What Are The Operations Of The Control Unit?

The control unit performs basic functions. It also explains that an instruction basically consists of at least two parts. The first part is the operation to be carried out like subtraction and multiplication etc. the second is the address which is used to locate the data or instructions to be manipulated. The control unit co-ordinates and control all hardware operations that is those of the peripheral units and the processor itself. It deals with each instruction in a two stage operation called the fetch-execute cycle. It first fetches the instruction from main storage via memory bluffer register and places it in the IR.

The location address of this instruction had earlier been place into the memory address register. When main storage receives an appropriate signal from the control unit it transfers into the memory buffer register. Then it interprets the instruction in the IR using decoding circuits as explained in the previous section and causes the instruction to be executed by sending command signals to the appropriate hardware devices. It might cause main storage to transfer data to the memory or it might cause the arithmetic and logical unit to perform some operations on the data in the accumulator. So this is the complete operation process of control unit.

The control unit interprets any instruction.It receives from the memory and directs the sequence of event necessary to execute each instruction. It also establishes the timing of these events. It is like a "traffic cop" of the system controlling the entire going in and coming out of the computer system.

The control unit directs and co-ordinates the entire computer system. Its functions involve controlling the input/output units and the logical/arithmetical operations of the central processing unit and transferring data to and from storage, within the given designed limits. This unit directs the system according to the procedure designed by its human operators and programmers. The control unit ensures that information is correctly placed in store, the programs, instructions and data are transferred properly from the input devices into the memory.Programs, instructions are retrieved in the proper sequence from the memory and     interpreted, and data is selected from memory as necessary. Control unit informs the arithmetic logic unit (ALU) of the precise operation to be performed and directs the transfer to he ALU of any data, which is needed for the operation. After execution of all the calculations and comparisons in ALU, the control unit transfer the results for output.

The Control Unit is one of the part of the Central Processing Unit. It directs  as well as coordinates all activities of a computer. Besides this, it is also responsible for the following tasks:
It controls the various input and output devices, storage of memory, controls the direction of all arithmetic and logical operations in addition to providing execution of programs.