Embedded System

Embedded System

INTRODUCTION:

An Embedded System:

An Embedded System is a system whose principal function is not computational, but which is controlled by a computer embedded within it. The computer is likely to be a microprocessor. The word embedded implies that it lies inside the overall system, hidden from view, forming an integral part of greater whole.

An Embedded System is one that has computer hardware with software embedded in it as one of its most important components. They are the applications that fuel some of the microprocessors that play a hidden but crucial role in our everyday lives. It may be either an independent system or a part of a larger system. As its software usually embeds in ROM (read only memory) it does not need secondary memories as in a computer.

An embedded system consists of three main components:

1 It has hardware.
2 It has main application software.
3 It has an operating system.

In case of an embedded system, the hardware is generally custom-built for system’s specific purpose, mainly because the requirements of each system vary considerably. For instance in a manufacturing unit of a chemical plant, a number of temperatures have to be measured with sensors and then certain operations are carried out. Where as in a mobile phone, the processor needs to carry out a great deal of communication protocols processing to make telephone calls, to perform voice processing. However, unlike in the preceding example, the mobile phone has a mass market, and the hardware developers must keep in mind the specific requirements of the protocols used in the mobile networks.

Hence, depending on the quantity and functionality needed, the embedded system hardware needs to be developed with the cost kept in mind.

The application software may perform concurrently the series of tasks or multiple tasks. It has an operating system that supervises the application software and provides a mechanism to let the processor run a process as per scheduling and do the context-switch between the various processes. RTOS (Real Time Operating System) defines the way the system works. It organizes access to a resource in sequence of the series of tasks of the system. It also schedules their working and execution. A small scale embedded system may not need an RTOS.

for more info visit.
http://www.enjineer.com/forum