The Fetch - Execute Cycle

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Keywords 🗝️

fetch‑execute cycle, fetch, decode, execute, CPU, control unit, arithmetic logic unit, ALU, registers, memory, instruction cycle, desktop PC 

Summary 📝

• The fetch–execute cycle is a core concept in how a CPU processes instructions.

• It is made up of three main stages: fetch, decode, and execute.

• Fetch: The CPU retrieves an instruction from main memory (RAM) using the Program Counter (PC) and stores it in a register.

• Decode: The Control Unit interprets the instruction, preparing necessary components for execution.

• Execute: The instruction is carried out by relevant parts of the CPU, such as the Arithmetic Logic Unit (ALU).

• The cycle repeats continuously while the computer is powered on and processing tasks.

• Registers such as the Program Counter (PC), Memory Address Register (MAR), Memory Data Register (MDR), and Accumulator (ACC) are involved in the process.

• This process allows a CPU to carry out software instructions, enabling a computer to function.