================================================================================ 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 May 13, 2020 Meeting (* means attended at least using audio) ANSYS Curtis Clark Intel Corp. Michael Mirmak* Ifiok Umoh Eric Edwards Keysight Technologies Radek Biernacki Mentor, A Siemens Business Arpad Muranyi* Micron Technology Justin Butterfield* Randy Wolff* SiSoft Walter Katz Mike LaBonte Teraspeed Labs Bob Ross* Zuken USA Lance Wang* Michael Mirmak convened the meeting. No patents were declared. Justin Butterfield took minutes. Review of Minutes: - Michael called for review of the minutes from the May 6, 2020 meeting. Walter Katz moved to approve the minutes. Bob Ross seconded. The minutes were approved without objection. Review of ARs: - Randy Wolff will review the example names and propose more clear names. - Randy reviewed the latest draft and this okay in the current draft. - Bob to send out EMD draft 9. - Bob reported this is done. - Michael will review item 14 in the bin list. - Michael commented he plans discuss this today. Opens: - Bob noted the subsections need renumbering. Michael suggested to add this to the bin list. - Randy stated he made edits to Voltage List keyword section, and we can review these. EMD Draft Review: Randy noted the changes to Voltage List including minor editorial fixes. He changed the Other Notes section to a bulleted list. Bob commented the original text had numbers indicating the priority, as multiple ways of doing this will likely be present. This defined how conflicts are resolved between different voltages. Randy asked if we can agree on an expected priority for these rules. Bob replied this is the issue. The other option is to make Voltage List non-operational. Arpad Muranyi asked if this information can be obtained from the Voltage Range inside the IBIS files. Bob replied, when a model is connected, Voltage Range takes precedence. Michael asked if this is for rail voltages that do not reach a model, such as pin straps. Bob replied, in the case that the Voltage List is tied to a model, it might not be used. Walter noted we may have a case with different IC vendors using different Voltage Range values. He asked how to handle a pullup resistor on this rail voltage. This can be resolved if the power is supplied externally. But, in the case it is not, this conflict needs to be resolved. Bob agreed it is an existing issue. Arpad commented we need to resolve the precedence when there are conflicts. Bob commented this was the intent with the suggested precedence list. Randy noted, for the Voltage List description, we have less detail in other similar keywords. Bob suggested the phrase "tells the parser" could be changed to "describes". Randy stated this language came out of the EBD section. Randy asked if signal_name or bus_label should be found in the EMD Pin List or Designator Pin List. Bob replied one solution would be to only use the EMD Pin List and only look at signal_name. This would be simple, but reduce the capability. We cannot have an internal supply, but it cannot be specified as a supply and connected with EMD Pin List. We would not document the bus_label voltages. This would require connecting to external SPICE voltage rails. This would be restricted to signal_names only. Bob favored this simplified version. Randy stated we could require that these names appear elsewhere in the EMD. Michael asked if we would make this a warning. Arpad asked if the parser is required to look into the IBIS files to make this determination. Bob replied this is a separate issue, and the EMD Pin List rails may be connected with a bus_label. The only thing that would have to be matched are the pin names. Randy asked, in the example Voltage List, if the names it uses are sufficient to look at the pin lists. Bob stated you always have to go to either the EMD Pin List or Designator pin list, as this translates these names to pin_names. The voltages could be different between the different pin lists. Randy commented the example is currently correct. Bob noted, if there is a signal_name or bus_label and there is a voltage defined that is not used, it is a waring. Randy noted we can expand the text to say this. Randy commented the sentence: "Not all names are required to be listed." on page 15 is too vague. He suggested to say: "Not all names of rail signals found under [EMD Pin List] and [Designator Pin List] are required to be listed.” Arpad suggested to say where. Michael suggested to give the context. Randy asked about the last sentence on page 14: "It is permitted to list bus_label voltages that are not defined in the [EMD Pin List] or [Designator Pin List] columns if the bus_label names are different than the associated signal_name names." Bob noted this is possible. If no bus_label is defined, the signal_name can be used as either signal_name or bus_label. The bus_label name defaults to the signal_name in this case. This is stating the default rule. Bob noted the bus_label can be used to breakout the routes for a single signal_name. Randy suggested to think about this sentence more. Bob asked if the order of the list was changed. Randy replied, yes, and we need to decide if there is a priority to Voltage Range vs. Voltage List. Bob commented we also need to deal with missing information. Michael added the last sentence on page 14 to the bin list. Randy will send out EMD draft 10 [AR]. Michael noted there are fundamental questions of how to parse and strictly enforce the rules. Next Meeting: The next meeting will be May 20. Randy moved to adjourn. Arpad seconded. The meeting adjourned without objection. ================================================================================ Bin List: EMD Comments to be Resolved: (See BIRD202.1 tracking spreadsheet) IBIS-ISS Parser: - IBIS-ISS parser scope document