Book Image

ARM® Cortex® M4 Cookbook

By : Mark Fisher, Dr. Mark Fisher
Book Image

ARM® Cortex® M4 Cookbook

By: Mark Fisher, Dr. Mark Fisher

Overview of this book

Embedded microcontrollers are at the core of many everyday electronic devices. Electronic automotive systems rely on these devices for engine management, anti-lock brakes, in car entertainment, automatic transmission, active suspension, satellite navigation, etc. The so-called internet of things drives the market for such technology, so much so that embedded cores now represent 90% of all processor’s sold. The ARM Cortex-M4 is one of the most powerful microcontrollers on the market and includes a floating point unit (FPU) which enables it to address applications. The ARM Cortex-M4 Microcontroller Cookbook provides a practical introduction to programming an embedded microcontroller architecture. This book attempts to address this through a series of recipes that develop embedded applications targeting the ARM-Cortex M4 device family. The recipes in this book have all been tested using the Keil MCBSTM32F400 board. This board includes a small graphic LCD touchscreen (320x240 pixels) that can be used to create a variety of 2D gaming applications. These motivate a younger audience and are used throughout the book to illustrate particular hardware peripherals and software concepts. C language is used predominantly throughout but one chapter is devoted to recipes involving assembly language. Programs are mostly written using ARM’s free microcontroller development kit (MDK) but for those looking for open source development environments the book also shows how to configure the ARM-GNU toolchain. Some of the recipes described in the book are the basis for laboratories and assignments undertaken by undergraduates.
Table of Contents (16 chapters)
ARM Cortex M4 Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Introduction


This chapter explains how to write functions in assembly language. Assembly language is a low-level programming language that is specific to a particular computer architecture. So, unlike programs written in high-level languages, programs written in assembly language cannot be easily ported to other hardware architectures. Assembly language programs are converted into object code by a program called an assembler. In practice, assembly language is used only rarely and most embedded software is written in a high-level language, such as C. Assembly language is only used when the programmer needs precise control over the machine architecture and needs to access specific registers or when execution time is an important consideration. Such occasions typically occur during the following:

  • Initializing the system

  • Servicing I/O devices

  • Handling interrupts

Assembly language programmers need a model of the computer architecture to enable them to write programs. This so called programmers' model...