Low Latency 40G Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

ID 813652
Date 4/01/2024
Public
Document Table of Contents

4.4.1. RX Preamble Pass-through or Removal

The Ethernet MAC RX deletes preamble bytes in normal mode and you can configure it to forward preamble bytes.

In the preamble pass-through mode, there is an additional l2_rx_peramble [63:0] bus to provide the custom preamble data to user. When l2_rx_startofpacket is asserted, l2_rx_preamble [63:0] provides the preamble data and l2_rx_data provides the first 16 bytes of frame data (starting from destination address).

In non-preamble pass-through mode, the preamble bytes are removed in RX and to align the SOP to the MSB.