BUS

• It is a collection of wires through which data is transmitted.
• The speed of a bus is measured in megahertz(MHz).
• The size of a bus(its width) is how many bits it can transfer at a time.

EG:A 64 bit computer has buses with 64 bit width.

• Can be unidirectional or bidirectional.
• There are three types of buses:-

1. Data Bus

• The most common is the data bus.A data bus carries data.
• It is an electrical path that connects the CPU,Memory,Input/output devices, and secondary storage devices.
• The bus contains parallel group of lines.
• The number of lines in bus affects the speed at which the data travels between different components.

2.Address Bus

• An address bus carries address information.It is a set of wires similar to the data bus but it only connects CPU and memory.

• Whenever the processor needs data from the memory,it places the address of data on the address bus.

• The address is carried to the memory where the data from the requested address is fetched and placed on the data bus.The data bus carried to the CPU.

3.Control Bus

• The control bus carries control information from the control unit to other units.
• The control information is used for directing the activities of all units.
• The control unit control the functioning of other units

Eg:I/O devices,Secondary storage etc.