Minutes from the May 17, 2016 ibis-atm meeting are attached. Two documents
purporting to be version 3 of a Pin Reference BIRD draft were shown, but
only one is uploaded to avoid confusion. The other had few changes.
DATE
AUTHOR <http://ibis.org/macromodel_wip/archive-author.html>
ORGANIZATION <http://ibis.org/macromodel_wip/archive-org.html>
TITLE <http://ibis.org/macromodel_wip/archive-title.html>
FORMATS
17-MAY-2016
Bob Ross
Teraspeed
Pin Reference BIRD draft 3
(zip
<http://ibis.org/macromodel_wip/archive/20160517/bobross/_Pin_Reference_BI
RD_draft_3.zip> )(docx
<http://ibis.org/macromodel_wip/archive/20160517/bobross/%20Pin%20Referenc
e%20BIRD%20draft%203/Pin_Reference_3_ross.docx> )
Mike
IBIS Macromodel Task Group
Meeting date: 10 May 2016
Members (asterisk for those attending):
ANSYS: * Dan Dvorscak
Curtis Clark
Broadcom (Avago): Xingdong Dai
Bob Miller
Cadence Design Systems: * Ambrish Varma
Brad Brim
Kumar Keshavan
Ken Willis
Cisco: Seungyong (Brian) Baek
eASIC: David Banas
Marc Kowalski
Ericsson: Anders Ekholm
GlobalFoundries: Steve Parker
Intel: * Michael Mirmak
Keysight Technologies: Fangyi Rao
* Radek Biernacki
* Ming Yan
Maxim Integrated Products: Hassan Rafat
Mentor Graphics: John Angulo
* Arpad Muranyi
Micron Technology: * Randy Wolff
Justin Butterfield
QLogic Corp.: James Zhou
Andy Joy
SiSoft: Walter Katz
Todd Westerhoff
* Mike LaBonte
Synopsys: Rita Horner
Teraspeed Consulting Group: Scott McMorrow
Teraspeed Labs: * Bob Ross
TI: Alfred Chong
The meeting was led by Arpad Muranyi.
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Opens:
- None.
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Review of ARs:
- Ambrish to check for a collaborator's feedback on his nearly ready new
version of the Backchannel proposal.
- This is in progress.
- Ambrish will be unable to get to this for a few weeks.
- Ambrish will send the latest BIRD 147 version to Bob and Walter, as
requested [AR].
--------------------------
Call for patent disclosure:
- None.
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Review of Meeting Minutes:
Radek motioned to approve. Dan seconded. No one objected.
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New Discussion:
[Pin Reference] BIRD draft:
- Michael M: Will this BIRD be addressed and a recommendation made by this
group?
- Arpad: That has not been discussed, but it probably will be.
- Radek: It might not be a separate BIRD, it could be included in the ground
cleanup BIRD.
- Bob: This should be a separate BIRD.
- Arpad: It would have a dependency and would have to be approved at the same
time as the other BIRD.
- Mike L: We would vote on all BIRDs considered for 6.2 together.
- The edited 6.2 docx file can pre-incorporate the anticipated BIRDs.
- Radek: [Pin Reference] was an alternative to extending [Pin Mapping].
- That would have been another BIRD.
- Michael M: [Pin Reference] should not be a large editorial effort.
- Any changes should be easily accommodated.
- Arpad: We should try make some progress on it today.
- Mike L showed a rev 1.3 of the BIRD draft.
- Bob: We may be crossing paths, I have my own edited version 1.3.
- There is a note paragraph in Mike L's version that should not be there.
- Mike L: An example has IBIS syntax commented out.
- We should not show commented out keywords in the IBIS specification.
- Radek: That could be omitted and the result would effectively be the same.
- Bob showed his rev 1.3 BIRD draft.
- Bob: This has to assume [Pin Mapping], and it is stated as such here.
- For RS232 there may be no 0V reference voltage available.
- Mike L: It needs to identify a reference terminal, not a voltage.
- Does a bus_label map to a single node?
- Bob: It may be several nodes that map to one bus_label.
- Mike L: The voltages such as Vinl/Vinh are specified for a [Model],
but we are giving the reference terminal at the component level?
- Bob: For PECL the threshold shifts up and down relative to 5V or 0V rails,
for example.
- Different voltages can have the dominant effect on this shift.
- Arpad: Should there be a different reference for voltages that
are divided down to produce a threshold reference?
- We should do this right, make sure it covers all possibilities.
- Radek: It could be an [External Reference].
- Bob: This BIRD as written is intended to shift between the chosen
voltage and the embedded reference.
- Arpad: We used to use 0.8 and 2.0 for TTL, but actual values could vary.
- Bob: Those voltages were based on having one diode tied to ground.
- It was very insensitive to VCC changes.
- Arpad: The question is if Vinl/Vinh are specification based or behavior based.
- Bob: They are specified levels.
- Arpad: If 30% and 70% of actual are specified, do we have a way to express
that?
- Bob: Only for typ/min/max, using [Model Spec].
- Arpad: That may not be sufficient if we need to model the effects of the
supply noise modulating the divided or "proportional" thresholds.
- Bob: It is not determined which voltage rail is the correct one for a given
technology.
- Mike L: It's whatever the model maker knows is correct.
- Radek: Agree.
- Bob: The model maker may not know.
- Arpad: Should we assume everything on a [Model] uses the same reference?
- For example, we might need to associate Vinl with a GND rail and Vinh with a
POWER rail. Could we add something to [Pin Reference] to indicate that?
- Bob: There probably is no demand for that.
- Bob: The model maker needs to understand what is usually put in for
common technologies.
- Radek: The examples help, but we can't impose anything.
- Bob: It needs to be clear enough to support the needs of future
technologies.
- Arpad: As long as we provide the means for model makers to describe what
they need to describe instead of writing a spec with assumptions or
predetermined rules, we won't have to worry about unforeseen needs in
the future.
- Mike L motioned to adjourn.
- Radek seconded.
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Next meeting: 24 May 2016 12:00pm PT
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IBIS Interconnect SPICE Wish List:
1) Simulator directives