Let's take this one step at a time. Let's start with port loss. I don't want to mix metaphors by going directly modal issue yet. I may be missing something in IBIS-AMI so help me understand this "baby step". It look to me like we are taking about the voltage transfer function (VTF). Forget the other modes for now. If I have a step response of a channel and don't know the impedance (really s11, s22) how can I find system voltage transfer function. In the frequency domain; for a channel, source, and load the VTF is. (Gamma_src-1)*s21*(Gamma_ld+1) --------------------------------------------------------------------------------- 1-s12*s21*Gamma_src*Gamma_Ld+s11*s22*Gamma_src*Gamma_Ld-s11*Gamma_src-s22*Gamma_ld Gamma_src=Source reflection Load_ld=load reflection S11,s22,s21,s12 = 2 port channel s-parameter This if is we consider all is linear. ...Rich -----Original Message----- From: Scott McMorrow [mailto:scott@xxxxxxxxxxxxx] Sent: Thursday, November 19, 2009 12:17 PM To: msteinb@xxxxxxxxxx Cc: Mellitz, Richard; wkatz@xxxxxxxxxx; IBIS-ATM Subject: Re: [ibis-macro] Re: FW: [IBIS-Users] AMI convolution It seems to me that a 2-port interface from a driver or receiver to the interconnect environment would be sufficient to characterize all multi-conductor interconnect modes, assuming that there is no driver-to-driver, receiver-to-receiver, or receiver-to-driver analog interactions on the silicon. Mike Steinberger wrote: > Rich- > > The output of the algorithmic model is a one dimensional waveform. If > you want to model modal behaviors, that will have to be done in the > analog model. For example, that's where the S parameter behaviors you > refer to are modeled; and depending on the EDA platform, those S > parameters can be multiconductor. > > By the way, what important modes do you think should be modeled? > > Mike S. > > Mellitz, Richard wrote: >> >> Hi Walter, >> >> I was thinking about this some. Does this flow preclude a modal >> impulse response flow? The single channel voltage transfer impulse >> response really requires 4 entities based on s11, s21, s12, and s22. >> A multi-conductor response requires more. >> >> ... Rich >> >> *From:* ibis-macro-bounce@xxxxxxxxxxxxx >> [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] *On Behalf Of *Walter Katz >> *Sent:* Wednesday, November 18, 2009 12:14 PM >> *To:* IBIS-ATM >> *Subject:* [ibis-macro] FW: [IBIS-Users] AMI convolution >> >> All, >> >> In case you are not in ibis-users@xxxxxxx . >> >> Walter >> >> Walter Katz >> >> 303.449-2308 >> >> Mobile 720.333-1107 >> >> wkatz@xxxxxxxxxx >> >> www.sisoft.com >> >> -----Original Message----- >> *From:* Walter Katz [mailto:wkatz@xxxxxxxxxx] >> *Sent:* Wednesday, November 18, 2009 12:00 PM >> *To:* Eric Monteiro; ibis-users@xxxxxxx >> *Subject:* RE: [IBIS-Users] AMI convolution >> >> Eric, >> >> Asking who is responsible for convolution is like asking who is >> responsible for Fourier Transform. Convolution is a mathematical >> technique that EDA tools can use on the input and output of AMI >> models, and convolution is a mathematical technique that can be used >> inside of the AMI model to apply a filter. The following describe who >> may or must use convolution for the "Preferred Flows". Preferred >> flows assume both the Tx and Rx model have Init_Returns_Filter=True >> and Use_Init_Ouput=True. >> >> Assuming a preferred statistical flow, the EDA tool supplies an >> impulse response of the channel to the TX Init function. Inside the >> Tx Init function (i.e. inside the AMI model), the model would compute >> an impulse response of its filter and return it to the EDA tool. The >> EDA tool would convolve this impulse response with the impulse >> response of the channel and present these results to the Rx Init. The >> Rx Init would determine the impulse response of its filter, and >> return it to the EDA tool. The EDA tool would then convolve it with >> the impulse response that was presented to Rx Init to determine the >> impulse response of the channel equalized by both the Tx an Rx >> filters. The EDA tool will process this and may use the convolution >> mathematic technique (e.g. on probability distribution functions) to >> generate bathtub curves and bit error rates. So in the preferred >> statistical flow the EDA tool does convolution and the AMI model >> might not. I could image that the AMI models may use the convolution >> technique to generate the impulse response of the filter. >> >> Assuming the preferred time domain flow, the EDA tool must first run >> the statistical flow (it need not analyze the results of Rx Init). >> The EDA tool supplies a stimulus waveform to Tx GetWave. The EDA tool >> may or may not use the convolution generate this waveform. The Tx >> GetWave will generate an equalized stimulus waveform with techniques >> that may or may not use convolution. The EDA tool must us uses >> convolution to apply the impulse response of the channel with this Tx >> equalized stimulus waveform. The waveform is then presented to Rx >> GetWave. Rx GetWave may or may not used convolution to apply its >> equalization filter to it's input. The output of Rx GetWave is a >> waveform, and clock ticks. The EDA tool may or may not use >> convolution to analyze this waveform to generate bathtub curves and >> bit error rate. So in the preferred time domain flow, the EDA tool >> must use convolution, and the AMI model might not. >> >> Walter >> >> Walter Katz >> >> 303.449-2308 >> >> Mobile 720.333-1107 >> >> wkatz@xxxxxxxxxx >> >> www.sisoft.com >> >> -----Original Message----- >> *From:* owner-ibis-users@xxxxxxx [mailto:owner-ibis-users@xxxxxxx]*On >> Behalf Of *Eric Monteiro >> *Sent:* Wednesday, November 18, 2009 10:55 AM >> *To:* ibis-users@xxxxxxx >> *Subject:* [IBIS-Users] AMI convolution >> >> Hi everyone, >> >> I was hoping someone could clarify who is responsible for convolution >> in IBIS-AMI (EDA tool, or the modeler). >> >> Clearly the convolution involving an FIR filter is upon the modeler, >> the convolution I speak of is the one that is done with the channel >> response. >> >> My understanding has been as follows: (please correct me if I'm wrong) >> >> (a) -- (Tx IC) -- (passive channel) --(b)--(Rx IC) >> >> You force an impulse at (a), measure the response at (b). (b) is the >> analog channel response hAC(t). GetWave then needs a wave, which >> should be an ideal bit train, convolved with the bit period (creates >> a piece wise linear wave) which is then convolved with hAC(t) to >> produce the wave fed into GetWave. There was discussion as to whether >> the modeler or the EDA tool should do the above convolution. Has it >> been decided who this task falls on? >> >> Best Regards, >> >> Eric Monteiro >> >> ------------------------------------------------------------------------ >> >> This communication contains confidential information intended only >> for the addressee(s). If you have received this communication in >> error, please notify us immediately and delete this communication >> from your mail box. >> >> >> -- >> This message has been scanned for viruses and >> dangerous content by *MailScanner* <http://www.mailscanner.info/>, >> and is >> believed to be clean. >> > > --------------------------------------------------------------------- > IBIS Macro website : http://www.eda.org/pub/ibis/macromodel_wip/ > IBIS Macro reflector: //www.freelists.org/list/ibis-macro > To unsubscribe send an email: > To: ibis-macro-request@xxxxxxxxxxxxx > Subject: unsubscribe > > -- Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax http://www.teraspeed.com Teraspeed(r) is the registered service mark of Teraspeed Consulting Group LLC --------------------------------------------------------------------- IBIS Macro website : http://www.eda.org/pub/ibis/macromodel_wip/ IBIS Macro reflector: //www.freelists.org/list/ibis-macro To unsubscribe send an email: To: ibis-macro-request@xxxxxxxxxxxxx Subject: unsubscribe