BUS
In early computers BUS were parallel electrical wires with multiple hardware connections. Therefore a bus is a communication system that transfers data between components inside a computer, or between computers. It includes hardware components like wires, optical fibers, etc and software, including communication protocols. The Registers, ALU, and the interconnecting BUS are collectively referred to as data paths.
Types of the bus
There are mainly three type of bus:-
- Address bus: Transfers memory addresses from the processor to components like storage and input/output devices. It’s one-way communication.
- Data bus: carries the data between the processor and other components. The data bus is bidirectional.
- Control bus: carries control signals from the processor to other components. The control bus also carries the clock’s pulses. The control bus is unidirectional.
The bus can be dedicated, i.e., it can be used for a single purpose or it can be multiplexed, i.e., it can be used for multiple purposes. when we would have different kinds of buses, different types of bus organizations will take place.
Introduction of ALU and Data Path
Representing and storing numbers were the basic operations of the computers of earlier times. The real go came when computation, manipulating numbers like adding and multiplying came into the picture. These operations are handled by the computer’s arithmetic logic unit (ALU). The ALU is the mathematical brain of a computer. The first ALU (Arithmetic Logic Unit) was indeed the INTEL 74181, which was implemented as part of the 7400 series TTL (Transistor-Transistor Logic) integrated circuits. It was released by Intel in 1970.