What are the Buses in Microcontroller?

A bus carries information in the form of signals. There are three main buses: address, data, and control.

1) The address bus is unidirectional and carries the addresses of memory locations indicating where the data is stored. The number of wires in the address bus determines the total number of memory locations. With a 13 bit address bus, for example, there would be 213 or 8192 memory locations.

2) The data bus is bi-directional and carries information between the CPU and memory or I/O devices. Computers are often classified according to the size of their data bus. The term “8-bit microcontroller” refers to a microcontroller with 8 lines on its data bus. The number of wires in the data bus determines the number of bits that can be stored in each memory location.

3) The control bus carries data which controls system activity. Often this data includes timing signals which synchronize the movement of other information.