micro- +"Ž controller
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. Available in numerous sizes and architectures, and also called a "computer on a chip," billions of microcontroller units (MCUs) are embedded each year in products from toys to appliances to automobiles. For example, a car or truck can employ 70 or more microcontrollers (see automotive systems). See CPU, RAM, ROM and clock.