Which of the following options represent the correct matching?
Which of the following options represent the correct matching?
Answer: B. 1→C, 2→D, 3→B, 4→A — Correct matching and explanations: 1 (Immediate): The address field contains the operand value in the instruction. Explanation: The actual data value is…
- A.
1→D, 2→C, 3→B, 4→A
- B.
1→C, 2→D, 3→B, 4→A
- C.
1→C, 2→D, 3→A, 4→B
- D.
1→A, 2→B, 3→C, 4→D
Attempted by 30 students.
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Correct answer: B
Correct matching and explanations:
1 (Immediate): The address field contains the operand value in the instruction. Explanation: The actual data value is encoded directly in the instruction, so no memory address is used to fetch the operand.
2 (Direct): The address field contains the address of the operand. Explanation: The instruction specifies a memory address; the processor uses that address to fetch the operand from memory.
3 (PC-relative): The effective address is obtained by adding a displacement to the program counter (PC). Explanation: The address used is relative to the current instruction location, useful for position-independent code and branching with offsets.
4 (Register Indirect): The operand’s offset is placed in a register such as BX, BP, SI, or DI as specified in the instruction. Explanation: The register holds an address (or offset) that the processor uses to access the operand in memory.
Using these definitions, the correct mapping is: 1 → Immediate (operand value in instruction), 2 → Direct (address of operand in instruction), 3 → PC-relative (PC + displacement), 4 → Register Indirect (operand offset in a register).