Instruction Set

Introduction

An instruction set is a collection of basic instructions that a computer's processor can execute. It defines the set of operations that a processor can perform.

Types of Instructions

• Arithmetic Instructions: Perform arithmetic operations such as addition, subtraction, multiplication, and division.
• Logical Instructions: Perform logical operations such as AND, OR, and NOT.
• Control Flow Instructions: Control the flow of program execution, such as jump, branch, and loop instructions.
• Data Transfer Instructions: Move data between registers, memory, or input/output devices.

Characteristics of Instruction Set

• Instruction Format: Defines the structure and layout of instructions.
• Addressing Modes: Defines how addresses are calculated and used.
• Instruction Complexity: Defines the complexity of instructions, such as simple or complex instructions.

Instruction Set Architectures (ISAs)

• RISC (Reduced Instruction Set Computing): Uses simple instructions that can be combined to perform complex tasks.
• CISC (Complex Instruction Set Computing): Uses complex instructions that can perform multiple tasks in a single clock cycle.

Importance of Instruction Set

• Processor Design: Defines the design and implementation of processors.
• Program Execution: Determines how programs are executed and how efficient they are.
• Code Generation: Affects the generation of machine code by compilers.