About this book

The ARM® Compiler armasm User Guide provides user information for the ARM assembler, armasm. It contains information on command-line options, instruction sets, and assembler directives.

Using this book

This book is organized into the following chapters:

Chapter 1 Overview of the Assembler

Gives an overview of the assemblers provided with ARM® Compiler toolchain.

Chapter 2 Overview of the ARM Architecture

Gives an overview of the ARM architecture.

Chapter 3 Structure of Assembly Language Modules

Describes the structure of assembly language source files.

Chapter 4 Writing ARM Assembly Language

Describes the use of a few basic assembly language instructions and the use of macros.

Chapter 5 Condition Codes

Describes condition codes and the conditional execution of ARM and Thumb code.

Chapter 6 Using the Assembler

Describes how to use the ARM assembler, armasm.

Chapter 7 Symbols, Literals, Expressions, and Operators

Describes how you can use symbols to represent variables, addresses, and constants in code, and how you can combine these with operators to create numeric or string expressions.

Chapter 8 NEON Programming

Describes the assembly programming of NEON hardware.

Chapter 9 VFP Programming

Describes the assembly programming of VFP hardware.

Chapter 10 Assembler Command-line Options

Describes the command-line options supported by the ARM assembler, armasm.

Chapter 11 ARM and Thumb Instructions

Describes the ARM and Thumb instructions supported by the ARM assembler, armasm.

Chapter 12 NEON Instructions

Describes the assembly programming of NEON™ technology.

Chapter 13 VFP Instructions

Describes the assembly programming of the VFP hardware.

Chapter 14 Wireless MMX Technology Instructions

Describes the support for Wireless MMX Technology instructions.

Chapter 15 Directives Reference

Describes the directives that are provided by the ARM assembler, armasm.

Chapter 16 Via File Syntax

Describes the syntax of via files accepted by armasm.

Appendix A Assembler Document Revisions

Describes the technical changes that have been made to the armasm User Guide.


The ARM Glossary is a list of terms used in ARM documentation, together with definitions for those terms. The ARM Glossary does not contain terms that are industry standard unless the ARM meaning differs from the generally accepted meaning.

See the ARM Glossary for more information.

Typographic conventions

Introduces special terminology, denotes cross-references, and citations.
Highlights interface elements, such as menu names. Denotes signal names. Also used for terms in descriptive lists, where appropriate.
Denotes text that you can enter at the keyboard, such as commands, file and program names, and source code.
Denotes a permitted abbreviation for a command or option. You can enter the underlined text instead of the full command or option name.
monospace italic
Denotes arguments to monospace text where the argument is to be replaced by a specific value.
monospace bold
Denotes language keywords when used outside example code.
Encloses replaceable terms for assembler syntax where they appear in code or code fragments. For example:
MRC p15, 0, <Rd>, <CRn>, <CRm>, <Opcode_2>
Used in body text for a few terms that have specific technical meanings, that are defined in the ARM glossary. For example, IMPLEMENTATION DEFINED, IMPLEMENTATION SPECIFIC, UNKNOWN, and UNPREDICTABLE.


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