Most models are generated/optimized for a particular application. IBIS models do a good job when looking at crosstalk, Signal Integrity and reflections in nets. That was the purpose of IBIS models when they were first envisioned. Your application is outside the intended purpose of an IBIS model. You are asking an IBIS model to characterize things that is not set up to do, nor intended to do. And the simulators are not designed to do what you want. If you need to accomplish both a turn on phenomena and signal integrity after the turn on event I'll suggest two different IBIS models. Run one simulation for the first clock cycle with a model with 3.3 nsec of dead time in its initial rise or fall depending on your application and minimum dead time in the next transition. Then run another model with minimum dead time to look at long term SI effects. You may have to modify many models in order to get all the turn on conditions met. Tom Dagostino Teraspeed(R) Labs 13610 SW Harness Lane Beaverton, OR 97008 503-430-1065 tom@teraspeed.com www.teraspeed.com Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 401-284-1827 -----Original Message----- From: owner-ibis@server.eda.org [mailto:owner-ibis@server.eda.org] On Behalf Of Akhilesh CHANDRA Sent: Monday, May 14, 2007 10:53 PM To: 'Dunbar, Tony'; ibis@server.eda-stds.org Cc: Akhilesh CHANDRA Subject: RE: [IBIS] How we can model startup time in IBIS. Hello Tony, Thanx for your reply. Initial delay is not important for SI simulations but if it's missing in our model then it's difficult to match spice and IBIS results also few customers use these models for delay calculation if I don't support this startup time then customer have only 300ps delay while in silicon it's 3.3ns. Regards Akhilesh -----Original Message----- From: owner-ibis@server.eda.org [mailto:owner-ibis@server.eda.org] On Behalf Of Dunbar, Tony Sent: Monday, May 14, 2007 10:22 PM To: ibis@server.eda-stds.org Subject: RE: [IBIS] How we can model startup time in IBIS. Hi Akhilesh, I've pondered this for a little while and all I can come up with is to ask why is this an important or even relevant functional detail to be included in a signal integrity simulation, presuming it is a signal integrity simulation you are wanting to do? An "initial delay" can be incorporated into the stimulus of some SI simulators but that is really intended to provide for driver-to-driver skew, whereas your brief description refers to "startup". Regards, Tony -----Original Message----- From: owner-ibis@server.eda.org [mailto:owner-ibis@server.eda.org] On Behalf Of Akhilesh CHANDRA Sent: Monday, May 14, 2007 4:18 AM To: ibis@server.eda-stds.org Cc: Akhilesh CHANDRA Subject: [IBIS] How we can model startup time in IBIS. Hello Experts, I am doing IBIS model of an IO operating at 800MHZ frequency. It have startup time of 3nsec. After 3ns design gives output of 800mhz frequency. If I model this time in waveform database of IBIS models the I have over clocking issue and design is not work at this high frequency. Can you help me to model this startup time. Is anyone make IBIS model of such designs. Regards Akhilesh -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993 -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993 -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993 -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993Received on Tue May 15 02:01:14 2007
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