Fangyi For a redriver, how is non-linearity in the receiver/driver handled. To me the simplest useful case would be a limiting amplifier. Scott Scott McMorrow Teraspeed® Consulting - A XXXXXX company 16 Stormy Brook Rd Falmouth, ME 04105 (401) 284-1827 Business http://www.teraspeed.com More to come ... soon. On Fri, Mar 14, 2014 at 1:20 PM, <fangyi_rao@xxxxxxxxxxx> wrote: > Please keep in mind that if one of the redriver Rx and Tx has GetWave, > then the entire impulse of the 1st channel must be removed from the final > impulse by deconvolution, which is known to be unreliable for long > impulses. Not to mention the complexities associated with cascaded > repeaters and with crosstalk. > > > > Regards, > > Fangyi > > > > *From:* ibis-macro-bounce@xxxxxxxxxxxxx [mailto: > ibis-macro-bounce@xxxxxxxxxxxxx] *On Behalf Of *Darshan Shah > *Sent:* Friday, March 14, 2014 9:51 AM > *To:* Walter Katz; ibis-macro@xxxxxxxxxxxxx > *Subject:* [ibis-macro] Re: Init Return Impulse models with Redriver > > > > Sure, we can work on this. > > > > -Darshan > > > > *From:* Walter Katz [mailto:wkatz@xxxxxxxxxx <wkatz@xxxxxxxxxx>] > *Sent:* Friday, March 14, 2014 7:07 AM > *To:* Darshan Shah; ibis-macro@xxxxxxxxxxxxx > *Subject:* RE: [ibis-macro] Init Return Impulse models with Redriver > > > > Darshan, > > > > You are correct, the spec is broken for Redrivers. Would you like to work > with me on creating a BIRD that will correct this? > > > > Walter > > > > *From:* ibis-macro-bounce@xxxxxxxxxxxxx [ > mailto:ibis-macro-bounce@xxxxxxxxxxxxx <ibis-macro-bounce@xxxxxxxxxxxxx>] *On > Behalf Of *Darshan Shah > *Sent:* Thursday, March 13, 2014 6:50 PM > *To:* ibis-macro@xxxxxxxxxxxxx > *Subject:* [ibis-macro] Init Return Impulse models with Redriver > > > > Hi, > > > > I have following setup for my simulation > > > > TX AMI model (Init_Return_Impulse = True, Getwave = False) à Upstream > Channel à Repeater RX (redriver and not retimer) AMI model > (Init_Return_Impulse = True, Getwave = False) à Repeater TX (redriver and > not retimer) AMI model (Init_Return_Impulse = True, Getwave = False) à > Downstream Channel à RX AMI model (Init_Return_Impulse = True, Getwave = > False) > > > > I have Init Return Impulse model for all the 4 serdes and no Getwave model. > > Also, RX (not repeater RX but RX at extreme right) has feature of auto > tuning. > > > > Looking into all the 9 steps of Repeater simulation (Page 224 of > ver6_0.pdf), it looks like there is no effect on RX Auto Adaptation > algorithm due to upstream channel. > > The way it works is Upstream channel IR is calculated (convolution of > upstream channel + TX serdes + Repeater RX serdes IR) which is upto step 3 > of spec. and then Downstream Channel IR is calculated (convolution of > downstream channel + Repeater TX serdes + RX serdes IR) which is upto step > 6 of spec. > > > > It looks like RX serdes eq. parameters are auto tuned based on IR > presented to RX serdes input which is IR of (downstream channel + Repeater > TX serdes) and hence effect of upstream channel, TX serdes and Repeater RX > serdes has no impact on RX adaptation algorithm which is incorrect. > > > > Please correct if I am wrong. > > Any help will be really appreciated. > > > > Thanks, > > Darshan >