The control unit( CU) is a component of the central processing unit( CPU) that processes the instructions from the instruction register and takes over the control of the instruction cycles in the central processing unit (CPU).
The control unit is directly connected to the arithmetic unit( ALU) via control and status lines. It controls the internal operations of the central processing unit, the data transport via the control bus between the memories and the peripheral devices. The control unit provides the data for the arithmetic unit and decodes the commands.
The control unit takes over the control of the complete program sequence with its individual commands in their time sequence.