Computer Organization and CPU Basics

Study Notes

Basic Concepts

Computer organization examines the physical components and their interactions within a computer system.
Computer architecture focuses on the functional operation of the computer system.
Crucial components include the CPU, memory (RAM, ROM), input/output devices, and buses.
Understanding computer organization aids in comprehending software-hardware interaction.
It provides a fundamental understanding of computer operation.

The Central Processing Unit (CPU)

The CPU acts as the computer's "brain."
It performs arithmetic and logical operations, fetches instructions, and executes them.
A CPU comprises an Arithmetic Logic Unit (ALU), a Control Unit, and registers.
The ALU executes calculations.
The Control Unit manages data and instruction flow within the CPU.
Registers are fast, small memory locations for temporary data storage.

Memory

Memory stores data and instructions needed by the CPU.
Two primary types are RAM (Random Access Memory) and ROM (Read-Only Memory).
RAM is volatile, losing data when power is off.
ROM is non-volatile, retaining data without power.
RAM stores currently active programs and data.
ROM typically stores permanent instructions, like boot-up code.
Cache memory is a speedy, small memory for faster access to frequently used data.

Input/Output (I/O)

Input devices allow data entry (e.g., keyboard, mouse, microphone).
Output devices display or transmit data (e.g., monitor, printer, speakers).
Specialized controllers facilitate CPU communication with I/O devices.
Modern systems often include peripherals like scanners, cameras, and network interfaces.

Buses

Buses are electrical pathways connecting computer components.
They transmit data, addresses, and control signals between components.
Types include the data bus, address bus, and control bus.
The data bus carries data.
The address bus specifies memory locations.
The control bus transmits control signals (e.g., read/write).
Bus width determines the amount of data transferred simultaneously.

Instruction Cycle

The CPU executes instructions in a continuous cycle; fetch, decode, execute, and store.
This cycle continuously operates while the computer is on.
Instructions are usually machine code, binary instructions for the CPU.

Number Systems

Computers primarily use the binary (base-2) number system for data.
Binary representation is crucial in computer systems.
Decimal (base-10), hexadecimal (base-16), and other systems are used for a more compact or human-readable representation.

Basic Computer Organization Models

Models describe how components connect.
The von Neumann architecture is a core model.
Data and instructions share the same memory space.
Modern computers evolve based on similar principles using the von Neumann model.
Other models exist like Harvard architecture, that separates instruction and data memory physically.
Understanding these models provides an overview of the structure of computers.

Computer Performance

Computer performance evaluates various factors such as CPU clock speed (GHz), memory access time, I/O speeds, and the number of CPU cores.
Bus architecture efficiency also impacts performance.

Description

This quiz covers the fundamental concepts of computer organization, focusing primarily on the structure and function of the Central Processing Unit (CPU). It explores key components such as memory, input/output devices, and the roles of the ALU and Control Unit. Understanding these concepts is essential for grasping how software interfaces with hardware.