Minutes from the 19 March ibis-atm meeting are attached.
BIRD198 and BIRD199 were discussed during the meeting and can be found here:
http://ibis.org/birds/
IBIS Macromodel Task Group
Meeting date: 19 March 2019
Members (asterisk for those attending):
ANSYS: Dan Dvorscak
* Curtis Clark
Cadence Design Systems: * Ambrish Varma
Brad Brim
Kumar Keshavan
Ken Willis
eASIC: David Banas
GlobalFoundries: Steve Parker
IBM Luis Armenta
Trevor Timpane
Intel: * Michael Mirmak
Keysight Technologies: Fangyi Rao
* Radek Biernacki
Ming Yan
Stephen Slater
Maziar Farahmand
Mentor, A Siemens Business: John Angulo
* Arpad Muranyi
Micron Technology: * Randy Wolff
* Justin Butterfield
SiSoft (Mathworks): * Walter Katz
* Mike LaBonte
SPISim: * Wei-hsing Huang
Synopsys: Rita Horner
Kevin Li
Teraspeed Consulting Group: Scott McMorrow
Teraspeed Labs: * Bob Ross
The meeting was led by Arpad Muranyi. Curtis Clark took the minutes.
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Opens:
- None.
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Review of ARs:
- Randy to investigate if/why/how a clock waveform input might be used.
- In progress.
- Michael M. to investigate if/why/how a clock waveform input might be used.
- In progress.
- Michael M. to check with IP experts on whether DC_Offset is useful for Tx.
- In progress.
- Randy to send out the modified C_comp draft, and Mike L. to post it to the ATM
archives.
- Done.
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Call for patent disclosure:
- None.
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Review of Meeting Minutes:
Arpad asked for any comments or corrections to the minutes of the March 05
meeting. Walter moved to approve the minutes. Bob seconded the motion.
There were no objections.
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New Discussion:
Rx_Receiver_Sensitivity BIRD draft_3:
Arpad reviewed the draft_3 he had recently sent out. He noted that the page
numbers and screen-shot of the affected text had been updated based on the
newly approved IBIS 7.0. Bob noted that he would prefer the text to be replaced
were cut and pasted from the spec. instead of as an image. Arpad said he was
willing to do either, but he leaned toward the screen shot because it was
permanent and not subject to style and formatting changes. No one else offered
an opinion. Bob noted that the line spacing settings in the Examples: and the
Descriptors: were off. Arpad corrected them. Arpad noted that these types of
unexpected formatting changes were why he preferred screen-shots. Mike said
that we might be able to improve the BIRD template and ensure it contains the
known styles from the IBIS document. But he noted that IBIS 7.0 itself had
required lots of manual formatting adjustments.
Walter moved that Arpad send out draft_4 (as modified in the meeting) for
posting to the ATM archives, and that he then submit it to the Open Forum as an
official BIRD, and that he submit it with an email indicating that ATM
recommends it. Bob seconded. There were no objections.
BIRD198 Review:
Bob and Arpad noted that at the Open Forum meeting Randy had suggested that we
could schedule some meetings at a later time, perhaps 5PM EDT, to make it easier
for the submitters to join from Japan. Walter suggested we discuss it first,
make sure we understand it, and correspond via email as a first step. We can
then decide if scheduling a few later meetings will be helpful.
Arpad noted that his primary technical question was whether this BIRD is
necessary now that BIRD189 has been approved. Do we need this for its
capabilities, or is it just a convenience relative to BIRD189? Mike L. noted
that the submitters' DesignCon presentation did not address BIRD189, but that
subsequent email discussions had made the convenience argument. Mike noted that
it is similar to the argument for the BIRD158 AMI Tstonefile parameters.
Walter noted that this proposal provides corners, but BIRD189 does not directly
support process corners. Mike L. noted that the proposal follows the precedent
of C_Comp and C_Comp_Corner, with C_pdn using strict numerical ordering and
C_pdn_corner using process corner ordering. Mike wondered if the legacy strict
numerical ordering parameters were necessary in a new proposal.
Walter said his fundamental question was "what is this model between?" It looks
like it's between two pins. Randy and Walter noted the intent is likely a model
between two signal_names. Arpad noted that in legacy IBIS [Pin Mapping] is an
example of the same issue. We only had pin names, so [Pin Mapping] uses pin
names (we had no pad names), but the buses defined by [Pin Mapping] are
implicitly shorting the pads. Arpad noted that he thought the submitters also
expected their model to be connected on the pad side.
Bob noted that BIRD189 supports Model_Group selections, so we can provide
different models for different corners, even if the explicit association with
a corner is not built in to BIRD189. Bob also noted that the proposal implies
that the current [Series Pin Mapping] is too complex, when in fact it's straight
forward. Arpad expressed concern about keyword inflation and adding new
keywords to support a very simplistic model. Walter noted that he would prefer
not to add keywords for which we will have to define their interaction with the
more general BIRD189. Ambrish said that similar arguments could have been
applied against BIRD158.
Walter and Arpad wondered if we might be better off focusing on improving the
convenience of using BIRD189 with respect to process corners. Walter proposed
that we could respond to the submitters with the following:
- Demonstrate how their model could be implemented in BIRD189.
- Acknowledge the current BIRD189 shortcomings with respect to corner.
- Ask if BIRD189 would be acceptable if we address the corner issues.
Walter and Mike L. took the AR to draft the email. Walter suggested we should
review it at the next ATM meeting and then send it to Murata-san, et. al.
- Michael M.: Motion to adjourn.
- Randy: Second.
- Arpad: Thank you all for joining.
AR: Walter and Mike L. to create a draft email response to the BIRD198
submitters.
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Next meeting: 26 March 2019 12:00pm PT
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IBIS Interconnect SPICE Wish List:
1) Simulator directives
