Minutes, IBIS Quality Task Group

26 November 2019

11:00-12:00 EST (08:00-09:00 PST)

ROLL CALL

Intel Corp.                         Michael Mirmak
Mentor, a Siemens Business          Arpad Muranyi
Micron Technology                 * Randy Wolff
Signal Integrity Software:        * Mike LaBonte
SPISim                              Wei-hsing Huang
Teraspeed Labs:                   * Bob Ross
Zuken USA:                        * Lance Wang

Everyone in attendance marked by *

NOTE: "AR" = Action Required.

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

Call for IBIS related patent disclosures:

- None

Call for opens:

- None

Review of previous meeting minutes:
Minutes from the November 12 meeting were reviewed.  Bob Ross moved to approve the minutes.
Lance Wang seconded.  Without objection the minutes were approved.


ARs:
- None


IBISCHK700 parser development:
Bob Ross said there could be an IBISCHK7.0.1 with 4 bug fixes.


IBISCHK7 source code license:
Bob Ross said we had 8 license agreements signed, with one more signature pending. We
were waiting for payments from 3 licensees. That would be 4 after the next signature. The
delays are due to long payment cycle policies. Mike LaBonte commented that revenue
from the license sales should cover life cycle costs for IBISCHK7.


New IBISCHK bugs:

BUG208:
Mike LaBonte showed BUG208.  Bob Ross described changes he had made to the bug report
drafted by Mike.  Mike showed the affected source code and explained the mechanism of
the bug.  He noted that he had fixed the code and tested that, and the testcase file
had checked successfully.  Randy Wolff asked if the fixed code had been tested with
Arpad's original parser hang testcase. Mike said it had not.

AR: Mike LaBonte to test IBISCHK7 fix with Arpad's original parser hang testcase

Mike asked when the bug report would be sent to Atul. Bob said the report should be
uploaded and then Bob will send the link to Atul. Bob noted that source code licensees
could fix their own copies immediately.

AR: Bob Ross to have BUG208 uploaded and notify the developer

BUG207:
Randy Wolff asked to discuss BUG207, which Mike showed.  Randy said the bug probably
should be addressed, asking about the level of difficulty. For his testcase it was
lucky that there was a simple workaround.  Mike LaBonte said it should be fairly easy
for IBISCHK to determine the curve state at the beginning and end points.  Bob Ross
said fixing this for all versions might break existing models.

Lance Wang asked for clarification about the nature of the bug, asking if IBISCHK
was not combining all of the curves for checking.  Randy said that was the case.
Lance asked how the original model was constructed, such that it used a Dynamic_clamp
for something that was static.  Randy said it allowed the extraction of the static
behavior to be handled separately.  Lance said the V-T curve could not have exactly
the same profile as a Dynamic_clamp in actual operation.  Mike agreed, noting that
dynamic clamps can be triggered by the received waveform.

Lance said IBIS extraction would usually have separate simulations for dynamic and
static characteristics.  Randy said there were two ways it could work. He was unable to
extract a V-T that would swing between 0 and 0.5V.  The driver didn't work that way,
it was designed to work with termination on all the time.  A clamp was appropriate
for that.  Mike noted that the text for Submodel did allow for static I-V curves.
Bob said in driving mode the Submodel I-V curve was enabled.  Randy said that there
were no checks for input mode.  Bob described presentations he had given on the subject.
Randy suggested having IBISCHK check including the currents of at least static Submodels.

Mike LaBonte said we needed to discuss whether a fix for this would apply to all IBIS
files containing [Driver Schedule] and [Submodel], or only to version 7.0+ files to
minimize the impact to existing files. He noted no IBIS language change necessitated
checking it only for 7.0+. He suggested the issue could be discussed in an Open Forum
meeting to involve more stakeholders.


IBIS-ISS parser:
Discussion was tabled.


Bob Ross moved to adjourn. Lance Wang seconded. Without objection the meeting ended.

Meeting ended: 12:07 ET

Next meeting December 3, 2019