Minutes, IBIS Quality Committee

14 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:

- None

New items:

- Anders: Why do we require [Voltage Range] for series models?
  - Bob: This was for consistency, to avoid rule branches
    - Adding special conditions makes a spider web
  - Simulators have no use for this
  - Bob: Some series devices were used to convert voltage levels
  - This is not important enough for a BIRD
  - Bob: The same applies to C_comp which is not always needed

Continued review of the IBIS Quality Specification:

5.5.3.	{LEVEL 2}  [Ramp] test fixture has no reactives
- We looked at the IBIS spec for [Ramp]
  - Anders: [Ramp] is not required for inputs, terminators, and series
  - Mike: [Ramp] disallows package effects, but waveforms allow it
    - Bob: This was added later, with IBIS 2.0
      - Kumar had proposed adding more elements to the [Ramp] fixture
      - Reference voltage, for example
    - Mike: [Ramp] may have seemed less important at that time
- Mike: Some model waveforms don't show the same dv/dt as [Ramp]
  - Anders: This mismatch can be a problem
    - Some simulators may use [Ramp] to decide timestep
- Bob: This check should be deleted
  - Mike: Inclined to keep it
  - Eckhard: Keep it
  - Anders: Do we state that data for [Ramp] is linear?
    - Bob: It is just 2 points
  - Mike: Model makers either understand this or not
  - Bob: We should avoid having too many checks
  - Anders: Who uses this, model user or maker?
    - Mike: Model maker
  - Pavani: Keep it
    - Have never seen reactives used
  - Moshiul: Delete it
    - Have never seen reactives used
    - Model users have no way to know
    - Correlation with waveforms should do the trick
  - David: Delete it
    - Avoid checks that IBISCHK can't do
    - Company has to observe over 100 I/O standards
    - This is a burden for the vendor
    - Eckhard: But then users will have to do it
- Mike: We could delete this and propose the IBISCHK enhancment

- Pavani: A capacitive fixture could produce a sawtooth waveform
  - How would you separate rise and fall for a sawtooth?
  - Maybe we should disallow reactives for waveforms
  - Mike: This would be an extreme case
    - It would never settle to a static value
  - Bob: That just needs to be documented
    - For high speed simulation the edges are most important
- Bob: We caution against reactives in the cookbook
  - If [Ramp] matches a waveform with reactives then Ramp may be wrong
  - Only the model generator knows

- Mike is unable to meet next week

Next meeting:

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

Meeting ended at 12:05 PM Eastern Time.
