IBIS Macromodel Task Group

Meeting date: 11 August 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, Cadence Design Systems

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Opens:

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Call for patent disclosure:

- No one declared a patent.

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Review of ARs:

- Walter investigate requirement for DC= on V element
  - It is optional

- All please send any other feedback on IBIS-ISS by email to Walter
  - Some had trouble opening the document

- Arpad send updated IBIS-ISS presentation to Walter
  - TBD

- Mike change web page to make items easily linkable
  - Some progress last week, but not done yet

- Todd ask Synopsys about public posting of the document
  - Walter: Todd reports that we have permission
    - Not completely sure that all points have been considered
    - We may need to clean up the copyright references
    - It can be posted as a working document, however

- Arpad write a BIRD to clarify time period accuracy requirements
  - TBD

- Todd: Write IBIS s-param BIRD
  - 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

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New Discussion:

We discussed Arpad's written review of IBIS-ISS:

1)  Overview:  "The IBIS Open Forum ... proposes"?
- This was left as-is.
- Randy: "Subckts" could be spelled out
- Bob: Put parentheses around "IBIS-ISS"
- Bob: We should avoid "standardization"
  - IBIS is a "specification", for example, not a standard
- We eliminated the subtitle.
2)  "May which to have a more limited set of characters."
    on pg. 6 doesn't make sense.
3)  "The first character in every line specifies how IBIS-ISS interprets the remaining line. "
    on pg. 10 incorrect English.
4)  Reference error on pg. 11
5)  "except in sub-circuits where instance names begin with X" 
    on pg. 11 is wrong...
- We fixed the language there
6)  Are scale factors case sensitive? pg. 12.
- Walter: No
- The difference between columns 1 and 3 is not apparent at first.
7)  "definitioneven" spelling error on pg. 13
- Fixed
- Eliminated reference to functions, which we do not support
8)  "When you select design parameter names, be careful to avoid conflicts with parameterized libraries."
    is impossible.  What are the scoping rules if it does happen?
- Walter: We do not support global parameters
- Arpad: It says we do not "recommend" them; they should be avoided
9)  "Traditional SPICE includes the basic sub-circuit, but does not provide a way to consistently name nodes. However, IBIS-ISS provides a simple method for naming subcircuit nodes and elements: use the subcircuit call name as a prefix to the node or element name."
    needs examples on pg. 14.
- This was deleted
10) "To delimit expressions, use single or double quotes." on pg 13
    conflicts with "To invoke the algebraic processor, enclose a complex expression in single quotes. "
    on pg. 17
- Arpad: There is a conflict between pages 13 and 17
- We changed it to support only single quotes, not double
11)  Unfinished sentence on pg 17:  "A later definition changes its value, or "
Eckhard: On page 20 need to add "in which the ..."
12)  pg. 22 talks about global parameters but doesn't explain how
     to make one as opposed to a local parameter.  Also, I don't see
     any scoping rules to explain what happens with parameter definitions
     in subcircuits.
- We removed this
- Walter added descriptions of how to define parameters
- Some discussion of whether instance call X=0 overrides .param X=3
13)  "Floating power supply nodes are terminated with a 1 megohm resistor and a warning message"
     on pg. 25  I didn't know a message can terminate circuit elements...  :-)
- We eliminated the "floating ... 1 meg resistor"
14)  pg. 26  "The first line of a netlist is always a comment"  doesn't
     apply to us, since we are only subcircuits.
- Deleted: we don't have netlists
15)  "Figure 40" on pg. 31 what is the figure?
- This was deleted
16)  There are references to page numbers which don't exist. on pg. 33-34
- Example: reference to page 96 on page 32 to describe W element matrices
  - Arpad: Should we have this at the end?
  - Walter: We did not include details like this in ICM
    - It is common knowledge

Arpad: Should we resolve the open questions here or in open-forum
- Walter: We should post it for comment
- Bob: We can post on the ATM website and tell the open forum

AR: Walter send updated IBIS-ISS to Mike L
AR: Mike L post IBIS-ISS to website and email open forum

Walter showed his IBIS-AMI proposal presentation:
- Convolving analog impulse response with input stimulus to send to Tx_GetWave
  does not handle non-LTI Tx_GetWave or inter-symbol interference
- TX_Init and Rx_Init should simply return waveforms, not convolve
  - Tools can easily convolve themselves
- Kumar: Non-LTI should not be a problem
  - Duty cycle distortion and post-processing can be handled
- Walter: Disagree
- Kumar: There is too much software investment to make changes
- Walter: Proof is needed that Tx_GetWave needs a digital input
- Arpad: There seems to be an issue over the terminology of "digital waveform"
- Walter: So far only SiSoft has released Tx_GetWave models
- Bob: Kumar could prepare a presentation to make his point next week
- Arpad: We need to have these points explained precisely so everyone can understand

Next meeting: 18 Aug 2009 12:00pm PT

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IBIS Interconnect SPICE Wish List:

1) Simulator directives
