Learn: Program Counter - Tracking the Next Instruction

Welcome!You've already learned about the CPU, its components, and how it processes instructions. Today, we'll focus on the Program Counter (PC), an essential register that helps the CPU keep track of what to do next.

What is the Program Counter (PC)?The Program Counter is a CPU register that stores the address of the next instruction to be executed. After the CPU fetches an instruction, the PC is updated to point to the next one.

Why is the Program Counter Important?The Program Counter ensures instructions are executed in the correct order. Without it, the CPU wouldn't know where to fetch the next instruction, and the computer wouldn't function properly.

How Does the Program Counter Work?During the fetch-decode-execute cycle, the CPU uses the address in the Program Counter to fetch the next instruction from memory. Once the instruction is fetched, the Program Counter increments to the address of the following instruction, ready for the next cycle.

What Happens When the CPU Jumps to a New Instruction?Sometimes, the Program Counter is updated to a completely different address, instead of incrementing by one. For example, this happens when a program includes a branch instruction, such as an IF statement that changes the flow of control.

Review Time!Great work! You've learned about the Program Counter, its role in the CPU, and how it interacts with the fetch-decode-execute cycle. Let's test your understanding!