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

Revision Note

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Expertise

Computer Science

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

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

to absolutely everything:

the (exam) results speak for themselves:

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