E-Tile Transceiver PHY User Guide

ID 683723
Date 4/01/2024
Document Table of Contents Master-Slave Configuration: Option 1

All four channels use a common FEC block, but FEC only uses one clock from the four available channels. You can select the source channel of the FEC clock in the FEC tab of Native PHY IP Parameter Editor through the RS-FEC Clocking Mode option. The selected source channel is considered the master. The other three channels use that same clock for clocking their TX and RX data paths, and are considered slave channels. An interruption on the master channel PMA, a PMA reset, for example, impacts the slave channels. This creates a dependency between the master and the slave channels. The figure below assumes that all four channels have a common reference clock source (0 PPM between all four channels).

Figure 68. PMA Direct 25 Gbps x 4 (FEC On)RS-FEC is also clocked by the TX PMA generated clock.