================================================================================ IBIS INTERCONNECT TASK GROUP https://urldefense.proofpoint.com/v2/url?u=http-3A__www.ibis.org_interconnect-5Fwip_&d=DwIGAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=DcQR-qLpQg5lIreuM6-NYECRIAFXt268PRNS5WO043M&m=0XcSBzGJRQnKLsslbqHqzg3Rz9cFcR9U5Q8mN31lzOI&s=JuOt1MH8hG8CaWO8J2DWX2Zxcc_UcSW-YxywKRIPEqk&e= Mailing list: ibis-interconnect@freelists.org Archives at https://urldefense.proofpoint.com/v2/url?u=http-3A__www.freelists.org_archive_ibis-2Dinterconn_&d=DwIGAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=DcQR-qLpQg5lIreuM6-NYECRIAFXt268PRNS5WO043M&m=0XcSBzGJRQnKLsslbqHqzg3Rz9cFcR9U5Q8mN31lzOI&s=-RuO11bt0NgSNZj5H3U9IDGgdX6DINBFCp-MHcuROs8&e= ================================================================================ Attendees from July 29, 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 July 15, 2020 meeting. Michael displayed the minutes. Randy noted a slash character on line 135. Randy moved to approve the minutes with this change. Walter seconded. The minutes were approved without objection. Review of ARs: - Randy to send out EMD draft18. - Randy reported this was done. Opens: - Bob would like to discuss Randy's pictures on cascaded models. He believes that he has come to a conclusion on a clarification with Walter. - Walter would like to table further the discussion on cascading. He has documentation to show why cascading should not be supported. He moved to prohibit cascading and stop further discussion. Arpad asked if this is needed by the industry. Bob commented the key point is the assignment of singal_name to a Designator can be repeated, and this is not permitted. Several of the configurations can be handled without cascading. Cascading discussion: Walter extracted Randy's pictures into several cases. The first case is a star routing with one CAD net consisting of four subcircuits, which are connected at pin U1.1. Every EDA tool will extract this as a single subcircuit. Bob noted all terminals are exposed on the subcircuit call, and it is possible to have different signal_names. Lance asked if these are the CAD net names. Walter replied these could all be the W-elements of the routing connecting to each Designator terminal. This would be extracted as a single subcircuit. Walter stated in another case you could have 2 CAD nets connecting to create an Extended Nets. Cascading only allows you to connect at the pins, and it is not practical to extract and not done by the EDA tool. The other issue is when the EDA tool uses the EMD this complicates making the connections. Walter asked if there are any cases where cascading is required. Randy asked if we would not allow the connection of EMD models with Designator terminals. Walter replied this is correct. Arpad commented the models could be connected and wrapped in one subcircuit. Randy agreed this would be a better approach. Bob was willing to accept this constraint, but we need to update the verbiage to reflect this. Walter thought the current text does reflect this constraint. Michael asked if the rules are sufficient to prevent the cascading of models. Bob suggested to clarify the verbiage to make this clear. Cascading is permitted in the Interconnect syntax with the connection of pin to pad and pad to buffer. Walter noted these models are done with different CAD systems, and this is similar to the extended nets. Bob agreed this would complicate the EMD syntax. Michael asked if there needs to be an adjustment to the specification. Walter noted the implication of this is the models can not be cascaded at the Designator pins. Bob noted the text prevents duplicate pin_name entries for the I/O pins at any one interface (connection rule 1.a.iv). Michael suggested to give an AR to Bob to add a statement to make this rule explicit. Bob will clarify the cascading restriction in connection rule 1.a.iv [AR]. Michael asked if there are any other issues to discuss on Randy's pictures. Randy asked how EMD can handle test points and if there is an explicit type of syntax for this. Walter replied there could be Designators for these, and these could be hanging or have an IBIS model. Michael asked if we want to look at connection test pads in the middle of the trace. Randy asked if the specification is clear on how to handle these. Walter replied there is a choice for the model maker to use the internal nodes of the IBIS-ISS or the Designator pins. Randy asked if there is anything we would want to add to make this clear. This could be a way for the model maker to make the user aware of the test point. Michael asked if the intent is to make these special to highlight the test points. Randy thought this could be a separate enhancement. Michael agreed. Arpad noted his tool allows for sorting of the designators for finding these. Walter agreed his tool can highlight the test point designators as well. EMD Draft19 Review: Bob stated there could be Aggressor_Only clarifications. Walter noted, when you have Aggressor_Only, you do simulate all lines, but the signals that have the Aggressor_Only tag cannot be used as a victim. The Aggressor_Only is applied to the extended net. Randy noted Aggressor_Only is an informational designation. Arpad agreed the Aggressor_Only nets must be simulated to capture the aggression. Randy noted there is highlighted text on page 37 which needs addressed. Bob had not taken any action on this. Randy commented we moved the text from another section. Michael asked if Bob can take a look at this section. Randy noted the comment also mentions having a bus_label. Randy and Bob will review the section 13.7 text [AR]. Bob noted there was one issue noted by Arpad, which is a sentence not making sense. Michael asked if Arpad can note the section this is in. Bob replied there was an email on this. Michael found it was in the second paragraph in the Usage Rules for Designator Pin List. He suggested to highlight this section. Bob had proposed some changes, but Arpad was not satisfied with this revision. Bob suggested to add this to the agenda for next time. Next Meeting: The next meeting will be August 5. 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