KSZ8051MNL Datasheet, PDF (23/66 Pages) Micrel Semiconductor – 10Base-T/100Base-TX Physical Layer Transceiver

KSZ8051MNL/RNL
3.4 Back-to-Back Mode – 100 Mbps Copper Repeater
Two KSZ8051MNL/RNL devices can be connected back-to-back to form a 100BASE-TX copper repeater.
FIGURE 3-5:
KSZ8051MNL/RNL TO KSZ8051MNL/RNL BACK-TO-BACK COPPER REPEATER
3.4.1 MII BACK-TO-BACK MODE (KSZ8051MNL ONLY)
In MII back-to-back mode, a KSZ8051MNL interfaces with another KSZ8051MNL to provide a complete 100 Mbps cop-
per repeater solution.
The KSZ8051MNL devices are configured to MII back-to-back mode after power-up or reset with the following:
• Strap-in pin CONFIG[2:0] (pins 18, 29, 28) set to 110.
• A common 25 MHz reference clock connected to XI (Pin 9) of both KSZ8051MNL devices.
• MII signals connected as shown in Table 3-3.
TABLE 3-3: MII SIGNAL CONNECTION FOR MII BACK-TO-BACK MODE (100BASE-TX COPPER
REPEATER)
KSZ8051MNL (100BASE-TX Copper)
[Device 1]
KSZ8051MNL (100BASE-TX Copper)
[Device 2]
Pin Name
RXDV
RXD3
RXD2
RXD1
RXD0
TXEN
TXD3
TXD2
TXD1
Pin Number
18
13
14
15
16
23
27
26
25
Pin Type
Output
Output
Output
Output
Output
Input
Input
Input
Input
Pin Name
TXEN
TXD3
TXD2
TXD1
TXD0
RXDV
RXD3
RXD2
RXD1
Pin Number
23
27
26
25
24
18
13
14
15
Pin Type
Input
Input
Input
Input
Input
Output
Output
Output
Output
 2016 Microchip Technology Inc.
DS00002310A-page 23