Structure and Function of Computer

The structure and function of the computer depict how the components of the computer are assembled, how they are interrelated to each other and what operations these components perform.

Being a complex system, the computer contains millions of electronic components. To understand the structure and function better we organize these electronic elements in a hierarchical structure.

Structure and Function of Computer

1. Function of Computer
   • Data Processing
   • Data Storage
   • Data Movement
   • Control
2. Structure of Computer
   • Main Memory
   • I/O
   • System Interconnection
   • Central Processing Unit

Function of Computer

If we generalize the functions of the computer, we can divide them into four categories. The four basic functions are as below:

1. Data Processing
2. Data Storage
3. Data Movement
4. Control

The figure above shows the four basic functions of the computer. Let us understand each of these functioning units.

Data Processing

If we talk of the computer, basically we consider it for performing computation. So, there must be a unit in the computer that would perform computation. For performing computation this unit must be capable of processing data.

It is the data processing unit that processes the data. It must also be able to process data in a wide variety of forms. Thus, the range of processing requirements is broader. Though there is a tremendous processing requirement, there are only a few methods or types for processing data.

Data Storage

Once the processing has been done there must be some means to store the final and intermediate results. Even though it seems that we enter the data into the computer, it processes that data and immediately produces the result. But still, the computer needs to store those pieces of data that are being worked on at the current moment.

The computer requires two kinds of data storage functions:

1. Short-Term Data Storage Function
2. Long-Term Data Storage Function

The short-term data storage function is generally used to store the intermediary result of any computation. The long-term data storage function is generally used to store the final result of any computation. It also involves the storage of files that can be subsequentially retrieved and can be updated.

Data Movement

Every computer has an input and output device that makes the computer move data between itself and outside the world. The input devices are meant for entering the data into the computer. It is the data that we need to process. The output devices are where the computer displays the produced result or the output data.

The operating environment of any computer requires both input and output peripheral devices. The computers are also capable of moving data over a longer distance i.e., to or from a remote device. We refer to this moving of data between the remote devices as data communication.

Data Controlling

We have learned about three functioning units’ data storage, movement and processing. As they are interrelated units, we require a unit that would control and synchronize the function of these units.

However, controlling of these three units is regulated by the individual who provides the instruction to the computer. In response to these instructions the control unit manages the resources of the computer and controls the performance of the functional units.

Knowing about the functional units lets us proceed with our discussion about the structure of the computer.

Structure of Computer

If we talk about the structure of a computer it is composed of several components. We can broadly classify these components into four types:

1. Main Memory: This structure of the computer is mainly used for storing the data.
2. I/O: These structural units of the computer are mainly used for moving data in or out of the computer.
3. System Interconnection: This structural component is held for moving the data and controlling the signal inside the computer. It provides communication between the functional units of the computer. This structure includes the system bus
4. Central Processing Unit: This structural component of the computer performs the controlling and processing function. Thus, it is also referred to as the processor.

A computer may have one or more of the above-discussed components. The traditional computers had a single processor but the modern or advanced computers have multiple processors. Even the processor can be classified into the components discussed below:

1. Control Unit: This unit controls all the operations of the processor.
2. Arithmetic & Logic Unit (ALU): This unit performs the computations while data processing.
3. Registers: It is the internal storage unit of the processor.
4. CPU Interconnections: This unit provides communication between the control unit, ALU and registers.

There are several ways to implement the control unit of the processor one of which is the microprogrammed approach that operates by executing the microinstructions.

In this way, the structure and function of the computer associatively decide how the components of the computer are assembled, how they are interrelated to each other and what operations these components perform.