Computer Buses and its types

Computer Buses

What is computer bus?

                                     A computer bus is the set of electronic path which computer sends and receive data to and from different components(parts)  of computer is called computer bus.

Computer Buses

Types of computer bus:

There are two types of computer bus. These buses are as follow:

(i)                  Expansion buses

(ii)                System buses

Now, the explanation of these buses are as follow.

Expansion buses:

                                                These buses are also known as External Buses. These  types of buses connect to the external or peripheral devices. The peripheral devices are keyboard, mouse, modem and printer etc.

System buses:

                                                These buses are also known as internal bus. The system buses are the part of motherboard or system board. These buses such as system buses are connect to the main component of computer such as CPU and main memory.

The system buses are divided into three further categories. These are as follow:

(i)                  Data Bus

(ii)                Address Bus

(iii)               Control Bus

What is Data Bus?

                                A data bus is the type of system bus thar is use to transfer data and instruction from one component if the computer to another is called Data Bus. The data bus is connect to the CPU, memory unit etc. Data bus concist of different parallel lines such as 8,16,32,64. Each line of the data bus can carry only one bit at a time. So, the data bus of 64 parallel line can carry 64 bit data at one a time.

                Data bus is the bi-directional. The word bi-directional means that these types of lines can send and receive data through this path. 

What is Address Bus?

                                                A type of System bus which is used to carry address information of the different components or part of computer is called Address bus. Every component of the computer system is assigned a unique number or  ID. This number or ID is called the address of that component or part that is assigned to it. When the any component of the computer system want to the communicate of another component of the computer, it uses address bus to specify the address of the destination or required component. 

To explain the working of address bus I want to describe an example. For example CPU want to read some data or instruction from the specific location of the memory.  Then it places the address of that memory location on the address bus. The address is carried to the memory location. The data from the requested memory  is fetched and placed on the address bus.

What is Control bus?

                                                A control bus is the type of system bus which CPU send control signals to different unit if the computer system is called control bus.

How the data is communicated between CPU and memory?

The data is communicated between CPU and main memory by using different buses such as address bus and control bus. To explain this point, I define a complete work. Suppose CPU want to read data from main memory or write data to main memory. it perform some following operations:

1.       First of all CPU places the address of the memory location on the address bus from where the CPU want to read data.

2.       In next step the address is carried to the memory.

3.       In this last step the data from the requested memory location is fetched and placed on the data bus.

And finally CPU read the data from the data bus.

Note: when the data is input to the computer , first it store to the main memory and then send to the CPU for processing. After processing it send to the output devices.