Subject: IBIS Open Forum 2/18/94 Meeting Min.

From: Derrick Duehren <[email-masked]>
Date: Mon, 28 Feb 94 19:12:07 PST

Text item: Text_1

Date:    February 28, 1994

From:    Derrick Duehren (503) 696-4299, fax (503) 696-4904
         [email-masked]
         Intel Program Manager
         (Will Hobb's IBIS Assistant)
         Intel Corporation
         5200 NE Elam Young Pkwy, Hillsboro, Oregon 97124 USA
         and
         Will Hobbs (503) 696-4369,  fax (503) 696-4210
         Intel Modeling Manager

Subject: Minutes from IBIS Open Forum 2/18/94

To:
Anacad                        Steffen Rochel
Ansoft                        Henri Maramis
Atmel Corporation             Dan Terry
Cadence Design                Sandeep Khanna, Chris Reed,
                              Pawel Chadzynski, Kumar*
Contec                        Maah Sango*, Dermott Lynch, 
                              Clark Cochran, Mike Venthon
Digital Equipment Corp.       Barry Katz*
High Design Technology        Michael Smith
HyperLynx                     Steve Kaufer, Kellee Crisafulli*
IBM                           Jay Diepenbrock*
IBM-Motorola alliance         Lynn Warriner*, Hoa Quoc*, John Burnett*
Integrity Engineering         Greg Doyle, Wayne Olhoft
Intel Corporation             Stephen Peters*, Don Telian, Will Hobbs*
                              Arpad Muranyi*, Derrick Duehren*
Interconnectix, Inc.          Bob Ross*
Intergraph                    Ian Dodd, David Wiens
IntuSoft                      Charles Hymowitz
Logic Modeling Corp.          Randy Harr
Mentor Graphics               Greg Seltzer, Ravender Goyal
Meta-Software                 Mei Wong, Mei-Ling Wei
MicroSim                      Arthur Wong*, Jerry Brown, Graham Bell
National Semiconductor        Syed Huq*
North Carolina State U.       Paul Franzon, Michael Steer, Steve Lipa
Performance Signal Integrity  Vivek Raghawan, Eric Bracken*
Quad Design                   Jon Powell
Quantic Labs                  Mike Ventham, Zhen Mu
Racal-Redac                   John Berrie*
Siemens Nixdorf               Werner Rissiek, Olaf Rethmeier*
Texas Instruments             Bob Ward
Thomson-CSF/SCTF              Jean Lebrun
Zeelan Technology             Hiro Moriyasu, George Opsahl

CC:
Intel Corporation             Randy Wilhelm, Jerry Budelman,
                              Intel IBIS team

In the list above, attendees at the 2/18/94 meeting are indicated by *

Upcoming Meetings:  Date:      Bridge:          Res:
                    3/11/94    (415) 904-8944   661901
                    4/1/94     (415) 904-8944   661905

All meetings are 8:00 AM to 10:00 AM PST (16:00 to 18:00 UTC).  We try to 
have agendas out 7 days before each open forum and meeting minutes out 
within 7 days after.  When you call into the meeting, ask for the IBIS 
Open Forum and give the bridge operator the reservation number.

Please note:  If you know of someone new who wants to join the e-mail 
reflector ([email-masked]) send e-mail to [email-masked].

------------------------------------------------------------------------------

2/18/94 Meeting Agenda
----------------------

8:00  Check-in
8:05  Intros of new IBIS participants                 Hobbs
8:10  Review of 1/28 minutes                          Hobbs
      Miscellany/Announcements                        Hobbs
        BIRDs
        Roster posted
        Please use CRLFs (Duehren)
      Opens for new issues                            All
      Treasurer's Report                              Hobbs
8:20  Press updates                                   Hobbs/All
      Progress toward enlisting new IC vendors        All
      IBIS 2.0 (ratification at DAC?, process?)       Hobbs
      IBIS Cookbook                                   Hobbs
      Dues (shelved till DAC?)                        Hobbs
      Standard driver?                                Muranyi, Powell
      Quality of support, validation                  Hobbs
8:40  BIRD 6, Differential Pin Spec.                  Ross
      BIRD 7, Open Specification Completion           Ross
      BIRD 8, Specification of V/I data monotonicity  Crisafulli
      Egg 1, mutual pin coupling                      Bracken
      BIRD 9, Other model types                       Ross
      Ramp measurement                                Reid, Ross, et. al.
      Spice to IBIS Converter                         Lipa (NCSU)
9:25  Canright paper                                  Ward
      Formal BNF notation (BIRD?)                     Reed, Harr
      BIRD 2, VIH, VIL Thresholds for Inputs          Powell
9:35  High freq. and EMI                              Goyal, et. al.
      Phased turn-on/off of multiple devices          Powell
9:55  Wrap-up, Next Meeting Plans                     Hobbs

Minutes
-------

1.  Intros of new IBIS participants
    New participant: Racal-Redac: Wants in-house tools support for IBIS (high-
                     speed and DRC tools)

    There were no corrections made to last month's minutes other than the 
    addition of the following new open forum participants from last month:
       Digital Equipment Corp.
       IBM-Motorola Alliance
       National Semiconductor

2.  Miscellany/Announcements
    The current BIRDs are posted on vhdl.org.  Apparently they were not posted 
    as individual files.  

    AR Derrick: to reorganize the BIRD files.  He expects to have this done by 
                3/4/94.  Note: Derrick now has sysop rights into vhdl.org (in 
                addition to Randy Harr of LMC).

    The roster of IBIS Open Forum participants has been posted to vhdl.org.

    Will Hobbs and Derrick Duehren have new email addresses.  The previous 
    addresses work, but the messages come through cleaner using the following 
    new addresses:

       [email-masked]
       [email-masked]

3.  Opens for new issues
    We need help for new people developing models (see #8, below).

4.  Treasurer's Report
    We now have a $2,600 balance.  Another golden parser was sold (to Anacad).

5.  Press updates
    EE Times of UK called Will Hobbs.  So far, they have only played 
    telephone tag.

    An EDA group (Open Model Forum) being formed to establish a universal 
    interface for logical models (EDA/Semi vendors getting together) met for 
    the first time this month and referenced IBIS as a model for how to 
    establish standards!

6.  Progress toward enlisting new IC vendors
    Will Hobbs is actively working with a new ASIC vendor (in a proprietary 
    relationship, so Intel can't say who, yet).

7.  IBIS 2.0 (ratification at DAC?, process?)
    We are trying to identify a good day at DAC to ratify IBIS 2.0.  The 
    DAC schedule is not out yet.  Will suggested that a steering committee 
    meet face-to-face before the DAC convention for a roll-up of the BIRDs 
    into 2.0.  This roll-up could then be distributed to the IBIS participants 
    for review before the DAC conference.  It was suggested that we hold the 
    IBIS meetings in the evenings at DAC as "Birds of a feather" sessions.

8.  IBIS Cookbook
    Lynn Warriner: We need an introductory toolkit (cookbook).  Access to 
    Kellee's package was helpful.

    The Intel version is nearly done.  Some of the text, such as "how to do
    measurements and extract the IBIS info" and "how to correlate against 
    SPICE", is generic and can be extracted.  A sanitized version as a
    starting place for an open IBIS cookbook should be ready in about a month.

    Kellee volunteered to help newcomers as well as help extract the open 
    version of the cookbook from Intel's proprietary version.

    National, DEC, IBM, and Motorola all asked for the cookbook.  IBM needs it 
    now.  They have an internal commitment to have the IBIS models out by 
    2/28/94.

9.  Dues
    None for now.  We will reevaluate them if the need arises.

    Later in the meeting, Kellee proposed limiting "official voting" rights to 
    those who have paid for the Golden Parser (GP).  Those that don't really 
    need it.  Silicon vendors, for example, could consider it a one-time dues 
    payment.  In other words, dues can be the GP fee, and you get the GP free.
    Official votes would come into play in case of dissension.

    AR Will: post list of current GP license holders.  Also post info on the 
             GP itself.   What it is, how to get it.  

    We will close on this issue in the next open forum meeting.

10. Standard driver, quality of support, validation
    Two topics we originally intended to treat separately are so intertwined 
    that the discussion continually bounced back and forth.  The basic 
    questions are:

    1.  Is there a standard circuit that all simulators use?

    2.  If not, how can we trust the results of the simulations after we 
        release the models?

        Related to this, if there is no standard model and no standard 
        simulator, how do silicon vendors know if the V/I tables they put in 
        IBIS models are correct?  How can the models be verified?

    Arpad prefers to not have his driver referred to as the "standard".  

    Kellee: Arpad's original model is not the standard, but a good starting 
    point.  It needs tweaks, as others have done.  

    Lynn: If you use VCCS (Volt Control Current Source) instead of resistors, 
    you end up with exponential response instead of linear.  It feels like we 
    need a mutually agreed upon simulation engine to verify integrity.  This 
    would help validate that the numbers that are extracted are correct.

    Maah: I don't think we (the Forum) are ready for selecting one simulator 
    as a standard, as we are all competitors.  Who's tool is chosen as the 
    standard?  Every vendor has responsibility to ensure the accuracy of their 
    own tool.  

    Lynn:  HyperLynx created a derivative of Arpad's model, Quad tuned theirs 
    for IBIS, other simulators will probably do it different ways.

    Kumar: There are many ways to implement the standard model.  We may want 
    to solve different problems, too, which affects how you implement the 
    model.

    Lynn: "We need a standard way of verifying V/I tables.  I probably 
    surfaced this mess last time.  I can generate V/I tables off simulation 
    and need a way to validate them."  

    Will: "The topologies shown in the Overview document are what Intel uses: a 
    couple of simple ones and a complex one to "break the model". 
    Within Intel, we use several different simulators and cross-check 
    the results."  Will is aware of at least 5 vendors' simulators used at 
    various Intel sites.

    Kellee:  We need a suite of simulations and models to validate simulators 
    and verify IBIS compliance among simulators.  We need to publish the test 
    suite, publish the expected results, and state that companies can self-
    certify, such as "Output results correlate closely with the expected data." 
    Leave it to simulator vendors to determine what "closely" means.  

    Q: Is there a test suite?
    A: Intel published one, although only for one type of model.  IBIS model 
       suppliers can publish the tests and results.  The results should "closely
       follow," with interpretation left to individual users.  Customers can see
       for themselves how closely the tool meets the IBIS form.

    AR Will: See if Intel/Don Telian can release waveforms for the 
             simulations in the Overview doc.  The data should end up in 
             Postscript format so the curves can be universally accessed.

    John Burnett: We need to specify which level of IBIS each company is 
    certified to.  Can we publish a list of vendors that have self-certified, 
    passed test suites? 

    AR Everyone: If, and when you self-certify (run the test suite), send email 
                 to [email-masked] so Derrick can add the 
                 information to the Participants Roster document.  Include what 
                 IBIS version level you support.

    Lynn: I want to push IBIS back into our entire product line, 100's of 
    parts.  I can feel comfortable in near term using a specific simulator, 
    but long-term, I need a standard simulator.  A prime element in 
    standardizing IBIS is a method for proving compliance.

11. Other Questions:

    Q: Regarding simulation at specific temperatures (0C, 50C, and 100C), are 
       we obligated to use these temperatures, or can we use whatever we specify
       our parts at (-20, 50, 120, or whatever)?  Is there a standard?
    A: No - use your own min/max temperatures.

    Kellee, Stephen: Use whatever temperatures give you the desired min and max 
    results.  We need a BIRD to clear up this set of questions.

    AR Lynn: Create a new BIRD.  Clarify that temperature used should reflect 
             the mix/ max of the component.  

    AR Derrick: Send BIRD.TXT to Lynn (Done).

    Q: What about dual voltage parts?
    A: Stephen: Intel uses two separate models.

12. BIRD 6, Differential Pin Spec.
    Bob Ross summarized the changes from 6.1, as documented in BIRD 6.2.
    We may want to expand this BIRD later.  Vdiff specifies difference of output
    values, pdelay now has polarity associated with it.  If positive, the 
    positive output is delayed with regard to negative output.  Pin package 
    delays can be speced separately from buffer delay differences.

    Kellee: Simulators need to know when to launch the ramp to achieve the 
    correct delay.  

    Bob: That's why we changed to tdelay instead of tskew; this actually 
    refers to launch delay rather than output delay.

    Vote taken: BIRD 6.2 was unanimously approved.

13. BIRD 7, Open Specification Completion
    Bob Ross summarized BIRD 7.2.  We discussed the differences in methodology 
    between BIRDs 7.2 and 2.1.  Are they two ways to do the same thing?  Worst 
    case, there will be some overlap.  Jon Powell was not present to comment 
    on BIRD 2.1.

    Vote taken: BIRD 7.2 was unanimously approved.

14. BIRD 8, Specification of V/I data monotonicity
    Kellee summarized, discussed what we should require to be monotonic in the 
    I/V tables: BIRD 8 proposes that user's choose voltage or current.  Feedback
    from the forum leaned in favor of requiring the voltage axis to be 
    monotonic.

    Arpad has recently seen a case where the current was non- monotonic; i.e., 
    a single voltage has two different current values.  

    AR Kellee: Repropose monotonic voltage and reopen discussion via email.

15. Egg 1, mutual pin coupling
    No discussion.

16. BIRD 9, Other model types 
    Bob Ross briefly discussed the intent of Bird 9, not looking for assent 
    yet.  By adding resistors as model types, we can eliminate unnecessary 
    processing of curves when a resistor would do.  As yet, the BIRD does not 
    address series (two-port) resistors. 

    AR Bob Ross: Add series resisters to BIRD 9. (Done)

17. Ramp measurement          
    No discussion.

18. Spice to IBIS Converter   
    No discussion.  Steve Lipa was not present to comment.  From Steve's email 
    messages, good progress has been made.  Steve plans to release his 
    converter to public domain.  Ramp is not yet incorporated.

    Steve is looking for SPICE models for testing the converter.

19. Canright paper            
    No discussion.

20. Formal BNF notation (BIRD?)
    Bob Ross did some work on the BNF parser.  Would like others to pick up on 
    it.

    Update: Steve Lipa is also working on the parser.  Bob posted his first 
    attempt to the reflector.

21. BIRD 2, VIH, VIL Thresholds for Inputs
    No discussion.

22. High freq. and EMI                    
    No discussion.

23. Phased turn-on/off of multiple devices
    No discussion.

24. Wrap-up, Next Meeting Plans           
    The next meeting is 3/11/94.