Intel 82559 用户手册
Intel 8255x 10/100 Mbps Ethernet Controller Family Open Source Software Developer Manual
5
Adapter and Controller Overview
2
Adapters based on an Intel
®
8255x device support the ANSI/IEEE 802.3u standard for 100BASE-
TX (100 Mbps operation) and 10BASE-T (10 Mbps operation).
2.1
Adapter Block Diagram
The main components of Intel Fast Ethernet adapters are:
•
A Fast Ethernet Media Access Controller (MAC), such as the 8255x, is the core component.
The MAC supports the Fast Ethernet ANSI/IEEE 802.3u standard.
The MAC supports the Fast Ethernet ANSI/IEEE 802.3u standard.
•
A Physical Layer (PHY) interface device is also required. The 82558, 82559, 82550, and
82551 components have an integrated PHY that supports 100BASE-TX and 10BASE-T.
Adapters based on the 82557 must include an appropriate PHY component for their design.
Adapters based on the 82557 must include an appropriate PHY component for their design.
•
A serial EEPROM is required to hold the adapter’s individual Ethernet node address and other
configuration information including fixed PCI configuration parameters.
The adapters are based on 100BASE-TX specifications. 100BASE-TX is a specific scheme
designed for use over 2 pairs of Category 5 unshielded twisted-pair cable. 100BASE-TX defines a
designed for use over 2 pairs of Category 5 unshielded twisted-pair cable. 100BASE-TX defines a
signaling scheme for 100 Mbps and provides compatibility with the existing 10 Mbps IEEE 802.3
10BASE-T signaling standard. Since only 2-wire pairs are used, TX technology allows full duplex
operation at 100 Mbps. The Intel 82555 is one possible TX solution.
operation at 100 Mbps. The Intel 82555 is one possible TX solution.
The block diagram below illustrates an Intel
®
PRO/100B adapter configuration based on the 82557
MAC with a TX or T4 PHY.
Figure 1. 82557 Network Interface Card Block Diagram
RJ-45
Filter
Module
100BASE-T4 or
100BASE-TX PHY
Intel® 82557
EEPROM
Optional
Flash
PCI Local Bus
MII