BUS SYSTEM: DATA BUS, ADDRESS BUS and CONTROL BUS

 A bus is a collection of wires, chips and slots inside the computer through which data are transmitted from one part of the computer to ano...

 A bus is a collection of wires, chips and slots inside the computer through which data are transmitted from one part of the computer to another to and fro from peripheral devices. It is often compared to a highway. It carries information from one component to another. It carries data, address, or control signal. One component of the component can interact with others by bus.

Bus consists three main parts:

• Control bus
• Address bus
• Data bus

Control Bus

A control bus is a computer bus that is used by the CPU to communicate with the devices that are connected to the computer system. It uses control signal which is originated from control unit. Control bus is used to transfer control signals from one component to another component. The control bus transmits the control signals such as device interrupt signal, byte enable signal, memory read or write signals and status signals.

Address Bus

Address bus is used by the CPU to send the address of the memory location or the input/output port that is to be accessed at the instant. It is a unidirectional bus i.e. the address can be transferred in one direction only and that is from CPU to the required location. 

If the address bus could carry 8 bit at a time, the CPU could address only 256 bytes i.e. 2^8 bytes of RAM.

Data Bus

Data bus is used to carry the data and instructions in both direction i.e. from the CPU to memory and peripheral devices and vice versa. Thus, it is a bidirectional bus. It is one of most important parts of the connections to the CPU because every program instruction and every byte of data must travel across the bus at some point.

It may be a 16-bit or 32-bit data bus. A 16-bit bus can transfer 2 bytes, 32-bit can transfer 4 bytes etc.

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