What is a Data bus? IGCSE O levels Computer Science

 Hi folks! Today we'll be going through a basic understanding of buses.

Buses are a very important part of computer architecture and they are found in the internal electronics of a computer system between Memory, CPU and peripheral devices. They are basically channels/wires through which the movement of data or execution of any instruction occurs.

Mainly buses can be divide into 3 categories:

Data bus:

It is a bi-directional bus(two way) that carries data between processor and memory(vice versa). If data travels from processor to memory then it is a "WRITE" operation. If data travels from memory to processor then it is a "READ" operation.

Next comes the Address bus:

The address bus is a uni-directional bus(ONE WAY) unlike a data bus. It is used to carry the address of a memory cell(specific location inside the memory) from "Processor to memory".

If I elaborate the concept of address bus then it carries the address of a particular location inside the memory(RAM) from which the data has to get "READ" or "WRITE". 

Finally, we have the most important Control Bus:

Now it is the most important bus among all of them due to its crucial functionality.

A control bus carries instructions regarding that whether  to perform a "READ" operation or a

"WRITE" operation.

If I elaborate on the concept of a control bus then it is a bus that carries commands which "Tells" that which operation has to be executed. Therefore, the control bus ensures the synchronisation between memory and processor, which is very important as far as the speed of execution is concerned for any computer system.

Note: In modern architecture, control buses are designed to carry data from peripherals as well. Data bus cannot perform this operation as it is the part of the processor and it cannot work until the processor grants permission to do so. Therefore control buses have a complex arrangement. They are uni and bi-directional.

Pictorial representation of Buses:

I hope it helped.

                                                                  Best of Luck!