KSZ8563R datasheet(21/221 Pages) MICROCHIP

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 2017-2018 Microchip Technology Inc.

DS00002418D-page 21

KSZ8563R

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 and PHY Auto-Negotiation Expansion

Status Register.

4.1.6

QUIET-WIRE FILTERING

Quiet-WIRE is a feature to enhance 100BASE-TX EMC performance by reducing both conducted and radiated emis-

sions from the TXP/M signal pair. It can be used either to reduce absolute emissions, or to enable replacement of

shielded cable with unshielded cable, all while maintaining interoperability with standard 100BASE-TX devices.

Quiet-WIRE filtering is implemented internally, with no additional external components required. It is enabled or disabled

for all PHYs at power-up and reset by a strapping option on the SDO pin. Once the device is powered up, Quiet-WIRE

can be enabled or disabled by writing to the appropriate control register.

The default setting for Quiet-WIRE reduces emissions primarily above 60MHz, with less reduction at lower frequencies.

Several dB of reduction is possible. Signal attenuation is approximately equivalent to increasing the cable length by 10

to 20 meters, thus reducing cable reach by that amount. For applications needing more modest improvement in emis-

sions, the level of filtering can be reduced by writing to certain registers.

4.1.7

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

4.1.8

REMOTE PHY LOOPBACK

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

receive data paths between the KSZ8563R and its Ethernet PHY link partner, and is supported for 10/100Mbps 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 KSZ8563R PHY 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 KSZ8563R PHY port transmits data back to the Ethernet PHY link partner.

KSZ8563R Datasheet(PDF) 21 Page - Microchip Technology