IBIS Macromodel Task Group

Meeting date: 30 November 2010

Members (asterisk for those attending):
Agilent:                    * Fangyi Rao
                            * Radek Biernacki
Ansoft:                       Chris Herrick
                              Danil Kirsanov
Ansys:                      * Samuel Mertens
Dan Dvorjak
                              Deepak Ramaswamy
Cadence Design Systems:       Terry Jernberg
                            * Ambrish Varma
Celsionix:                    Kellee Crisafulli
Cisco Systems:              * Mike LaBonte
                              Stephen Scearce
			    * Ashwin Vasudevan
Ericsson:                     Anders Ekholm
IBM:                        * Greg Edlund
Intel:                        Michael Mirmak
LSI Logic:                    Wenyi Jin
Mentor Graphics:            * John Angulo
                              Vladimir Dmitriev-Zdorov
                              Zhen Mu
                            * Arpad Muranyi
Micron Technology:            Randy Wolff
Nokia-Siemens Networks:     * Eckhard Lenski
Sigrity:                      Brad Brim
                              Kumar Keshavan
                            * Ken Willis
SiSoft:                     * Walter Katz
                              Mike Steinberger
                            * Todd Westerhoff
ST Micro:                     Syed Sadeghi
Teraspeed Consulting Group:   Scott McMorrow
                            * Bob Ross
TI:                         * Casey Morrison
Vitesse Semiconductor:        Eric Sweetman
Xilinx:                       Mustansir Fanaswalla

The meeting was lead by Arpad Muranyi

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Opens:

- Introduction of new members:
  - Deepak Ramaswamy is making sure his tool follows the standard
  - Dan Dvorjak is trying to be more involved in IBIS developments
  - Sam Mertens has joined before, trying to follow AMI progress

- Arpad: We will not meet Dec 27, returning Jan 4

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Call for patent disclosure:

- none

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Review of ARs:

- Arpad update Version BIRD:
  - Done and Posted

- Arpad update Typos BIRD:
  - Done and Posted
  - Removed use of "deprecated"

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New Discussion:

Arpad showed the Typos BIRD draft:
- Fangyi:
  - Page 2 & 140: Can we combine these together?
  - Bottom of Page 4: If a branch is a leaf it can't have a sub-branch
    - Walter: Yes, we have that rule
    - Arpad: This would be a good list discussion
  - Page 5: We should say the DLL strings are only In or InOut
    - Arpad: Out should be allowed
    - Todd: Reserved_Parameters are Info, not passed to DLL
    - Fangyi: Res Par are not In or InOut
    - Todd: We should take this out
    - Walter: The fact it is two sections only matters to the AMI file
- Please send comments to Arpad

Arpad showed the Version BIRD draft:
- Bob: Is this posted?
- Arpad: It is in our archive section
- Arpad showed the ATM archive page
- Arpad showed Version_BIRD_2.txt
  - Fixes were highlighted
- Todd: There should be an example
  - It should show how to express strings
- Bob: The BIRD template has an example section
  - Should it be InOut?
- Todd: It should be Info
- Arpad: It could be passed in for checking
- Mike: It would be good to pass Info to the DLL for checking
- Walter: It would be better to just create an In, not pass AMI_Version
- Todd: Anything could be declared Model_Specific for this
- Fangyi: AMI_Version is reserved?
- This was verified in the BIRD
- Ken: Is this a problem for IBISCHK
- Bob: We will maintain 5.1 forever
  - IBISCHK has to support checking of every major version
  - This time we will retain support for a minor version, 5.1
  - In documentation we might tag parameters by which version introduced them
- Fangyi: Are separate IBIS_Version and AMI_Version a problem for the parser?
- Todd: It knows how to check every version
- Bob: We will never fix the 5.0 version because it is flawed
  - We should clarify that a higher DLL versions will support lower AMI files
- Todd: Why are they not a matched set?
- Radek: We see no reason to separate them
- Arpad: The need for this was related to the flow diagram
- Walter: In 5.0 strings do not have to be double quoted
  - In 5.1 they do
- Arpad: We had other reasons too
- Todd: The question is why we would support different IBIS versions in AMI
  files
- Walter: If IBIS updates old AMI models might not work
- Todd: We don't have to use new versions
  - No one has to change to avoid using double quotes
- Walter: IBIS has a rule that you can bump up IBIS_Version with no problem
- Todd: I wouldn't do that if it will break it
- Arpad: There is a specific problem with 5.0
- Radek: If you don't need 5.1 IBIS features, don't use 5.1
- Ken: Why not put IBIS_Version in the AMI file?
- Arpad: AMI_Version also serves for deprecation of AMI features
- Ken: This may be dangerous
- Todd: The expectation is that IBIS_Ver can be increased and nothing changes
  - There is no benefit in that
  - Old models can be passed off as new
  - Doing the same in AMI perpetuates a bad practice
  - We should not hold AMI files to the same rule
- Arpad: We are not ready to vote on this
- Bob: There are several reasons for doing it, but somewhat mushy
  - It's like .pkg files
- Ken: But .pkg files use IBIS_Version
- Walter: Touchstone is independent
- Todd: We are trying to
  - Provide model longevity
  - Provide problem fixing
  - Improve parts of the spec that are dead
- Ambrish: It should be OK as long as it is clear to developers
- Bob: We do not require 5.0 files to have any 5.0 features
  - Default and Value can be used together in 5.0
  - That has been deprecated
  - Format is technically illegal in 5.0, but it is supported by the parser
- Todd: Some models will pass 5.0 but changing them to say 5.1 they will fail
- Arpad: If we link AMI to IBIS_Version existing models will have to be
  updated
- Todd: Or they stay at 5.0
  - Why carry this baggage for eternity?
- Ambrish: We should be able to keep a model at 5.0
- Arpad: To use analog features 5.1 will be needed
  - Then you lose the ability to use AMI 5.0
  - At least .pkg and .ebd files have this own IBIS_Version fields
- Walter: We are spending a lot of time to discuss something that is not so
  important

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Next meeting: 07 November 2010 12:00pm PT

Next agenda:
1) Typos BIRD draft
2) Version BIRD draft
3) BIRD 121-124 discussions

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IBIS Interconnect SPICE Wish List:

1) Simulator directives