Hi Steve, As was stated in the original question: "I'm looking for some technique or algorithm to determine the desired amount of equalization just by examining each silicon's input signal". Therefore I think that the purpose was to find equalization in every analog portion separately. Digital processing in the silicon itself is not involved. We cannot generate the combined 4-port model that includes switches and channels, or equally we shouldn't produce combined model for the channels separated by switches. Switch is not something that can contribute to the transfer function or S-parameters, because it is a heavily non-linear transformation - similar to A/D converter. Logically, it also does not make sense to combine links because if the first switch fails (produces incorrect bit) all others should fail too, and no equalization in the subsequent links will help. Therefore equalization should be constructed separately for each analog link. In Hyperlynx FastEye, there is a possibility to find optimal set of FFE and DFE taps, given the channel schematic, S-parameters or its equivalent step or pulse response. Vladimir -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Stephen Zinck Sent: Tuesday, November 23, 2010 6:28 AM To: 'Havermann, Gert'; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: optimize Equalization and De-emphasis settings Hi Gert, If you are using Altera or Broadcom, they have applications that automate this process (other vendors may also have this capability). All you do is provide a 4-port S-parameter model of your system and the tool will tell you the required settings for the most open eye. Pretty cool. I use SIWave from Ansoft to extract all the features for a particular link (BGA pads, traces, accurate via models, passive pads, etc.). The output of this tool is 4-port S-parameters. If multiple system S-parameter files are required for each element (switch-backplane-switch), these models are then concatenated in Ansoft's Designer SI. This tool can accurately concatenate S-parameter files into a single file for the entire system. Best regards, Steve Stephen P. Zinck High-Speed Signal Integrity Consulting Interconnect Engineering Inc. P.O. Box 577 South Berwick, ME 03908 Phone - (207) 384-8280 Email - szinck@xxxxxxxxxxxxxxxxxxxxxxxxxxx Web - www.interconnectengineering.com -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Havermann, Gert Sent: Tuesday, November 23, 2010 07:05 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] optimize Equalization and De-emphasis settings Dear Experts, is there any way to determin the optimum settings for Equalization and De-emphasis in a channel simulation? Situation: I'm running simulations of cascaded channels (driver-PCB-switch-PCB-switch-PCB-reclocker-PCB-Receiver). Each silicon has analog equalization and de-emphasis, only some have ECR, thus i can't just simulate section by section. Simulation takes very long, thus I would like to start with optimum settings. I'm looking for some technique or algorithm to determin the desired amount of equalization just by examining each silicon's input signal (Eye, spectrum, timing...). Any thoughts or paper reference is appreciated. BR Gert http://www.mesago.de/de/SPS/home.htm Besuchen sie uns auf der SPS/IPC/Drives in Nürnberg, vom 23. - 25. November 2010, in Halle 10, Stand 130. -------------------------------------------------------------------------- Absender ist HARTING Electronics GmbH & Co. KG; Sitz der Gesellschaft: Espelkamp; Registergericht: Bad Oeynhausen; Register-Nr.: HRA 5596; persönlich haftende Gesellschafterin: HARTING Electronics Management GmbH; Sitz der Komplementär-GmbH: Espelkamp; Registergericht der Komplementär-GmbH: Bad Oeynhausen; Register-Nr. der Komplementär-GmbH: HRB 8808; Geschäftsführer: Edgar-Peter Duening, Torsten Ratzmann ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu