IBIS Macromodel Task Group

Meeting date: 03 March 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
* 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
  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 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
  Vladimir Dmitriev-Zdorov
  Vikas Gupta, Xilinx
  Vuk Borich, Agilent
* Walter Katz, SiSoft
  Zhen Mu, Cadence Design Systems

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Opens:

Arpad: There was a conversation about s-params on the si-list recently
- Scott McMorrow asked why we would want to restrict s-params
  - Michael M: We must decide how much to say about quality, above and beyond format
  - Bob: Tools try to take care of these problems

Michael M: 2 years ago at DesignCon scope makers were interested in an AMI-like approach
- Walter: We did not ask scope makers to join us this time
  - They do a channel TDR to get equivalent impulse response
  - They have internal RX models
- Michael M: We should invite them to join a meeting

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Call for patent disclosure:

- No one declared a patent.

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Review of ARs:

- Todd:   Start a BIRD for IBIS s-params
  - TBD

- 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:

Continued discussion of IBIS Interconnect SPICE:
- Walter showed his IBIS Interconnect SPICE document
- Page 12:
  - This call has N nodes plus a reference node
  - Assuming the reference node is DC
  - Params: MNAME (model name), TYPE=s or y
  - Only FBASE and FMAX are commonly used
    - This seems to be required to make HSPICE work
  - Arpad: What is the order of precedence for instance vs. model params?
  - Radek: Do FBASE and FMAX truncate the file data?
    - We have to look into this
    - Randy: They are frequency points used for transient analysis
  - Arpad: Use of a single reference node makes all other ports single ended
    - Does this limit us?
    - Walter: One should be fine for what we are doing
    - Bob: Any port can be used as a reference node
      - Radek: That does not sound right
      - Michael M: Are we sure each port is a node?
      - Bob: The manual says this
    - Michael M: There are at least 3 terminal arrangements
      - HSPICE seems to use 2:
        - One reference for all nodes
        - One reference for each node
  - Bob: It may be best to copy the HSPICE description verbatim
    - Walter: We may want to limit how we use it
    - Michael M: We can invite Synopsys to join us to explain it
  - Mike L: Can TSTONFILE be used on the S call to bypass .MODEL?
    - Walter: Don't think so
    - Arpad: It would be a nice feature, maybe we should do it
      - Walter: Maybe as a next step
- Page 13:
  - The W element N= param is redundant
    - It can be determined from the number of terminals
  - HSPICE recommends not using RLCGFILE (deprecated)
  - NODEMAP is used when W elem calls an s-param
  - We have to know what the units of the model are to call it correctly
    - It could be inches, meters, whatever
  - TABLE model syntax is more complicated
    - It is similar to W model in ICM
  - Michael M: Suggest:
    - RLCG and TABLE .MODEL allow you to change order of matrices
    - The RLGC file has a more rigid format, easy to get wrong
    - How do we handle interpolation?
    - We should exclude geometric models
    - Randy: Would like to support RLGCFILE because models exist
  - Mike L: Are Rs and Gd still used?
    - Walter: Yes, quite accurate for stripline
    - Radek: Agree
  - Arpad: Does W have to support S format?
    - Radek: It is OK if only the S element has this
  - Radek: SP model format used by tabular format is very flexible
    - This is LMODEL, CMODEL, RMODEL, GMODEL
    - This may be difficult to use, goes far beyond W element
- Page 6:
  - We have to verify the list of functions
  - Arpad: ** can be used for ^
  - Walter: In HSPICE .PARAM can contain a node, but not here
    - Arpad: Not so sure, params are supposed to be static
      - Maybe it would use the DC operating point
    - This needs to be verified
- Page 9:
  - Not all EFGH elements support all options shown
- Page 10:
  - Bob: We should drop Foster Pole-Residue form
    - Radek: This is useful
    - We will keep it

AR: Todd invite Synopsys to join us for a syntax review

Arpad: We should add the details to make this a complete manual
- Walter that is the next step, but it is not trivial
  - Would be better to have a better source than PDF
- Arpad: Do we want to use the HSPICE format?
  - Walter: We should use HSPICE format
  - Bob: We should show that we are not hiding the origin of the document
    - We will need the source documents
  - Walter: Would prefer to just highlight the sections we are using
  - Mike L: There are PDF converters to other formats
    - Walter: It's easier to have it already in coherent document format

AR: Walter send updated IBIS Interconnect SPICE proposal to Mike L for posting
AR: Mike L post updated IBIS Interconnect SPICE proposal 

Next meeting: 10 March 2009 12:00pm PT

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