07-10-2010, 12:06 PM
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EMBEDDED SYSTEMS full report
S. Ramesh
ABSTRACT
Many embedded systems have substantially different design constraints than desktop computing applications. No single characterization applies to the diverse spectrum of embedded systems. However, some combination of cost pressure, long life-cycle, real¬-time requirements, reliability requirements, and design culture dysfunction can make it difficult to be successful applying traditional computer design methodologies and tools to embedded applications. Embedded systems in many cases must be optimized for life-cycle and business-driven factors rather than for maximum computing throughput. There is currently little tool support for expanding embedded computer design to the scope of holistic embedded system design. However, knowing the strengths and weaknesses of current approaches can set expectations appropriately, identify risk areas to tool adopters, and suggest ways in which tool builders can meet industrial needs.
INTRODUCTION:
If we look around us, today we see numerous appliances which we use daily, be it our refrigerator , the microwave oven, cars, PDAs etc. Most appliances today are powered by something beneath the sheath that makes them do what they do. These are tiny microprocessors, which respond to various keystrokes or inputs. These tiny microprocessors, working on basic assembly languages, are the heart of the appliances. We call them embedded systems. Of all the semiconductor industries, the embedded systems market place is the most conservative, and engineering decisions here usually lean towards established, low risk solutions. Welcome to the world of embedded systems, of computers that will not look like computers and wonâ„¢t function like any thing we are familiar with.
As the name signifies, an Ëœembedded systemâ„¢ is built into a noncomputing device, say a car, TV or toy. We can define an embedded system as a computing device, built in to a device that is not a computer, and meant for doing specific computing tasks. In general engineering terms, embedded systems are used for the control of industrial or physical processes. In computer science terms, embedded systems are distributed reactive systems. Typically these systems have to react to stimuli from their environment in real time. This can be of high importance in situations where a lot of signal processing must be carried out on the inputs inorder to compute the outputs. e.g., multimedia applications.
Embedded systems have been around us for about as long as computer themselves. These were first used in the late 1960s to control electro mechanical telephone switches. As computer industry has moved towards smaller systems over the last decade or so, embedded systems have also moved along with this trend.
Classification:
Embedded systems are divided into autonomous, realtime, networked & mobile categories.
Autonomous systems: They function in standalone mode. Many embedded systems used for process control in manufacturing units& automobiles fall under this category.
Realtime embedded systems: These are required to carry out specific tasks in a specified amount of time. These systems are extensively used to carryout time critical tasks in process control.
Networked embedded systems: They monitor plant parameters such as temperature, pressure and humidity and send the data over the network to a centralized system for on line monitoring.
Mobile gadgets: Mobile gadgets need to store databases locally in their memory. These gadgets imbibe powerful computing & communication capabilities to perform realtime as well as nonrealtime tasks and handle multimedia applications.
Reference: http://studentbank.in/report-embedded-sy...z11bgNhDvH