Datasheet
2016-2018 Microchip Technology Inc. DS00002202C-page 25
KSZ8081MNX/RNB
3.7.1 STRAIGHT CABLE
A straight cable connects an MDI device to an MDI-X device, or an MDI-X device to an MDI device. Figure 3-6 shows
a typical straight cable connection between a NIC card (MDI device) and a switch or hub (MDI-X device).
FIGURE 3-6: TYPICAL STRAIGHT CABLE CONNECTION
3.7.2 CROSSOVER CABLE
A crossover cable connects an MDI device to another MDI device, or an MDI-X device to another MDI-X device.
Figure 3-7 shows a typical crossover cable connection between two switches or hubs (two MDI-X devices).
TABLE 3-5: MDI/MDI-X PIN DEFINITION
MDI MDI-X
RJ-45 Pin Signal RJ-45 Pin Signal
1 TX+ 1 RX+
2 TX– 2 RX–
3 RX+ 3 TX+
6 RX– 6 TX–
RECEIVE PAIR
TRANSMIT PAIR
RECEIVE PAIR
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
TRANSMIT PAIR
MODULAR CONNECTOR
(RJ-45)
NIC
STRAIGHT
CABLE
10/100 ETHERNET
MEDIA DEPENDENT INTERFACE
10/100 ETHERNET
MEDIA DEPENDENT INTERFACE
MODULAR CONNECTOR
(RJ-45)
HUB
(REPEATER OR SWITCH)