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MSP430 Microcontroller Basics

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MSP430 Microcontroller Basics
John H. Davies

AMSTERDAM • BOSTON • HEIDELBERG • LONDON
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“To Elizabeth.”

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Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Chapter 1: Embedded Electronic Systems and Microcontrollers . . . . . . . . . . . . . . . . . . . 1
1.1
1.2
1.3
1.41.5
1.6
1.7

What (and Where) Are Embedded Systems? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Approaches to Embedded Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Small Microcontrollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Anatomy of a Typical Small Microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . 15
Where Does the MSP430 Fit? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Chapter 2: The Texas Instruments MSP430 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8

The Outside View—Pin-Out . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
The Inside View—Functional Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Central Processing Unit. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Memory-Mapped Input and Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Clock Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Exceptions: Interrupts and Resets ....