Microcontroller User's Manual

17-8 MCF5282 User’s Manual MOTOROLA
Functional Description
17.4.5 Network Interface Options
The FEC supports both an MII interface for 10/100 Mbps Ethernet and a 7-wire serial
interface for 10 Mbps Ethernet. The interface mode is selected by the RCR[MII_MODE]
bit. In MII mode (RCR[MII_MODE] = 1), there are 18 signals defined by the IEEE 802.3
standard and supported by the EMAC. These signals are shown in Table 17-5 below.
The 7-wire serial mode interface (RCR[MII_MODE] = 0) operates in what is generally
referred to as the “AMD” mode. 7-wire mode connections to the external transceiver are
shown in Table 17-6.
Table 17-5. MII Mode
Signal Description EMAC pin
Transmit Clock ETXCLK
Transmit Enable ETXEN
Transmit Data ETXD[3:0]
Transmit Error ETXER
Collision ECOL
Carrier Sense ECRS
Receive Clock ERXCLK
Receive Data Valid ERXDV
Receive Data ERXD[3:0]
Receive Error ERXER
Management Data Clock EMDC
Management Data
Input/Output
EMDIO
Table 17-6. 7-Wire Mode Configuration
SIGNAL DESCRIPTION EMAC PIN
Transmit Clock
ETXCLK
Transmit Enable
ETXEN
Transmit Data
ETXD[0]
Collision
ECOL
Receive Clock
ERXCLK
Receive Data Valid
ERXDV
Receive Data
ERXD[0]