Hi, I'm using ICX for SI/timing analysis. One thing I noticed, if a driver IBIS specified a large reference load (e.g., 50pF for uP), I will always end up with a negative propagation delay since my actual loading is much smaller compared with reference load. Would like to understand how I should correct the number to reflect my actual loading for timing analysis. I would think we can get the internal logic delay of driver through: (Tco - time_to_Vmeas@reference load); But then, how shall I add buffer delay for a real load and propagation delay for a real load--taking into account all the reflection effect (e.g., a daisy-chained bi-directional data bus). Thanks Perry -- Perry Qu Design & Qualification | 600 March Road Alcatel Canada | Ottawa, ON K2K 2E6, Canada DID: (613) 7846720 | FAX: (613) 5993642 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu