Technical Reference Guide

Chapter 5

INPUT/OUTPUT INTERFACES

5. Chapter 5 INPUT/OUTPUT INTERFACES

5.1INTRODUCTION

This chapter describes the standard (i.e., system board) interfaces that provide input and output (I/O) porting of data and specifically discusses interfaces that are controlled through I/O-mapped registers. The following I/O interfaces are covered in this chapter:

♦ Enhanced IDE interface (5.2)

page 5-1

♦ Diskette drive interface (5.3)

page 5-4

Serial interfaces (5.4)

page 5-8

Parallel interface (5.5)

page 5-11

♦ Keyboard/pointing device interface (5.6)

page 5-16

♦ Universal serial bus interface (5.7)

page 5-22

Audio subsystem (5.8)

page 5-26

♦ Network Interface Controller (5.9)

page 5-32

5.2ENHANCED IDE INTERFACE

The enhanced IDE (EIDE) interface consists of primary and secondary controllers integrated into the south bridge component of the chipset. Two 40-pin IDE connectors (one for each controller) are included on the system board. Each controller can be configured independently for the following modes of operation:

Programmed I/O (PIO) mode – CPU controls drive transactions through standard I/O mapped registers of the IDE drive.

8237 DMA mode – CPU offloads drive transactions using DMA protocol with transfer rates up to 16 MB/s.

Ultra ATA/100 mode – Preferred bus mastering source-synchronous protocol providing transfer rates of 100 MB/s.

5.2.1IDE PROGRAMMING

The IDE interface is configured as a PCI device during POST and controlled through I/O-mapped registers at runtime. Operating systems other than DOS or Windows may require using Setup (F10) for drive configuration.

Compaq D315 and hp d325 Personal Computers 5-1

Featuring the AMD Athlon XP Processor

Second Edition - April 2003

Page 83
Image 83
HP D315 manual Enhanced IDE Interface, IDE Programming