KSZ9563RNXC-TR datasheet(22/226 Pages) MICROCHIP

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KSZ9563R

DS00002419D-page 22

 2017-2018 Microchip Technology Inc.

For 1000BASE-T mode, auto-negotiation is always required to establish a link. During 1000BASE-T auto-negotiation,

the master and slave configuration is first resolved between link partners. Then the link is established with the highest

common capabilities between link partners.

Auto-negotiation is enabled by default after power-up or hardware reset. Afterwards, auto-negotiation can be enabled

or disabled via bit 12 of the PHY Basic Control Register. If auto-negotiation is disabled, the speed is set by bits 6 and

13 of the PHY Basic Control Register, and the duplex is set by bit 8.

If the speed is changed on the fly, the link goes down and either auto-negotiation or parallel detection initiate until a

common speed between the KSZ9563R and its link partner is re-established for a link.

If link is already established and there is no change of speed on the fly, the changes (for example, duplex and pause

capabilities) will not take effect unless either auto-negotiation is restarted through bit 9 of the PHY Basic Control Regis-

ter, or a link-down to link-up transition occurs (i.e. disconnecting and reconnecting the cable).

After auto-negotiation is completed, the link status is updated in the PHY Basic Status Register, and the link partner

capabilities are updated in the PHY Auto-Negotiation Link Partner Ability Register, PHY Auto-Negotiation Expansion

Status Register, and PHY 1000BASE-T Status Register.

4.1.8

LinkMD® CABLE DIAGNOSTICS

The LinkMD® function utilizes Time Domain Reflectometry (TDR) to analyze the cabling for common cabling problems,

such as open circuits, short circuits and impedance mismatches.

LinkMD® works by sending a pulse of known amplitude and duration down the MDI or MDI-X pair, and then analyzing

the shape of the reflected signal to determine the type of fault. The time duration for the reflected signal to return pro-

vides the approximate distance to the cabling fault. The LinkMD® function processes this TDR information and presents

it as a numerical value that can be translated to a cable distance

4.1.9

REMOTE PHY LOOPBACK

This loopback mode checks the line (differential pairs, transformer, RJ-45 connector, Ethernet cable) transmit and

receive data paths between the KSZ9563Rand its Ethernet PHY link partner, and is supported for 10/100/1000 Mbps at

full-duplex.

The loopback data path is shown in Figure 4-2 and functions as follows:

• The Ethernet PHY link partner transmits data to the KSZ9563RPHY port.

• Data received at the external pins of the PHY port is looped back without passing through the MAC and internal

switch fabric.

The same KSZ9563RPHY port transmits data back to the Ethernet PHY link partner.

KSZ9563RNXC-TR Datasheet(PDF) 22 Page - Microchip Technology