Learn: Functions of the CPU

Welcome!I've reviewed your growth areas and created this lesson to help strengthen your understanding of the functions of the CPU. Let's dive into how the CPU operates and why it's critical to computer systems.

What is the CPU?The Central Processing Unit (CPU) is the brain of the computer. It processes instructions, performs calculations, and controls the flow of data within the system. Without it, no computer could function!

The Fetch-Decode-Execute CycleThe CPU uses the fetch-decode-execute cycle to process instructions. It fetches an instruction from memory, decodes what needs to be done, and executes the instruction. This cycle happens repeatedly and very quickly, allowing computers to perform millions of operations per second.

The ALU (Arithmetic Logic Unit)The Arithmetic Logic Unit (ALU) performs mathematical calculations and logical operations. Examples include addition, subtraction, and logical comparisons like AND and OR. It's essential for processing data and making decisions.

The Control Unit (CU)The Control Unit (CU) directs the CPU's operations. It manages the flow of data between the CPU, memory, and input/output devices. Think of it as the organiser ensuring everything runs smoothly.

RegistersRegisters are small, fast storage areas within the CPU. They temporarily hold data, instructions, or addresses during processing. Key registers include the Program Counter (PC), Memory Address Register (MAR), and Memory Data Register (MDR).

Clock SpeedClock speed measures how quickly the CPU can process instructions. It's measured in Hertz (Hz), with 1 GHz equalling 1 billion cycles per second. Higher clock speeds generally mean faster processing but can generate more heat.

CacheThe CPU uses cache to store frequently accessed data. Cache memory is faster than RAM and reduces the time needed to fetch data. Larger caches improve performance but increase cost.

Review Time!Great work! You've learned about the CPU's components and functions. Now let's test your understanding with a few questions.