F-Tile Triple-Speed Ethernet Intel® FPGA IP User Guide

ID 741328
Date 4/03/2023

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5.2.7. Auto-Negotiation

Auto-negotiation is an optional function that can be started when link synchronization is acquired during system start up. To start auto-negotiation automatically, set the AUTO_NEGOTIATION_ENABLE bit in the PCS control register to 1. During auto-negotiation, the PCS function advertises its device features and exchanges them with a link partner device.

If the SGMII_ENA bit in the if_mode register is set to 0, the PCS function operates in 1000BASE-X. Otherwise, the operating mode is SGMII. The following sections describe the auto-negotiation process for each operating mode.

When simulating your design, you can disable auto-negotiation to reduce the simulation time. If you enable auto-negotiation in your design, set the link_timer time to a smaller value to reduce the auto-negotiation link timer in the simulation.