Digital Signal Processing and Applications with the OMAP - L138 eXperimenter

Donald S. Reay

• Publisher: Wiley
• Year: 2012
• Print ISBN: 9780470936863
• eBook ISBN: 9781118228951
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Waves & Wave Mechanics

Teaches digital signal processing concepts via hands-on examples

The OMAP-L138 eXperimenter is the latest inexpensive DSP development system to be adopted by the Texas Instruments University Program. The OMAP-L138 processor contains both ARM and DSP cores and is aimed at portable and mobile multimedia applications. This book concentrates on the demonstration of real-time DSP algorithms implemented on its C6748 DSP core.

Digital Signal Processing and Applications with the OMAP-L138 eXperimenter provides an extensive and comprehensive set of program examples to aid instructors in teaching DSP in a laboratory using audio frequency signals—making it an ideal text for DSP courses at senior undergraduate and postgraduate levels.

Subjects covered include polling-based, interrupt-based, and DMA-based I/O methods, and how real-time programs may be run using the board support library (BSL), the DSP/BIOS real-time operating system, or the DSP/BIOS Platform Support Package.

Chapters include:

• Analog input and output with the OMAP-L138 eXperimenter

• Finite impulse response filters

• Infinite impulse response filters

• Fast Fourier transform

• Adaptive filters

• DSP/BIOS and platform support package

Each chapter begins with a review of background theory and then presents a number of real-time program examples to reinforce understanding of that theory and to demonstrate the use of the OMAP-L138 eXperimenter and Texas Instruments Code Composer Studio integrated development environment.

Chapter 1

OMAP-L138 Development System

• OMAP-L138 processor
• Code Composer Studio™ IDE version 4
• Use of the OMAP-L138 eXperimenter
• Programming examples

This chapter gives an overview of the OMAP-L138 processor and Logic PD's Zoom OMAP-L138 eXperimenter development system. It describes how to install and start using version 4 of Texas Instruments (TI) Code Composer Studio integrated development environment (IDE). Two example programs that demonstrate hardware and software features of the eXperimenter board and of the Code Composer Studio IDE are presented. It is recommended strongly that you review these examples before proceeding to subsequent chapters.

1.1 Introduction

The Logic PD Zoom OMAP-L138 eXperimenter kit is a low-cost development platform for the Texas Instruments OMAP-L138 processor. This device is a dual-core system on a chip comprising an ARM926EJ-S general-purpose processor (GPP) and a TMS320C6748 digital signal processor. In addition, a number of peripherals and interfaces are built into the OMAP-L138 as shown in Figure 1.1.

Figure 1.1 Functional block diagram of OMAP-L138 processor. (courtesy of Texas Instruments)

The eXperimenter makes a significant number of the OMAP-L138 interfaces available to the user, as shown in Figure 1.2. This book is concerned with the development of real-time digital signal processing (DSP) applications and therefore makes use of the DSP (C6748) side of the device and of the TLC320AIC3106 (AIC3106) analog interface circuit (codec) connected to the OMAP-L138's multichannel audio serial port (McASP). The ARM side of the device is not used by the examples in this book. Connection to a host PC running the Code Composer Studio IDE is via XDS100v1 JTAG emulation built in to the eXperimenter. The Code Composer Studio IDE enables software written in C or assembly language to be compiled and/or assembled, linked, and downloaded to run on the C6748. Details of the OMAP-L138, TMS320C6748, TLC320AIC3106, eXperimenter, and Code Composer Studio IDE can be found in their associated datasheets [1–5] and in the TI wiki [6]. The purpose of this chapter is to introduce the installation and use of the eXperimenter for hands-on DSP experiments.

Figure 1.2 Logic PD Zoom OMAP-L138 eXperimenter baseboard (courtesy of Logic PD).

1.1.1 Digital Signal Processors

A digital signal processor is a specialized form of microprocessor. Its architecture and instruction set are optimized for real-time digital signal processing. Typical optimizations include hardware multiply accumulate (MAC) provision, hardware circular and bit-reversed addressing capabilities (for efficient implementation of data buffers and fast Fourier transform (FFT) computation), and Harvard architecture (independent program and data memory systems). In many respects, digital signal processors resemble microcontrollers. Typically, they provide single-chip computer solutions integrating on-board volatile and nonvolatile memory and a range of peripheral interfaces, and have a small footprint, making them ideal for embedded applications. In addition, digital signal processors tend to have low power consumption requirements. This attribute has been extremely important in establishing the use of digital signal processors in cellular handsets. However, the distinctions between digital signal processors and other more general-purpose microprocessors are blurred. No strict definition of a digital signal processor exists and semiconductor manufacturers apply the term to products exhibiting some, but not necessarily all, of the above characteristics as they see fit.

Digital signal processors are used for a wide range of applications, from communications and control to speech and image processing. They are found in cellular phones, disk drives, radios, printers, MP3 players, HDTV, digital cameras, and so on. Specialized (particularly in terms of their on-board peripherals) DSPs are used in electric motor drives and in a range of associated automotive and industrial applications. Overall, digital signal processors are concerned primarily with real-time signal processing. Real-time processing means that the processing must keep pace with some external event, whereas non real-time processing has no such timing constraint. The external event to keep pace with is usually the analog input. While analog-based systems with discrete electronic components including resistors and capacitors are sensitive to temperature changes, DSP-based systems are less affected by environmental conditions such as temperature. Digital signal processors embody the major advantages of microprocessors. They are easy to use, flexible, and economical.

Texas Instruments OMAP-L138 device combines a C6748 DSP with an ARM926EJ-S general-purpose processor to produce a dual-core solution for handheld and other embedded applications. ARM926EJ-S provides the benefits of a 32-bit RISC processor, well suited to implementing user interfaces and running operating systems.

C6748 is a member of the Texas Instruments TMS320C6000™ DSP family of digital signa...

Table of contents

• Cover
• Title Page
• Copyright
• Dedication
• Preface
• List of Examples
• Chapter 1: OMAP-L138 Development System
• Chapter 2: Analog Input and Output with the OMAP-L138 eXperimenter
• Chapter 3: Finite Impulse Response Filters
• Chapter 4: Infinite Impulse Response Filters
• Chapter 5: Fast Fourier Transform
• Chapter 6: Adaptive Filters
• Chapter 7: DSP/BIOS and Platform Support Package
• Index
• Eula