================================================================================ IBIS INTERCONNECT TASK GROUP Mailing list: ibis-interconnect@freelists.org ================================================================================ Attendees from May 17, 2023 Meeting (* means attended at least using audio) ANSYS Curtis Clark Intel Corp. Michael Mirmak* Michael Brownell Keysight Technologies Ming Yan Marvell Steve Parker MathWorks Walter Katz Micron Technology Justin Butterfield Siemens EDA Arpad Muranyi*, Randy Wolff* ST Microelectronics Aurora Sanna Teraspeed Labs Bob Ross* University of Illinois Jose Schutt-Aine Zuken USA Lance Wang* ---------- Michael Mirmak convened the meeting and took minutes. No patents were declared. Michael showed the minutes of the previous meeting. Arpad Muranyi moved to approve them; Lance Wang seconded. The minutes were approved without objections. Michael summarized the state of his AR to get the test equipment documentation on Touchstone posted to the IBIS web page. He is working with Steve Parker to determine the best location for the documents and copyright disclaimer. Arpad noted that no progress had been made on an AR he took that was somehow not logged -- to post his latest draft -- as the minutes didn't clearly describe what changes were still needed. He is working with Randy Wolff to made necessary adjustments. Bob Ross reviewed his TSIRD6 draft. The draft differs from TSIRD5 in that it points out the strategy and key items to include in Touchstone to support the new versions even without the Version keyword. Bob's draft distinguishes between "internal" version 1.1 designations and an explicit [Version] 2.1 designation. Bob noted that the option line syntax is optional in 2.1 (this does not mean that the octothorpe or pound character may be omitted). Arpad noted that having a single reference resistance should still be allowed for 2.1. Wordsmithing will be needed to properly explain the rules here. Bob notes that the option line parametrs may appear in any order, except the R and the following R values. More wordsmithing may be needed here as well to clarify this. The team agreed that some research may be needed to confirm that S-parameters are always normalized. Randy noted that, on page 4, normalization only applies for single values. Arpad may already have inquired about this to his colleague Vladimir; it may be possible. We may not normalize in Touchstone 2 because we have multiple values; will the data be normalized? Randy replied that the document is not changing the default behavior. Bob stated that, if we declare multiple references, regardless of version, then the normalization is with respect to those references. Arpad added that, in 1.0 we used normalization, but we can't have both normalized and unnormalized data in the same file. Bob replied that this is a new rule: normalization applies to 1.1 if we have multiple values. Normalization is done with respect to those values. Randy replied that we need to state this new rule explicitly in the document. Arpad observed that, if we have a 2.0 file where # and [Reference] are present, and we assume no normalization, then we have two conflicting indications. He advocated making a simple rule: multiple values are not normalized, single values should be normalized. Randy suggested the document require the same treatment between the various versions for a single value of reference resistance. Bob stated that the team needs to know what Synopsys HSPICE does. [AR] Michael will ask Ted Mido. Arpad asked about overrides for values on the [Reference] line. Will these values override what is on the option line? The new rules for 2.1 files involve overrides; Arpad asked about single-value references. Overrides may also need to apply for single values. Arpad added that the rules conflict for overriding vs. forced matching between the reference locations. A single value in # vs. a [Reference] with multiple values (none of them 50) implies that [Reference] wins. But with 1.1 rules, they have to match. Randy asked whether, with a 2.1 file, why would we even put multiple values in the # line if we have [Reference]. Michael replied that our assumption in the 2.0 document was that [Reference] would be written first, and its contents copied to # line. Bob agreed. Arpad suggested that we may not need downgrading of the option line at all; if the option line is extended, we don't need [Reference] at all. Arpad doesn't mind stopping work on his TSIRD in favor of Bob's; he does not think both should go forward in parallel. Bob agrees. [AR] Arpad to assemble a logic table on overrides, references, and version. How do they interact, and how should they? What if we had a rule that multiple values are allowed in only one location, not in both? [AR] Bob to make changes identified so far to his TSIRD. Randy noted that, as both documents are drafts, there is no need to withdraw one. One will become the next TSIRD to be officially submitted and voted. Arpad asked whether he should continue work on TSIRD5. Michael replied that he should look over the current TSIRD5 and make sure every feature and rule gets ported over to 6. Bob and Arpad become co-authors on the new combined document. Bob added that the references are really moving us back to considering the proper measurement setup for extraction. Arpad moved to adjourn the meeting. Randy seconded. The meeting adjourned. Next Meeting: The next meeting will be April 26, 2023 unless cancelled. ================================================================================ Bin List: 1. Draft Touchstone document separating version 1.0 and 2.0 2. Encapsulating Touchstone 1.0 data 3. Touchstone 2.0 draft with TSIRD3 and TSIRD4 4. Pole-residue format 5. Port naming 6. Alternatives to the Touchstone 1.0 option line 7. Enable Cascading of S-parameters Through W-element 8. Touchstone 3.0 draft outline (dependent on several items above) Tabled ARs: - Arpad to give an example of the physical connectivity needed for EMD automation.