The world has become highly constrained by time. The ever-changing scenario of the world demands replacement of human supervision by automated systems. Embedded system is the brainchild of the intellectuals, which has proven to be such desired systems. This paper is an attempt to throw some light on this topic. This gives an overview about some concepts of embedded systems. The concept starts with the classification of three basic parts
- Hardware concepts of embedded systems
- Software concepts of embedded systems
- Applications of embedded systems
A study of hard ware concepts provides insight of physical architecture of embedded systems like micro controller, microprocessor etc. Software concepts considered as brain of the embedded systems and it controls the hardware. Finally we mention few of the ever growing applications of the embedded systems in the real world. A system is an arrangement in which all its units assemble and work together to do one or many tasks according to fixed plans, programs, or set of rules. Let us examine one example.
Automatic clothes washing machine
The important hardware components include its status display panel, the switches and dials for user-defined programming, a motor to rotate, its power supply and control unit, an inner water level sensor, a solenoid valve for letting water in and other valve for letting water to drain out .The system program is to wash the dirty clothes placed in tank, which rotates or spins in pre-programmed steps and stages. It follows a set of rules sequentially:
A computer is a system that has the following components.
- A microprocessor
- A large memory comprising the following tasks:
- Primary Memory (RAM, ROM AND cache memories)
- Secondary Memory
- Input like keyboard, mouse, scanner, digitizer etc.
- Output like video monitor, printer, etc.
- Networking units like Ethernet card, front-end processor based drivers, etc.
- I/O units like a modem, fax cum modem, etc.
An embedded system is one that has computer -hardware with software embedded in it as one of its most important component. It is dedicated computer-based system for an application(s) or products. It may be either an independent system or a part of a large system. As its software usually embeds in ROM it does not need secondary memories as in a computer. It has three main components:
- Application software that performs currently the series of Tasks or multiple tasks.
- It has a real time 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 switching between various tasks.
Components of Embedded system hardware
An embedded system has software designed to keep in view three constraints:
- Available system memory.
- Available processor speed
- The need to limit power dissipation when running the system continuously in Cycles of wait for events, run, stop and wake-up.
- An embedded system is a system whose principle function is not computational, but which is controlled by a computer embedded in it. The computer likely to be a microprocessor or micro controller. The word embedded implies that it lies inside the overall system, hidden from view, forming an internal part of greater whole.
- An embedded system is a microcontroller based, software-driven, reliable, real time control system, autonomous, or human-or network-interactive, operating on diverse physical variables and in diverse environments, and sold into a competitive and cost-conscious market.