Minutes, IBIS Quality Committee

07 Oct 2008

11-12 AM EST (8-9 AM PST)

ROLL CALL
  Adam Tambone
  Anders Ekholm, Ericsson
  Barry Katz, SiSoft
  Benny Lazer
  Benjamin P Silva
  Bob Cox, Micron
* Bob Ross, Teraspeed Consulting Group
  Brian Arsenault
* David Banas, Xilinx
* Eckhard Lenski, Nokia Siemens Networks
  Eric Brock
* Guan Tao, Huawei Technologies
  Gregory R Edlund
  Hazem Hegazy
  Huang Chunxing, Huawei Technologies
  John Figueroa
  John Angulo, Mentor Graphics
  Katja Koller, Nokia Siemens Networks
  Kevin Fisher
  Kim Helliwell, LSI Logic
  Lance Wang, IOMethodology
  Lynne Green
* Mike LaBonte, Cisco Systems
  Mike Mayer, SiSoft
* Moshiul Haque, Micron Technology
* Pavani Jella, TI
  Peter LaFlamme
  Randy Wolff, Micron Technology
  Radovan Vuletic, Qimonda
  Robert Haller, Enterasys
  Roy Leventhal, Leventhal Design & Communications
  Sherif Hammad, Mentor Graphics
  Todd Westerhoff, SiSoft
  Tom Dagostino, Teraspeed Consulting Group
  Kazuyoshi Shoji, Hitachi
  Sadahiro Nonoyama

Everyone in attendance marked by *

NOTE: "AR" = Action Required.

-----------------------MINUTES ---------------------------
Mike LaBonte conducted the meeting.

Call for patent disclosure:

- No one declared a patent.

AR Review:

- Mike post IQ spec 1.1ai draft
  - Done

New items:

Continued review of the IBIS Quality Specification:

- Mike: The 1.1ai draft IQ spec as posted may not have revision note for
  changes that were made to 5.5.1

5.5.2.	{LEVEL 2}  [Ramp] R_load present if value other than 50 ohms
- IBISCHK can't check for this
- Mike: It would have been better if R_load were always required
  - Bob: IBIS did not have R_load initially
- Is this level a 2 check?
  - Mike: what goes wrong if R_load is wrong?
    - It is possible to check [Ramp] against equivalent waveforms
    - Bob: Would ODT be checked?
  - Mike: R_load affects neither waveforms nor timing
    - But not all models have waveforms
- We agreed to leave this check unchanged

5.5.3.	{LEVEL 2}  [Ramp] test fixture has no reactives
- Mike: Sometimes we see IBIS files with [Ramp] not matching waveforms
  - Sometimes min/max V are taken from peaks, not endpoints
    - Some buffers have a reverse bump before the real edge begins
  - Maybe sometimes reactive fixtures are used
- Bob: There was some discussion in the past about adding more [Ramp] params
- Moshiul: If the model is made from measurement this is unavoidable
  - Bob: The fixture RLC can be de-embedded when the model is made
- Moshiul: What do we recommend for waveforms with regard to reactives?
  - The IQ spec has no mention of prohibiting reactives in the waveform checks
  - 5.5.7 makes an allowance for waveform reactives
- Should we allow reactives?
  - Guan: It should be OK, but Ramp and waves should have same fixture.
  - David: Why are reactives a problem?
    - Mike: An R-only fixture waveform is needed for simulators to calc K factor
      - If there are reactives they have to be de-embedded
    - Bob: We had to allow for reactive fixtures when this was created.
      - I-V and V-T tables have to be smooth to avoid abrupt K changes
  - David: Are we moving away from bench measured models?
    - Mike: There is pressure to avoid those because min/max is not present
    - There may be some models that have the package de-embedded
  - Moshiul: Are simulator algorithms dealing with the problem?
    - Bob: Some simulators may even ignore reactives
  - Mike: If L & C are de-embedded from the model the [LC]_fixtures are absent
    - Simulators should simulate it the same way

- Moshiul: The IBIS spec discourages reactives
  - Mike: Then IQ should be able to ban them

- Mike: Should we have a new 5.4 check banning reactives in waveforms?
 - We will discuss this next week

Next meeting:

14 Oct 2008 11-12 AM EST (8-9 AM PST)

Meeting ended at 12:07 PM Eastern Time.
