What is a CPU:
CPU or Central processing unit is the brain of the computer system. Functions of CPU varies from data processing to controlling input-output devices. Each and every instruction no matter how complex or simple, it has to go through the CPU. In this article we will learn various components of CPU and their functions.
So, let us say we press a key on the keyboard and it instantly appears on our computer monitor so the CPU of the computer is what makes this possible. The central processing unit is also responsible for storing data or information, intermediate results and instructions in the memory system. It also controls the operations of all other parts of the computer system.
Functions of a CPU:
CPU generally performs the arithmetical and logical operations, controlling of different input-output devices. These operations are performed based on some predefined algorithms and instructions normally referred as computer programs.
A CPU mainly consists of ALU (Arithmetic & Logic Unit), Control Unit and Memory Unit. These 3 units are the primary components of a CPU. Various functions of CPU and operations are generally performed by these 3 units are described below.
Components of CPU and their functions :
The primary job of the memory unit is to store data or instructions and intermediate results. Memory unit supplies data to the other units of a CPU. In Computer Organization, memory can be divided into two major parts primary memory and secondary memory. Speed and power and performance of a memory depends on the size and type of the memory.
When an instruction is processed by the central processing unit, the main memory or the RAM (Random Access Memory) stores the final result before it is sent to the output device. All inputs and outputs are intermediate and are transmitted through the main memory.
It is the unit which controls all the operations of the different units but does not carry out any actual data processing operation. Control unit transfers data or instruction among different units of a computer system. It receives the instructions from the memory, interprets them and sends the operation to various units as instructed.
Control unit is also responsible for communicating with all input and output devices for transferring or receiving the instruction from the storage units. So, the control unit is the main coordinator since it sends signals and find the sequence of instructions to be executed.
Arithmetic and logic unit:
ALU can also be subdivided into 2 sections namely, arithmetic unit and logic unit. It is a complex digital circuit which consists of registers and which performs arithmetic and logical operations. Arithmetic sections perform arithmetic operations like addition, subtraction, multiplication, division etc. All other Complex operations can also be performed by repetition of these above basic operations.
The logic unit is responsible for performing logical operations such as comparing, selecting, matching and merging of different data or information.
So basically ALU is the major part of the computer system which handles different calculations. Depending on the design of ALU it makes the CPU more powerful and efficient.