L- and H-Tile Transceiver PHY User Guide

ID 683621
Date 1/30/2024
Public
Document Table of Contents

2.4.2.3.3. KR-FEC Functionality for 64B/66B Based Protocols

You can use the KR-FEC block in the Enhanced PCS for both 10GBASE-KR/Ethernet and custom protocol implementation, provided that the protocol is 64B/66B based. This block is designed according to IEEE802.3 Clause 74 , and can be used up to the maximum datarate of the transceiver channel.

For example, you can implement the Superlite II V2 protocol running four bonded lanes at 16 Gbps across a lossy backplane (close to 30 dB of IL at 8 GHz), and use the KR-FEC block in addition to RX equalization, to further reduce BER. Note that you incur additional latency that inherently occurs when using FEC. For the KR-FEC implementation mentioned in the example above, the latency is approximately an additional 40 parallel clock cycles for the full TX and RX path). The latency numbers depend on the actual line rate and other PCS blocks used for the protocol implementation. Refer to the Intel FPGA Wiki for more information about high speed transceiver demo designs.

Note: The material in the Intel FPGA Wiki is provided AS-IS and is not supported by Intel Corporation.

Refer to the KR FEC Blocks and RX KR FEC Blocks sections for more information about the KR-FEC blocks.

Refer to the 64B/66B Encoder and Transmitter State Machine (TX SM) and 64B/66B Decoder and Receiver State Machine (RX SM) sections for more information about the 64B/66B encoder and decoder.