microcontroller
A single chip that contains the processor (the CPU), non-volatile memory for the program (ROM or flash), volatile memory for input and output (RAM), a clock and an I/O control unit. Also called a "computer on a chip," billions of microcontroller units (MCUs) are embedded each year in a myriad of products from toys to appliances to automobiles. For example, a single vehicle can use 70 or more microcontrollers.
Microcontrollers come in all sizes and architectures, with the smaller, commodity chips costing as little as 50 cents in quantities of 10,000.
 |
| One of the First |
|---|
| This diagram shows the components of a Motorola 6801. Introduced in 1978, it was one of the first semiconductor products to claim the "computer on a chip" moniker. |
 |
| Actual Images |
|---|
| These highly magnified images are of the actual 6801 chip. The middle picture shows all 256 bytes of RAM memory with barely six bits revealed at the bottom (400x magnification). |
 |
| They Don't Get Much Smaller |
|---|
| These PICmicro chips from Microchip (www.microchip.com) are the world's smallest microcontrollers. Used in a myriad of applications, such chips can sell for as little as 50 cents in quantities of 10,000 (2007 dollars). |
microcontroller [
¦mī·krō·kən′trōl·ər]
(electronics)
A microcomputer, microprocessor, or other equipment used for precise process control in data handling, communication, and manufacturing.
