Systems ArchitectureKey Facts

The Three Buses - Data Highways

Part of CPU ArchitectureGCSE Computer Science

This key facts covers The Three Buses - Data Highways within CPU Architecture for GCSE Computer Science. Revise CPU Architecture in Systems Architecture for GCSE Computer Science with 15 exam-style questions and 12 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 5 of 7 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 5 of 7

Practice

15 questions

Recall

12 flashcards

The Three Buses - Data Highways

Buses are the communication pathways connecting CPU components to memory and peripherals:

  • Address Bus (one-way) - Carries the memory ADDRESS (WHERE to look). Like a postcode telling the postman which house. Goes FROM CPU TO memory only.
  • Data Bus (two-way) - Carries the actual DATA (WHAT is being transferred). Like the actual letter being delivered. Goes both ways between CPU and memory.
  • Control Bus (two-way) - Carries COMMAND signals (read, write, clock). Like instructions telling the postman what to do. Coordinates everything.
Memory Trick: ABC

Address = WHERE (like an address on an envelope)

Data = WHAT (the actual content)

Control = HOW (read? write? when?)

Keep building this topic

Read this section alongside the surrounding pages in CPU Architecture. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for CPU Architecture

Which component of the CPU carries out arithmetic and logical operations?

  • A. Control Unit
  • B. Cache
  • C. Arithmetic Logic Unit (ALU)
  • D. Program Counter
1 markfoundation

Name three main components of the CPU and state the purpose of each.

3 marksstandard

Quick Recall Flashcards

What does CPU stand for?
Central Processing Unit
What does ALU stand for?
Arithmetic Logic Unit

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