Learn: Program Counter - Tracking the Next Instruction

Welcome!Welcome! I've reviewed your growth areas and created this lesson to help you strengthen your understanding of the Program Counter and its role in the fetch-execute cycle. We'll also cover related concepts like the Memory Address Register (MAR) and other key registers.

What is the Program Counter?The Program Counter (PC) is a register used in the CPU as part of the fetch-execute cycle. It contains the memory address of the next instruction the CPU will execute. It ensures the CPU processes instructions in the correct order.

How does the Program Counter work?During each cycle, the Program Counter sends the address of the next instruction to the Memory Address Register (MAR). After the instruction is executed, the PC is updated to point to the address of the following instruction. This process ensures that the CPU executes instructions sequentially.

Memory Address Register (MAR)The Memory Address Register (MAR) holds the address of the memory location that the CPU will read or write to. It works together with the Program Counter during the fetch-execute cycle to locate the instruction or data in memory.

What Registers Do - The Big PictureRegisters are small, fast storage locations inside the CPU. They store temporary data, memory addresses, and intermediate results during the execution of instructions. They ensure the CPU can function efficiently.

Memory Data Register (MDR)The Memory Data Register (MDR) temporarily stores the data that has been read from memory or that needs to be written back to memory. It works alongside the MAR during the fetch-execute cycle.

Von Neumann ArchitectureThe Von Neumann Architecture describes how a computer stores programs and data in the same memory. The CPU reads instructions and data from memory, executes them, and updates registers like the Program Counter to track progress.

Review Time!Great work! You've learned about the Program Counter, Memory Address Register, and other key registers. Let's test your understanding with a final review.