IBIS Macromodel Task Group

Meeting date: 22 March 2011

Members (asterisk for those attending):
Agilent:                    * Fangyi Rao
                            * Radek Biernacki
Ansoft:                       Chris Herrick
                              Danil Kirsanov
Ansys:                        Samuel Mertens
                            * Dan Dvorscak
                              Deepak Ramaswamy
                              Jianhua Gu
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
Snowbush IP:                  Marcus Van Ierssel
ST Micro:                     Syed Sadeghi
Teraspeed Consulting Group:   Scott McMorrow
                            * Bob Ross
TI:                           Casey Morrison
                              Alfred Chong
Vitesse Semiconductor:        Eric Sweetman
Xilinx:                       Mustansir Fanaswalla

The meeting was lead by Arpad Muranyi

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Opens:

- Arpad mentioned recent agenda additions
  - Bob asked to talked about the parser

- Mike said he would be unable to attend and take minutes Mar 29

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Call for patent disclosure:

- None

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Review of ARs:

- Radek start email thread about Crosstalk BIRD issues
  - Done
  - Radek: We need time to read it before discussing
    - There is a modification at the bottom that needs to be pasted in

- Arpad submit BIRD 120 with new changes to the Open Forum
  - Added sentence about GetWave block size
  - Done

- Ambrish draft update BIRD for Table syntax
  - Done

- Bob check BIRD 127 for type clarification possibilities
  - Done

- Ambrish start a BIRD on task list row 25
  - In progress

- Ken draft BIRD for multiple channels
  Done

- Bob write a BIRD on correcting Table 1-3 in the spec.  (Row 23).
  - In progress

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New Discussion:

Arpad quickly reviewed the list of items to talk about

Arpad showed Ambrish's Table Format clarification BIRD
- Arpad: We should be able to decide on submitting this
  - One comment was about needing an example
  - An example from the analysis section could be used
- Ambrish: Would rather have that in the main text of the spec
- Arpad: We usually do have examples with each keyword
- Ambrish: This introduces thing not yet covered in the spec
- Arpad: We might find another place for it further down
- Bob: This section describes AMI file syntax, not DLL syntax
- Arpad: This has the problem of having row names only for multiple rows
  - It also has a named list with no Table keyword
- Ambrish: This BIRD introduces only one new rule
- Bob: Do we need multi-row tables sent to the DLL?
- Ambrish: No
- Bob: We could hard code the number of columns
- Ambrish: One person creates the AMI and DLL
- Bob: The EDA tool sends the data to the DLL
- Radek: A number might be interpreted as a name
  - There could be something to say if rows have names
  - Or we could decide that one row tables have no names
- Ambrish: That would break some models
- Arpad: Would it break models if it is for new IBIS rev only?
  - Then we could have row names for all tables, including 1 row
- Bob: We would have to accept that existing models are broken
  - Tools will look for new models
- Scott: The parser has to know what to look for
- Arpad: I still need to know if old models will break
- Bob: It would be up to tools to parse based on the version
- Ken: What if RX and TX use different versions?
- Radek: That has to be accommodated
- Arpad: This applies to AMI parsing
  - The DLL can't depend on the version
- Radek: Tools will have to remember the AMI version for each DLL
  - Once we have a new version we have to do this
- Walter: Do not allow Table to be Input
  - Pass the table data as a strings with parentheses
  - Few models will be broken
- Ken: Working models should be accepted as is
- Arpad: The syntax of those models are non-compliant
  - They are not a great concern
  - We need a good syntax for 5.1 forward
- Walter: SiSoft has changed many models to solve problems
- Arpad: If tables can't be Input, they still could be Info
- Walter: Table rows can have any arbitrary ID
- Ambrish: The 5.0 spec does not mandate that the first table item is a number
- Walter: It is the ID
- Bob: The spec does not say it can be anything but a number
  - The example is not clear
  - It is called row number and it starts with -50
- Arpad: We need to define Table syntax now
- Walter: The recommendation last year was to use Table only for jitter
- Arpad: Should we have a new keyword and let Table die?
- Ambrish: Is multi-row input required?
- Walter: Strings with parentheses can do it
- Ambrish: Tables would be better if well defined
- Bob: Using strings changes the type
  - There are better ways to fix this
  - Adding one rule allows us to use the existing syntax
    - For multi-row tables the DLL must hard code the number of columns
    - No change for single row tables
  - We also have to decide if labels are sent to the DLL
- Arpad: We need to fix the spec which doesn't spell out the syntax
- Ambrish: The AMI file makers will decide how they want it
  - We could say every row has a name
- Arpad: If this is Info how does the tool know the meaning of the label
- Ambrish: If it's one row the DLL knows that
- Radek: It should be consistent
- Walter: Having one tree parse is elegant
  - HSPICE is complex because it has lots of parsers
  - This is where we are headed
- Arpad: Do we agree to fix the existing syntax?
  - Or will we create a new syntax?
- Ambrish: We should fix it
- Mike, Walter and Bob agreed 
- Bob: It has to be well defined
- We decided to fix the existing syntax
- Arpad: Should we try to be backward compatible
- Ken: We should be backward compatible
- Mike: We should prefer clarity over compatibility
- Bob: Current usages are only implied
- Walter: We can't force tools to support models made from bad interpretations
  - We need a well defined spec
- Ken: Can we vote on direction next week?
- Arpad: We can discuss this beginning with a forwarded email

Ken: Was there any feedback on crosstalk?
- Arpad: The email came out just recently
- Radek: It can be forwarded again

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Next meeting: 29 Mar 2011 12:00pm PT

Next agenda:
1) Task list item discussions

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IBIS Interconnect SPICE Wish List:

1) Simulator directives
