Datasheet
2017 Microchip Technology Inc. DS00002348A-page 15
KSZ8873MLL/FLL/RLL
3.1.10.2 Crossover Cable
A crossover cable connects an MDI device to another MDI device, or an MDI-X device to another MDI-X device.
Figure 3-2 shows a typical crossover cable connection between two switches or hubs (two MDI-X devices).
3.1.11 AUTO-NEGOTIATION
The KSZ8873MLL/FLL/RLL conforms to the auto-negotiation protocol, defined in Clause 28 of the IEEE 802.3u speci-
fication.
Auto-negotiation allows unshielded twisted pair (UTP) link partners to select the best common mode of operation. In
auto-negotiation, link partners advertise their capabilities across the link to each other. If auto-negotiation is not sup-
ported or the KSZ8873MLL/FLL/RLL link partner is forced to bypass auto-negotiation, the KSZ8873MLL/FLL/RLL sets
its operating mode by observing the signal at its receiver. This is known as parallel detection, and allows the
KSZ8873MLL/FLL/RLL to establish link by listening for a fixed signal protocol in the absence of auto-negotiation adver-
tisement protocol.
The link up process is shown in Figure 3-3.
FIGURE 3-2: TYPICAL CROSSOVER CABLE CONNECTION
Receive Pair Receive Pair
Transmit Pair
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Transmit Pair
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)
Crossover
Cable