Write short note on ‘Central Processing Unit’.

Central Processing Unit (CPU): It is the nerve centre of any digital computer system. It coordinates and controls the activities of all other units and preforms all the arithmetical and logical process to be applied to the data. CPU has three separate hardware sections — (i) internal memory (ii) arithmetic unit and (iii) a control section. Chip (a thin silicon wafer containing a large amount of integrated electronic circuitary) is the building block of a computer and performs various functions e.g. doing arithmetic operations, serving as the computer’s memory or controlling other chips.

The Control Unit: The role of control unit is quite similar to a traffic cop. It interprets each instructions issued by a program and then initiates the appropriate action to carry out the instructions.

The Arithmetic Unit (ALU): It performs arithmetic comparison and logical operation. Arithmetic operations include addition, subtraction, multiplication and division. Comparison operations involve comparing one data item to another to determine if the first item greater than, equal to or less than the other item.

Logical operations use conditions alongwith logical operations such as AND, OR and NOT. For example, if only non-salaried employee can receive overtime pay, the ALU must verify that the employee is non-salaried AND worked more than 30 hours before computing an overtime wage.

Memory : During processing the instructions to be executed as well as the data required by those instructions are placed into memory by the processor. The memory is a temporary storage place for data instructions and informations.