multichannel audio serial port (McASP). Th e 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 Com-
poser 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.
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 optimi-
zations 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 (indepen-
dent 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 require-
ments. Th is 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
1.1 Introduction 3
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