KSZ9563RNXC datasheet(21/226 Pages) MICROCHIP

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 2017-2018 Microchip Technology Inc.

DS00002419D-page 21

KSZ9563R

• For 10BASE-T/Te, pre-emphasis is used to extend the signal quality through the cable.

4.1.7

AUTO-NEGOTIATION

The device conforms to the auto-negotiation protocol as described by IEEE 802.3. Auto-negotiation allows each port to

operate at either 10BASE-T/Te, 100BASE-TX or 1000BASE-T by allowing link partners to select the best common mode

of operation. During auto-negotiation, the link partners advertise capabilities across the link to each other and then com-

pare their own capabilities with those they received from their link partners. The highest speed and duplex setting that

is common to the two link partners is selected as the mode of operation. Auto-negotiation is also used to negotiate sup-

port for Energy Efficient Ethernet (EEE) via the next page feature.

The following list shows the speed and duplex operation mode from highest to lowest.

• Priority 1: 1000BASE-T, full-duplex

• Priority 2: 1000BASE-T, half-duplex

• Priority 3: 100BASE-TX, full-duplex

• Priority 4: 100BASE-TX, half-duplex

• Priority 5: 10BASE-T/Te, full-duplex

• Priority 6: 10BASE-T/Te, half-duplex

If auto-negotiation is not supported or the KSZ9563R link partner is forced to bypass auto-negotiation for 10BASE-T/Te

and 100BASE-TX modes, the KSZ9563R port sets its operating mode by observing the signal at its receiver. This is

known as parallel detection, and allows the KSZ9563R to establish a link by listening for a fixed signal protocol in the

absence of the auto-negotiation advertisement protocol.

The auto-negotiation link-up process is shown in Figure 4-1.

FIGURE 4-1:

AUTO-NEGOTIATION AND PARALLEL OPERATION

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