Computer System Overview and Fetch-Execute Cycle

Computer System Overview

• A computer is an electronic device that takes input, processes data, and delivers output.

Fetch-Execute Cycle

• A computer follows a set of instructions known as a computer program to process data.
• The fetch-execute cycle involves fetching instructions from main memory, decoding them, and executing them in a continuous and repetitive cycle.
• The CPU fetches the next instruction from main memory (RAM) and brings it back into the CPU during the fetch cycle.
• The CPU decodes the instruction and breaks it down to determine what needs to be done.
• The CPU executes the instruction, which may involve retrieving data from main memory, performing calculations, or storing information back into main memory.

CPU Components

• A desktop computer has two critical components: memory (stores the program) and the central processing unit (CPU, carries out instructions).
• The CPU is typically located under a large fan in a desktop computer.

Clock Speed

• The fetch-execute cycle occurs billions of times per second, measured in hertz (Hz), with one hertz equal to one cycle per second.

Computer System Overview

• A computer is an electronic device that takes input, processes data, and delivers output.

Fetch-Execute Cycle

• A computer processes data by following a set of instructions known as a computer program.
• The fetch-execute cycle involves three stages: fetching, decoding, and executing instructions.
• The CPU fetches instructions from main memory (RAM) during the fetch cycle.
• The CPU decodes the instruction to determine what needs to be done.
• The CPU executes the instruction, which may involve retrieving data, performing calculations, or storing information back into main memory.

CPU Components

• A desktop computer has two critical components: memory (stores the program) and the central processing unit (CPU, carries out instructions).
• The CPU is typically located under a large fan in a desktop computer.

Clock Speed

• The fetch-execute cycle occurs at a rate of billions of times per second.
• Clock speed is measured in hertz (Hz).
• One hertz is equal to one cycle per second.