GTS Ethernet Intel® FPGA Hard IP User Guide

ID 817676
Date 8/05/2024
Public
Document Table of Contents

A.5. Auto-Negotiation and Link Training

The Auto-Negotiation and Link Training for GTS Ethernet Intel® FPGA Hard IP implements the auto-negotiation and link training for GTS Ethernet ports. You must instantiate the GTS Auto-Negotiation and Link Training for Ethernet Intel® FPGA Hard IP and connect it to the base Ethernet IP. Each AN/LT IP supports one Ethernet rate with same FEC mode and can be shared with up to 16 Ethernet ports.

Turn on the Enable auto-negotiation and link training parameter in the GTS Ethernet Intel® FPGA Hard IP parameter editor to configure support for auto-negotiation and link training. Once enabled, you must instantiate one GTS AN/LT for Ethernet Intel FPGA IP instance per each type of GTS Ethernet Intel® FPGA Hard IP Ethernet port. Then, configure the same rate and FEC mode for both IPs.

If you plan to integrate multiple Ethernet rates on your tile, you must instantiate multiple GTS AN/LT IPs. For instance, to support 10G and 25G Ethernet rates with auto-negotiation and link training features, you must instantiate two AN/LT IP instances.

The AN/LT IP is independent of the base Ethernet IP; there are two steps that must be completed for successful operation:
  • AN/LT IP and Base IP Connections
  • AN/LT IP Configuration

Once configured and both IPs are brought out of reset, the AN/LT functionality operates automatically. Based on the configuration, the AN/LT IP initiates the AN/LT flows, and the Base IP Ethernet function is temporarily disabled. Upon completion of AN/LT, the Base IP is reconfigured into "data mode" and functions as a standard Ethernet port. If the RX Ethernet link goes down, the AN/LT IP may restart the auto-negotiation flow, depending on the configuration.

At any time, the user can access the AN/LT IP CSRs to monitor status, modify configuration, or interrupt and restart the flow for any Ethernet ports connected to that AN/LT IP instance. If the user resets the AN/LT IP itself, the AN/LT IP restarts the auto-negotiation flow on all connected Ethernet ports.

For an example of proper AN/LT connectivity and configuration, the user can generate an example design from the GTS Ethernet IP GUI with the Enable auto-negotiation and link training checkbox selected. This instantiates the AN/LT IP alongside the standard Ethernet example design and testbench. Note that generating an example design directly from the AN/LT IP GUI is not supported.