IBIS Macromodel Task Group Meeting date: 01 Nov 2011 Members (asterisk for those attending): Agilent: Fangyi Rao * Radek Biernacki Altera: * David Banas Ansys: Samuel Mertens * Dan Dvorscak * Curtis Clark Arrow Electronics: Ian Dodd Cadence Design Systems: Terry Jernberg Ambrish Varma Celsionix: Kellee Crisafulli Cisco Systems: Ashwin Vasudevan Syed Huq Ericsson: Anders Ekholm IBM: Greg Edlund Intel: Michael Mirmak LSI Logic: Wenyi Jin Mentor Graphics: * John Angulo Zhen Mu * Arpad Muranyi Vladimir Dmitriev-Zdorov Micron Technology: Randy Wolff NetLogic Microsystems: Ryan Couts Nokia-Siemens Networks: * Eckhard Lenski QLogic Corp. James Zhou Sigrity: Brad Brim Kumar Keshavan Ken Willis SiSoft: * Walter Katz Todd Westerhoff Doug Burns * Mike LaBonte Snowbush IP: Marcus Van Ierssel ST Micro: Syed Sadeghi Teraspeed Consulting Group: Scott McMorrow * Bob Ross TI: Casey Morrison Alfred Chong Vitesse Semiconductor: Eric Sweetman Xilinx: Mustansir Fanaswalla The meeting was lead by Arpad Muranyi ------------------------------------------------------------------------ Opens: - Arpad reviewed the upcoming meeting schedule - No meeting Nov 15 & 22, Dec 27 - Mike: US DST time shift is Nov 6. -------------------------- Call for patent disclosure: - None ------------- Review of ARs: - None ------------- New Discussion: BIRD 140: - Arpad showed version 2 of his "Corner Notes" presentation - Slide 15: - What Model_types can be AMI? - This affects the min/max <> slow/fast mapping issue - Many typ/min/max keywords are eliminated if Terminator not allowed - Only [Diff Pin] and [External Model] would remain - Slide 17: - Mapping is stated for I-V V-T - It is sort of stated as a "conservative approach" for C_comp - Slide 18: - Define which Model_types are allowed - Mapping of min/max for Pin[Diff ] [External Model] - Reiterate for I-V, V-T, C_comp - BIRD 133 is not needed - Walter: - We can assume fast = min for [External Model] - The faster part should have less skew - - Arpad: A Terminator is the same as a receiver, but it has no thresholds - With AMI we don't do those measurements - It is hard to see why Terminator is needed for AMI - S-params would be better than these RLC keywords - Walter: Several vendors use Terminator and [R Series] - No objection if we restrict AMI to Input and Output types - Arpad: Agree - Bob: Series can be used as diff terminator - Arpad: This is only because we have pseudo-diff models - With IBIS-ISS we can have true differential - Bob: We should not make these types illegal - Radek: Agree, we should allow them - Walter: We should not handle typ/min/max for them - BIRD 120 would do it - Arpad: We should warn about typ/min/max issues for these - Bob: No spec statement that Rgnd min < max - The parser warns though - That message could be removed - Radek: We should at least recommend not to use them - Bob: It would be OK to not have Terminator because that is just a stub - Radek: We can disallow if we feel strongly about it - Arpad: There might be a gap between 5.1 and 5.2 - Without IBIS-ISS model makers might have no solution during the gap - John: Only [Rac] and [Cac] pose a problem - Bob: We only need a note that Terminator might not be supported in all tools - Arpad: Can we add the warning text to BIRD 140? - John: I would rather disallow Terminator and Series models - Bob: Where does [Algorithmic Model] reside? - Arpad: in [Model] - Bob: [Algorithmic Model] does not make sense under Terminator - Arpad: Actually there can be two models connected to a pin - single plus series - Bob: [Algorithmic Model] should be restricted from Series types - Arpad: Can we exclude AMI from Series types? - No objection - Bob: There should be a new BIRD for that - It does not belong on a corner BIRD - Bob: [Diff Pin] tdelay* was for statistical use, tolerances - Arpad: The jitter parameters are better - Bob: The TT parameter is similar, it only shows how bad your part is - Walter: Agree with Bob - Arpad: Should this be addressed in later analog BIRDs? - Walter and Radek agreed - No objections - Radek: It is a good suggestion to clarify for I-V, V-t, C_comp, etc. - Maybe it should be for IBIS in general, not just AMI - Arpad: I will rewrite BIRD 140 AR: Arpad rewrite BIRD 140 to disallow AMI Terminator, etc. Walter showed the jitter BIRD 123.3 - Walter: Draft 2 fixes typos - Added paragraphs to introduction - Critical that people review in detail - Walter read the paragraphs - Bob: Is this BIRD text or explanation? - It refers to the BIRD itself - Walter: That may change in the final version - Arpad: Will jitter show up in common mode? - Walter: Getwave inputs are diff, do not account for channel common mode issues - Skew on the TX would not be modeled correctly - This is a non-trivial change to Getwave - Skew under 20% is not an issue - Don't know of any buffers that bad - People are worrying about common mode diff coupling - It is independent of the CDR - Arpad: Will this be in the spec? - Walter: The group can decide - Arpad: This might be useful to explain the jitter parameters - Bob: It would fit into the analysis section - Arpad: We should check each jitter description against this ------------- Minutes by Mike LaBonte Next meeting: 08 Nov 2011 12:00pm PT Next agenda: 1) Task list item discussions ------------- IBIS Interconnect SPICE Wish List: 1) Simulator directives