IBIS Macromodel Task Group

Meeting date: 25 May 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
* 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:

- Ambrish asked about LiveMeeting issues

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Call for patent disclosure:

- No one declared a patent.

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Review of ARs:

- Arpad:  Update section 2 text based on updated AMI flow
  - In progress

- Bob: Discuss ISS spec review process at Open Forum
  - Michael Mirmak accepted the editing task

- 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
  - Would like to discuss in this meeting

- 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

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New Discussion:

Arpad showed the new AMI flow diagrams:
- Spelling errors were fixed
- "StatEye type analysis" changed to "Statistical analysis"
- There were no further comments on this

Arpad showed the updated IBIS-AMI Flow Correction BIRD:
- Statement of the Issue is updated
- All of section 2 is replaced
- Arpad had compared the files side by side with WinMerge
- Fangyi: On page 6, 2nd paragraph of Step 2:
  - This seems to imply statistical analysis
- Arpad: There is some difference between the text and the flow drawing
  - This is a fine point
- Ken: What if Tx uses a modified impulse response and Rx uses GetWave?
  - Statistical analysis would shut off the GetWave part
- Todd: This gives channel output without EQ
- Ken: You want to allow that
- Todd: Right, we don't want to call things invalid if not necessary
- Fangyi: This is about how the tool interprets it, not the real value
  - Use_Init_Output is not valid here
- Todd and Ambrish agreed
- Todd: The slide is titled "statistical"
- Arpad: Each file has it's own Use_Init_Output
- Ambrish: Each is valid for it's own model
- Arpad: How will a result be displayed if it is not used?
  - The 2nd note is the problem here
  - The tool has to disregard TRUE or FALSE settings
- Todd: That flow is really talking only about time domain
- Fangyi: There should be separate flows for statistical and time domain
- Ambrish: It would be best to disallow it, not disregard
- Todd: GetWave flags have nothing to do with statistical
  - These are "don't cares" for that
  - The spec does not elaborate that
- Fangyi: Agree
- Ken: Agree
  - It should be valid if only one of Tx and Rx has GetWave
- Arpad: The flags on slide 2 are required to be meaningful
- Todd: Are people assuming flow #7 means you can't do statistical?
  - Note 1 means if both are FALSE then the model does nothing
  - In time domain the model does nothing
- Walter: Have to watch out for TX and RX usage
  - Used on the input to TX GetWave, not output
- Todd: The effect of the impulse response must be felt
- Ambrish: Page 145 says EDA tool must use it
- Arpad: This has nothing to do with Init output
  - Each AMI is associated with Tx or Rx
  - It is not clear which one the flag applies to on this page
- Todd: The letter of the law here is a little broken in places

Arpad showed pages 144 & 145 of the IBIS spec:
- Arpad: Two sentences were combined into one
  - Together these give us Note 1
- Ambrish: The logic is not correct
- Arpad: The policy is to avoid having conditions where there is no result
- Todd: Sometimes one model is Init only and the other is GetWave only
  - We have neglected this case
  - The Rx EQ effect will be missing
- Arpad showed slide 7:
  - We enumerated all cases
- Todd: That is for time domain only
  - John was right in calling for at least a warning
- Ken: Can we run statistical analysis when one is missing?
- Scott: There could be an approximation used?
- Mike: EDA tools should warn as they see fit
  - But we should explain the issues
- Ambrish: We can't predict all possible problem scenarios
- John: We need to have these cases understood
- Arpad: We can't count on GetWave doing something in a statistical analysis
- Walter: An Rx might have only clock recovery
  - That would be fine for statistical analysis
  - There would simply be no clock ticks from GetWave
- Arpad: So we should not force Use_Init_Output TRUE
- Ken: Right

AR: Arpad update AMI flow diagram and text

Walter: Would like to get my 4 BIRDs published

AR: Mike post BIRDs from Walter

Next meeting: 1 June 2010 12:00pm PT

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IBIS Interconnect SPICE Wish List:

1) Simulator directives