Deep Dive in Computer

Computer

It is a set of several functional components, where they are working together.

                All the functional components of the computer are interconnected to each other and can shared their data and resources or itself with each other.

To understand the concept of the computer organization and architecture, we have to study the block diagram of the computer.

Block diagram of the computer :-

It is the graphical representation of the connection of different functional component.

 Control Line

---------------   

Data Flow

_____________       

There are four major functional components of the computer :-

1. Input Unit
2. Output Unit
3. CPU
4. ALU

Input Unit :-

• This unit is responsible to perform the input operation.
• All the input devices belong to the input unit.
• There is an input interface with input unit , which converts the data from user acceptable form to computer acceptable form.

Output Unit :-

• It is responsible for output operation.
• All the output devices belong to this unit.
• There is an output interface , which converts the data from computer acceptable form to user acceptable form.

CPU (Central Processing Unit) :-

• As the name suggested it is responsible to perform all the operations going on within the computer.
• It is also known as the 'brain of the computer'.
• It is a semi conductor chip, i.e. a VLSI(Very Large Scale Integrated Circuit) chip.

Circuit   -  No. of transistors

SSI (Small Scale Integrated Circuit)      -         1-10

MSI (Medium Scale Integrated Circuit)   -      11-100

LSI (Large Scale Integrated Circuit)        -      101-1000

VLSI (Very Large Scale Integrated Circuit)  - 1001-10000

ULSI (Ultra Large Scale Integrated Circuit)  - 10000-onward

• CPU has three components :- 

1. ALU
2. CU
3. Registers

ALU (Arithmetic and Logical Unit) :-

• As the name suggested it is responsible to perform all the arithmetic and logical operations within the computer.
• The ALU always works with the content of registers.
• It works according to the control instructions generated by the control unit.

CU (Control Unit) :-

• It is used to control and manage the entire activities going on within the computer , by generating the control instructions.
• It is also known as 'brain within the brain'.

Registers :-

• These are inbuilt with the CPU , so it is also known as 'CPU Register'.
• These are the smallest and the fastest memory within the computer.
• The registers are digital sequential circuit, made by the combination of flip-flops, where one flip-flops can stores one bit of information.
• An n-bit register is made by n flip flops.
• In a CPU if its data register can store n-bits of data , then the word-length of that CPU is of n-bits , which means that the CPU can access n-bits of data at a time.
• A CPU has a number of registers, where the sizes and their numbers depend on the CPU organization.

NOTE :- Since, the CPU always works with the content of the RAM (Random Access Memory),so it is also known as the working area of computer and the RAM is also known as the part of CPU.