Minutes from the January 12, 2022 IBIS Interconnect Task Group meeting are
attached.
Regards,
Justin
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IBIS INTERCONNECT TASK GROUP
http://www.ibis.org/interconnect_wip/ ;
Mailing list: ibis-interconnect@xxxxxxxxxxxxx
Archives at //www.freelists.org/archive/ibis-interconn/ ;
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Attendees from January 12, 2022 Meeting (* means attended at least using audio)
ANSYS Curtis Clark
Intel Corp. Michael Mirmak*
MathWorks Walter Katz
Micron Technology Justin Butterfield*
Randy Wolff*
Siemens EDA Arpad Muranyi*
ST Microelectronics Aurora Sanna*
Teraspeed Labs Bob Ross*
Zuken USA Lance Wang*
Aurora Sanna introduced herself. She is from ST Microelectronics, which joined
IBIS earlier this year, and she is interested how they can contribute to IBIS.
Many people in the company are involved with modeling and IBIS in particular.
Aurora is currently working on package modeling. She is also interested in how
the committee and task groups work. Michael Mirmak gave a brief overview of
the IBIS Open Forum and Task Group structure, to explain how new features and
technical improvements are made in the IBIS-managed documents.
Michael convened the meeting. No patents were declared.
Justin Butterfield took minutes.
Review of Minutes:
- Michael called for review of the minutes from the February 17, 2021 meeting.
Michael displayed the minutes. Arpad Muranyi moved to approve the minutes.
Randy Wolff seconded. The minutes were approved without objection.
Review of ARs:
- None.
Opens:
- Michael noted we have the Touchstone 3.x topic to discuss.
- Arpad noted that three BIRD drafts had been discussed in the ATM Task Group.
Two drafts were to be transferred to Interconnect. The third has not yet
been written.
- Aurora noted that, with IBIS 7, there is a possibility to integrate
Touchstone models into IBIS. She asked how to make the Touchstone models
fast and simple for the model user. She asked if there is an alternative
model format to consider both high speed accuracy and fast simulation, or if
there are guidelines to address this with Touchstone.
Touchstone 3:
Michael mentioned and showed the existing TSIRD list with three changes to
Touchstone, including binary and sparse matrix formats for compression. All
three of these changes have been approved, but none of the three have been
integrated into Touchstone yet. Arpad noted we also had a survey, where the
topic of using the pole-zero coefficient format was discussed. Bob Ross
commented the pole-zero format has not been officially proposed in a TSIRD.
Randy noted S-parameter is the common model format for packages, but each tool
has its own algorithm and method to interpret the S-parameter. He also noted
the pole-zero model could be done in the IBIS-ISS format.
Michael asked if we have any restrictions in IBIS 7.x requiring a specific
Touchstone version. Arpad replied there is no restriction on the Touchstone
version in IBIS currently. Randy noted there are some tools which do not
support Touchstone 2, and he has had to down convert models to Touchstone 1 for
customers. Aurora also experienced some tools not supporting the triangular
matrix feature in Touchstone 2.
Aurora asked how it is possible that the EDA tools do not support all the
features. Arpad commented sometimes EDA tool vendors may have other priorities
based on their customer needs. Randy noted there may also be disagreements
about whether a feature is needed in IBIS or not, causing some to not support
it right away.
Bob noted Vladimir has presented the pole-zero format in the past, but there is
no TSIRD proposal. Bob suggested Radek as a possible author. Arpad suggested
we should decide on the direction of the Touchstone specification before
writing any new TSIRDs. Bob commented Walter's proposal is to make the
keywords optional and that will effect our future direction. Arpad suggested
to discuss further when Walter can attend.
Designator Pin Relaxation:
Arpad noted, currently, all of the pin_names must be listed in the Designator
Pin List keyword. The intent of the BIRD is to relax this requirement. For
draft 3 of the BIRD proposal, Arpad updated the text to say that all of the
pin_names are allowed in the Designator Pin List keyword, but not required.
EMD NC Pins:
Arpad was considering a third BIRD draft to address NC pins in EMD. The
problem is, if there are many NC type pins, new signal_names would have to be
created for all of them. Walter had previously proposed to have NA in the
signal_name column for NC pins. Randy commented we do not want to break any
IBIS 7.1 models with these rules. Bob noted we took out NC in the EMD
specification, since a terminator could be added. He does not like adding NA
in the signal_name. Arpad suggested a rule for NC pins that the signal_name
becomes meaningless.
Next Meeting:
The next meeting will be January 19.
Arpad moved to adjourn. Randy seconded. The meeting adjourned without
objection.
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Bin List:
1. TS 3.x â remove requirement for bracketed keywords?
2. Pole-zero support for Touchstone
3. New version of Touchstone to include 3 TSIRDs
4. Clarification BIRD drafts from ATM
