ISA

What is an ISA?

An ISA (Instruction Set Architecture) is a set of instructions that a CPU can execute, defining how software interacts with the hardware, determing what a CPU can do and how it does it.

Key Components of an ISA:

1. Instruction Set:

   • A collection of all the machine language instructions that a processor can execute. These include arithmetic operations (like add, subtract), data transfer instructions (like load, store), and control flow instructions (like jump, branch).

2. Data Types:

   • The types of data the CPU can handle, such as integers, floating-point numbers, and characters.

3. Registers:

   • Small, fast storage locations within the CPU that hold data temporarily during processing. The ISA defines the number and types of registers available.

4. Addressing Modes:

   • The methods by which instructions access data in memory. Common modes include direct, indirect, and indexed addressing.

5. Memory Architecture:

   • Defines how memory is organized, accessed, and managed by the CPU. This includes concepts like memory segmentation, paging, and virtual memory.

Examples of ISA

• x86

• ARM