# 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](/notes/computer-concepts/isa/registers.md): * 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](/notes/computer-concepts/isa/x86.md) * [ARM](/notes/computer-concepts/isa/arm.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://digitalgarden.batamladen.com/notes/computer-concepts/isa.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.