Ethernet Controller

16 Ethernet Controller

The Stellaris® Ethernet Controller consists of a fully integrated media access controller (MAC) and network physical (PHY) interface. The Ethernet Controller conforms to IEEE 802.3 specifications and fully supports 10BASE-T and 100BASE-TX standards.

The Stellaris® Ethernet Controller module has the following features:

■Conforms to the IEEE 802.3-2002 specification

–10BASE-T/100BASE-TXIEEE-802.3compliant. Requiresonlyadual1:1isolationtransformer interface to the line

–10BASE-T/100BASE-TX ENDEC, 100BASE-TX scrambler/descrambler

–Full-featured auto-negotiation

■Multiple operational modes

–Fulland half-duplex 100 Mbps

–Fulland half-duplex 10 Mbps

–Power-saving and power-down modes

■Highly configurable

–Programmable MAC address

–LED activity selection

–Promiscuous mode support

–CRC error-rejection control

–User-configurable interrupts

■Physical media manipulation

–Automatic MDI/MDI-X cross-over correction

–Register-programmable transmit amplitude

–Automatic polarity correction and 10BASE-T signal reception

16.1Block Diagram

As shown in Figure 16-1 on page 429, the Ethernet Controller is functionally divided into two layers: the Media Access Controller (MAC) layer and the Network Physical (PHY) layer. These layers correspond to the OSI model layers 2 and 1. The CPU accesses the Ethernet Controller via the MAC layer. The MAC layer provides transmit and receive processing for Ethernet frames. The MAC layer also provides the interface to the PHY layer via an internal Media Independent Interface (MII). The PHY layer communicates with the Ethernet bus.

Preliminary