Could someone give me a good formal definition of what an embedded system is? Is it a microprocessor? If not, then does every embedded system have a microprocessor in it? Could anyone give me some examples of what is and what is not an embedded system?

 

Could someone give me a good formal definition of what an embedded system is? Is it a microprocessor? If not, then does every embedded system have a microprocessor in it? Could anyone give me some examples of what is and what is not an embedded system?

An embedded system is a computer system designed for specific control functions within a larger system, often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal computer (PC), is designed to be flexible and to meet a wide range of end-user needs. Embedded systems control many devices in common use today.

Embedded systems contain processing cores that are either microcontrollers or digital signal processors (DSP). The key characteristic, however, is being dedicated to handle a particular task. Since the embedded system is dedicated to specific tasks, design engineers can optimize it to reduce the size and cost of the product and increase the reliability and performance. Some embedded systems are mass-produced, benefiting from economies of scale.

That's a formal definition. Took me 5 seconds to query Wikipedia.

You should try doing that too, it's a very useful resource.

 

An Embedded system is also defined as:

Any microcontroller based device in which the user has no idea they are interacting with a computer.

It tightens the specification up a bit from Wiki, but both are valid. This definition is a bit restraining, however. Things that come to mind are Coffee makers, toasters and other appliances, aircraft instruments, and some Christmas lights.

Boils down to "User cannot modify internal operation of system". (expand by adding peripherals, edit code, etc)

 

Does this mean that, say, the video card of a computer is an embedded system? If that is the case, does that mean than a video card has a microprocessor?

 

Video cards aren't exactly embedded, as the specifications for their CPUs and memory bandwidth are published so that users get an idea of speed. Very frequently, for certain operations, video cards are faster as processors than the system CPU would be at the same operation. However, the video card processors (massively parallel) need to be programmed in a different language. Example: Folding@Home: 3Ghz CPU calculates about 300 packets a day, while the GPU (video card version) calculates around 6,000 packets per day. This only works with "heavy math" operations, but works. Drawing faster than realtime 3D at 1920x1080 with 24 bit color takes far more processing power than any single CPU made today.

A more apt example of an embedded system would be a computer mouse, which has a small uC in it to convert movement to USB signals.