In PCIe Gen-3 applications, the specification requires Rx-Tx link training to establish and optimize signal conditioning settings at 8 Gbps. In link training, the Rx partner requests a series of FIR - preshoot and de-emphasis coefficients (10 Presets) from the Tx partner. The Rx partner includes 7-levels (6 dB to 12 dB) of CTLE followed by a single tap DFE. The link training would pre-condition the signal with an equalized link between the root-complex and endpoint. Note that there is no link training in PCIe Gen-1 (2.5 Gbps) or PCIe Gen-2 (5.0 Gbps) applications. The DS80PCI402 is placed in between the Tx and Rx. It would help extend the PCB trace reach distance by boosting the attenuated signals with its equalization, so that the signal can be more easily recovered by the downstream Rx. In Gen 3 mode, DS80PCI402 transmit outputs are designed to pass the Tx Preset signaling onto the Rx for the PCIe Gen 3 link to train and optimize the equalization settings. The suggested setting for the DS80PCI402 are EQ=00, VOD = 1.2 Vp-p and DEM = 0 dB. Additional adjustments to increase the EQ or DEM setting should be performed to optimize the eye opening in the Rx partner. See the tables below for Pin mode and SMBus mode configurations.