Todd, I went back to IBIS 3.2 to recheck what it said about thesholds. Here is what I found on page 23: | | Vinh, Vinl rules: | | The threshold subparameter lines provide additional min and | max column values, if needed. The typ column values are still | required and would be expected to override the Vinh and Vinl | subparameter values specified elsewhere. Note: the syntax | rule that require inserting Vinh and Vinl under models remains | unchanged even if the values are defined under the [Model | Spec] keyword. I'm not sure what was originally intended since, Vinl & Vinh are supposed to be the corners of the process under worst case environmental voltage and temperature anyway. I'm sure you know all this. But, if others are listening maybe it should be repeated for the record. I've looked at over 600 IBIS files from a wide variety of sources and recollect seeing, at most, two instances of min and max values of Vinl and Vinh given in addition to typical. However, your question is quite interesting in light of timing getting very tight. Like on the Pentium III and beyond. Also, it isn't quite clear to me if Vinl - Vinh indicates +/- 3 sigma, +/- 6 sigma, "worst case," or what. Best Regards, Roy "Todd Westerhoff" <twester@xxxxxxxxxxx> on 07/27/2001 01:11:10 PM Please respond to twester@xxxxxxxxxxx Sent by: "Todd Westerhoff" <twester@xxxxxxxxxxx> To: ibis@xxxxxxx, si-list@xxxxxxxxxxxxx cc: (Roy Leventhal/MW/US/3Com) Subject: [SI-LIST] IBIS and device performance Hi all, This particular question is going to both the SI and IBIS reflectors, as the issues touch both groups. Question 1 (for the SI-listers) How often are people seeing IBIS models that use the [Model Spec] keyword to list min/typ/max values for parameters like Vinl, Vinh and Vmeas? Are you seeing this commonly, or was your response "what is he talking about"? Question/Comment 2 (for the IBISians) Is there any definitive, short, concise document that lists which combinations of which IBIS parameters are meant to represent best, typical, and worst-case component-level performance? As an example, the [max] section of a V/I curve would clearly indicate best-case device performance, but you'd have to combine that with the [min] value of a parameter like c_comp. So - for best case conditions, the EDA tool and the model creator both have to use the same set of conventions of combining parameters for best, typical and worst case device performance. Is there a table anywhere that defines this? Todd. Todd Westerhoff SI Engineer Hammerhead Networks 5 Federal Street Billerica, MA 01821 twester@xxxxxxxxxxx ph: 978-671-5084 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field 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 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field 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