Minutes, IBIS Quality Committee 16 Dec 2008 11-12 AM EST (8-9 AM PST) ROLL CALL Adam Tambone * Anders Ekholm, Ericsson Barry Katz, SiSoft Benny Lazer Benjamin P Silva Bob Cox, Micron * Bob Ross, Teraspeed Consulting Group Brian Arsenault * David Banas, Xilinx * Eckhard Lenski, Nokia Siemens Networks Eric Brock * Guan Tao, Huawei Technologies Gregory R Edlund Hazem Hegazy Huang Chunxing, Huawei Technologies John Figueroa John Angulo, Mentor Graphics Katja Koller, Nokia Siemens Networks Kevin Fisher Kim Helliwell, LSI Logic Lance Wang, IOMethodology Lynne Green * Mike LaBonte, Cisco Systems Mike Mayer, SiSoft * Moshiul Haque, Micron Technology * Pavani Jella, TI Peter LaFlamme Randy Wolff, Micron Technology Radovan Vuletic, Qimonda Robert Haller, Enterasys Roy Leventhal, Leventhal Design & Communications Sherif Hammad, Mentor Graphics Todd Westerhoff, SiSoft Tom Dagostino, Teraspeed Consulting Group Kazuyoshi Shoji, Hitachi Sadahiro Nonoyama Everyone in attendance marked by * NOTE: "AR" = Action Required. -----------------------MINUTES --------------------------- Mike LaBonte conducted the meeting. Call for patent disclosure: - No one declared a patent. AR Review: - Mike propose IBISCHK bug for 5.5.6 - This has been drafted. - Still not sure if it should be proposed. New items: - Eckhard emailed a document "Possible Errors-revised-16dec08.doc" - This topic (Section 6) will be discussed in this meeting. - In a previous meeting David had proposed a discussion of correlation - This is section 7 and will be discussed after section 6. Review of Eckhard's document: 6.1. {LEVEL 2} Typ/min/max order of parameters correct - We have been filtering out checks that call only for observance of the IBIS specification. - We deleted this check 6.2. {LEVEL 3} C_comp checked in both input and output mode - Mike: There has been some controversy on this topic - David: Some structures produce a very wide C_comp range - Lower pin capacitance is a competitive issue - One idea is to release IBIS files with: - C_comp = C_comp_off - C_comp_on value commented out - Bob: This might be a good cookbook suggestion - David: There should be a more elegant way to do this - Mike: The ibis-atm group is considering using [External Circuit]s - This would allow C_comp to depend on voltage, frequency, and state - David: Should there be separate state keywords? - There are 9 possible C_comp state values: (hi, lo, tri) x (typ, min, max) - Moshiul: In most cases tri gives good correlation - David: Having the right value gives better rise/fall time correlation - David: We should agree in the IQ spec what the best practice is - We are not yet certain what the "mission" of section 6 is - Should IBIS files get bonus points for meeting these? - Bob: The lack of C_comp typ/min/max correlation is a problem - C_comp is the only IBIS keyword that does not follow typ/slow/fast corners - New C_comp keywords could address this - A 4th dimension is the actual pad voltage, not the driven state - Methods to determine C_comp: - Using ramp sweeps to calculate C covers a wider voltage range - Can also AC sweep the bias point - There is a way to sweep frequency - A TDR can be used to see the C_comp blip - All of these methods give different results - David: Section 6 should be for guidance, not affecting IQ scores - Mike: We could have an IQ score letter to signify extra checks - Section 6 could be called "Consistency Checks" - There are two separate topics here: - How to represent C_comp - Detecting C_comp values that are guessed or incorrectly determined - Mike: Will IC vendors have trouble with a C_comp consistency check? - Moshiul: No Problem - Pavani: Agree: We do correlation checks. - Moshiul; Sometimes devices are used in different modes - This results in changing C_comp - Mike: We could have a 5.x "driving and non-driving" mode - This coule be check 5.1.4 - David: We may be adding confusion with that - Bob: We should insert 5.1.5 as a conditional check: - For higher speed applications consider a check that calls for more detailed C_comp - Separate driving and non-driving values, for example AR: Moshiul draft new IQ check for reasonable C_comp for high speed AR: Mike post 1.1ak IQ spec with deletions processed and renumbered Discussion of meeting dates - The next 2 Tuesdays might be poorly attended due to holidays - We decided to meet 6 Jan 2009 Next meeting: 6 Jan 2009 11-12 AM EST (8-9 AM PST) Meeting ended at 12:08 PM Eastern Time.