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2.4 / EMBEDDED SYSTEMS AND THE ARM 47

Table 2.7 Examples of Embedded Systems and Their Markets [NOER05]

Market Embedded Device
Ignition system
Automotive Engine control
Brake system
Digital and analog televisions
Set-top boxes (DVDs,VCRs, Cable boxes)
Personal digital assistants (PDAs)
Kitchen appliances (refrigerators, toasters, microwave ovens)
Consumer electronics Automobiles
Toys/games
Telephones/cell phones/pagers
Cameras
Global positioning systems
Robotics and controls systems for manufacturing
Industrial control
Sensors
Infusion pumps
Dialysis machines
Medical
Prosthetic devices
Cardiac monitors
Fax machine
Photocopier
Office automation Printers
Monitors
Scanners

Embedded systems far outnumber general-purpose computer systems, encom-
passing a broad range of applications (Table 2.7).These systems have widely varying
requirements and constraints, such as the following [GRIM05]:
• Small to large systems, implying very different cost constraints, thus different
needs for optimization and reuse
• Relaxed to very strict requirements and combinations of different quality re-
quirements, for example, with respect to safety, reliability, real-time, flexibility,
and legislation
• Short to long life times
• Different environmental conditions in terms of, for example, radiation, vibra-
tions, and humidity
• Different application characteristics resulting in static versus dynamic loads, slow
to fast speed, compute versus interface intensive tasks, and/or combinations
thereof
• Different models of computation ranging from discrete-event systems to those
involving continuous time dynamics (usually referred to as hybrid systems)
Often, embedded systems are tightly coupled to their environment. This can
give rise to real-time constraints imposed by the need to interact with the envi-
ronment. Constraints, such as required speeds of motion, required precision of
measurement, and required time durations, dictate the timing of software operations.