Minutes from the 08 November ibis-atm meeting are attached.
IBIS Macromodel Task Group
Meeting date: 08 November 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:
- None.
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Review of ARs:
- Walter to put the file name relaxation proposal into a BIRD format.
- In progress.
- Michael Mirmak to update his Format and Usage Out Clarifications BIRD draft
based on the discussions.
- In progress.
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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]
- Walter: Motion to approve the minutes.
- Dan: Second.
- Arpad: Anyone opposed? [none]
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New Discussion:
Relaxation of IBIS filename restrictions:
- Walter: [sharing the most recent proposal email (with rev3 of the proposal)]
- Latest email has a brief explanation of the relative path directory:
- I think the only issue that is in contention is if "Path Names" in a
"File" referenced in an "IBIS File" shall be relative to the directory
containing the "File" or the directory containing the "IBIS File".
The answer must be relative to the directory containing the "File".
How else could you use this same AMI model or Interconnect Model Set
file in different "IBIS Files".
- Arpad: Because the particular file may not even know where its top level
parent .ibs file is. So it can't contain paths relative to the
directory containing the top level .ibs file.
- Walter: Exactly.
- Discussion: Bob and Radek agreed with Walter's proposal and Arpad's statement.
Radek noted that his objections in the previous week's meeting were caused by
confusion over the use of the term "parent file" in the original draft, which
Walter had meant to be the file containing the reference but others including
Radek had thought was a reference to the top level .ibs file. All were in
agreement that file name entries made in any file (.ibs, .ebd, .pkg, etc.)
should be relative to the directory containing that file.
- Walter: [Reviewing proposed changes to the [File Name] keyword]
- I've added a separate bullet for each of 3 rules.
- I've added a new statement that there may not be a "/" in the file name.
- This is the easiest way to address Bob's requirement that the [File Name]
keyword itself must still contain a name only (no path).
- After reviewing the spec. again, I found that there are several places
that prohibit "/" at the end of the filename, so I've re-introduced that
restriction to this version of the proposal.
- Proposed changes to BIRD 147.3:
- Replacing the existing "alphanumeric identifier" language for BCI_ID
with text referring to the general file name guidelines.
- Bob R.: Technically (as defined in Section 3), the file name extension is the
part after the "." (e.g., "ami", "ibs", "pkg" "ebd").
- Walter: References to ".ami", etc. are ubiquitous. I don't want to tackle
that cleanup now, but I agree it should be done.
- Discussion: Bob wanted to replace uses of the word "folder" with directory or
subdirectory. Walter agreed. Bob expressed concern about the appearance of
fully qualified paths in the examples. Walter noted that these paths were
given for illustrative purposes only, and were there to show the actual file
hierarchy that existed and corresponded to the given IBIS file name examples.
However, Walter agreed to remove the absolute path information from the
examples.
- Bob R.: DLL_ID could use the same language change as BCI_ID.
- Walter: We could do that. I will make that change.
- Bob R.: I'm not sure if expanding DLL_ID to allow path information could cause
conflicts with DLL_PATH.
- Arpad: Perhaps we could say that the DLL_ID path is relative to the DLL_PATH?
- Bob R.: That might be one way to resolve it. I'm not sure we have to resolve
anything. I just want us to think about any interactions we might
cause.
- Bob M.: DLL_PATH is a path to the directory where the .dll executable came
from.
- That is completely different from DLL_ID, which, if it has a directory
associated with it, would be a working directory path.
- DLL_PATH allows the executable model to find other things it might rely on.
- Bob R.: We don't have a separate BCI_PATH because we don't need it.
- Bob M.: Yes, we don't need a search path in that application, just the
way to specify a working directory.
- Bob R.: The changes Walter is proposing are valid for BCI_ID and DLL_ID.
- Bob M.: Yes, I believe so.
- Bob R.: I will revise BIRD 147.3 to adopt the new language for BCI_ID.
- Walter: I will update draft 3 to make draft 4 and send it out for Mike
LaBonte to post.
Bob Ross and Radek's discussion of Editorial Task Group Issues:
- Bob R.: Summary:
- Discussed more about a proposed [Local Reference] keyword.
- Now working on the terminal names related to [Local Reference] and all
the other [* Reference] keywords.
- More work on the node-collapse rule, whereby if values of two [* Reference]
keywords' voltages are all the same then their nodes can be considered one.
- We've discovered an exception that may be legal with a [Pin Mapping]. If
you have two nodes that would be collapsed, for example the [Pullup
Reference] and [POWER Clamp Reference] values are all the same, but in the
[Pin Mapping] the pullup_ref and power_clamp_ref columns specify different
bus labels, then you might still have two separate supply paths. You
would need to preserve a different routing to those two nodes. We have
to think about this case some more.
- Phraseology issue:
- For [* Reference] keywords, their descriptions state:
"Defines a voltage rail other than that defined by" [Voltage Range] or 0.
- We should state that it defines a voltage rail that "overrides" the
[Voltage Range].
- Radek: In other words, "other than" is incorrect.
- We also have an interrelated issue with BIRD 181.2, where the definition of
the I/V tables is via providing nodes for the pad and the power and ground
supplies, and those nodes are not really clearly defined in the spec.
- Bob R.: Yes, there's an attempt to list the nodes but they're never formally
defined.
- Arpad: One final question. Should we cancel the meeting on the week of
Thanksgiving (meeting on November 22)?
- Radek: I move that we cancel the meeting on November 22.
- Ambrish: Second.
- Arpad: Anyone opposed? [none]
- Okay, so we will meet next week (November 15), but not on November 22.
- Walter: Motion to adjourn.
- Bob R.: Second.
- Arpad: Thank you all for joining.
AR: Walter to create draft 4 of the file name relaxation proposal and send it
to the ATM list (for Mike LaBonte to post).
AR: Bob R. to create BIRD 147.4 to incorporate discussed changes to BCI_ID.
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Next meeting: 15 November 2016 12:00pm PT
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IBIS Interconnect SPICE Wish List:
1) Simulator directives
