Low Latency 40-Gbps Ethernet IP Core User Guide

ID 683745
Date 3/08/2021
Public
Document Table of Contents

3.2.3. LL 40GbE IP Core RX Datapath

The LL 40GbE RX MAC receives Ethernet frames from the PHY and forwards the payload with relevant header bytes to the client after performing some MAC functions on header bytes.

Figure 21. Flow of Frame Through the MAC RX Without Preamble Pass-Through Illustrates the typical flow of frame through the MAC RX when the preamble pass-through feature is turned off. In this figure, <p> is payload size, and <s> is the number of pad bytes (0–46 bytes).
Figure 22. Flow of Frame Through the MAC RX With Preamble Pass-Through Turned On Illustrates the typical flow of frame through the MAC RX when the preamble pass-through feature is turned on. In this figure, <p> is payload size, and <s> is the number of pad bytes (0–46 bytes).

The following sections describe the functions performed by the RX MAC: