Question

In a microprocessor, the register which holds the address of the next instruction to be fetched is :

• A. Accumulator
• B. Program counter
• C. Stack pointer
• D. Instruction register

Hint:

Program Counter (PC): \[ \text{Stores address of next instruction} \] Instruction Register (IR): \[ \text{Stores current instruction} \]

Answer 1

The Correct Option is B

Concept: The Program Counter (PC) is a special-purpose register in a microprocessor. Its main function is: \[ \text{To store the memory address of the next instruction to be executed} \] After fetching an instruction, the program counter automatically increments to point to the next instruction.

Step 1: Understand the role of Program Counter. The processor executes instructions sequentially. To know where the next instruction is located, the processor uses: \[ \text{Program Counter} \] Thus: \[ PC \rightarrow \text{Stores address of next instruction} \]

Step 2: Analyze option A. Accumulator stores arithmetic and logic operation results. Hence: \[ A \text{ is incorrect} \]

Step 3: Analyze option B. Program counter stores next instruction address. Thus: \[ B \text{ is correct} \]

Step 4: Analyze option C. Stack pointer points to top of stack memory. Therefore: \[ C \text{ is incorrect} \]

Step 5: Analyze option D. Instruction register stores currently decoded instruction, not its address. Hence: \[ D \text{ is incorrect} \]

Step 6: Write the final answer. Therefore, the correct option is: \[ \boxed{(B)\ \text{Program counter}} \]