control unit

(1) Within the processor, the circuitry that locates, analyzes and executes each instruction in the program. See process control, industrial automation and control network.

(2) Within the computer, hardware that performs the physical data transfers between memory and a peripheral device, such as a disk or screen. See controller.

A Rather Large Control Unit

This is the CPU control unit of the ILIAC IV computer in the 1960s. Today, the equivalent circuitry fits on the head of a pin. (Image courtesy of The Computer Museum History Center, www.computerhistory.org)

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(processor)

control unit - The part of a CPU responsible for performing the machine cycle - fetch, decode, execute, store.