Embedded systems are small, fast, and very powerful tools, gadgets and equipments which have become part of our everyday life. They are those computer systems that do not look like computer systems to the everyday user. They form a part of a larger system or product, part of anything, from mobile phones to medical devices, from agricultural farming tools to manufacturing equipments. An embedded system is a micro-processor based system that is built to control a function or range of functions and is not designed to be used by the user in the same way that a personal computer (PC) is (Heath, 2003).
It is a combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to perform a dedicated function (Netrino, 2011). In some cases, embedded systems are part of a larger system or product, as in the case of an antilock braking system in a car. Although the user can make choices concerning the functionality, he cannot change the functionality of the system by adding or replacing software as is possible with the PC.
In a PC, you can change functionality from word processing to games and then to mathematical computation by simply changing the software application but this is not possible in embedded systems. An embedded system is designed to perform one or a few dedicated and/or specific functions but with choices and different options (Michael, 2007; Heath 2003).
Fig1 and Fig2 are examples of embedded systems. Today, more microprocessors around the globe are used in embedded systems rather than in PCs. Those already large numbers are increasing at a phenomenal rate as the devices that surround us in our everyday lives become smarter. This is a consequence of an insatiable drive towards having control over devices and access to data anywhere, anytime. Needless to say we prefer them connected – wired or wireless.
Fig1: Picture of the internals of an ADSL modem/router. (A modern example of an embedded system. Labeled parts include a (4), RAM (6), and flash memory (7)).
Fig2: PC Engines’ ALIX.1C Mini-ITX embedded board with an x86 AMD Geode LX 800 together with Compact Flash, miniPCI and PCI slots, 44-pin IDE interface, audio, USB and 256MB RAM
Why do we need embedded systems?
The first reason why we need embedded systems is because general-purpose computers, like PCs, would be far too costly for the majority of products that incorporate some form of embedded system technology (Christoffer, 2006). Another reason why we need embedded systems is because general-purpose solution might also fail to meet a number of functional or performance requirements such as constraints in power-consumption, size-limitations, reliability or real-time performance etc.
The digital revolution, started decades ago, has reached a stage that we cannot conduct our normal modern daily lives without this technology. Indeed, it is safe to say that we already own at least one piece of equipment, which contains a processor, whether it is a phone, a television, an automatic washing machine or an MP3 player.
The colossal growth of processing power in small packages has fuelled the digital revolution. All sectors of the economy have been influenced by the digital revolution and the industry has experienced tremendous developments in all aspects of engineering disciplines (Bruce, 2011).