About Lesson
The Instruction Set Architecture (ISA) defines the set of instructions that a computer’s processor can understand. These instructions are fundamental to the machine’s operation and dictate how software communicates with hardware. The ISA forms the interface between software and hardware, and determines the computer’s functionality.
Key Elements of ISA:
- Instruction Format: The binary code that defines how an instruction is structured, including the operation code (opcode) and operands.
- Addressing Modes: Specifies how operands are addressed, such as direct, indirect, or register addressing.
- Data Types: Defines the types of data the processor can handle, like integers, floating-point numbers, or characters.
- Registers: Defines the general-purpose and special-purpose registers used for storing intermediate data and control information during instruction execution.
Types of Instruction Sets:
- RISC (Reduced Instruction Set Computing): Uses a small, simple set of instructions that can be executed in a single clock cycle. Examples include ARM and MIPS.
- CISC (Complex Instruction Set Computing): Uses a larger set of complex instructions that can perform multi-step operations in a single instruction. Examples include x86.