Learn: Systems Architecture (1.1.1)

Welcome!Today we're learning about Systems Architecture, specifically the purpose of the CPU and how it processes instructions. 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, performs calculations, and manages tasks to make the computer work. Without it, your computer wouldn't be able to do anything!

The Fetch–Execute CycleThe CPU uses the fetch–execute cycle to process instructions. It works in three main steps:Fetch: The CPU gets an instruction from memory.Decode: It figures out what the instruction means.Execute: It carries out the instruction.This cycle happens very quickly, allowing the computer to process many instructions per second!

Common CPU ComponentsThe CPU has several key components:ALU (Arithmetic Logic Unit): Performs calculations and logical operations.CU (Control Unit): Directs the operations of the CPU, controlling the flow of data.Cache: Small, fast memory located close to the CPU, storing frequently used instructions and data.Registers: Very fast, small storage used to hold data temporarily during processing.

Von Neumann ArchitectureMost computers use the Von Neumann architecture. This means that instructions and data are stored in the same memory. The CPU uses registers to keep track of the current instruction, its data, and results.

Registers in the CPURegisters are special memory locations within the CPU used during the fetch–execute cycle:Memory Address Register (MAR): Stores the memory address of the instruction or data.Memory Data Register (MDR): Stores the data fetched from memory or the data to be written to memory.Program Counter (PC): Keeps track of the memory address of the next instruction.Accumulator: Stores the running result of calculations performed by the CPU.

Factors Affecting CPU PerformanceThe speed of a CPU is affected by three main factors:Clock Speed: The number of instructions the CPU can process per second. Higher speeds mean faster performance.Cache Size: Larger cache sizes allow the CPU to store more data close by, reducing the time to access frequently used information.Number of Cores: More cores allow the CPU to process multiple instructions at the same time, improving multitasking.

Embedded SystemsEmbedded systems are computers built into devices to perform specific tasks. Examples include washing machines, microwaves, and traffic lights. They are usually small, efficient, and designed for a single purpose.

Review Time!Great work! You've learned about Systems Architecture, including the CPU, fetch–execute cycle, registers, performance factors, and embedded systems. Now let's test your understanding with final questions.