Computer Architecture and CPU

Introduction

• Computer Architecture: A plan of a computer system that determines how its components interact and process data.
• CPU (Central Processing Unit): The main component of the computer, often referred to as the brain of the computer.
• Main purpose of the machine: To process data.

Components of Computer Architecture

1. Input Unit

   • Input devices such as keyboard, mouse, scanner, joystick, light pen, etc.

2. Processing Unit

   • Main component: CPU
   • Main components of CPU:
     • Control Unit (CU): Controls input and output devices.
     • Arithmetic Logic Unit (ALU): Performs mathematical and logical operations.
     • Memory: For temporary data storage, also called cache memory.

3. Output Unit

   • Output devices such as monitor, printer, speaker, headphones, plotter, etc.

CPU (Central Processing Unit)

• Key components of CPU: Control Unit, Arithmetic Logic Unit, Memory Unit
• CPU tasks:
  • Transfer instructions and data from main memory to registers.
  • Execute instructions in sequence.
  • Transfer processed data back to main memory.
• Assembly Language: The CPU uses this language.
• Memory:
  • Primary memory: Such as Random Access Memory (RAM)
  • Secondary memory: Such as hard disks, SSDs

Motherboard

• Motherboard: The main circuit board of the computer, connects all important components.
• Main components: CMOS battery, BIOS chip, fan, expansion slots, SMPS, PCI slots, processor chip, buses

Buses

• Internal Bus: Connects main memory, CPU, and other internal components.
• External Bus: Connects peripheral devices, I/O ports, expansion slots.

Instruction Cycle

• Phases: Fetch, Decode, Execute, Store

Key Points

• Control Unit: Organizes data processing.
• Arithmetic Logic Unit: Performs mathematical and logical operations.
• Memory Unit: Stores data on both a temporary and permanent basis.

Review Questions

1. What is the main function of a computer?
2. Why is the CPU called the brain of the computer?
3. What are the main components of the motherboard?
4. What are the types of buses?
5. Describe the phases of the instruction cycle.