Learn: The Fetch-Decode-Execute Cycle

Welcome!Hi there! You've already learned about why the CPU is essential. Now, let's build on that by exploring how the CPU carries out instructions using the Fetch-Decode-Execute Cycle.

What is the Fetch-Decode-Execute Cycle?The Fetch-Decode-Execute Cycle is the process the CPU uses to carry out instructions. It is repeated for every program instruction the CPU processes. This cycle ensures the computer works efficiently and follows the program's instructions step by step.

Step 1: FetchThe CPU fetches an instruction from memory. The Memory Address Register (MAR) holds the address of the instruction, and the Memory Data Register (MDR) temporarily stores the instruction fetched from that address.

Step 2: DecodeDuring the decode stage, the Control Unit (CU) interprets the fetched instruction. It decides what needs to be done and prepares the CPU for the execute step.

Step 3: ExecuteFinally, the CPU carries out the decoded instruction in the execute stage. This could involve calculations, moving data, or sending instructions to other hardware components.

Why is the Fetch-Decode-Execute Cycle important?This cycle allows the CPU to process instructions systematically. Without it, a computer would not be able to perform tasks or run programs efficiently.

Review Time!Great work so far! You've learned about the Fetch-Decode-Execute Cycle and its key steps. Now let's test your understanding with a few questions.

Well done!You've completed the lesson on the Fetch-Decode-Execute Cycle. Remember, this cycle is the foundation of how computers process instructions and perform tasks. Keep practising to solidify your understanding!