Computer Architecture

2026 Syllabus Objectives

By the end of this topic, you should be able to:

  1. Understand the role of the CPU and what a microprocessor is

    • Explain how the CPU processes instructions and data
    • Define what a microprocessor is (an integrated circuit on a single chip)

  2. Understand Von Neumann architecture and the Fetch-Decode-Execute cycle

    • Explain the purpose of CPU components (ALU, CU, and registers)
    • Describe how the FDE cycle works, including the role of each component
    • Understand how buses transmit data, addresses, and signals

  3. Explain how CPU characteristics affect performance

    • Understand what cores, cache, and clock speed are
    • Explain how each characteristic affects CPU performance

  4. Understand CPU instruction sets

    • Explain what an instruction set is
    • Understand that instruction sets use machine code

  5. Describe embedded systems

    • Explain the purpose and characteristics of embedded systems
    • Identify devices that use embedded systems

1. The CPU and Microprocessors

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What is the CPU?

The CPU (Central Processing Unit) is the "brain" of the computer. Its job is to fetch, decode, and execute instructions.

Think of it like this:

  • You type something on your keyboard (input)
  • The CPU processes what you typed by following instructions
  • The result appears on your screen (output)

The CPU is central to all computing devices, including:

  • Laptops and desktop computers
  • Mobile phones and tablets
  • Games consoles
  • Smart devices

How the CPU Works: Input → Process → Output

StepExample
InputYou press a key on your keyboard to type the number "5"
ProcessThe CPU executes an instruction like "ADD" - it adds 5 to another number already stored
OutputThe result of the calculation (e.g., "15") appears on your monitor

Key Point: The CPU doesn't just "process data" - it specifically fetches instructions from memory, decodes them to understand what to do, and then executes them to get a result.

What is a Microprocessor?

A microprocessor is a hardware chip that contains the CPU.

More specifically:

  • It's a type of integrated circuit (a complex electronic component)
  • It's contained on a single chip (a small piece of silicon)
  • It houses the CPU and sometimes other components like memory controllers and input/output interfaces

Simple way to remember: The CPU is a component that processes instructions. The microprocessor is the physical chip that the CPU sits on.

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