IBIS Macromodel Task Group Meeting date: 12 September 2023 Members (asterisk for those attending): Achronix Semiconductor: Hansel Dsilva Amazon: John Yan ANSYS: * Curtis Clark * Wei-hsing Huang Aurora System: * Dian Yang Cadence Design Systems: * Ambrish Varma Jared James Google: Hanfeng Wang GaWon Kim Intel: * Michael Mirmak * Kinger Cai Chi-te Chen Liwei Zhao Keysight Technologies: Fangyi Rao Majid Ahadi Dolatsara Stephen Slater Ming Yan Rui Yang Marvell: Steve Parker Mathworks (SiSoft): Walter Katz Graham Kus Micron Technology: Justin Butterfield Missouri S&T: Chulsoon Hwang Yifan Ding Zhiping Yang Rivos: Yansheng Wang SAE ITC: Michael McNair Siemens EDA (Mentor): * Arpad Muranyi * Randy Wolff Teraspeed Labs: * Bob Ross Zuken USA: * Lance Wang The meeting was led by Arpad Muranyi. Curtis Clark took the minutes. -------------------------------------------------------------------------------- Opens: - None. ------------- Review of ARs: Kinger: Send out draft1 of BIRD223.1 with the changes and updates noted during the ATM meeting. - Done. Michael: Send out draft7 of the [AMI Test Data] proposal including more feedback from Fangyi and the ATM meeting. - Done. -------------------------- Call for patent disclosure: - None. ------------------------- Review of Meeting Minutes: Arpad asked for any comments or corrections to the minutes of the August 29th meeting. Michael moved to approve the minutes. Ambrish seconded the motion. There were no objections. -------------- New Discussion: BIRD223.1: Kinger reviewed the changes in draft1 of BIRD223.1. These were enumerated in the email he had sent with draft1 (also see ATM minutes from August 29, 2023). He noted that he had decided to change the S in SPIM from "standard" to "streamlined". He also noted that [Interconnect Model Group] had been removed from the proposed changes to the .ibs parameter tree. He said it had originally been included to indicate where the new [Device SPIM Group] parameter should be added in the tree, but it had caused confusion and [Interconnect Model Group] might not even exist in each .ibs file. Kinger said that he was already working on draft2 and incorporating feedback Bob had sent in reply to draft1. He had updated the various date fields in the header per Bob's suggestion, and he said he would add the enumerated list of changes in BIRD223.1 to the Background Information section. Bob requested that Kinger remove the italics from equations 1-7 to make them easier to read. Kinger agreed. Kinger said he would send draft2 to the ATM list and plan to submit it to the IBIS Open Forum prior to its next meeting on Friday, September 15th. Arpad asked everyone to review draft2 and provide any feedback prior to Friday. [AMI Test Data] proposal: Michael said the changes in draft7 were relatively minor and captured the feedback from the previous ATM meeting and Fangyi's email reply to draft6. Michael moved on to discussion of the suggestions Ambrish had provided in an email reply to draft7. Ambrish said he thought draft7 was still a bit difficult to follow because of the cross referencing between statistical and time domain Sub-params. He said that requiring even a purely time domain model to use the Statistical_configuration Sub-param seemed convoluted and confusing. He proposed a new Impulse_matrix_file Sub-param, which would contain the impulse response passed into AMI_Init() regardless of the Type of the simulation. This would eliminate the need for overloading the Stimulus_file Sub-param to provide an impulse response in the statistical case. It would also eliminate the need for the Statistical_configuration Sub-param, which had been introduced solely to provide the impulse response to AMI_Init() for a time domain simulation. Michael said his recollection was that the initial intent of AMI_Init() had been initialization of the model, and the modification of the impulse response to support statistical simulation had been added later. (Michael noted that others did not necessarily agree with his recollection of the evolution of AMI_Init()). Michael asked if Ambrish was trying to go back to that original intent and isolate the difference between statistical flow and the initialization process required for the time domain flow. Ambrish agreed that he wanted to keep that distinction clear, and he said he thought we had maintained that distinction in the specification. He said the AMI flows carefully note that a model can support statistical, or time domain, or both. Michael asked for confirmation that Ambrish's proposed changes seeking to decouple the statistical and time domain Sub-params would still support models for which the time domain flow depended on what was passed to AMI_Init(). Ambrish said his changes did not affect this at all. He said models that adapt in AMI_Init() and then use the adaptation as a starting point for time domain simulations maintain all that information internal to the model. Ambrish noted that we would no longer need the Stimulus_file Sub-param when the Type is Statistical because the Impulse_matrix_file is used. In addition, we no longer would need the extra Statistical_configuration Sub-param in time domain simulations because the Impulse_matrix_file provides the IR passed to AMI_Init(). Bob asked about corners and the fact that "typ" appeared in the names of many Sub-params in the examples. Michael said that we had previously decided that corners were not really relevant to these keywords and Sub-params. In this proposal we are naming a specific model and providing the test inputs and the expected outputs. We want the model maker to provide filenames that are descriptive. Michael said he would adopt the other two changes Ambrish had proposed in his email response. One was editorial in nature, and the other was to change the Sub-param Waveform_file to Golden_waveform_file to make its intent more clear. Ambrish again noted that params such as sample_interval, which implicitly rely on the descriptions of the AMI_Init() and AMI_GetWave() function signatures, should not appear until after the function definitions are introduced. Michael said he would send out a draft8 incorporating the changes discussed in the meeting. - Curtis: Motion to adjourn. - Ambrish: Second. - Arpad: Thank you all for joining. New ARs: Kinger: Send out draft2 of BIRD223.1 with the changes and updates noted during the ATM meeting. Michael: Send out draft8 of the [AMI Test Data] proposal including more feedback from Ambrish and the ATM meeting. ------------- Next meeting: 19 September 2023 12:00pm PT ------------- IBIS Interconnect SPICE Wish List: 1) Simulator directives