microcontroller - Computer Definition
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 myriad 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.