Minutes from the 14 July ibis-atm meeting are attached.
IBIS Macromodel Task Group
Meeting date: 14 July 2020
Members (asterisk for those attending):
Achronix Semiconductor Hansel Dsilva
ANSYS: * Curtis Clark
* Wei-hsing Huang
Cadence Design Systems: Ambrish Varma
Ken Willis
* Jared James
Google: * Zhiping Yang
Intel: Michael Mirmak
Keysight Technologies: * Fangyi Rao
Radek Biernacki
* Ming Yan
Todd Bermensolo
Stephen Slater
* Rui Yang
Marvell Steve Parker
Mentor, A Siemens Business: * Arpad Muranyi
Micron Technology: * Randy Wolff
Justin Butterfield
SiSoft (Mathworks): * Walter Katz
Mike LaBonte
Teraspeed Labs: * Bob Ross
Zuken USA: * Lance Wang
The meeting was led by Arpad Muranyi. Curtis Clark took the minutes.
--------------------------------------------------------------------------------
Opens:
- Rui Yang introduced himself. He completed his PhD at the Univ. of Houston in
May. His research topic was biomedical implants in an MRI environment. He
now works for Keysight. Ming noted that Rui had joined their team and is
working on IBIS-ISS models.
-------------
Review of ARs:
- Randy to draft some ideas for the component name and signal name Reserved
Parameters proposal and send them to the ATM list.
- Done.
--------------------------
Call for patent disclosure:
- None.
-------------------------
Review of Meeting Minutes:
Arpad asked for any comments or corrections to the minutes of the June 30
meeting. Randy moved to approve the minutes. Ming seconded the motion.
There were no objections.
-------------
New Discussion:
Component and signal name Reserved Parameters proposal:
Randy shared and reviewed the email he had sent to ATM. It contained the
definitions and descriptions of two new Reserved Parameters, Component_Name
and Signal_Name, and was already in BIRD style format.
Randy recalled that at the previous meeting we had discussed the idea of the
executable model maintaining a list or look-up table based on the Component
name and signal_name from the IBIS file. The combination of the two could form
a unique identifier for the signal being simulated, e.g., for a particular DQ.
The EDA tool would pass this information in via the new parameters. Randy noted
language in his draft that states that if one of the parameters exists then they
both must exist. Arpad asked if that language should appear earlier in the
definitions of the parameters, for example in the Required: section. Randy said
he had checked existing parameters' definitions and followed precedent. Randy
noted that he was primarily thinking about the Rx direction, but his proposal
supports the Tx and Rx directions. Curtis said he thought Randy's proposal
captured the spirit of the discussion at the previous meeting and looked good.
Fangyi said it looked good.
Randy noted that he'd had additional discussions with Michael Mirmak. Michael
supports this proposal, but he is also thinking about some different concepts
to indicate a particular strobe and its associated nibble or byte. Arpad asked
if the concepts were different enough to be a separate BIRD. Randy said he
thought Michael's new concepts were unique and should go in a separate BIRD.
Randy wondered if we should provide some way for the model maker to provide a
default behavior in case the EDA tool didn't have the Component and signal_name
information available. Arpad asked if the EDA tool should put "NA" or an
empty string in the parameters in that case. Bob said that could get confusing.
Arpad asked Randy to draft a formal BIRD proposal. Randy agreed and said he
would add some new language related to defaults.
Supporting PI modeling/simulation in IBIS
Zhiping recalled that he had introduced the overall topic several meetings ago,
and he said he welcomed any questions or thoughts on the topic. He noted that
he has a paper to be published and presented at the upcoming IEEE EMC 2020 SI+PI
conference. He said he thought PI modeling was a hot topic that could
potentially draw more people into participating in IBIS. Arpad asked Zhiping
to send the presentation information to the ATM list.
Zhiping observed that IBIS had been heavily involved in SerDes simulations and
I/O simulations in general. He asked what ideas people had to help draw PI
people into IBIS discussions. Arpad suggested that presentations at IBIS
summits, such as the one coming up in conjunction with the IEEE EMC SI+PI, and
meetings like ATM help people keep informed about the needs of the industry in
general. This can help generate discussion and activity. Zhiping noted that
his upcoming EMC conference paper is focused on CCM (continuous conduction mode)
operation of the switched power supply. He said that perhaps for the
accompanying IBIS Summit at the end of the conference he could add some slides
on new progress they'd made in modeling the DCM as well.
Arpad reiterated his comments from earlier meetings that he would like to see
more papers and presentations on the topic. He thought that from the IBIS
specification perspective we need to see brainstorming on how PI information
could be included in IBIS to help satisfy industry needs. Zhiping noted, for
example, a FET that could be included inside the PMIC or a separate component.
He said that a few key properties could be very useful to model the FET for
power performance, for example the DC resistance of the switch or parasitic
capacitance. These might be captured as new keywords in IBIS.
Arpad said he was interested in the usage model and if/how people would combine
PI simulations with I/O. He expressed concern about the fundamentally different
time scales of GHz I/O and kHz PI simulations. Zhiping noted one example of a
situation when SI and PI simulations were tightly coupled. He said first
generation fingerprint sensors on iPhones used a serial peripheral interface
(SPI) to connect to the CPU. He said that a switching FET charging circuit used
to adjust the virtual ground of the fingerprint sensor had switched in the kHz
range. It caused so much noise that it caused the SPI (MHz range) signaling to
fail. So they had to model the switch behavior and consider SI and PI together
to ensure proper operation.
Randy suggested Zhiping could present some of his earlier IBIS Summit
presentations at an upcoming ATM meeting. Zhiping agreed to send links to past
DesignCon IBIS Summit presentations and information about the upcoming paper
and presentation at EMC SI+PI.
- Curtis: Motion to adjourn.
- Randy: Second.
- Arpad: Thank you all for joining.
AR: Randy to create a BIRD draft for the Component_Name and Signal_Name
Reserved Parameters proposal.
AR: Zhiping to email links to past Summit presentations and info about his
upcoming EMC SI+PI conference presentation to ATM.
-------------
Next meeting: 21 July 2020 12:00pm PT
-------------
IBIS Interconnect SPICE Wish List:
1) Simulator directives
