Subject: IBIS Accuracy Subcommittee Minutes - 11/05/98

From: Gregory R Edlund <[email-masked]>
Date: Fri, 6 Nov 1998 12:24:07 -0500

IBIS Accuracy Subcommittee Minutes

Thursday, November 5, 1998
Held at Compaq Computer, Maynard, MA

Attendees

Greg Edlund, IBM (by phone)
Bob Haller, Compaq Computer
Peter LaFlamme, Fairchild Semiconductor
Harvey Stiegler, Texas Instruments (by phone)

Time and location of next meeting to be determined.

MILESTONES

Pass 2 of the test board has been fabricated, assembled, and is currently in
testing.  Those of you who have been waiting for the design files can expect
them before the end of 1998.  The Test Board Application Note make take a while
longer.  The subcommittee will post a notice to the reflector when these events
occur

October 15, 1998: IBIS Accuracy Test Board tested - demo at PCB East IBIS
Summit.
October 15, 1998: Rough draft of IBIS Accuracy Spec distributed at PCB East
IBIS Summit.
November 22, 1998: Submit final draft of DesignCon99 paper.
February 1999: Present the IBIS Accuracy Specification at DesignCon99.

EDITING

No activity this meeting.

The IBIS Accuracy Specification should be made available on the web as soon as
possible to increase visibility and the potential for feedback.  The
subcommittee would like to see a link to the spec from somewhere within the
main IBIS web page if possible.

DESIGNCON99

Most of the group activity has been focused on the final draft of the
DesignCon99 paper, which includes taking data from the test board.  HP will be
providing test equipment for the demo that accompanies the paper: HP54750
digital oscilloscope and TDR, FET probes, power supply, and multimeter.  Bob
Ross has suggested the possibility of space at the IBIS booth, and this topic
will be up for discussion at the next Open Forum.  The Accuracy Subcommittee
would also like to suggest setting up IBIS development software from one or
more vendors and demonstrating curve overlay techniques.

FUTURE ACTIVITIES

Once the DesignCon99 final draft is done, the subcommittee will return to
activities related to the IBIS Accuracy Specification and the test board.
These include:

1. Finish writing the rough draft of the IBIS Accuracy Specification.
2. Publish the test board design files.
3. Write and publish the IBIS Accuracy Test Board Application Note.
4. Implement feedback from the IBIS community.

There seems to be a strong body of opinion that the IBIS Accuracy Specification
needs to be decoupled from the question of simulator accuracy.  One possible
means suggested for accomplishing this goal is VT tables.  However, VT tables
presently lack the capability of transmission line loads.  This means a new
BIRD, which would delay the introduction of the first draft.  We began debating
ways to implement VT tables into the spec, but decided to table the discussion
until after we submit the DesignCon99 final draft.

Including VT tables in the spec represents a significant amount of work.
Indeed, parts of the spec would have to be re-written.

We are coming to the realization that no matter what direction we take on the
implementation of VT tables, much of the next year of the IBIS Accuracy
Subcommittee will be spent dealing with simulation questions and advanced model
features, including advanced I/O buffer designs.

Greg Edlund
Advisory Engineer, AS/400 System Timing
IBM
3650 Hwy. 52 N, Dept. HDC
Rochester, MN 55901
[email-masked]