An embedded system is a special-purpose system in which the computer is completely encapsulated by the device it controls. Unlike a general-purpose computer, such as a personal computer, an embedded system performs pre-defined tasks, usually with very specific requirements. Since the system is dedicated to a specific task, design engineers can optimize it, reducing the size and cost of the product. Embedded systems are often mass-produced, so the cost savings may be multiplied by millions of items.
Handheld computers or PDAs are generally considered embedded devices because of the nature of their hardware design, even though they are more expandable in software terms. This line of definition continues to blur as devices expand
Embedded systems are designed to do some specific task, rather than be a general-purpose computer for multiple tasks. Some also have real-time performance constraints that must be met, for reason such as safety and usability; others may have low or no performance requirements, allowing the system hardware to be simplified to reduce costs.
The software written for embedded systems is often called firmware, and is stored in ROM or Flash memory chips rather than a disk drive. It often runs with limited hardware resources: small or no keyboard, screen, and little RAM memory
WHAT IS THE NEED OF EMBEDDED SYSTEMS
It is EMBEDDED because the micro controller is ‘inside ‘some other system. For example a micro controller is ‘EMBEDDED’ into your other TV, car, or application
EXAMPLES OF EMBEDDED SYSTEMS
Automatic teller machines (ATMs)
Avionics, such as inertial guidance systems, flight control hardware/software and other integrated systems in aircraft and missiles
Cellular telephones and telephone switches
Computer equipment such as routers and printers
engine controllers and antilock brake controllers for automobiles
home automation products, like thermostats, air conditioners, sprinklers, and security monitoring systems
household appliances, including microwave ovens, washing machines, television sets, DVD players/recorders