Intel® Cyclone® 10 GX Transceiver PHY User Guide

ID 683054
Date 4/14/2023
Document Table of Contents Byte Serializer Serialize x2 Mode

The serialize x2 mode is used in high-speed applications such as the PCIe Gen1 or Gen2 protocol implementation, where the FPGA fabric cannot operate as fast as the TX PCS.

In serialize x2 mode, the byte serializer serializes 16-bit, 20-bit (when 8B/10B encoder is not enabled), 32-bit, and 40-bit (when 8B/10B encoder is not enabled) input data into 8-bit, 10-bit, 16-bit, and 20-bit data, respectively. As the parallel data width from the TX FIFO is halved, the clock rate is doubled.

After byte serialization, the byte serializer forwards the least significant word first followed by the most significant word. For example, if the FPGA fabric-to-PCS Interface width is 32, the byte serializer forwards tx_parallel_data[15:0] first, followed by tx_parallel_data[31:16].