============================================================================== IBIS INTERCONNECT TASK GROUP Mailing list: ibis-interconnect@freelists.org ============================================================================== Attendees from April 22, 2026 Meeting (* means attended at least using audio) Chipletz Stephen Newberry Intel Corp. Michael Mirmak* MathWorks Walter Katz Siemens EDA Weston Beal, Arpad Muranyi*, Randy Wolff* Synopsys Ted Mido, Edna Moreno ============================================================================== Michael Mirmak called the meeting to order. No patents were declared. Michael reviewed the minutes of the April 15 meeting. Randy Wolff moved to approve the minutes; Arpad Muranyi seconded. Michael noted that all ARs in the previous minutes had been closed, except for distribution of minutes from February 18 and March 4. Michael reviewed draft 29 of the Port Mapping proposal. Three issues were the focus of the discussion: 1) Treatment of models and shorting vs. * character (wildcard) 2) Proper definition of RefDes 3) Proper definition/use of : syntax Arpad noted that the EMD pin format is not designator.pin; this is simply an EMD pin. Randy added that the format is covered by the specification definition. Arpad asked how we know "U2.GND" is a pin_name or a signal_name. EMD could have signal names called "GND". How do we know if it's a signal name? Randy replied that the function is location-based within the syntax. Arpad showed pin names in an example from IBIS to clarify the usage. For IBIS Interconnect, Randy noted that Pullup_ref, Pulldown_ref, etc. are all Type P. Answering Michael's question, the rules regarding Type are correct. The team confirmed that Group only exists in Touchstone, not IBIS Interconnect. In IBIS, only Bus_label exists. Randy added that, regarding Group and Bus_label, for IBIS Interconnect and EMD, there better be a way of translating them. Michael suggested that the document seems to be missing definitions for syntax that's allowed. Arpad asked why the document uses pins for Bus_label. Randy answered that, for Interconnect in IBIS 8.0, we have Terminal_type, which is Pin Rail or Pad Rail. The syntax would be similar to: Pin_Rail:Bus_label Pad_Rail:Bus_label Randy added that we didn't bring the Terminal_type qualifier syntax from Table 49 in IBIS 8.0 over to Touchstone Port Mapping. For rails: Pin_ or Pad_ or Buffer_ should be followed by "Rail". The syntax would be: pin:Bus_label:name Michael took the AR to add the connectivity to IBIS to the document. [AR] The language is different between the two formats. Randy noted that EMD is simpler, and the structure was already covered. Michael asked whether we still need Group. Randy replied that he is not sure why. Arpad added that, in EMD, we need it; he was not sure for IBIS Interconnect, however. Arpad continued that the idea to add grouping was for different reasons, not this. Randy noted that the original idea for Group was different than Bus_label, but we shouldn't be using it in these IBIS cases. It is OK for general Port Mapping, however. Randy added that, if we had a complete power example, it might clarify the distinctions. Michael noted that the eventual PIM/SPIM proposal and clustering may involve Group. Randy agreed but stated that he was arguing for taking Group out of these IBIS examples as it does the same thing. Michael suggested that, in the future, we should take Group out of the IBIS Interconnect and EMD examples. Randy noted that the "-like" examples could use Group. Arpad suggested that an analysis woudl show if the Group definitions are really synonymous. The team fixed Example 5 during real-time discussion. Arpad noted that, in Example 12, the "rail signal name" is a signal name (in contrast to a pin name) for a rail. This was noted in response to a question from Michael. Arpad asked what one does if the fourth column in an IBIS EMD pin list isn't present. Do you use the signal name? Randy suggested not using that structure here, but just in IBIS. For Example 12, Randy noted that GND should be a bus_label in IBIS for this, to match. GND is not a special name. Arpad replied that GND is still a bus_label in Example 12. He asked whether, for the first three lines, the intent is that GND *is* the Bus_label for U1. He though this was referring to the EMD Bus_label connecting to U1, U2, and U3. He added that we don't look inside the IBIS file to find corresponding Bus_labels; we only look at the EMD definitions. Randy suggested this is similar to what we did with interconnect; see table 49 with "Y". Arpad suggested examining the IBIS 8.0 EMD Syntax example 1, where name, signal_name, signal_type, and bus_label are present in separate columns. Note that the VDD1 Bus_label is used only for EMD. Arpad asked whether the first three Port lines in Example 12 are meant to correspond to Bus_labels. He suggested that the fourth line should have Bus_label in front of GND without RefDes. Arpad moved to adjourn the meeting; Randy seconded. The meeting adjourned without objection.