Russell, Very well said indeed. Michael E. Vrbanac Russell D. Moser wrote: > I am proud to see such spirited discussion and questions especially from >those with who I have had the opportunity to work with. > > I propose a thought that has been discussed over time. > > We feel (@ Orion) that we are at a point (and have been for awhile) in our >SI efforts where computational capacity and modeling methods are approaching >the variability of the components. > > Simply put, we have seen that variations in PWB, connector and cable >assemblies have finally been able to be discerned due to the granularity of >our models and simulators. > > In a former capacity, way back in the late 80's, we had customers ask how >our models correlated with manufacturing variability. As you'd expect, we >were working at edge rates of 1-5ns where such perturbations were not >discernable. > > Noting edge rates under 150ps (although those edges are quickly slowed), >our once lumped devices have now exposed their internal variability such as >those of internal geometries (in the case of connectors), materials (PWB >resin pooling, dielectric variability) and lay (in the case of cables. > > Many of us who have been around for quite awhile keep this in mind while >developing product, models and designs, I offer this as a bit of wisdom for >those whom are just entering into the field of SI. Do not de-focus on the >real-world nature of the components that we wish to model. > > >Regards, >___________________ >Russell D. Moser >Orion Group >r.moser@xxxxxxxxxxxxxxxxx >www.theoriongroup.net >717.914.0116 > > >~~~~~~~ >This communication is for use by the intended recipient and may contain >privileged, confidential or copyrighted (under applicable law) information. >You are hereby formally notified, if you are not the intended recipient, >that any use, copying or distribution of this e-mail, partially or in its >entirety, is strictly prohibited. Please notify the sender by return e-mail >and delete this e-mail from your system. Unless explicitly stated >otherwise, this e-mail does not constitute a contract offer, a contract >amendment, or an acceptance of a contract offer. This e-mail does not >constitute a consent to the use of sender's contact information for direct >marketing purposes or for transfers of data to third parties. >copyright 2004 by The Orion Group > > > > > >>-----Original Message----- >>From: si-list-bounce@xxxxxxxxxxxxx >>[mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Zanella, Fabrizio >>Sent: Tuesday, July 27, 2004 10:12 AM >>To: si-list@xxxxxxxxxxxxx >>Subject: [SI-LIST] Re: SI Simulation of GHz signals >> >>Does anyone have pointers to detailed explanations of the >>techniques required for the following techniques required for >>5Gbs and above SI simulations? >>Probability Distribution Function (PDF) plots, Bathtub Curves (CDF). >>Also, what is the maximum allowable crosstalk in dB from the >>surrounding channels at the operating frequency when measured >>with respect to the insertion loss on the channel? >> >>Thanks,=20 >>Fabrizio Zanella >> >>-----Original Message----- >>From: si-list-bounce@xxxxxxxxxxxxx >>[mailto:si-list-bounce@xxxxxxxxxxxxx] >>On Behalf Of Craig Clewell >>Sent: Tuesday, July 27, 2004 8:48 AM >>To: clifford@xxxxxxxxxxxxx >>Cc: si-list@xxxxxxxxxxxxx >>Subject: [SI-LIST] Re: SI Simulation of GHz signals >> >>Hi Clifford,=20 >> >>If you are really interested in running the s parameters in >>HSPCIE to speed up your simulation times (and your part >>vendor won't supply them) you may want to set up an ac >>analysis for the "parts" and run each one individually. You >>can generate the S parameters within HSPICE, or any other >>simulator using discrete components. I keep some handy >>netlists available that I re-use over and over again that >>allow me to just drop in single part models. You also may >>want to create a macro in Excel, or a script in MatLab, >>etc... that will take your output and format it into a >>Touchstone file. =20 >> >>If you do this work up front you can train your monkey to >>re-use the netlist and macro over and over again. This will >>also allow you to quickly go back and investigate each piece >>of the system on its own, and build up a library of S >>parameter files for devices that you re-use. >>When you want to put the system together you can then drop in >>all the s parameter files from your library. >> >>...just an idea >> >>Craig >> >> =20 >> >> >> >>>Hello >>>I would like to perform reliable simulation of GHz signals (up to >>>3.125GHz), specifically Xilinx RocketIO. I would like to >>> >>> >>include in the >> >> >>>simulation the effects of the following: >>>Driver->PCB trace (incl. vias)->connector->cable->connector->PCB >>>trace(incl. vias)->Receiver >>> >>>The models that I have obtained from the various vendors are HSPICE >>>models. I have evaluated two of the most recommended S.I. toolchains: >>>Mentor G. HyperLynx and Cadence Spectraquest. Both tools use >>> >>> >>HSPICE as >> >> >>>the simulation engine, and essentially act as a front-end gui to >>> >>> >>HSPICE, >> >> >>>as well as extracting the PCB trace/via models. My >>> >>> >>experiences thusfar >> >> >>>with both tools have not been good. Anything but the most >>> >>> >>simplistic of >> >> >>>traces causes the tools to either crash or take rediculous time to >>>process (of the order of hours for even a simple net). A >>> >>> >>further issue >> >> >>>is that both of these tool vendors claim that the HSPICE >>> >>> >>simulator is >> >> >>>not necessary, and that the simulation can be performed >>> >>> >>without it, but >> >> >>>practically this is not the case, due to a lack of availability of >>>reliable models in anything other than HSPICE format. The conversion >>> >>> >>>from HSPICE to any of the custom modelling types is also, in my >>opinion, >> >> >>>non-trivial and potentially an extremely tedious manual process. >>> >>>I believe that S-Parameter based simulation provides much faster >>>simulation, but again there is a lack of availability of S-Parameter >>>models. >>> >>>Can anyone recommend a method for simulating the above >>> >>> >>signals that is >> >> >>>simple, robust and reliable, or is the simulation of such >>> >>> >>signals still >> >> >>>premature? Coming from a HW design background, I am fairly >>> >>> >>new to S.I., >> >> >>>but it seems surprising that there is no industry-standard >>> >>> >>modelling >> >> >>>type (equivalent of IBIS) that cable/connector vendors will provide, >>> >>> >>but >> >> >>>maybe this level of simulation is in its infancy, and S-Parameter >>> >>> >>models >> >> >>>will emerge as the standard? >>> >>>Is the simulation of such signals entirely necessary? I am dubious >>> >>> >>about >> >> >>>the reliability of the results of such simulations, and I am >>> >>> >>wondering >> >> >>>whether it is not more practical to just take all the precautions >>>possible and hope for the best! >>> >>>Please let me know if you have any advise, or a good solution to my >>>dilemma! >>> >>>Kind regards, >>>Clifford >>> >>> >>> >>>------------------------------------------------------------------ >>>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 FAQ wiki page is located at: >>> http://si-list.org/wiki/wiki.pl?Si-List_FAQ >>> >>>List technical documents are available at: >>> http://www.si-list.org >>> >>>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 >>> >>>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 FAQ wiki page is located at: >>> http://si-list.org/wiki/wiki.pl?Si-List_FAQ >>> >>>List technical documents are available at: >>> http://www.si-list.org >>> >>>List archives are viewable at: =20 >>> //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 >>>=20 >>> >>> >>>=20 >>> >>> >>> >>------------------------------------------------------------------ >>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 FAQ wiki page is located at: >> http://si-list.org/wiki/wiki.pl?Si-List_FAQ >> >>List technical documents are available at: >> http://www.si-list.org >> >>List archives are viewable at: =20 >> //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 >> =20 >> >>------------------------------------------------------------------ >>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 FAQ wiki page is located at: >> http://si-list.org/wiki/wiki.pl?Si-List_FAQ >> >>List technical documents are available at: >> http://www.si-list.org >> >>List archives are viewable at: =20 >> //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 >> =20 >> >> >> >>------------------------------------------------------------------ >>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 FAQ wiki page is located at: >> http://si-list.org/wiki/wiki.pl?Si-List_FAQ >> >>List 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