Intel 21143 manual Functional Overview, Network Interface, Signal gep0/auibnc Description

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

This design guide provides a description of how to implement 100BASE-TX and 10BASE-T network connections using the 21143 PCI/CardBus 10/100 Mb/s Ethernet LAN Controller (referred to as the 21143).

While this document will not provide specific recommendations for physical layer devices, it will provide design recommendations and layout recommendations.

This application note provides a description of how to implement 100BASE-TX and 10BASE-T network connections using the 21143 PCI/CardBus 10/100 Mbs/s Ethernet LAN Controller (referred to as the 21143).

1.0Functional Overview

This section provides an overview of the 21143 and the implementation of 100 Mb/s and 10 Mb/s network connections using MII-based or SYM-based PHY devices.

1.121143 Overview

The 21143 is a single-chip bus master Ethernet/Fast Ethernet device that supports direct memory access (DMA) and has direct interfaces to both the CardBus and the PCI local bus. The 21143 implements a direct interface to the CardBus or PCI bus through a single 50-pin connection, which consists of the control and address/data signals.

The 21143 provides a complete implementation of the IEEE 802.3 Ethernet specification. This includes the attachment unit interface (AUI), twisted-pair (10BASE-T) interface, MII SYM port interface, and the interface through the media access control (MAC) layer that creates a direct interface to the PCI bus.

The PCI interface utilizes only about 10% of the bus bandwidth during fully networked operation for 100 Mb/s Fast Ethernet reception or transmission. This bus master design results in high throughput between the system and the network.

1.2Network Interface

The 21143 physical layer design supports AUI drop cable Ethernet and 10BASE-T twisted-pair (TP) Ethernet connections. The 21143 gep<0>/aui_bnc (pin 100), which is software controlled, provides for a connection of either the AUI (10BASE5) or BNC (10BASE2) network connector. Table 1 describes the function of this pin.

Table 1. Signal gep<0>/aui_bnc Description

Program State

Function

 

 

0

AUI port enabled; BNC port disabled.

 

 

1

BNC transceiver (or DC-to-DC converter) enabled; AUI port disabled

 

 

AUI signals interface with the Manchester encoder/decoder portion of the 21143. The 21143 supports 10BASE5 thickwire and 10BASE2 ThinWire connections. The 10BASE2 connection requires an external transceiver.

Design Guide

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Contents Design Guide Intel 21143 PCI/CardBus 10/ 100Mb/s Ethernet LAN ControllerDesign Guide Contents Revision History TablesDate Revision Description 001 First releaseFunctional Overview Signal gep0/auibnc Description21143 Overview Network InterfaceSYM-Based PHY Block Diagram MII-Based PHY Block DiagramTwisted-Pair Signals AUI SignalsSignal Pin Number 21143 PortsSYM Signals MII Signals10BASE-T Twisted-Pair Network Port Network ConnectionBASE-T Network Connection with Buffers BASE-T Network Connection Without Buffers Minimum Components Required for 10BASE-T Ready DesignsInternal vs. External Design Features Description of 100-Ready Daughtercard Block DiagramDesign Features Internal Optional Daughtercard3 100-Ready External Module Design Description of 100-Ready External Module Block Diagram5 MII/SYM Pin Listing MII/SYM Pinout Sheet 1MII/SYM Pinout Sheet 2 AUI Network PortAUI 10BASE5 Network and Pin Connections AUI 10BASE2 Network Connection Media-Specific Components Access Type Components Available Part NumbersBASE-T Media-Specific Components BASE2 and 10BASE5 Media-Specific Components21143 Requirements Pin Requirements When Not Using the Jtag PortUnused Jtag Port Requirements Current Reference and Capacitor Input RequirementsCrystal and Crystal Oscillator Connections Crystal SpecificationsSpecification Value Units Ground and Power Planes Signal Routing and Placement1 3.3 V Power Supply LED Status SignalsDesign Considerations Suggestions for Quiet Ground and Power PlanesDesigning the Ethernet Corner on Motherboards Suggestions for FCC ComplianceSuggestions for Routing

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.
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