System Bus

Inside the micro computer work of bus is to connect microprocessor and thereby connected peripherals . In other words we can say that buses provide a communication path between microprocessor and peripheral . Namely buses are the group of wires. Which are carrying bits.
Inside microprocessor system three types of buses are present .

• Address Bus 
• Data Bus
• Control Bus

1. Address Bus - Address bus is unidirectional because the microprocessor is addressing a specific memory location. Namely in this bus 16 bit address carried in one direction only. Microprocessor used 16 bit to send memory address.                                  
2. Data Bus - Data bus is bi-directional bus. Data bus can transmit data in both direction. Namely in this data is transmitted from one part of a computer to another. The size of a bus, known as its width, is important because it determines how much data can be transmitted at one time. For example, a 16- bit bus can transmit 16 bits of data, whereas a 32- bit bus can  transmit 32 bit of data.                                                                      
3. Control Bus - Microprocessor use control bus for timing signal. Control bus is also unidirectional. A control bus is used by the CPU to communicate with devices that are contained within the computer. This occurs through physical connections such as cables or printed circuits.