Ward, Texas Instruments
  Samuel Mertens, Ansoft
  Sam Chitwood, Sigrity
  Sanjeev Gupta, Agilent
  Scott McMorrow, Teraspeed Consulting Group
  Shangli Wu, Cadence Design Systems
  Sid Singh, Extreme Networks
  Stephen Scearce, Cisco Systems
  Steve Kaufer, Mentor Graphics
  Steve Pytel, Ansoft
  Syed Huq, Cisco Systems
  Syed Sadeghi, ST Micro
  Ted Mido, Synopsys
  Terry Jernberg, Cadence Design Systems
  Todd Westerhoff, SiSoft
  Vladimir Dmitriev-Zdorov, Mentor Graphics
  Vikas Gupta, Xilinx
  Vuk Borich, Agilent
* Walter Katz, SiSoft
  Wenyi Jin, LSI Logic
  Zhen Mu, Mentor Graphics

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Opens:

- Arpad: Kumaran Krishnasamy asked for jitter params for PCIe Gen3
  - Will Walter's BIRD handle this?
- Walter: This is about the compliance of a channel
  - This is not about actual buffer operation
  - IBIS has stayed away from that kind of thing
- Arpad: This is a spec parameter not a model parameter?
- Walter: Yes
- Arpad: We can table to a later time

- Michael M: We need a discussion about having a tech writer work on our spec
  - Also do we have to use plain text?
    - The IBIS charter requires transmission in emails by plain text
      - http://www.eda.org/ibis/docs/eia_org.txt
  - TechAmerica has a tech writer we can use
    - We can ask to have a template format developed

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

- none

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

- Arpad: Make Flow BIRD corrections and email
  - Done

- Ken: Send email to group about Format
  - Done

- Ken: Talk with Walter about Flow BIRD issues
  - Done

- Ambrish: Make Flow BIRD changes and email
  - Done

- Arpad:  Write parameter passing syntax proposal (BIRD draft)

          for  -AMS models in IBIS that is consistent with the
          parameter passing syntax of the AMI models

- TBD:    Propose a parameter passing syntax for the SPICE
          - [External ...] also?
          - TBD

- Arpad:  Review the documentation (annotation) in the macro libraries.
          - Deferred until a demand arises or we have nothing else to do

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

Arpad showed the Min/Typ/Max BIRD:
- Equal signs added back to range definition
  - Min should be allowed to equal Max
- Bob: This is sufficient
- Mike L motioned to vote to approve this BIRD for release to the Open Forum:
  - Bob seconded
- Roll call votes:
  Y  Cadence Design Systems
  Y  Ericsson
  Y  Mentor Graphics Corp.
  Y  Teraspeed Consulting Group
  Y  Agilent
  Y  Intel Corp.
  Y  Cisco Systems
  Y  Micron Technology
  Y  SiSoft
- The motion passed

Arpad showed an email with his rewrite of the Flow BIRD:
- Arpad: It was easier for me to rewrite the BIRD than to suggest changes
- Arpad: Step 3 in section 6b is the issue
- Ambrish: There is more to that section than the email shows
- Arpad showed the BIRD document
- Ken: Will this be the new baseline BIRD?
  - The one I sent last night could be the baseline
- Ambrish: I could explain my edits
  - Changes at the end of section 1 were removed
  - 2.1 and 2.2 fixed to not talk about system simulation
  - Section 3 talks about system simulation
  - Disagree with Arpad's comment on Step 9
- Arpad: It specifies "with the channel impulse response"
  - Saying what is convolved is misleading
  - We can discuss this externally
- Ken: So 9/20 is the baseline

Deprecation:
- Arpad: The new flow for 5.1 has no Use_Init_Output at all
  - We can't claim people can use it going forward in new models
  - Version numbering could handle this
- Walter: A new version param would be OK
  - The classical definition of deprecation is something we think will no
    longer be supported at some point
  - We should just not allow Use_Init_Output, but it requires a version param
- Arpad: Should this be applied to other params like Format?
- Walter: We don't want to make it too painful to convert to 5.1
- Arpad: Is it acceptable for older models to fail?
- Bob: That is the problem
  - Not all EDA tools are at the same version
- Arpad: Will anyone ever want to just put 5.1 on an old file?
  - No one should do that
- Michael M: Model librarians never just renumber models
  - They might use sections of old models in new files
  - They might renumber to get better checks
- Walter: Using the IBIS version would be a mistake
  - The .ami file is separate from the IBIS file
- Michael M: Agree that can be a problem
- Bob: Must EDA vendors support all versions?
- Mike: IBIS itself has had that problem
  - Some files would have commented out content
- Walter: Only one model out there uses Use_Init_Output=true && GetWave_Exists=true
- Michael M: What if a model is compliant to one version and not others?
- Bob: We can declare some params to be no-ops
- Michael M: A 5.0 model keyword should be legal forever, until the file becomes 5.1
- Walter: The parser works like that now
  - The problem is if the IBIS file version dictates how the .ami is parsed
- Michael M: We should find out how much work this change will be
- Arpad: The 5.1 parser could simply ignore the deprecated keywords
- Bob: We should not render older models erroneous
- Walter: It's easy to write a parser to ignore Format
- Fangyi: What happens if I use a new TX models with an old RX model?
- Walter: Use_Init_Output effectively does not exist, it is not an issue
- Arpad: If the spec does not cover Format can tools ignore it?
- Bob: Everything that is legal should be covered
- Arpad: This could complicate writing the spec
- Walter: It could be described in one place
- Mike: Many specs have a Deprecated Keywords section
  - Or we could simply ignore all unrecognized keywords
  - A problem with Format is that keywords under it must be promoted
- Arpad: There is a similar level problem with Value
- Walter: I had covered this with defaults are for missing items
  - Default only has meaning for a List
- Bob: The parser doesn't check for some of these things
  - We should make these keywords option for the next release
  - We have to document the reserved words we have created
- Walter: We should go "cold turkey" with a deprecation section
  - The purpose of deprecation is easy transition
- Arpad: It sounds like we agree
- Walter: We should vote on this next week

Next meeting: 30 September 2010 12:00pm PT

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IBIS Interconnect SPICE Wish List:

1) Simulator directives
