CPU Components & Their Function (OCR GCSE Computer Science)

CPU Components & Their Function

What are the components of the CPU?

• The CPU is made up of 4 key components

  • Arithmetic Logic Unit (ALU)

  • Control Unit (CU)

  • Cache

  • Registers

• Each of the components sits within the CPU

What is the function of each component?

Arithmetic logic unit (ALU)

•  Performs arithmetic operations

• Performs logical decisions
  

  • IF X > 5 THEN
          DO ……….

Control unit (CU)

• Coordinates how data moves around the CPU by sending signals to control the flow of the data 

• Decodes the instructions fetched from memory

Cache

• Very small, very fast memory located in the CPU which is used to provide quick access to frequently used instructions and data

• The more cache there is, the more data can be stored, which speeds up the performance of the CPU

• It prevents the CPU from having to repeatedly fetch frequently used instructions from RAM

Registers

• Extremely small, extremely fast memory located in the CPU

• Each register has its very own specific purpose

• More details about the individual registers can be found here