16-12-2009, 04:46 PM
Embedded systems
An embedded system is a computer system designed to perform one or a few dedicated functions.They are controlled by one or more main processing cores that is typically either a microcontroller or a digital signal processor (DSP). Embedded reflects the fact that they are an integral part of the system. In many cases, their embeddedness may be such that their presence is far from obvious to the casual observer.
Difference from normal computers:
-Closed loop system
No or very restricted human - computer interface
-No or very restricted maintenance possibilities
Part of competitively priced products (high volumes)
-Tight resource constraints: They may have very little memory and must operate on less power.
-Part of engineering product
High product generation frequency
-Often many variants
Malfunction may lead to damage
The program written for embedded systems are referred to as firmware, and are stored in ROM or Flash memory chips.
Processors used in embedded systems
They can be broadly be classified into microprocessors and microcontrollers. Microcontrollers have built in peripherals such as memory so that their cost is reduced compared to that of microprocessors.
Implementation
SoC(system on a chip) can be implemented as an application-specific integrated circuit (ASIC) or using a field-programmable gate array (FPGA). Such SoCs contain a complete system consisting of multiple processors, multipliers, caches and interfaces on a single chip.
Applications of embedded systems
1.Signal processing (e.g., face recognition) Often use DSP
chips for vision, audio, or other signal processing.
2.Telecommunications systems employ numerous embedded systems from telephone switches for the network to mobile phones at the end-user.
3.Command and control : Often huge military systems and systems of systems (e.g., a fleet of warships with inter- connected computers).
4.Consumer electronics: personal digital assistants (PDAs), mp3 players, mobile phones, videogame consoles, digital cameras, DVD players, GPS receivers, and printers, washing machines, microwave ovens, dishwashers etc.
project report download:[attachment=614]