Datasheet

KSZ8795CLX

DS00002112B-page 16  2016-2017 Microchip Technology Inc.

3.1.7.2 Crossover Cable

A crossover cable connects an MDI device to another MDI device, or an MDI-X device to another MDI-X device. The

following diagram shows a typical crossover cable connection between two switches or hubs (two MDI-X devices).

3.1.8 AUTO-NEGOTIATION

The KSZ8795CLX conforms to the auto-negotiation protocol as described by the 802.3 committee. Auto-negotiation

allows unshielded twisted pair (UTP) link partners to select the highest common mode-of-operation. Link partners adver-

tise their capabilities to each other and then compare their own capabilities with those they received from their link part-

ners. The highest speed and duplex setting that is common to the two link partners is selected as the mode-of-operation.

Auto-negotiation is supported for the copper ports only.

The following list shows the speed and duplex operation mode (highest to lowest):

• 100BASE-TX, full-duplex

• 100BASE-TX, half-duplex

• 10BASE-T, full-duplex

• 10BASE-T, half-duplex

If auto-negotiation is not supported or the KSZ8795CLX link partner is forced to bypass auto-negotiation, the KSZ8795-

CLX sets its operating mode by observing the signal at its receiver. This is known as parallel detection, and allows the

KSZ8795CLX to establish link by listening for a fixed-signal protocol in the absence of auto-negotiation advertisement

protocol. The auto-negotiation link up process is shown in Figure 3-3.

FIGURE 3-2: TYPICAL CROSSOVER CABLE CONNECTION

RECEIVE PAIR RECEIVE PAIR

TRANSMIT PAIR

CROSSOVER

CABLE

10/100 ETHERNET

MEDIA DEPENDENT INTERFACE

10/100 ETHERNET

MEDIA DEPENDENT INTERFACE

MODULAR CONNECTOR (RJ-45)

HUB

(REPEATER OR SWITCH)

MODULAR CONNECTOR (RJ-45)

HUB

(REPEATER OR SWITCH)