Learn: Characteristics of the CPU

Welcome!Today we'll explore the characteristics of the CPU (Central Processing Unit). This is a key part of your GCSE Computer Science studies. Let's break it down step by step!

What is the CPU?The CPU (Central Processing Unit) is the brain of the computer. It processes instructions and performs calculations to carry out tasks. Without the CPU, a computer cannot function.

Key Components of the CPUThe CPU is made up of several key components:ALU (Arithmetic Logic Unit) — Performs calculations (maths) and logical operations.CU (Control Unit) — Directs the CPU by managing instructions and coordinating actions.Cache — Small, very fast memory close to the CPU. It stores frequently used data for quick access.Registers — Super-fast storage locations within the CPU for temporary data.

RegistersRegisters are small, fast storage locations in the CPU. They store temporary values needed for processing. Examples include:Program Counter (PC) — Keeps track of the address of the next instruction.Memory Address Register (MAR) — Stores the address of data in memory.Memory Data Register (MDR) — Holds the data being read or written.Accumulator — Stores intermediate results of calculations.

The Fetch–Execute CycleThe CPU operates in steps called the fetch–execute cycle. These are:Fetch — The CPU retrieves the next instruction from memory.Decode — The instruction is decoded to understand what needs to be done.Execute — The CPU carries out the instruction (e.g., calculations, moving data).This cycle runs repeatedly, allowing the computer to operate smoothly.

Factors Affecting CPU PerformanceThe speed and efficiency of a CPU depend on several factors:Clock Speed — Determines how many instructions can be processed per second. Measured in GHz.Cache Size — Larger cache allows quicker access to frequently used data.Number of Cores — More cores allow the CPU to process multiple tasks simultaneously.

Embedded SystemsEmbedded systems are computers within other devices, such as washing machines or car engines. They are designed for specific tasks and are usually simpler than general-purpose computers.

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