Chapter 1 Introduction

1.5.1 VALUES

Hexadecimal values are indicated by a numerical or alpha-numerical value followed by the letter “h.” Binary values are indicated by a value of ones and zeros followed by the letter “b.” Numerical values that have no succeeding letter can be assumed to be decimal unless otherwise stated.

1.5.2 RANGES

Ranges or limits for a parameter are shown using the following methods:

Example A: Bits <7..4> = bits 7, 6, 5, and 4.

Example B: IRQ3-7, 9 = IRQ signals 3 through 7, and IRQ signal 9

1.5.3 REGISTER NOTATION AND USAGE

This guide uses standard Intel naming conventions in discussing the microprocessor’s (CPU) internal registers. Registers that are accessed through programmable I/O using an indexing scheme are indicated using the following format:

03C5.17h

Index port

Data port

In the example above, register 03C5.17h is accessed by writing the index port value 17h to the index address (03C4h), followed by a write to or a read from port 03C5h.

1.5.4 BIT NOTATION AND BYTE VALUES

Bit designations are labeled between brackets (i.e., “bit <0 >”). Binary values are shown with the most significant bit (MSb) on the far left, least significant bit (LSb) at the far right. Byte values in hexadecimal are also shown with the MSB on the left, LSB on the right.

1-4Compaq D315 and hp d325 Personal Computers Featuring the AMD Athlon XP Processor

Second Edition – April 2003