What does ALU mean in HARDWARE

An Arithmetic Logic Unit (ALU) is a digital electronic circuit that performs arithmetic and logic operations such as add, subtract, AND, OR, NOT, shift and compare. It is the heart of the central processing unit (CPU) in a computer system.

An ALU takes two numbers from registers or memory locations as inputs and generates one output dependent on an operation code. The main functioning of the ALU involves performing basic operations on binary numbers like addition, subtraction, multiplication and division. It is also used to perform logical operations such as OR operation, AND operation and NOT operation.

An ALU consists of four main components - a data input buffer register, a set of arithmetic/logic circuits, a carry-lookahead generator and an output buffer register. The data input buffer holds the two operands that are going to be operated on by the ALU; these operands can come from either memory or internal registers inside the CPU. The arithmetic/logic circuits then performs any combination or manipulations that are required before producing a result, which is stored into the output buffer register prior to being sent away from the CPU core itself.

ALUs are essential components in computers for performing calculations and executing instructions; they are widely used in many devices such as smartphones and tablets for making calculations quickly without using floating point data types or large amounts of programming codes. They are generally used in embedded systems which require persistent calculation speed and accuracy regardless of changes in power supply or temperature fluctuations.

An ALU can execute different types of instructions depending upon its architecture but commonly these include mathematical computations such as Addition/Subtraction/Multiplication/Division, Logical comparisons between two values (equal to, greater than, less than etc), Boolean operations including AND, OR, NOT bitwise operations like shifting bits left or right etc.

An Arithmetic Logic Unit typically operates on two pieces of data at a time referred to as 'operands' which could be 8-bit or 16-bit binary numbers depending upon its design and architecture. Besides raw binary numbers it can also handle other forms such as integers, fractions, floating points etc by combining multiple steps together. For instance multiplying two fractions would involve first converting them into decimals followed by doing normal multiplication operating steps.

Generally speaking most AIUs do not have this capability built in unless specifically designed otherwise ; however Branching instructions support can be added externally if needed. This usually requires additional integrated circuits called Control Units connected alongside with the AIUs itself.