Assembly Language Overview

Study Notes

Assembly Language

Assembly language is a low-level programming language that is designed for a specific family of processors. It allows developers to represent machine language instructions in a more human-readable form, making it easier to understand and debug. In this article, we will discuss the key aspects of assembly language, including instructions, memory management, interrupts, registers, and syntax.

Instructions

Assembly language instructions are represented by a mnemonic code that represents a specific operation. For example, the add instruction represents the addition operation. Each instruction has a corresponding machine language instruction that the processor can understand.

Memory Management

Assembly language programs use a segmented memory model, where memory is divided into segments. Each segment has its own address space and can hold data or code. This allows for efficient use of memory and can increase the addressable memory size.

Interrupts

Interrupts are signals sent to the processor that cause it to temporarily stop executing the current instruction and execute a different instruction. In assembly language, interrupts can be handled by interrupt service routines (ISRs) that are stored in specific memory locations. The CPU jumps to the address pointed by the interrupt vector register when an interrupt occurs.

Registers

Registers are processor components that hold data and addresses. Assembly language programs use registers to store and manipulate values. Each processor has its own set of registers, and the layout and usage of these registers can vary between processors.

Syntax

Assembly language statements are entered one statement per line. Each statement follows the format:

[label] mnemonic [operands] [;comment]

The fields in the square brackets are optional. A basic instruction has two parts, the first one is the name of the instruction (or the mnemonic), which is to be executed, and the second are the operands or the parameters of the command.

Description

Explore the key aspects of assembly language, including instructions, memory management, interrupts, registers, and syntax. Learn how assembly language represents machine language instructions in a more human-readable form.