ALU Full Form:- In computer science, an arithmetic logic unit is a type of digital circuit that helps perform various operations on binary numbers. The arithmetic logic unit mainly performs two operations, arithmetic operation and bitwise operation. The circuits of Arithmetic Logic Units are used in the construction of various computer-based devices such as CPU, FPU and GPU. Input is how the operation will be performed, and the inputs to the ALU are called operands. Simultaneously the output is the final result obtained after applying all the operations. In an arithmetic logic unit circuit, both inputs and outputs reside between external status registers and the ALU.
Arithmetic Logic Unit Circuit
The Arithmetic Logic Unit circuit is based on combinational logic. This means that both input and output work asynchronously with each other. If the input changes, the output in the ALU also changes. The external mechanism of the ALU circuit consists of sequential logic. Sequential logic ensures that the output will arrive on time.
Signal in ALU
The ALU communicates using digital signals. It transmits or receives messages from external circuitry through electrical signals. When an Arithmetic Logic Unit circuit works, the ALU receives input from external circuitry after processing all operations. The ALU sends the output to external circuitry.
A typical ALU circuit consists of three buses arranged in parallel. These three buses are Input, Output and Result. A and B input the inputs to the ALU circuit, and after processing the operations, C will arrive. C is the output. The word size of all three buses remains the same.
An opcode is the operation selection code of an arithmetic logic unit circuit. An opcode contains a value that represents a specific logic or operation on the input values. The size of the opcode ID is not fixed; It depends on the number of operations that can be performed by the ALU. For example, a 2-bit opcode can have at most 4 operations.
ALU Full Form: Work Done by ALU
The arithmetic logic unit mainly performs arithmetic and bitwise operations. These are displayed here in detail.
Arithmetic Operations in ALU
- Add the sum of two binary numbers (a+b). Output comes as C
- Add with Carrying: Sum and carry (a+b+y) of two input numbers. Output comes as C
- Subtract: One number is subtracted from two input numbers. Output comes as C
- Increment: One is added to the value of the input. Output comes as C
- Deficit: Input price gets minus. Output comes as C
Bitwise Logical Operators in ALU
- AND: Bitwise AND takes two number inputs as A or B. It provides output by combining with no. Output comes as C
- Exclusive OR: Bitwise OR takes two numbers as input. Output comes as C
- People’s Complement: In this operation all the input values are inverted, and the output comes in the form of C
Bit Shift Operator in ALU
ALU shift operations change the state of A or B. Move the weather left or right. Here are some of the different types of shift operands used in the ALU catalogue:
- Arithmetic Shift: Arithmetic shift operation works as two’s complement integer
- So, Logical Shift: Under this operation zero moves towards the input number
- rotate: rotate operation works as a circular buffer on the input value
- Rotate via carry: The carry bit and the input number perform the circular buffer under this operation
ALU Full Form: Applications of ALU
The arithmetic logic unit helps in performing various logical applications in the CPU and other computer devices. These:
Multi-Precision Arithmetic in The ALU
Multiple-precision arithmetic is a type of algorithm that plays a major role in performing various arithmetic operations. Multiple precision arithmetic algorithms operate on large inputs that have a larger word size than the ALU can handle. To facilitate this algorithm, the operands are organized by size. Operands can be arranged from most significant input (MS) to least significant input (LS) and vice versa.
Multiple-precision arithmetic operations work directly with pieces of the operands, producing identical pieces as a result.
Complex Operations in ALU
ALU is designed to work on various complex tasks of computer science. But, sometimes, some unwanted things like high complexity, large size and high power consumption hinder the complex operation. Due to this the area of ALU is limited to simple tasks. So, To overcome this problem, external processor circuitry is used. These processors perform various complex operations by arranging the values of the operands.
ALU Full Form: Applications of Arithmetic and Logic Unit
The arithmetic and logic unit (ALU) is an essential component of a computer processor and is used in a wide range of applications. Some of the major applications of ALU include:
- So, Personal computer: ALUs are in personal computers to perform calculations and comparisons to perform a wide range of software applications, including word processing, spreadsheet, and graphics software.
- Servers: ALUs are in servers to perform the necessary calculations and comparisons to process requests from clients and provide appropriate responses.
- Mobile devices: The ALU is in mobile devices such as smartphones and tablets to perform the calculations and comparisons needed to run applications and access the Internet.
- Embedded Systems: ALUs are systems, which are computer systems to perform a specific task within a larger device or system. Examples include aircraft control systems, medical equipment, and automotive systems.
Arithmetic and Logic Unit Types
There are several different types of arithmetic and logic units (ALU) that can be in a computer processor:
- Also, Integer ALU: An integer ALU is to perform arithmetic and logical operations on integers, which are whole numbers with no decimal component. This type of ALU typically performs basic arithmetic operations such as addition, subtraction, multiplication, and division.
- Floating-point ALU: Floating-point ALU is to perform arithmetic and logical operations on floating-point numbers, which are numbers with a decimal component. This type of ALU typically performs more complex calculations, such as those involving scientific or financial data.
- Bit-slice ALU: A bit-slice ALU is a series of smaller ALUs that are responsible for performing operations on a specific set of bits. This allows the ALU to perform a large number of operations by breaking them down into smaller pieces.
- Hybrid ALU: A hybrid ALU is a combination of different types of ALU, and is to perform a wide range of arithmetic and logical operations. This type of ALU is typically in more powerful and sophisticated computer processors.
FAQs on ALU Full Form
What do you understand by CPU and ALU?
CPU stands for Central Processing Unit while ALU stands for Arithmetic and Logical Unit.
What is the function of ALU?
The ALU performs simple addition, subtraction, multiplication, division, and logical operations, such as OR and AND. Memory stores program instructions and data.
What is the interpretation of ALU?
So, An arithmetic logic unit (ALU) is a digital circuit to perform arithmetic and logic operations. It represents the fundamental building block of a computer’s Central Processing Unit (CPU). Modern CPUs have very powerful and complex ALUs. In addition to the ALU, modern CPUs have a control unit (CU).
How many types of ALU are there?
An ALU consists of three types of functional parts: storage registers, operational logic, and sequencing logic, as shown in the figure.
ALU is hardware or software?
Also, The Arithmetic Logic Unit (ALU) is one of the fundamental blocks of the Central Processing Unit (CPU) of a computer. The CPU is responsible for managing all of a computer’s software and hardware resources, and the ALU helps facilitate this process.
How many ALUs does a CPU have?
The processor consists of three sections namely Arithmetic Logic Unit (ALU), Control Unit and Registers. Control Unit: The control unit makes decisions and sends appropriate signals down its lines to other parts of the computer.
What are the 2 components of ALU?
So, In some processors, the ALU is into two units: an arithmetic unit (AU) and a logic unit (LU). Some processors have more than one AU – for example, one for fixed-point operations and another for floating-point operations.
What are the three components of ALU?
Also, a typical ALU consists of three types of functional parts: storage registers, operational logic, and sequencing logic.