An embedded system is hardware with specialized software dedicated to the hardware.

The hardware defines the cost point of the product while the software defines the functionality and performance as far as the hardware allows.

Depending on cost and power consumption targets, an embedded system will likely contain special-purpose processors and peripherals.

Many processors used in embedded systems will have built-in features that eliminate the need for add-on chips (such as built-in memory controllers, usb interfaces, analog to digital interfaces, ethernet interfaces). Not only do these integrated processors save system cost, they also increase manufacturing reliability and system performance, decrease board space and reduce parts inventory requirements for manufacturing.

A Consumer Carbon Monoxide Detector

One good example of an embedded system is a consumer carbon monoxide detector.

Essentially, such an embedded system will need to reach the consumer's hands at a cost, let's say, of $50. This usually means that a manufacturer will have to sell it for $25. To allow for any margin at all, the manufacturer will probably have to make it for no more than $12 or so.

Manufacturing such an embedded device will preclude any but the lowest cost processors (say, $1 or $2) and will likely mandate low power use (such as a processor that can be run with only a few batteries).

Other variations are possible, of course; being able to connect the detector to a main power source would remove the need for batteries but will still require power management to the embedded device. If the detector must operate even when the power in the home or workplace is out, some sort of battery system must be employed.

A Personal Digital Assistant (PDA)

Another example of a highly integrated, reasonably low cost, embedded system is a Personal Digital Assistant (PDA). There are may varieties of PDAs, of course, but all will likely share common features such as:

• a low cost, low power processor
• a processor with an integrated display interface
• an interface for uploading from and downloading to the PDA (likely using an interface integrated on the processor).