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