Computer Buses

Computer Buses

In Computer a bus or bus is a communication system that transfers data between components inside a computer, or between computers. This expression covers all related hardware components (wire, optical fiber, etc.) and software, including communication protocols.  You can think of a bus as a highway on which data travels within a computer. When used in reference to a personal computer, the term bus usually refers to the internal bus. This is a bus that connects all the internal computer components to the CPU and main memory. There's also an expansion bus that enables expansion board  to access the CPU and memory. 

In early computer systems, all the data traveled across actual cables, which got pretty messy. Large bundles of wires were organized using bus bars, which is where the term 'bus' comes from. Nowadays, most of these wires are typically gold-plated traces (or tiny flat wires) on the computer's motherboard , a large flat surface that all the electronic stuff gets mounted to. The most critical connection of any computer system is the system bus.Cables are still used in present-day computer systems, in particular, to connect external devices. The most common type of connection is a Universal Serial Bus (or USB), which you can probably recognize. Many peripheral devices, such as printers and scanners, use a USB connection.

There are three types of Buses.

1.The data bus:- Data bus is the most common type of bus. It is used to transfer data between different components of computer. The number of lines in data bus affects the speed of data transfer between different components. The data bus consists of 8, 16, 32, or 64 lines. A 64-line data bus can transfer 64 bits of data at one time.

2.The address buss:- Many components are connected to one another through buses. Each component is assigned a unique ID. This ID is called the address of that component. It a component wants to communicate with another component, it uses address bus to specify the address of that component. The address bus is a unidirectional bus. It can carry information only in one direction. It carries address of memory location from microprocessor to the main memory.

3.The Control bus:-Control bus is used to transmit different commands or control signals from one component to another component. Suppose CPU wants to read data from main memory. It will use control is also used to transmit control signals like AcKS (Acknowledgement signals).