Learn: What Registers Do (Big Picture)

Welcome!Welcome back! You've already learned about the importance of the CPU and the fetch-decode-execute cycle. Today, we'll explore what registers do and why they are essential to the CPU's operation.

What Are Registers?Registers are small, super-fast storage locations within the CPU. They temporarily hold data and instructions needed for processing. They are critical because they speed up the CPU's operations compared to accessing main memory.

Memory Address Register (MAR)The Memory Address Register (MAR) holds the memory location of the next instruction or data that the CPU needs. It acts like a pointer to tell the CPU where to look in memory.

Memory Data Register (MDR)The Memory Data Register (MDR) stores the actual data or instruction fetched from memory. It works closely with the MAR to retrieve and hold information temporarily.

Program Counter (PC)The Program Counter (PC) keeps track of the address of the next instruction to be executed. After an instruction is fetched, the PC is updated to point to the following one, ensuring the CPU processes instructions in sequence.

Accumulator (ACC)The Accumulator (ACC) holds the intermediate results of calculations and operations performed by the CPU. It is crucial for processing arithmetic and logic tasks quickly.

Review Time!Great job! You've learned about the MAR, MDR, PC, and ACC. Let's test your understanding with a few final questions.