What Is the FEIP?
Depending on the type of media you use between the MII connection on the port adapter and your
switch or hub, the network side of your 100BASE-T transceiver should be appropriately equipped
with SC-type or ST-type connectors (for optical fiber), BNC connectors, and so forth. Figure 17
shows the pin orientation of the female MII connector on the port adapter.
The MII receptacle uses 2-56 screw-type locks, called jackscrews (shown in Figure 17), to secure
the cable or transceiver to the MII port. MII cables and transceivers have knurled thumbscrews
(screws you can tighten with your fingers) that you fasten to the jackscrews on the FEIP MII
connector. Use the jackscrews to provide strain relief for your MII cable. (The RJ-45 modular plug
has strain relief functionality incorporated into the design of its standard plastic connector.)
Figure 17 shows the MII connector.
Figure 17
Jackscrew
Table 3 lists the MII connector pinout and signals. MII cables are available commercially.
Table 3
Pin
14–17
12
11
13
3
4–7
9
10
8
18
19
2
22–39
1, 20, 21, 40
1. Any pins not indicated are not used.
2. Tx_CLK and Rx_CLK are generated by the external transceiver.
20 Fast Ethernet Interface Processor (FEIP) Installation and Configuration
MII Connection (Female)
Pin 21
Pin 1
MII Connector Pinout
1
In
Out
–
Yes
Yes
–
–
Yes
–
Yes
–
Yes
Yes
–
Yes
–
Yes
–
Yes
–
Yes
–
Yes
–
–
–
–
–
–
–
In/Out
Description
–
Transmit Data (TxD)
–
Transmit Clock (Tx_CLK)
–
Transmit Error (Tx_ER)
–
Transmit Enable (Tx_EN)
–
MII Data Clock (MDC)
–
Receive Data (RxD)
–
Receive Clock (Rx_CLK)
–
Receive Error (Rx_ER)
–
Receive Data Valid (Rx_DV)
–
Collision (COL)
–
Carrier Sense (CRS)
Yes
MII Data Input/Output (MDIO)
–
Common (ground)
–
+5.0 volts (V)
2