================================================================================ 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 November 3 Meeting (* means attended at least using audio) ANSYS Curtis Clark Cadence Design Systems Bradley Brim Cisco David Siadat Intel Corp. Michael Mirmak Keysight Technologies Radek Biernacki*, Ming Yan Mentor, A Siemens Business Arpad Muranyi* Micron Technology Justin Butterfield*, Randy Wolff* SAE ITC Maureen Lemankiewicz, Logen Johnson Signal Integrity Software Walter Katz*, Mike LaBonte* Teraspeed Labs Bob Ross* University of Aveiro in Portugal Wael Dghais Mike LaBonte convened the meeting. No patents were declared. Justin Butterfield took minutes. Review of Minutes: - Mike called for review of the minutes from the November 1 meeting. Randy Wolff moved to approve the minutes. Walter Katz seconded. The minutes were approved without objection. Review of ARs: - Michael to contact Radek Biernacki to ask about changes. - Radek stated he has not received an email from Michael yet, but he did review minutes from last time. - Mike to incorporate changes from Bob Ross into BIRD189.5 draft10. - Mike reported that this is done. - Arpad Muranyi to work with Bob and Walter on Sets and Groups language. - Arpad reported that this is started but not yet complete. Opens: - None BIRD189.5_draft10_v3 Review: Mike noted that he started with the version that Radek sent out and added the changes discussed on Wednesday. The BIRD history is updated accordingly. The Unused_port_termination subparameter no longer includes the word "directive". There are now three options for Unused_port_termination, which include Open, Reference and Resistor, while the per port termination option has been removed. Mike added a comment about naming the third option "resistor" or "resistance". Bob noted that there should be a value for the resistance in a third column of the example. Unused_port_termination Options: Radek noted that he still would like the per port value, and he prefers Bob's original proposal with the per port termination option for Unused_port_termination. He also likes the name "resistor", as we are terminating with a component. Bob noted there are various syntactical options for per port termination which are cumbersome. If a value other than the reference impedance is needed, there is the option to wrap the model in an IBIS-ISS subcircuit. Radek noted that this is the case for all of the Unused_port_termination options. Bob replied that the Unused_port_termination is a shortcut. Walter stated that the shortcut simplifies the models and allows the EDA tool to reduce the number of ports. He thought that the group was mostly in favor of removing the per port termination option and that we should hold a vote. Radek stated that we need to address the potential needs of model makers, and the per port values remove ambiguity on how to terminate the unused ports. Walter stated he would like submit a motion to have three options for Unused_port_termination of Open, Reference, and Resistance with no per port termination option. Bob commented that the per port option can always be added to the specification later. Randy commented that we don't want to preclude adding per port termination to the specification later, and we might want to wait for model makers to request the feature. Mike commented that you would only use per port termination if you have many models needing different port terminations and want to simplify the models with the shortcut. He asked if there are going to be enough such cases to justify adding the feature. Walter moved to have three options for Unused_port_termination of Open, Reference, and Resistance with the per port termination option removed. Bob seconded the motion. Radek objected to the motion. The roll call vote tally was: Keysight - No Mentor - Yes Micron - Yes SiSoft - Yes Teraspeed Labs - Yes The roll call vote concluded with a tally of Yes – 4, No – 1, Abstain – 0. The motion passed. Walter noted that for the "resistor" versus "resistance" naming issue, the Touchstone specification uses resistance and impedance. Bob noted that in the IBIS-ISS specification both are used, and the same is true in the IBIS specification. Bob noted both options could be correct. Radek noted that resistor means a component while resistance means a value. Walter thought impedance might also imply reactance terms. Walter moved to change the Unused_port_termination selection of Resistor to Resistance in BIRD189.5 draft10. Arpad seconded the motion. Bob objected to the motion. The roll call vote tally was: Keysight - Abstain Mentor - Yes Micron - Yes SiSoft - Yes Teraspeed Labs - No The roll call vote concluded with a tally of Yes – 3, No – 1, Abstain – 1. The motion passed. Bob noted that there might be other places in the document that need changed. Walter agreed and noted there might also be places where the word "resistor" makes sense and should be retained in the document. File_TS0: Bob asked what the remaining issue regarding File_TS0 was. Radek stated that the issue is how the global ground is handled. Bob commented that there is no port assigned to node 0, as it is an outside connection. Radek asked if we require that pulldown_ref is also connected to node 0 for File_TS0 cases. Arpad replied no, and it is assumed that the tool will connect the reference to node 0. In IBIS we do not have node 0 defined, but it is only affecting the Interconnect Model. Radek stated that it could be a problem if the pulldown_ref was not connected to node 0 and the Touchstone file is. He suggested to have some restrictions around File_TS0 usage. Walter asked if Radek could write up the required restrictions. Mike suggested to continue the File_TS0 restriction discussion in the ATM meeting on Tuesday. The next meeting is tentatively scheduled for Wednesday November 3. Randy moved to adjourn. Radek seconded. The meeting adjourned without objection.