ARMv7-M ArchitectureReference Manual

Copyright 2006-2008, 2010 ARM Limited. All rights reserved.ARM DDI 0403D (ID021310)

ARMv7-M Architecture Reference ManualCopyright 2006-2008, 2010 ARM Limited. All rights reserved.

Release Information

The following changes have been made to this document.

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Change history

Date Issue Confidentiality Change

June 2006 A Non-confidential Initial release

July 2007 B Non-confidential Second release, errata and changes documented separately

September 2008 C Non-confidential, Restricted Access Options for additional watchpoint based trace in the DWT, plus errata updates and clarifications.

12 February 2010 D Non-confidential Fourth release, adds DSP and Floating-point extensions, and extensive clarifications and reorganization.

ii Copyright 2006-2008, 2010 ARM Limited. All rights reserved. ARM DDI 0403DNon-Confidential, Unrestricted Access ID021310

Restricted Rights Legend: Use, duplication or disclosure by the United States Government is subject to the restrictions set forth in DFARS 252.227-7013 (c)(1)(ii) and FAR 52.227-19.

This document is Non-Confidential but any disclosure by you is subject to you providing notice to and the acceptance by the recipient of, the conditions set out above.

In this document, where the term ARM is used to refer to the company it means ARM or any of its subsidiaries as appropriate.

Note The term ARM is also used to refer to versions of the ARM architecture, for example ARMv6 refers to version 6 of the ARM architecture. The context makes it clear when the term is used in this way.

ARM DDI 0403D Copyright 2006-2008, 2010 ARM Limited. All rights reserved. iiiID021310 Non-Confidential, Unrestricted Access

iv Copyright 2006-2008, 2010 ARM Limited. All rights reserved. ARM DDI 0403DNon-Confidential, Unrestricted Access ID021310

ContentsARMv7-M Architecture Reference Manual

PrefaceAbout this manual .............................................................................. xxiiUsing this manual .............................................................................. xxiiiConventions ...................................................................................... xxviFurther reading ................................................................................. xxviiFeedback ......................................................................................... xxviii

Part A Application Level ArchitectureChapter 1 Introduction

A1.1 About the ARMv7 architecture, and architecture profiles ............... A1-32A1.2 The ARMv7-M architecture profile ................................................. A1-33A1.3 Architecture extensions .................................................................. A1-35

Chapter 2 Application Level Programmers ModelA2.1 About the application level programmers model ........................... A2-38A2.2 ARM processor data types and arithmetic ..................................... A2-39A2.3 Registers and execution state ........................................................ A2-46A2.4 Exceptions, faults and interrupts .................................................... A2-50A2.5 Coprocessor support ...................................................................... A2-52A2.6 The optional Floating-point extension ............................................ A2-53

ARM DDI 0403D Copyright 2006-2008, 2010 ARM Limited. All rights reserved. vID021310 Non-Confidential, Unrestricted Access

Contents

Chapter 3 ARM Architecture Memory ModelA3.1 Address space ............................................................................... A3-82A3.2 Alignment support .......................................................................... A3-83A3.3 Endian support ............................................................................... A3-85A3.4 Synchronization and semaphores .................................................. A3-89A3.5 Memory types and attributes and the memory order model .......... A3-99A3.6 Access rights ................................................................................ A3-109A3.7 Memory access order .................................................................. A3-111A3.8 Caches and memory hierarchy .................................................... A3-120

Chapter 4 The ARMv7-M Instruction SetA4.1 About the instruction set .............................................................. A4-124A4.2 Unified Assembler Language ....................................................... A4-126A4.3 Branch instructions ...................................................................... A4-129A4.4 Data-processing instructions ........................................................ A4-130A4.5 Status register access instructions .............................................. A4-140A4.6 Load and store instructions .......................................................... A4-141A4.7 Load Multiple and Store Multiple instructions .............................. A4-144A4.8 Miscellaneous instructions ........................................................... A4-145A4.9 Exception-generating instructions ................................................ A4-146A4.10 Coprocessor instructions ............................................................. A4-147A4.11 Floating-point load and store instructions .................................... A4-148A4.12 Floating-point register transfer instructions .................................. A4-149A4.13 Floating-point data-processing instructions ................................. A4-150

Chapter 5 The Thumb Instruction Set EncodingA5.1 Thumb instruction set encoding ................................................... A5-152A5.2 16-bit Thumb instruction encoding ............................................... A5-156A5.3 32-bit Thumb instruction encoding ............................................... A5-164

Chapter 6 The Floating-Point Instruction Set EncodingA6.1 Overview ...................................................................................... A6-190A6.2 Floating-point instruction syntax .................................................. A6-191A6.3 Register encoding ........................................................................ A6-194A6.4 Floating-point data-processing instructions ................................. A6-195A6.5 Extension register load or store instructions ................................ A6-197A6.6 32-bit transfer between ARM core and extension registers ......... A6-198A6.7 64-bit transfers between ARM core and extension registers ....... A6-199

Chapter 7 Instruction DetailsA7.1 Format of instruction descriptions ................................................ A7-202A7.2 Standard assembler syntax fields ................................................ A7-207A7.3 Conditional execution ................................................................... A7-208A7.4 Shifts applied to a register ........................................................... A7-212A7.5 Memory accesses ........................................................................ A7-214A7.6 Hint Instructions ........................................................................... A7-215

vi Copyright 2006-2008, 2010 ARM Limited. All rights reserved. ARM DDI 0403DNon-Confidential, Unrestricted Access ID021310

Contents

A7.7 Alphabetical list of ARMv7-M Thumb instructions ........................ A7-216

Part B