============================================================================== IBIS INTERCONNECT TASK GROUP Mailing list: ibis-interconnect@freelists.org ============================================================================== Attendees from December 10, 2025 Meeting (* means attended at least using audio) ANSYS Curtis Clark, Wei-hsing Huang, Juliano Mologni Arista Networks Jim Antonellis Broadcom James Church Chipletz Stephen Newberry* 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 ============================================================================== Michael Mirmak convened the meeting. No patents were declared. Michael reviewed the minutes of the December 3, 2025 meeting. Arpad Muranyi moved to approve; Randy Wolff seconded. The meeting minutes were approved without objection. Michael noted that there were no additional agenda items, and that all previous ARs had been closed. Michael reviewed the latest draft changes in the Port Mapping proposal. One concern related to the dual nature of the "UD" (User-Defined) parameter, which can appear within a Port line, as well as separately on a line after the Port declarations. Arpad suggested that the "Port declarations" language is ambiguous and should be clarified. Michael asked whether the team wanted to keep the double syntax support for UD? Randy suggested that UD be kept on its own line; otherwise understanding and tool/parser support would be overly complicated. Arpad asked whether we have UD format examples outside of the two in the syntax definition section. Michael stated there were none. Randy replied that UD is a glorified comment, but that Walter Katz, as the author of the parameter, should be the one to decide. Walter suggested that the second example of UD in the text is associated with a port; the first isn't. Arpad asked whether UD is port-wide or terminal-specific. Walter suggested that it could be associated with the "-" symbol. The UD feature Probe_Angle is port-associated; SijStatus is not port-associated. Michael replied that any parser will treat this as a comment no matter what. Randy asked whether parentheses would be allowed within UD definitions. Arpad suggested just counting parenthesis for matching purposes to determine which were part of the format and which were comments. Michael replied that general strings may not be allowed due to reserved terms and characters. Michael took the AR to expand the end-of-text examples for UD (Randy suggested putting Probe_Angle on a Port line). [AR] Walter stated that he does not like use of "+" characters at all (every terminal is implied to be "+"). Arpad replied that, if no "+" were allowed, how would you identify port vs. terminal-oriented parameters? Walter stated that only Logical, Net, and Physical names are related to "+"; the tools can distinguish between port- and terminal-oriented usage based on the names. Arpad disagreed; more explicit information makes the name-value pairs easier to parse. Walter asked what makes the relationship clear for the human reader, which should be the focus. Arpad replied that the most important thing is lack of ambiguity. Michael noted that a specific order for the name-value pairs is not required. Arpad asked whether the nested parentheses (()) would be required for the "+" and "-" symbols. Michael asked whether the syntax should keep the grouping rule about parentheses? Randy replied that files would be easier to create without it. Arpad suggested using {} for big groups, and also asked about the benefits for supporting any order. Michael cautioned the team to remember how IBIS handled columns of data; if certain column orders are assumed, then adding features may become very difficult. Walter suggested that Type should be terminal-oriented, while Diff_port refers to the terminal, not to the pair or port. Michael reiterated that Diff_port is intended for display only, with no reference (return path) involved. Walter stated that Diff_port should appear on the positive terminal only, both locations. In response to a question from Michael, Randy noted that you will have a GSSG probe indirectly in at least one of the current draft examples. Arpad showed two variants of SPICE differential probing syntax, in response to Walter's Diff_port suggestion: V1(T1p, T1n) - V2(T2p, T2n) V1(T1p) - V2(T2p) The second line is a simplification or common shorthand, where ideal node 0 is assumed to be the reference terminal. But the approach also means the resulting data has no dependency on reference terminals. Walter stated that V1 and V2 must have the same return path; Arpad disagreed. Walter suggested that, if these are differential, they have same return path. Arpad replied that, if I have a differential pair, V1 and V2 are the pair, not the terminals; pairing is not based on the terminal but on the port. Michael asked whether one can have a single "differential terminal"? Randy noted that one might want to display data in mixed-mode terms, rather than single-ended terminals with references. Arpad and Randy suggested that one does not have to have matched name-value pairs between the "+" and "-" terminals. All the data is informational and optional. Walter replied that, if you don't have any negatives (e.g., imagine no Physical name-value pair declarations), then you don't need "+" either. Randy stated that he was also leaning toward removing the "+" symbol. Michael asked whether the draft should be revised to remove "-" too. Walter stated that one needs to have Physical, Logical, and Net and these need "-" for referencing. Arpad asked about having "-" on a whole group or "-" on each name-value pair. Walter expressed a preference for "-" on each one; Randy added that this allows any order of declaration. Michael suggested that "-" is simply shorter macro for "Reference". Arpad suggested this would be a lot cleaner. Randy noted that the GSSG probe example was already shown in the simple Port 1,2,3,4 example early in the document. Arpad requested a third, common-base transistor example. Michael took the AR to create this. [AR] Michael asked whether we still need a diagram for the transistor examples. The team agreed this was no longer needed. Michael took the AR to draw up a new draft and send it to the reflector. [AR] Michael noted that the end of the year holidays would mean many absences. Arpad stated that the IBIS-ATM Task Group would have its last 2025 meeting on December 16. Michael proposed December 17th as the last 2025 Interconnect meeting, with January 7 being the next meeting. No objections were raised. Arpad moved to adjourn; Randy seconded. The meeting adjourned without objection.