These days, the once obscure engineering term ''DSP'' (short for digit
al signal processing) is working its way into common use. It has begun
to crop up on the labels of an ever wider range of products, from hom
e audio components to answering machines. This is not merely a reflect
ion of a new marketing strategy, however; there truly is more digital
signal processing inside today's products than ever before. But why is
the market for DSP processors booming? The answer is somewhat circula
r: As microprocessor fabrication processes have become more sophistica
ted, the cost of a microprocessor capable of performing DSP tasks has
dropped significantly to the point where such a processor can be used
in consumer products and other cost-sensitive systems. As a result, mo
re and more products have begun using DSP processors, fueling demand f
or faster; smaller, cheaper, more energy-efficient chips. Although fun
damentally related, DSP processors are significantly different from ge
neral-purpose processors (GPPs) like the Intel Pentium or PowerPC. The
authors explain what DSP processors are and what they do. They also o
ffer a guide to evaluating DSP processors for use in a product or appl
ication.