Minutes from the 13 December ibis-atm meeting are attached.
The following documents, which were discussed during the meeting, have been
submitted as BIRDs.
188 Expanded Rx Noise Support for AMI
<http://ibis.org/birds/bird188.docx> Michael
Mirmak, Intel Corporation December 13, 2016
187 Format and Usage Out Clarifications
<http://ibis.org/birds/bird187.docx> Michael
Mirmak, Intel Corporation December 13, 2016
IBIS Macromodel Task Group
Meeting date: 13 December 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
IBM Luis Armenta
Trevor Timpane
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
Kevin Li
Teraspeed Consulting Group: Scott McMorrow
Teraspeed Labs: * Bob Ross
TI: Alfred Chong
The meeting was led by Arpad Muranyi.
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Opens:
- Reminder: The meeting on December 27th is cancelled.
- Arpad noted that if we had any time left after discussing the current topics
then he wanted to review the list of Pending BIRDs. In particular, he wanted
to discuss BIRD 158.3 because models written to BIRD 158.3 continue to be
released by IC vendors despite the fact that it has never been approved.
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Review of ARs:
- Michael M. to incorporate discussed changes into the Deterministic Noise
Support BIRD draft and send out draft 4.
- Done. Posted to the ATM work archive.
- Michael M. to incorporate discussed changes into the Format and Usage Out
Clarifications BIRD draft and send out draft 4.
- Done. Posted to the ATM work archive.
- Bob R. to incorporate discussed changes and send out BIRD 184.2 draft 1.
- Done. Submitted to the Open Forum as BIRD 184.2.
- Bob R. to incorporate discussed changes and send out BIRD 185.2 draft 1.
- Done. Submitted to the Open Forum as BIRD 185.2.
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Call for patent disclosure:
- None.
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Review of Meeting Minutes:
- Arpad: Does anyone have any comments or corrections? [none]
- Bob R.: Motion to approve the minutes.
- Michael M.: Second.
- Arpad: Anyone opposed? [none]
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New Discussion:
Rx Deterministic Noise Support in AMI:
- Michael M.: [sharing draft 4]
- The only changes in this version are simplifications of the names:
- Rx_UnboundedGaussianNoise changed to Rx_GaussianNoise.
- Rx_BoundedUniformNoise changed to Rx_UniformNoise.
- These were the changes agreed upon last meeting.
- The terms unbounded and bounded are clearly stated in the definitions.
- Radek: The only issue I have is that "deterministic" still appears.
- I would remove it.
- Michael M.: Agreed, I will replace the five instances of "deterministic."
- Radek: Motion to submit this to the Open Forum with these changes.
- Arpad: Second. [no one opposed]
Format and Usage Out Clarifications BIRD:
- Michael M.: [sharing draft 4]
- Added new solution requirements (to fit the new BIRD template).
- The text changes are all in the introductory portion of "Format."
- The changes make sure we draw the correct distinction between handling of
In and InOut vs. Out, Info, and Dep.
- Curtis: In the second sentence of the introductory paragraph:
"... according to the Format selected."
- Would "specified" be a better word than "selected"?
- Michael M.: Yes.
- Arpad/Radek: To be clear, should we say, "specified in the .ami file."?
- Michael M.: Agreed.
- Bob R.: This BIRD is a clarification based on a BUG report about an ambiguous
error message.
- Michael M.: Yes, in the Background section of the BIRD I refer to BUG 183.
- Michael M.: Motion to submit this draft BIRD to the Open Forum with the
changes suggested.
- Bob R.: Second. [no one opposed]
Review of the Pending BIRDs list from the weekly agenda:
Pending BIRDs, expected to be rejected:
- Michael M: Many of these are related to what is being discussed in the
Interconnect task group.
- Assuming the latest draft of the Interconnect proposal is almost ready, soon
we can get it to the Open Forum and that should clear the way for action on
many of these.
Pending BIRDs, expected to be accepted (in discussion):
- Arpad/Mike L.: We can remove the BIRDs that have already been accepted.
- BIRDs 180, 182 and 183 can be removed from this list.
- BIRD 147.1 can be changed to BIRD 147.4.
Pending BIRDs awaiting discussion:
161.1 Supporting Incomplete and Buffer-only [Component] Descriptions:
- Michael M.: This will have to be modified based on whatever the Open Forum
does with BIRD 184.2.
- BIRD 161.1 touches the [Pin] keyword in similar ways to 184.2.
- Bob R.: We shouldn't need this at all anymore.
- BIRD 184.2 changes "must include all pins" to "should".
- Optional parameters to discuss incomplete models are no longer needed.
- Michael M.: BIRD 161.1 also addresses the issue of probing locations.
- The current probing location Sub-Params of the [Component] keyword are
not really used. Even if they were, they are out of date because they
currently assume "Pin" and "Die" are the only probing locations.
- The Interconnect proposal will also affect some of that language.
- We also have the issue that AMI deals with locations farther inside the
buffer than the die or the pad.
- So BIRD 161.1 might need to be restructured completely or split in two.
- Walter: For the purposes of this discussion, we know that BIRD 161.1 is in
Michael M.'s court. He can potentially modify it based on acceptance
of other BIRDs.
166 Resolving problems with Redriver Init Flow:
- Walter: Everyone agrees that the Init flow for Redrivers that is currently
given in the IBIS specification is wrong.
- My BIRD was simply to change the flow so that we give the right input to
each Rx AMI_Init().
- Fangyi and Vladimir have accepted this change, but they wanted to expand the
proposal to include additional inputs and outputs.
- They gave several presentations on their proposal, but it has been some time
since the last one.
- I think we should ask them to write a BIRD proposal, or we should untable
this BIRD in the Open Forum and get it sent back here to revisit and move
forward.
- Radek: I think their proposal was getting feedback and moving in the right
direction.
- They did not have all the details settled.
- I think Walter agreed with the changes, too.
- Walter: I did not object to them, but I don't think they are necessary.
- By delaying action on BIRD 166, the IBIS spec has had the wrong flow for
another year. We should correct the flow.
- Arpad: Is the proposal from Fangyi and Vladimir in conflict with yours?
- Could we act on yours, and then enhance it later with theirs?
- Walter: Yes, theirs would be a compatible add-on to mine.
- Arpad: Why don't we approach it that way?
- I will take the AR to send an email to check with Vladimir and Fangyi.
- Walter: Their proposed changes are independent of redrivers.
- They propose a general enhancement to Rx AMI_Init().
- Radek: Yes, it's independent, but it was motivated by the correction for
redrivers.
158.3 AMI Touchstone file (R) Analog Buffer Models
- Walter: This introduced a "Tstonefile" Reserved parameter to tell the EDA tool
to use a Touchstone file for the on-die S-parameter.
- It did not move forward because of a desire to use [External Model] to do
it.
- I have yet to see an IC vendor deliver an IBIS file with an [External Model]
that uses a Touchstone file for an on-die S-parameter.
- That's why I have not recommended that we move to reject this BIRD.
- I think this is the way many people are doing on-die S-parameters, because
they haven't figured out how to do it with [External Model].
- Arpad: That is the problem. That's why I brought it up.
- I don't necessarily care which syntax we use, but I don't want models being
written using an unofficial syntax.
- Walter: I understand.
- Some IC vendors haven't been able to figure out how to generate [External
Model] syntax for this.
- Arpad: I recently helped a customer convert a model from 158.3 syntax to
[External Model] syntax.
- I can convert from one to the other without additional info from the
original model maker.
- I could produce a slide or two on that process.
- Perhaps we should just ratify 158.3 and be done with it?
- It's completely equivalent, it's just a syntax issue.
- Radek: BIRD 158.3 could still be approved in its latest form, or perhaps in a
simplified form.
- We got stuck on issues of common mode and other things that could not be
handled properly in the differential-only mode that we consider for AMI.
- Otherwise, if we go back and simplify it to just reflect the way that people
use it, then the discussion may go fairly quickly.
- Bob R: What do you mean by simplified?
- Radek: We started putting in voltage levels and other things that complicated
the original proposal.
- Walter: I will work with Radek and review 158.3 with him.
- We will come to agreement on it and then bring it back here to ATM.
165 Parameter Passing Improvements for [External Circuit]s
- Arpad: This is one of my proposals.
- The problem is that [External Circuit]s and [External Model]s are
are instantiated on different levels in the IBIS hierarchy.
- When we added a parameter passing mechanism in BIRD 160, the oversight for
[External Circuit] was that the parameter definitions and passing mechanisms
were only defined for [External Circuit] and not [Circuit Call].
- Since [Circuit Call] is what is used to instantiate an instance of [External
Circuit], not having the parameter passing mechanism there means all
instances of an [External Circuit] have the same parameter values.
- That is too rigid and not what we intended.
- This BIRD proposes that the same parameter passing syntax be made available
to [Circuit Call].
- Michael M.: Motion to adjourn.
- Curtis: Second.
- Arpad: Thank you all for joining.
AR: Michael M. to submit the Deterministic Noise Support BIRD draft, with the
discussed changes, to the Open Forum.
AR: Michael M. to submit the Format and Usage Out Clarifications BIRD draft,
with the discussed changes, to the Open Forum.
AR: Arpad to email Vladimir and Fangyi to discuss moving forward with BIRD 166
or their proposal.
AR: Walter and Radek to review BIRD 158.3.
AR: Arpad to produce some slides on converting between BIRD 158.3 syntax and
the equivalent [External Model] syntax.
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Next meeting: 20 December 2016 12:00pm PT
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IBIS Interconnect SPICE Wish List:
1) Simulator directives
