The main function microprocessor [ CPU ] is to execute the computer program. The computer program contains set of machine instructions. The CPU executes the program.
In order to execute the program, the CPU has to perform number of arithmetic and logical operations as per the program instructions. These operations are performed by the ALU.
The ALU is an essential part of each central processing unit [ CPU ]. The CPU is also alternately referred to as processor or a microprocessor.
The ALU is also a crucial component of the Graphics Processing Unit [ GPU ] . A GPU is a dedicated processor used for handling the graphics processing which improves the system performance.
Depending upon the microprocessor architecture, the CPU and GPU can contain one or more Arithmetic and logic units. The ALU for the GPU is optimized for rapid graphics processing.
The ALU is a fundamental building block of all microprocessor. From simple to highly advanced microprocessor, all the processor chips, the ALU is a essential component.
In this article, you will learn what is arithmetic logic unit, how ALU works, functions of the ALU, logic gates and other important topics related to the central processing unit [ CPU ] and ALU.
Arithmetic Logic Unit [ ALU ] In Computer Architecture
Arithmetic Logic Unit In Computer Architecture
Table Of Contents
- What Is Arithmetic Logic Unit ?
- The ALU And CPU Architecture.
- What Are ALU Operations ?
- ALU And Boolean Algebra.
- What Are Logic Gates ?
- Functions Of The ALU .
- Arithmetic And Logic Operations.
- How Arithmetic Logic Unit Works.
- Arithmetic Logic Unit - FAQ
- COA Other Topics.
ALU And CPU Architecture
The ALU is a crucial component of all the microprocessor chips. And therefore, The ALU operations can be best understood in the context of how CPU works.
The CPU stands for the central processing unit and it functions as a brain of the computer system. The CPU is an integrated circuit chip and crucial component of the computer system.
It is CPU is responsible to process the data as per the program instructions. The CPU provides the processing power to the computer by performing complex calculations.
The processor internally consists of three functional units. These functional units are control unit [ CU ], arithmetic and logic unit [ ALU ] and the memory unit [ MU ].
The control unit [ CU ] decodes the operation code [ Opcode ] part of the machine instruction. The CU then directs the arithmetic logic unit [ ALU ] to perform a specific operation as per the operation code.
The ALU operates on the data [ Operand ] part of the machine instruction and processed data is stored into the memory unit [ MU ].
During the program execution, the CPU stores the program instructions and data into the internal high speed memory unit of the CPU. The memory unit consists of CPU registers.
What Are Arithmetic And Logic Operations ?
The ALU is a part of the processor and the number of operations supported by the processor [ operations performed by the ALU ] depends upon the instruction set architecture of the processor.
The modern processor contains highly advanced ALU circuit that is capable of performing complex arithmetic and logic operations.
The ALU is said to be a combinational circuit because the ALU circuit internally consists of combination of both arithmetic Unit and the logic unit.
Arithmetic Operations
The ALU performs both arithmetic and logic operations. The arithmetic operations of the ALU include all the basic mathematical operations.
For example, the ALU arithmetic operations includes addition, subtraction, division multiplication and raise to the power.
Logic Operations
All the decision making operations based on the conditional logic are said to be the logical operations.
The ALU logical operations include the grater than [ ≥ ] less than [ ≤ ] , comparison, equal to shifting operations, Boolean operations comparisons [ XOR, OR, AND, and NOT operations ].
The ALU supports only binary operations. The arithmetic and logic unit internally consists of AU [ arithmetic unit ] and the LU [ logic unit ].
ALU Arithmetic Operations
ALU Logic Operations
+ Addition
= Equal To , ≠ Not Equal To
- Subtracition
> Greater Than
÷ Division