============================================================================== IBIS INTERCONNECT TASK GROUP Mailing list: ibis-interconnect@freelists.org ================================================================================ Attendees from December 18, 2024 Meeting (* means attended at least using audio) ANSYS Curtis Clark, Wei-hsing Huang, Juliano Mologni Arista Networks Jim Antonellis Broadcom James Church Intel Corp. Michael Mirmak*, Xiaoning Ye Keysight Technologies Ming Yan Marvell Steve Parker MathWorks Walter Katz Micron Technology Justin Butterfield Siemens EDA Weston Beal, Arpad Muranyi*, Randy Wolff* Simberian Yuriy Shlepnev ST Microelectronics Aurora Sanna Synopsys Ted Mido, Edna Moreno University of Illinois Jose Schutt-Aine Zuken USA Lance Wang Michael Mirmak convened the meeting. No patents were declared. Michael reported that the minutes from the previous meeting were not yet available for review. Both these (December 11) and the minutes from the previous meeting (December 4) will be distributed on the reflector in the near future. Arpad Muranyi reviewed his proposed example updates to the IBIS specification, including two new examples 2b and 2c. He mentioned having brainstormed with Weston Beal about different referencing schemes. Michael suggested that the issue is the proper identification of terminals and the method of data extraction. The data needs to include identification of (a) how the data was extracted and (b) the association of the reference with individual terminals. Just allowing use of a separate N vs. N+1 wrapper isn't enough. Arpad highlighted how S8P and S6P formats can be used to describe, with proper referencing, the same structure. Michael pointed out that he did not like the way the connection of IBIS was shown in the in S6P, etc. examples. Arpad advocated including the corrected examples in IBIS 8.0. This would mean releasing IBIS 8.0 now, then releasing Touchstone 3.0 with details about port-mapping. IBIS 9.0 would lock down how interface connections are made using Touchstone 3.0. Arpad also mentioned the Touchstone 2.0 issues raised by Walter Katz. Randy Wolff noted that these concepts will need education to be provided to the industry outside of the IBIS community. This would include Eric Bogatin, DesignCon papers, etc. - and industry-wide effort. Arpad suggested asking Eric to include this in his classes, etc. We also need to do a lot of convincing to get tool vendors (hardware) to get this done. Arpad noted that probing definitions and approaches are also a problem. Michael suggested that the team could generate a "quick turn" IBIS 8.0 BIRD that includes the examples plus drawings. Randy replied that IBIS 8.0 may miss its current release schedule (implied to be DesignCon); these could be treated as purely editorial changes. Randy suggested expanding the "known issues" document to capture these changes and reporting this to other teams (IBIS-ATM, the Open Forum, etc.). Michael advocated finishing IBIS 8.0 as currently defined, with these updates made as part of a separate effort. Should we hold Touchstone 3.0 while we test out IBIS 9.0 connections? Or finish Touchstone 3.0 first? Arpad stated that he would like to have IBIS and Touchstone updates both released simultaneously. Michael replied that we need a table of allowed IBIS structures for a given Touchstone definition, then define a larger table for how each Touchstone variant can be connected to that given Touchstone definition. Randy advocated limiting IBIS support options now, and expanding options in a later version. Michael will send the latest IBIS 8.0 draft to Arpad for editing to include the updated examples. [AR] Arpad will update the draft with five new or revised examples. [AR] Arpad noted that he would also like to see discussed what was learned from Yuriy Shlepnev's presentation(s) to the team. Arpad's takeaway was that Yuri and Arpad agreed on the equivalence of the S6P and S8P instances as Arpad defined them. The ideal is S6P with per-port referencing, but S8P with a floating reference is just as good. Michael suggested there are at least three choices on how to enforce/check connection of S6P vs. S8P with other circuit structures such as, for example, an S3P. Arpad highlighted the subtle distinction between "potential" and "voltage" in Yuriy's second presentation; voltage is a potential difference, but potential doesn't require a referencing scheme. Arpad moved to adjourn the meeting; Randy seconded. The meeting adjourned without objection. The next meeting will be held January 8, 2025. ================================================================================ Bin List: 1) Complete port naming proposal (Katz et al) 2) Complete/revise Touchstone 3.0 draft outline (Mirmak) 3) Complete ISS-IRD 1 Draft - enable cascading of S-parameters through W-element (Mirmak) - TABLED Tabled ARs: - Arpad to give an example of the physical connectivity needed for EMD automation.