Intel® 21143 PCI/CardBus 10/100Mb/s Ethernet LAN Controller

3.2.3100-Ready External Module Design

Figure 7 shows a block diagram of a 100-Ready design using an external module.

Figure 7. 10BASE-T 100-Ready External Module Block Diagram

21143

MII/SYM

MII or

MII or

10/100

RJ45

Custom

Custom

 

 

PHY Layer

Connector

 

 

Connector

Connector

 

10BASE-T

RJ45

 

 

 

 

 

Connector

 

 

 

 

Optional

AUI

 

 

 

 

AUI Coaxial

Coaxial

 

 

 

 

Transceivers

Connector

 

 

 

PCI

 

 

 

 

 

Bus

 

 

 

 

 

 

 

 

 

 

LJ-05188.AI4

3.2.4Description of 100-Ready External Module Block Diagram

The blocks in the100-Ready external module block diagram represent the following components:

21143 — A 21143 with all of the external components for operating the network connection (reference parts, XTAL, and so on). The 21143 can use the PCI bus, and the MII/SYM, 10BASE-T, and AUI coaxial ports for communication.

Optional external MII/SYM daughtercard — A daughtercard with a 100 Mb/s or 10/100 Mb/s PHY that interfaces with an MII connector or custom connector. The daughtercard uses the magnetics to connect to the RJ45 connector.

MII connector — An MII or custom connector that connects with the MII/SYM port of the 21143.

RJ45 — A network connection.

3.2.5MII/SYM Pin Listing

Table 7 describes the MII/SYM pin multiplexing enabling the full flexibility for both network connections options using the same internal connector for the MII-based or the SYM-based PHY device (for detailed implementation notes, refer to the specific PHY device section in this document).

Table 7. MII/SYM Pinout (Sheet 1 of 2)

Pin Number

MII Interface Function

SYM Interface Function

 

 

 

117

mii_crs

sd

 

 

 

118

mii_clsn

sym_rxd<4>

 

 

 

119

mi_txd<3>

sym_txd<3>

 

 

 

120

mi_txd<2>

sym_txd<2>

 

 

 

121

mi_txd<1>

sym_txd<1>

 

 

 

14

Design Guide

Page 14
Image 14
Intel 21143 manual 3 100-Ready External Module Design, Description of 100-Ready External Module Block Diagram

21143 specifications

The Intel 21143 is a widely recognized Ethernet controller that has played a significant role in the development of networking technology throughout the late 1990s and early 2000s. This controller, part of Intel's line of networking solutions, was designed primarily for desktop and server systems, catering to the needs of both home and enterprise-level networking.

One of the main features of the Intel 21143 is its support for the IEEE 802.3 standard, allowing it to facilitate Ethernet networking at speeds of up to 100 Mbps. The 21143 supports both the 10Base-T and 100Base-TX Ethernet standards, making it versatile for different network environments. Its ability to auto-negotiate between these speeds ensures compatibility with a wide range of network devices, enhancing its utility in mixed-speed networks.

The Intel 21143 employs an advanced shared memory architecture that enables efficient data transfer and reduces CPU overhead. This feature ensures that the controller can handle higher throughput while allowing the CPU to focus on other tasks. Additionally, the controller supports a direct memory access (DMA) transmission capability, providing further enhancements in data handling and overall system performance.

An important characteristic of the Intel 21143 is its onboard processor, which allows it to offload certain networking tasks from the host CPU. This results in improved overall system performance, as the main processor is freed from handling all network traffic. The controller supports Full Duplex operation, enabling simultaneous sending and receiving of data, effectively doubling the potential bandwidth for each connection.

Another notable technology integrated into the Intel 21143 is its built-in support for TCP/IP checksum calculations. By offloading this computationally intensive task from the CPU, the controller enhances network performance, particularly in data-intensive applications such as file transfers and video streaming.

The Intel 21143 was primarily used in PCI (Peripheral Component Interconnect) applications, which facilitated ease of integration into existing systems. Its compatibility with various operating systems, including Windows and Linux, made it a popular choice among developers and users alike.

Overall, the Intel 21143 Ethernet controller has been instrumental in evolving networking technology. Its impressive features, efficient architecture, and robust performance have solidified its position in the market, paving the way for future advancements in Ethernet networking. Even today, the principles and technologies introduced with the Intel 21143 continue to influence modern networking solutions.