Signal Processor, or
is a semiconductor device used for processing signals digitally. A
signal, in this context, traditionally refers to an analog signal (such as
analog voltage) that has been converted into a digital one so that it can
be processed mathematically. Nowadays, however, almost every piece
of information has been digitized, so a digital signal may be any
- digital audio/video data,
betting odds, or even the weight of clothes in a washing machine.
Analysis of such digital signals for a variety of purposes can be easily
accomplished by a DSP.
encompasses a large variety of actions performed on signals -
filtering, encoding/decoding, compression/decompression, amplification,
modulation, level detection, pattern matching, mathematical/logical
operations, and much more. These processes are performed on a signal for a
number of reasons: to enhance it; reduce its component noise; make its
transmission and reception more effective, efficient, and faster;
transform it; make it
interact with other signals in special ways; facilitate its use in digital
analysis, monitoring, or control; etc. A DSP has built-in
capabilities to perform these signal processing functions easily.
A DSP is very similar to a
fact, it is regarded by many as a special microprocessor created
process signals. Both a microprocessor and a DSP can execute
instructions, accept input digital data, perform operations on them, and
output digital data. The fundamental difference between a DSP and a
microprocessor is what
their built-in processing capabilities were designed for.
A DSP is a
device that's equipped with a multitude of
functions specifically intended for processing a digital signal, whereas a
microprocessor is designed to be a
device. A microprocessor would be able to handle many different
applications, such as word processing, spreadsheets, databases, and, well,
even digital signal processing. However, it can not be as good as a
DSP when it comes to serious DSP applications.
in technology seem to indicate the possibility though that the distinction
between a DSP and a microprocessor will soon be
Microprocessors are becoming more and more sophisticated that some of them
are now equipped with
true DSP capabilities. It will just be a
matter of time before high-end microprocessors will have the capability to
perform high-end signal processing, or any high-end task for that matter.
A DSP is also very similar to
a microprocessor as far as
architecture is concerned, i.e., it has many
parts that are also seen in a microprocessor, such as data and address
buses, an Arithmetic-Logic Unit (ALU), a program control unit,
assorted flags and
registers, etc. It also has its own native
which defines what it can be programmed to do. Programming DSP's is no
longer complicated too, with the existence of various development kits in
the market that support DSP software development using high-level
programming languages such as C.
Many DSP applications deal
real-world analog signals (such as sound, light, analog voltage,
analog current, temperature, pressure). Since a DSP can only process
digital signals, there is a need to convert analog signals first into
digital data before they can be processed by a DSP. After
processing, there is again a need for the DSP to convert these digital
data back into the original real-world analog signal format. In such
applications, the DSP must be supported by an
(ADC) and a digital-to-analog converter (DAC), which will perform the
required analog-digital and digital-analog conversions, respectively.
DSP's are commonly used include: 1) digital sound and image
processing; 2) digital communications; 3) consumer
electronics (e.g., mobile phones, faxes, computer peripherals such as
modems and sound cards, and digital entertainment systems such as DVD
players and digital TV); 4) medical electronics; and 5) industrial and
There are currently four
major companies that produce DSP's, namely, Texas Instruments, Analog
Devices, Motorola, and Lucent Technologies. Examples of commercially
available DSP's include:
10 to 50 MIPS 16-bit fixed-point DSP's; 40-bit accumulator; 24-bit
40 MIPS, 32-bit floating point DSP's;
32-bit floating-point with 40-bit accumulator and 16/24-bit fixed point DSP's;
DSP568xx: 20 MIPS 16-bit fixed-point DSP's;
IEEE format floating-point DSP with two complete 32-bit data and address
- Texas Instruments'
Low cost fixed-point DSP's with 16-bit data, 32-bit registers;
Multiple 50 MHz 32-bit fixed-point processors combined with a
RISC supervisory processor in a single multi-chip module.
What is a
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