The CPU & Microprocessors (Cambridge (CIE) O Level Computer Science)

Revision Note

James Woodhouse

Written by: James Woodhouse

Reviewed by: Lucy Kirkham

The CPU & Microprocessors

What is the purpose of the CPU?

  • The purpose of the Central Processing Unit (CPU) is to fetch, decode and execute instructions

  • The CPU is the brain of the computer and its job is to take an input, process data and produce an output

  • It is central to all devices including:

    • Laptops

    • Desktops

    • Games-Consoles

    • Mobile Devices

  • The words CPU and Microprocessor are interchangeable and can be used to mean the same thing

  • A microprocessor is a type of integrated circuit on a single chip

  • Data and commands are inputted by the user using an input device, the central processing unit (CPU) processes data by executing instructions and the results are outputted to an output device

  • Below is an example of data being inputted, processed and the results being outputted

Step

Example

Input

A keyboard is used to input a number

Process

If the instruction being executed is ADD, the inputted value is added to an existing value

Output

The result of the calculation is outputted to the user via the monitor

microprocessor

A diagram showing the input, process, output sequence followed by computer systems

Last updated:

You've read 0 of your 5 free revision notes this week

Sign up now. It’s free!

Join the 100,000+ Students that ❤️ Save My Exams

the (exam) results speak for themselves:

Did this page help you?

James Woodhouse

Author: James Woodhouse

Expertise: Computer Science

James graduated from the University of Sunderland with a degree in ICT and Computing education. He has over 14 years of experience both teaching and leading in Computer Science, specialising in teaching GCSE and A-level. James has held various leadership roles, including Head of Computer Science and coordinator positions for Key Stage 3 and Key Stage 4. James has a keen interest in networking security and technologies aimed at preventing security breaches.

Lucy Kirkham

Author: Lucy Kirkham

Expertise: Head of STEM

Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels.Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the East Midlands, where her role was to support and coach teachers to improve Maths teaching for all.