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

ID 813652
Date 11/25/2024
Public
Document Table of Contents

4.4.1.1. IP Core Preamble Processing

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

In Enable preamble passthrough is selected, 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.