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Chapter 10

Auto-Negotiation

This chapter provides general guidelines for using the Auto-Negotiation function of the Ethernet 1000BASE-X PCS/PMA or SGMII core. Auto-Negotiation is controlled and monitored through the PCS Management Registers and is only available when the optional MDIO Management Interface is present. For more information, see Chapter 9, “Configuration and Status.”

Overview of Operation

For either standard, when considering Auto-Negotiation between two connected devices, it must be remembered that:

Auto-Negotiation must be either enabled in both devices, or:

Auto-Negotiation must be disabled in both devices.

1000BASE-X Standard

 

 

Virtex-II Pro Device

 

 

Link Partner

Ethernet 1000BASE-X

 

 

PCS/PMA or SGMII

 

 

Ethernet

Core

 

 

Auto-Neg Adv

 

 

Media

Optical

Auto-Neg Adv

Access

(Reg 4)

(Reg 4)

Fibre

Controller

 

 

 

 

 

MDIO

 

 

 

Link Partner Ability

 

Link Partner Ability

 

Base (Reg5)

 

Base (Reg5)

CoreConnect

 

 

 

PowerPC

 

 

 

an_interrupt

 

 

Figure 10-1:

1000BASE-X Auto-Negotiation Overview

IEEE 802.3 clause 37 describes the 1000BASE-X Auto-Negotiation function that allows a device to advertise the modes of operation that it supports to a device at the remote end of

Ethernet 1000BASE-X PCS/PMA or SGMII v9.1

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Xilinx 1000BASE-X manual Auto-Negotiation, Overview of Operation