Hi Vladimir, Your Comment "After Tx INIT, you have an equalized IR, and this is sent to Rx INIT. Rx may add its own equalization" No after TX_INIT, I don't have equalized IR and IR after TX is exactly same as channel IR (as GetWave don't modify IR) And hence, RX Init_Return_Impulse works on channel IR (which is un-equalized from TX), so DFE and CTLE will try to equalize channel IR (and not the TX equalized channel IR). Once quick experiment I did: GetWave TX Model ------ > Channel ------ > Init_Return_Impulse RX Model If I change TX De-Emphasis Value, CTLE and DFE on RX side stays at the same value for all the simulations. -Darshan From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Dmitriev-Zdorov, Vladimir Sent: Wednesday, February 26, 2014 5:21 PM To: Darshan Shah; ibis-macro@xxxxxxxxxxxxx Subject: [ibis-macro] Re: Simulate with Init_Impuse_Return on RX and GetWave on TX Darshan, This is the case when the Rx's equalization effect should be separated from Tx equalization. After Tx INIT, you have an equalized IR, and this is sent to Rx INIT. Rx may add its own equalization. However, since Tx also has GetWave which may apply similar equalization to the input waveform, you need to "eliminate" Tx equalization from the impulse response after it is updated by Rx. The idea is that this IR should only contain equalization from Rx but not Tx (since we don't have Rx GetWave but have Tx GetWave). I don't know what is the tool you are using. The correct flow should be to find the Rx equalization "filter" (i.e. an operator that creates Rx equalization) and apply it to the original non-equalized IR. Then, use this IR for the bit by bit analysis. I believe this idea is described in 5.1 AMI flow. Vladimir From: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Darshan Shah Sent: Wednesday, February 26, 2014 6:05 PM To: ibis-macro@xxxxxxxxxxxxx<mailto:ibis-macro@xxxxxxxxxxxxx> Subject: [ibis-macro] Simulate with Init_Impuse_Return on RX and GetWave on TX Hi, I have case in which TX and RX are from different vendors. RX is Impulse_Init_Return only (No GetWave Function is available) and TX is GetWave only (No Init_impuse_Return is available). When I run this simulation, IR of passive channel and analog models of TX and RX is created. Let's call it IR1 (Let say IL of channel is 20dB, so IR1 is impulse response of 20dB IL) Let say TX is set to -6dB de-emphasis. IR1 is send to GetWave of TX model which outputs waveform which is 6dB de-emphasized. But IR1 is not affected due to Getwave function of TX. What I have seen in the simulation is this IR1 is also send to RX Init_Impuse_Return function and RX Equalizer works on 20dB channel rather than 20dB + (-6dB de-Emphasis) channel. And hence I always get over-equalized response in simulation. What is solution to this? Please help. Thanks, Darshan