Embedded system
Picture of the internals of a Netgear ADSL
modem/router. A modern example of an em-
bedded system. Labelled parts include a mi-
croprocessor (4), RAM (6), and flash memory
(7).
An embedded system is a special-pur-
pose computer system designed to perform
one or a few dedicated functions,[1] often
with real-time computing constraints. It is
usually embedded as part of a complete
device including hardware and mechanical
parts. In contrast, a general-purpose com-
puter, such as a personal computer, can do
many different tasks depending on program-
ming. Embedded systems control many of the
common devices in use today.
Since the embedded system is dedicated
to specific tasks, design engineers can optim-
ize it, reducing the size and cost of the
product, or increasing the reliability and per-
formance. Some embedded systems are
mass-produced, benefiting from economies of
scale.
Physically, embedded systems range from
portable devices such as digital watches and
MP4 players, to large stationary installations
like traffic lights, factory controllers, or the
systems controlling nuclear power plants.
Complexity varies from low, with a single mi-
crocontroller chip, to very high with multiple
units, peripherals and networks mounted in-
side a large chassis or enclosure.
In general, "embedded system" is not an
exactly defined term, as many systems have
some element of programmability.
For
example, Handheld computers share some
elements with embedded systems — such as
the operating systems and microprocessors
which power them — but are not truly em-
bedded systems, because they allow different
applications to be loaded and peripherals to
be connected.
Examples of embedded
systems
PC Engines’ ALIX.1C Mini-ITX embedded
board with an x86 AMD Geode LX 800 to-
gether with Compact Flash, miniPCI and PCI
slots, 22-pin IDE interface, audio, USB and
256MB RAM
An embedded RouterBoard 112 with
U.FL-RSMA pigtail and R52 miniPCI Wi-Fi
card widely used by wireless Internet service
providers (WISPs) in the Czech Republic.
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