IBIS Macromodel Task Group

Meeting date: 22 September 2009

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 McGrath, Synopsys
  David Banas, Xilinx
  Deepak Ramaswany, Ansoft
  Donald Telian, consultant
  Doug White, Cisco Systems
* Eckhard Lenski, Nokia-Siemens Networks
  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, Cadence Design Systems
  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
  Shangli Wu, Cadence Design Systems
  Sid Singh, Extreme Networks
  Stephen Scearce, Cisco Systems
* 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
  Vikas Gupta, Xilinx
  Vuk Borich, Agilent
  Walter Katz, SiSoft
  Zhen Mu, Mentor Graphics

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Opens:

- Fangyi: Any update on the parser?
  - Michael M: We received a new draft code
    - It is behaving as expected
    - Minor typos in error strings
    - Need volunteers to compile for platforms other than DOS and Linux
  - Bob: Would like to have Reserved_parameters relaxed
    - That will take a BIRD
  - Michael M: We need to know what platforms people want soon

- Arpad: Email from Eric Monteiro

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

- No one declared a patent.

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

- Walter to send his presentation to Mike LaBonte.  
  - Done

- Arpad to add flow changes to his block diagram presentation and send to 
  Mike LaBonte.
  - Done

- Mike change web page to make items easily linkable
  - in progress

- Arpad Write a clarification BIRD to discuss accuracy issues related to the 
  various AMI clock_tick algorithms in an IBIS-AMI DLL
  - TBD

- Todd: Update the BIRD for IBIS S-parameter box based on feedback from discussion
  - No update

- 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

- 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 an email from Eric Monteiro:
- It contains 2 links referencing SiSoft presentations
- Eric sees conflicting statements:
  - One page says to measure Rx input
  - Other pages say to measure Rx output
- Arpad showed the presentation to verify the pages
- Todd: The first slide does not represent what AMI does
  - It says "Traditional SerDes Simulator Flow"
- Arpad: It should be measured at the Rx pad for channel characterization
- Todd: Agree, the receiver's network should load the channel
- Fangyi: There is no other choice
- Arpad showed email from Eric asking if measured at point D
- Slide 3 IBIS-AMI Serial Channel has arrows that do not denote measure points
- Fangyi: So we are arguing the definition of a channel?
- Arpad: There are separate pictures for channel characterization and AMI flow
- Fangyi: How does this reflect the asymmetric relationship between rise and fall?
  - Arpad: That would be a long discussion
  - Todd: We have to fix Tx_GetWave
  - It is left to model vendors

Arpad showed Walter's document "New Reference Flow":
- page 12:
  - One bullet has (if both Tx and Rx Use_Init_Output are true)
  - Arpad: What about the other cases?

Arpad showed his document AMI Flows:
- This shows the flows graphically
- Page 1 is Walter's proposal, page 2 is current
- Only difference between pages 1 & 2 are order between Tx_GetWave and convolution
- Fangyi: Tx_GetWave is inside Tx, so why is channel response included?
- Todd: The original idea was to let filters accommodate the channel
  - But currently that makes no sense
- Page 3:
  - Walter's proposal with true/false branching shown
  - Fangyi: The first implementation does not have Tx_Init Return Filter
    - Those booleans are not needed
  - Arpad: Walter's presentation explains the need
  - For Rx the convolution output is the same regardless of the boolean
  - The truth table for Tx_GetWave operation has 4 outcomes
  - John: Is Walter depending on the exact times of the bit stream?
  - Arpad: The wavy equal sign indicates there may be non-LTI effects
  - Fangyi: Why can't we put filter into channel response?
  - Todd: There is no good reason to do it
    - The model should just return the impulse response
  - Fangyi: It would eliminate one flag
  - Arpad: The flag is there for backward compatibility
    - We could say if Use_Tx_Init_Output is true then Use_Init_Returns_Filter is true
  - Fangyi: There should then be a note about that
    - The "or" in the notes would have to go away
- Page 4:
  - Tx_GetWave convolution truth table has only 2 entries
- Page 5:
  - Same as page 4 but with Rx_GetWave, no Tx_GetWave
- Page 6:
  - Neither Tx_GetWave nor Rx_GetWave
  - There is only 1 truth table entry
  - John: So given LTI the wavy equal is now an equal
- Page 7:
  - Waveform comes from some other tool such as SPICE
  - Use_Tx_Init_Output must be false
  - Fangyi: So we do not need Init_Returns_Impulse
  - Arpad: This is for backward compatibility
  - Fangyi: Old models will not work with the new flow
  - Todd: I wouldn't want to write that parser
  - Now that we see the flow we can see things we might get rid of
  - Todd: I need to be able to say that Init does nothing

Next meeting: 22 Sep 2009 12:00pm PT

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IBIS Interconnect SPICE Wish List:

1) Simulator directives