Motorola MCF5281 사용자 설명서

MOTOROLA

Chapter 17.  Fast Ethernet Controller (FEC)  

17-1

This chapter provides a feature-set overview, a functional block diagram, and transceiver
connection information for both the 10 and 100 Mbps MII (Media Independent Interface),
as well as the 7-wire serial interface. Additionally, detailed descriptions of operation and
the programming model are included.

The Ethernet Media Access Controller (MAC) is designed to support both 10 and 100 Mbps
Ethernet/IEEE 802.3 networks. An external transceiver interface and transceiver function
are required to complete the interface to the media. The FEC supports three different
standard MAC-PHY (physical) interfaces for connection to an external Ethernet
transceiver. The FEC supports the 10/100 Mbps MII and the 10 Mbps-only 7-wire
interface, which uses a subset of the MII pins. 

The FEC incorporates the following features:

• Support for three different Ethernet physical interfaces:

— 100-Mbps IEEE 802.3 MII
— 10-Mbps IEEE 802.3 MII
— 10-Mbps 7-wire interface (industry standard)

• IEEE 802.3 full duplex flow control
• Programmable max frame length supports IEEE 802.1 VLAN tags and priority
• Support for full-duplex operation (200Mbps throughput) with a minimum system 

clock rate of 50MHz

• Support for half-duplex operation (100Mbps throughput) with a minimum system 

clock rate of 25 MHz

• Retransmission from transmit FIFO following a collision (no processor bus 

utilization)