[ibis-macro] Nov. 2, 2010 IBIS ATM minutes

  • From: "Randy Wolff (rrwolff)" <rrwolff@xxxxxxxxxx>
  • To: <ibis-macro@xxxxxxxxxxxxx>
  • Date: Wed, 17 Nov 2010 08:55:53 -0700

Minutes from the Nov. 2, 2010 IBIS ATM group meeting are attached.

Randy

Randy Wolff 
SI Modeling Manager 
Signal Integrity R&D Group 
Micron Technology, Inc. 
208-363-1764 
 <<20101102.txt>> 

IBIS Macromodel Task Group

Meeting date: 2 November 2010

Members (asterisk for those attending):
Agilent:                      Fangyi Rao
                            * Radek Biernacki
Ansoft:                       Chris Herrick
                              Danil Kirsanov
Cadence Design Systems:       Terry Jernberg
                            * Ambrish Varma
Celsionix:                    Kellee Crisafulli
Cisco Systems:                Mike LaBonte
                              Stephen Scearce
Ericsson:                     Anders Ekholm
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
Texas Instruments:          * Casey Morrison
                            * Alfred Chong
Teraspeed Consulting Group: * Scott McMorrow
                            * Bob Ross
Vitesse Semiconductor:        Eric Sweetman
Xilinx:                       Mustansir Fanaswalla

(NOTE: The list above has been pruned to include only those attending at
       least one meeting in the past year, and reorganized by company.)

The meeting was lead by Arpad Muranyi

------------------------------------------------------------------------
Opens:

- Arpad: Set meeting schedule for next two months

  - November 9    No ATM meeting - Asian Summit (China)
  - November 16   No ATM meeting - Asian Summit (Japan)
  - November 23   No meeting due to US Thanksgiving holiday
  - November 30   Yes
  - December 7    Yes
  - December 14   Yes
  - December 21   Yes
  - December 27   No meeting
  - January 4     Yes


--------------------------
Call for patent disclosure:

- none

-------------
Review of ARs:

- Arpad update the Typos BIRD draft
    - say the Typ is the implicit default for all types
    - Discuss with Walter parameter Default/Value examples
    - done

- Arpad AR from Open Forum on BIRD 114.2:  Update BIRD 114.1 to
    include statements on escape characters in strings, and
    correct multi-line misinterpretation possibilities
    - done

-------------
New Discussion:

Discuss Arpad's Typos_Format_Value_Default BIRD draft

http://www.vhdl.org/pub/ibis/macromodel_wip/archive/20101026/arpadmurany
i/IBIS-AMI%20Typographical%20Corrections%20BIRD%20draft%204/Typos_Format
_Value_Default_BIRD_4.pdf

Arpad: Ready for a vote, would like a vote in the next meeting. Any comments?
  Bob: Where format is 'optional (being deprecated)', remove 'being 
depractated' 
       since it is optional.
  Arpad: Remembers being asked to include this text.
  Ambrish: Supports removing this text.  
  Arpad: Will remove the text.

Arpad: Asked Bob to write-up a suggestion for changing one of the notes.


Discuss Version BIRD draft

http://www.vhdl.org/pub/ibis/macromodel_wip/archive/20101026/walterkatz/
IBIS-AMI%20New%20Reserved%20Parameter%20AMI_Version%20BIRD%20draft%201/V
ersion_BIRD_1.pdf

Arpad: No comments received so far by email.
  Walter: Make sure we agree that if an existing IBIS 5.0 model referencing AMI 
    to the IBIS 5.0 definition of AMI, then if we change the IBIS version to 5.1
    is it still ok to have the older AMI model satisfying older AMI parsing 
    rules.  If the AMI file was legal before, is it still legal?
  Radek: No decision on that yet. 
  Bob: We should differentiate IBIS 5.1.  Can an IBIS 5.1 parser bring in an 
AMI 
    version 5.0 (without a version number). The parser should be able to.  This 
    does make an AMI version required for 5.1 and above.
  Walter: Intent of BIRD is for IBIS 5.1 models to support both 5.0 and 5.1 AMI 
    models. He doesn't think the BIRD is clear on this intent.
  Ken: If you update the IBIS file to 5.1, you should update the AMI file to 
5.1.
  Scott: Taking the contrary view.  An IBIS file could have multiple models in 
it.  
    Various models within the file could have features of various versions of 
    IBIS.  If no version in AMI file, it should revert to IBIS 5.0 for parsing 
    requirements.  He argued that there should be a return parameter from the 
DLL
    that identifies its version. This provides an error check.
  Walter: Make AMI_Version InOut instead of Info.  The EDA tool could tell if 
    there is a problem.
  Ken: Why shouldn't the versions be required to be the same?
  Walter: This breaks fundamental concepts of IBIS.


Discuss BIRD 119 / 121-124

  BIRD121:
  Walter: Comment to change DLLPAth to DLL_Path.
    Will change DLLid to DLL_ID.
    Samples_Per_Bit, there are models that require this.
  Ken: Is there a clash between models if Tx has one and Rx has another?
  Walter: Calls this situation torque conversion.  Must run each model with 
    different samples per bit.  Must convert impulse responses, stimulus files 
and 
    waveforms.
  
  BIRD122:
  Walter: Comments that the template is ok but other templates are needed as 
well.
    Described step function generation using the templates. Arrow on Tx model 
is 
    where the analog and AMI models split.  In Rx, Voh and Vol are allowing 
gain.
  Arpad: Needs clarification of Tr and Tf on Rx template.
  Walter: Mistake to add Tr and Tf on Rx template.
  
  Arpad: In Tx, does input to triangle have a shape?
  Walter: All those elements generate step response that is a PWL that goes 
    between Vol and Voh with rise time of Tr, Tf. 
    
  John: Noted some signs missing in Tx equations.
  
  Scott: This is a voltage mode circuit, how do you model a current mode Tx?
  Walter: model is only for generation of correct step response.
  
  Ken: This seems redundant when ISS will be coming into IBIS.
  Walter: We don't have ISS in IBIS.  This is being requested by several 
    companies, because this model comes from their internal tools.  Most 
vendors 
    actually supply a .s4p model
  Radek: Thinks the .s4p model should be the model supplied.
  
  Scott: What is the impedance of the summer?
  Walter: Thinks this is infinite impedance, direct conversion.
  Scott: Make sure this is defined.
  Arpad: Wouldn't the output of the summer driving ports 1 and 3 in the Tx be 
    zero impedance, an ideal driver?
  Scott: Summer is idealized voltage source with zero impedance. But the 
    S-parameter block has a defined impedance, so this sets up a reflection 
    boundary.  S11 needs to be there or you get the wrong response (also S12, 
S21).
  Walter: IC vendors are doing it this way already.
  Scott: This isn't about model makers, this is about writing a correct spec.
  Walter: Write it up for Mike Steinberger to respond to.
  Scott: Has already done this.  Others on the committee will need to respond 
as 
    well.
  Ambrish: Why shouldn't we look at other proposals on the table and choose the 
    best option?
  Walter: This BIRD will not be changed for other options.  BIRDs 116-118 
provide 
    another option.
  Scott: All he asks is that SiSoft provide a technical justification for their 
    methodology.  SiSoft is the lead on this BIRD so needs to provide the 
    technical details from the other BIRD sponsors such as Cisco and IBM.
    
  Scott: fundamentally there is a loss of energy, so where did it go?
  Casey: Can't the S-parameter be representing a perfectly terminated system?
  Scott: Yes, but this isn't perfectly terminated.  The authors need to justify 
    this.
  
  Arpad: Summer needs to be converted into its electrical equivalent.
  Ken: Questioning investment in hard-coded subcircuits as opposed to flexible 
    circuits.
  Walter: The model maker will not give a more specific subcircuit, they will 
    convert that to an S-parameter file
  Scott: These are Opal parameters.  Should these be added in a specific hard 
    coded way or add them in a more general way?
  Walter: My obligation is to explain this BIRD, but the Open Forum will vote 
on it.
  Arpad: This committee should be supplying technical feedback to improve 
quality 
    of the BIRD.  It will be up to the Open Forum to vote on each and every 
BIRD 
    to decide what is finally supported.  This committee can either provide
    technical assistance to the authors of the BIRDs or let them work on their 
own
    and let them submit the BIRDs to the Open Forum for discussion and vote as 
best
    as they can.

  
-------------
Next meeting: 30 November 2010 12:00pm PT

Next agenda:
- BIRD 119 / 121-124
- Any other new BIRDs

-------------
IBIS Interconnect SPICE Wish List:

1) Simulator directives

Other related posts: