IBIS Macromodel Task Group

Meeting date: 6 January 2009

Members (asterisk for those attending):
  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
* David Banas, Xilinx
  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, Agilent
  Joe Abler, IBM
* John Angulo, Mentor Graphics
  John Shields, Mentor Graphics
  Ken Willis, Cadence Design Systems
  Kumar
  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 Comeau, Cadence Design Systems
  Richard Mellitz, Intel
  Richard Ward, Texas Instruments
  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
  Terry Jernberg, Cadence Design Systems
* Todd Westerhoff, SiSoft
  Vikas Gupta, Xilinx
  Vuk Borich, Agilent
* Walter Katz, SiSoft
  Zhen Mu, Cadence Design Systems

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Opens:

Happy New Year!

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Call for patent disclosure:

- No one declared a patent.

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Review of ARs:

- Michael M:  Confirm with Synopsys whether "used by permission" can be used
              as the official indicator on relevant documents.
  - Email from Michael M indicates no progress.

- 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

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New Discussion:

Discussion of IBIS specification direction:
- Arpad: Walter had listed some items last time.
  - We are going back and forth
- Walter:
  - Interconnect needs a total overhaul
  - SiSoft has made enhancements to IBIS
    - These appear as comments

Walter showed his list of recommended IBIS changes:
- 1) Many keywords must be deprecated:
     - Bob: Deprecating is a dangerous course
     - David: Better indexing may help
- 2) Implement keywords for diff and high speed:
   - a. Final Stage subckt
   - b. True differential 
   - c. Differential std load subckt
   - d. Common Mode Voltage
   - e. Simple N-tap FIR EQ for TX
     - This would have a voltage into an impedance
   - f. Simple LTI impedance model
     - Bob: Would this be algorithmic?
     - Walter: AMI is needed for RX
       - This would be a built-in AMI model
   - g. Cookbook for IBIS diff models
     - Arpad: The existing cookbook may cover this
- 3) [Specification] keyword to point to industry std specs:
   - David: How does the simulator use it?
   - Walter: IBIS would have to update now and then
   - Mike L: So the valid values would have to be exactly defined
     - Walter: There would have to be some registration authority
     - Bob: So each tool would have to implement all of these
   - David: Is there an example of this?
     - Walter: A document was sent out with an example
     - It might be JEDEC-103.7
   - David: If a human must interpret this, then it might be a comment
   - Arpad: The tool would implement the spec any way it wants
     - There may be some problems regarding spec versions
     - Bob: A lot of these documents aren't perfect
- 4) We need to start over on package models:
  - David: Is the implicit 1-1 mapping the problem?
    - Walter:
      - Has to be distributed
      - Has to be independent
      - Has to have coupling
    - David: Doesn't RLC handle this?
      - Arpad: It doesn't have G
      - Todd: It's an approximation, but not accurate enough
- 5) Large packages need sparse Touchstone
- 6) External Model DLL API:
  - This would allow [External Model] to call a DLL instead of a ckt file
  - Would handle more complicated models
- 7) ODT should have a separate place in the model:
  - It should be simpler than [Submodel]
- 8) Touchstone 2 does not address Port Data

Arpad: It would take a lot of meetings to do these things
- Bob: We could divide an conquer; pick one at a time
  - Deprecation could stall us
- Radek: EDA vendors have to support old features anyway

Mike L: The [Specification] keyword implies a list of reserved value
  descriptions
  - This could be a separate document that could change more often than IBIS
  - Tools could compete on their implementations
  - The scope and meaning of the values would have to be well described
- Arpad: Some vendors may get ahead of others in implementing

AR: Walter send color-coded version of his "Recommended course of action for IBIS"

Next meeting: 13 January 2009 12:00pm PT

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