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A router, an example of an embedded system. Labelled parts include a microprocessor (4), RAM (6), and flash memory (7). An embedded system is a special-purpose computer system designed to perform a dedicated function. Unlike a general-purpose computer, such as a personal computer, an embedded system performs one or a few pre-defined tasks, usually with very specific requirements, and often includes task-specific hardware and mechanical parts not usually found in a general-purpose computer. Since the system is dedicated to specific tasks, design engineers can optimize it, reducing the size and cost of the product. Embedded systems are often mass-produced, benefiting from economies of scale. Physically, embedded systems range from portable devices such as digital watches and MP3 players, to large stationary installations like traffic lights, factory controllers, or the systems controlling nuclear power plants. In terms of complexity embedded systems run from simple, with a single microcontroller chip, to very complex with multiple units, peripherals and networks mounted inside a large chassis or enclosure. Mobile phones or handheld computers share some elements with embedded systems, such as the operating systems and microprocessors which power them, but are not truly embedded systems themselves because they tend to be more general purpose, allowing different applications to be loaded and peripherals to be connected.
|Contents | |[hide] | |1 Examples of embedded systems | |2 History | |3 Characteristics | |3.1 User interfaces | |3.2 Simple systems | |3.3 In more complex systems | |3.4 CPU platform | |3.5 Peripherals | |3.6 Tools | |3.7 Debugging | |3.8 Reliability | |3.9 High vs Low Volume | |4 Embedded software architectures | |4.1 Simple control loop | |4.2 Interrupt controlled system | |4.3 Cooperative multitasking | |4.4 Preemptive multitasking | |4.5 Microkernels and exokernels | |4.6 Monolithic kernels | |4.7 Exotic custom operating systems | |5 See also | |6 References | |7 External links |
[pic] Examples of embedded systems
• Avionics, such as inertial guidance systems, flight control hardware/software and other integrated systems in aircraft and missiles • Cellular telephones and telephone switches
• Engine controllers and antilock brake controllers for automobiles • Home automation products, such as thermostats, air conditioners, sprinklers, and security monitoring systems • Handheld calculators
• Handheld computers
• Household appliances, including...