Chapter 17

Fast Ethernet Controller (FEC)

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.

17.1 Overview

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.

17.1.1 Features

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)

MOTOROLA

Chapter 17. Fast Ethernet Controller (FEC)

17-1

Page 357
Image 357
Motorola MCF5281, MCF5282 user manual Chapter Fast Ethernet Controller FEC