Question

In 8086 microprocessor, the instruction used to copy the word from the top of the stack to the flag register is

• A. PUSH
• B. PUSHF
• C. POP
• D. POPF

Hint:

PUSHF: \[ FLAGS \rightarrow STACK \] POPF: \[ STACK \rightarrow FLAGS \]

Answer 1

The Correct Option is D

Concept: The stack stores data in Last-In-First-Out (LIFO) order. Special instructions exist for transferring flag register contents to and from the stack.

Step 1: Recall stack instructions.
\[ PUSHF \] pushes flag register contents onto the stack. \[ POPF \] pops data from the stack into the flag register.

Step 2: Interpret the question.
The question asks for copying the word from the top of stack into the flag register. This is exactly the operation of \[ POPF. \]

Step 3: State the answer.
\[ \boxed{\text{POPF}} \]