====================================================================== IBIS INTERCONNECT TASK GROUP http://www.ibis.org/interconnect_wip/ Mailing list: ibis-interconnect@freelists.org Archives at http://www.freelists.org/archive/ibis-interconn/ ====================================================================== Attendees from November 11 Meeting (* means attended) ANSYS Curtis Clark Cadence Design Systems Bradley Brim Cisco David Siadat Intel Corp. Michael Mirmak* Keysight Technologies Radek Biernacki* Mentor Graphics Arpad Muranyi* Micron Technology Justin Butterfield*, Randy Wolff* SAE ITC Maureen Lemankiewicz* Signal Integrity Software Walter Katz*, Mike LaBonte Teraspeed Labs Bob Ross* University of Aveiro in Portugal Wael Dghais No patents were declared. During Opens, Maureen Lemankiewicz noted that Dorothy Lloyd is out of the office temporarily and that Maureen would be covering for her. She asked about any questions regarding SAE; none was raised. Radek Biernacki noted that he would miss next week’s meeting . Michael Mirmak asked for comments on the November 4th meeting. Bob Ross commented that the link at the top of the minutes to ibis.org should be used in place of the eda.org link. Michael replied that the change would be made starting with the Nov. 11 meeting. Arpad Muranyi moved to approve the minutes of the November 4 meeting. Randy Wolff seconded. No objections were raised. The motion carried and minutes were approved Mike LaBonte was given the action, in absentia, to post the minutes. Arpad reported on his AR to contact Prof. Daniel de Zutter of the University of Ghent regarding semiconducting reference planes. In brief, there is no impact on IBIS Interconnect efforts. The treatment in Prof. de Zutter’s paper refers only to field-solver algorithms and equations; the end result is still an RLGC matrix or network, which can still be represented with S-parameters. This should still be easily described using IBIS-ISS. Michael will add a link to plus the title of the relevant IEEE paper. Arpad may still contact Prof. de Zutter to alert him to the Interconnect group’s efforts. Michael reviewed the latest Interconnect proposal draft, number 25. He noted that IBIS packages use keywords, but the new Interconnect structure uses equivalent subparameters. This may not be a problem, but should be considered. Bob suggested that the use of the term “records” is not preferred over “lines”. Randy observed that [Bus Labels] and [Die Supply Pads] are within the Component scope. Michael changed the text appropriately. Michael noted a potential problem that multiple interconnect files could be associated with a single .ibs file, and a single interconnect file can be associated with multiple .ibs files. Do we need indirection, like .subckt, to ensure that reuse can actually work? Is reuse even possible? Bob suggested no indirection was needed. Bus or Rail Labels should be a superset of Pin Mapping. Michael replied that a test case was needed. Terminal records use Pin_name. Randy will come up with a separation test case. He noted that a memory die has 4, 8, or 16 DQs, perhaps within the same die model. For packages, he has different structures to map these. He might be able to re-use the die model, but he won’t be able to re-use the package. Bob replied that one can’t interface a pin-specific portion. He won’t support abandoning the concept, but it needs further checking. The key problem is that Terminal records rely on a specific pin name set, which is dependent on Component. Michael showed a new extension, “.ict”, which the document uses in place of “.ipkg”. The only use of the extension is to an obscure photo or image format not used today. Bob raised the concern that, if the extension is a reference to photo file, it might bring up a photo viewer on some systems. Michael noted that some changes were made to unterminated resistance assumptions, allowing a larger value than 1 megaohm so long as it is reported. Bob prefers 1 gigaohm. Michael raised a concern about eventual numerical significance; using a small value of resistance might become significant as signal speeds increase and parasitic values shrink. Bob suggested value be reported. Other issues: - The document’s organization should include a subsection or grouping within the Component section of the specification to include Bus Labels, Interconnect Model Selector, and Pin/Rail Mapping in one group ahead of everything else, perhaps next to Pin Mapping. Interconnect Model Selector should appear next to Package Model selector. The document should prohibit Begin Package Model - Lower/upper case still needs checking - Touchstone file extension vs. number of ports still needs checking - Drawings still need adding Michael raised the meeting schedule, noting that the next meetings would be on the 18 an 25th of November. He noted that he cannot attend at least one of these. Arpad volunteered to act as chair, if we get a minutes-taking volunteer. Randy volunteered. Randy moved to adjourn. Arpad seconded.