GTS Transceiver PHY User Guide

ID 817660
Date 10/07/2024
Public
Document Table of Contents

2.5.1. FEC Loopback Mode

Both Fiecode ad RS-FEC suppot a loopback mode, offeig vaious debuggig optios.
You ca eable the FEC loopback mode paamete i the IP Paamete Edito GUI. Whe you eable the FEC loopback mode, the output of the TX FEC block is looped back to the RX FEC as show i the followig figue. Fo moe ifomatio about eablig the FEC loopback mode efe to FEC Optios. You ca also eable the FEC loopback mode by cofiguig the fec_lpbk_e egiste (0x70000[1]).
Figue 22. FEC Loopback Mode
Note: The FEC loopback mode equies a additioal step sice the o_x_is_lockedtodata sigal is deasseted if the i_x_seial_data is ot togglig. This causes the had IP blocks such as the TX/RX PMA Iteface, PCS, FEC ito a eset state ad pevets ay loopback i these digital blocks to fuctio coectly. You must pefom a wite to the x_igoe_lock2data egiste (0x10018 bit[0]) to oveide the RX PMA status sigals (efe to RX PMA Status Sigals table fo moe ifomatio) so that these had IP blocks ca come out of eset ad the FEC loopback mode ca fuctio.