IBIS Macromodel Task Group Meeting date: 13 September 2022 Members (asterisk for those attending): Achronix Semiconductor: Hansel Dsilva Amazon: John Yan ANSYS: * Curtis Clark * Wei-hsing Huang Cadence Design Systems: * Ambrish Varma Jared James Google: Hanfeng Wang GaWon Kim Intel: Michael Mirmak * Kinger Cai * Chi-te Chen Alaeddin Aydiner Keysight Technologies: Fangyi Rao Majid Ahadi Dolatsara Ming Yan Radek Biernacki Rui Yang Luminous Computing David Banas Marvell Steve Parker Mathworks (SiSoft): Walter Katz Mike LaBonte Micron Technology: * Randy Wolff * Justin Butterfield Missouri S&T * Chulsoon Hwang * Yifan Ding Rivos Yansheng Wang SAE ITC Michael McNair Siemens EDA (Mentor): * Arpad Muranyi Teraspeed Labs: * Bob Ross Waymo: Zhiping Yang Zuken USA: * Lance Wang The meeting was led by Arpad Muranyi. Curtis Clark took the minutes. -------------------------------------------------------------------------------- Opens: - None. ------------- Review of ARs: - Kinger to send draft1 of the SPIM BIRD 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 August 30th meeting. Ambrish moved to approve the minutes. Randy seconded the motion. There were no objections. -------------- New Discussion: Pre-driver PSIJ BIRD draft introduction: Chulsoon reviewed a new BIRD draft introducing [Pre-driver PSIJ Sensitivity] as a new keyword. He noted that his team had presented on the topic at several IBIS summits (presentation links included at the end of the BIRD draft), and we could review those presentations if necessary. He said the goal is more accurate PSIJ simulation with IBIS. The keyword, along with its two Sub-params Rising Edge and Falling Edge, provides the PSIJ sensitivity in s/V for the rising and falling edges. Chulsoon noted that one requirement is that the pre-driver use the same power domain as the buffer, as this is modeling a pre-driver effect based on fluctuations in the power rail used by the IBIS buffer. Randy said that the effect being modeled is non- linear, but the assumption is that within a limited range of interest a single value for each edge is a reasonable approximation. Randy said one area where they would like feedback is on how much detail and background on the derivation, algorithms, etc., should be provided. Arpad said he preferred that the BIRD focus primarily on what will change in the specification. He said the Background: section could be used to provide more detail. Since the Background: section already provided links to the presentations, and they were sufficiently rigorous, he thought it was sufficient. Chulsoon said he would send the draft to the ATM list for review. Bob asked whether Chulsoon's draft and Kinger's recent presentations on PSIJ would have to be rationalized. Chulsoon said he thought they were complementary concepts and couldn't be combined. He said his was for time domain and Kinger's was for frequency domain. Kinger said he thought they might be able to converge if he included a DC point in his frequency domain approach. PSIJ frequency domain proposal: Kinger reviewed a BIRD draft related to his recent summit presentation: https://urldefense.proofpoint.com/v2/url?u=https-3A__ibis.org_summits_aug22_cai2.pdf&d=DwIGAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=DcQR-qLpQg5lIreuM6-NYECRIAFXt268PRNS5WO043M&m=_uAN_PAJludqj7WELaw_FGGl0FU9OwV9gRCWqWgihWIQFZ-pak4TquYwHdL8ahIg&s=S2DIhn4OMgrEU6RO0v9LsZ7OYMcd8VMExq2UVoiB-F0&e= Kinger introduced a new [PSIJ Sensitivity] keyword, which provides jitter sensitivity values in s/V at different frequencies. He said the goal was to take into account the collective power noise in all the rails. He said Chulsoon's proposal was focused on pre-driver effects, and he thought the addition of a 0 Hz value in his proposal would be equivalent to Chulsoon's. Kinger introduced a [PSIJ Sensitivity Group] keyword. He said this came out of discussions with Michael Mirmak about whether two things sharing the same power rail might have different sensitivities. For example, you might have PCIe_Gen4 or PCIe_Gen5 using different groups to specify different sensitivities. Chulsoon said their investigation suggested that different values were necessary for the rising and falling edges, and he wasn't sure whether the frequency domain approach would handle that. Randy noted that another difference was that Kinger's approach was scoped under [Component]. Chulsoon's was scoped by [Model], and separate sensitivities could be specified for each [Model]. With Kinger's approach it is broken out by voltage rail, and the assumption is that all models on that specific voltage rail have the same PSIJ sensitivity. Arpad noted that IBIS is predominantly focused on time domain waveforms. He asked how Kinger envisioned this frequency domain information being used. Kinger said that IBIS currently doesn't really cover the PI domain. This new PSIJ sensitivity data is being proposed assuming that a simulator will have been able to generate information about the noise on each power rail. Kinger said that for AMI simulations this PSIJ sensitivity could be incorporated as a post processing step similar to the way random jitter is handled. Kinger said he would work on cleaning up his proposal for further review at the next meeting. - Randy: Motion to adjourn. - Bob: Second. - Arpad: Thank you all for joining. AR: Chulsoon to send the Pre-driver PSIJ Sensitivity BIRD draft to the ATM list. ------------- Next meeting: 20 September 2022 12:00pm PT ------------- IBIS Interconnect SPICE Wish List: 1) Simulator directives