Control unit

A control unit is the part of a CPU or other device that directs its
operation. The outputs of the unit control the activity of the rest of the
device. A control unit can be thought of as a finite state machine.

At one time control units for CPUs were ad-hoc logic, and they were
difficult to design. Now they are often implemented as a microprogram that
is stored in a control store. Words of the microprogram are selected by a
microsequencer and the bits from those words directly control the different
parts of the device, including the registers, arithmetic and logic units,
instruction registers, buses, and off-chip input/output. In modern
computers, each of these subsystems may have its own subsidiary controller,
with the control unit acting as a supervisor. (See also CPU design and
computer architecture.)

Free Ajax Scripts - Mortgages - Wester Union - Loans - Loans