====================================================================== IBIS EDITORIAL TASK GROUP http://www.ibis.org/editorial_wip/ Mailing list: ibis-editorial@freelists.org Archives at http://www.freelists.org/archive/ibis-editorial/ ====================================================================== Attendees from July 29 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* Mentor Graphics 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. Minutes from the July 15 meeting were not available for review. Opens - Radek asked for time to discuss pin reference alternatives. Comment Disposition from Offline Review of Draft 1: Mike showed an email from Bob Ross describing our historical IBIS editorial process. Mike suggested we could abandon the IBIS 6.1 draft he created, in favor of asking Michael Mirmak to start it over. Bob said we have always followed a rigorous process and that Michael Mirmak has always been the editor, although for IBIS 6.0 Michael was on sabbatical and others took over. Mike said Michael Mirmak will next be available for editorial meetings Aug 26. Bob said Michael Mirmak catches things that we tend to miss, noting that we often find things in BIRDs just before we vote on them. Mike said we would suspend work on the 6.2 draft in favor of working on the BIRDs discussed in the prior meeting. He also suggested this process document should be posted somewhere, with cleanups mentioned by Bob. Walter said he agrees with the process. Walter said his IBIS 6.2 draft revisions incorporated ideas we discussed, and should be viewed as an example of what 6.2 might look like. He felt it was a useful exercise, and he and Bob had has a chance to review the draft revisions item by item. They had agreed that we might not want the [Bus Label] and [Pin Reference] changes in IBIS 6.2, but we need a clear list of BIRDs to incorporate. Bob said we have not yet agreed on final wording for several changes. Individual BIRDs for IBIS 6.2: Mike showed a list of IBIS 6.2 BIRD candidates. Most of these were not yet drafted, and Mike gave them letter identifications. Bob suggested BIRD D should be folded into BIRD 180, and that the [Bus Label] proposal might be a new BIRD separate from E. Mike suggested we should try to assign requester names to the undrafted BIRDs. Walter said we might not do F. Walter suggested a new BIRDs H, I, and J, which were added to the list, based on other changes found in his IBIS 6.2 draft. Bob said H could be folded into B. Bob suggested new BIRDs K, L, and M, added to the list. Bob agreed to be the requester for K, related to know wording issues. Mike showed an email from Radek regarding pin reference alternatives: Radek said he saw three alternatives for understanding how reference connections might be made in the case where a buffer connects to a channel model through a W-line package model. Case A was the legacy representation. Radek noted that C_comp was not in the picture, and that in IBIS 6.1 it connects to "GND". Walter said A is the most common case, and that exceptions are RS232 and ECL. Radek said in the pictures the upper right box gave the supplies, and the box on left enclosed IBIS data. He said a [Define Package Model] would have to be referenced to something that was not in the picture. Either it would a GND symbol or user would have to decide what to do with it. Radek said one could connect the channel reference terminal(s) to the Ref signal, but he noted that the Ref signal didn't enter the IBIS model. He said that if you had a GND pin it is likely to be the reference connection for everything that needs a reference connection. Radek said in case C we would identify the reference terminal to connect to Pulldown, but it was not the external Ref terminal. He noted that in simulation we couldn't have a floating reference for the channel. Radek said he would be fine with either B or C, asking for agreement on one of these. Bob suggested this should be discussed in more detail at ATM meetings. He said case C implied that the W element also needed a reference terminal. Radek added that the W element could be coupled, or it could be an S-parameter model. Bob said there may be problems if we end up specifying reference rails with unintended voltages. Walter cautioned that the term "reference" can mean two things. It might mean what you measure a voltage against, or it might mean a return path. The bottom terminal in the figures was usually a signal on a plane layer, against which a transmission line is imaged. That signal might not connect to any component in figure C, and that would violates rules. Radek said he could rework the image to correct that. Walter said there were cases such as RS323 where ground is an external reference, and ECL which has no ground. He said in the ECL case the W line better be imaged on the plane correctly, somehow. Radek said in C we didn't have the pin reference, so the buffer would float. Arpad said this could be discussed in ATM meetings. Walter suggested the question should be what the EDA tool needs to do. Bob moved to adjourn. Radek seconded the motion. The meeting adjourned.