An instruction is stored at location 700 with its address field at location 701. The address field has the value 150. The location 150 contains the value  20. A processor register R₁ contains the value 120. Which of the option regarding the effective address of the instruction operand for respective addressing mode is incorrect?
 

(A) Direct effective address = 150
(B) Indirect effective address = 20
(C) PC‐Relative effective address = 702
(D) Register indirect effective address = 120


Answer: (C)

Explanation: Direct: EA = 150
Indirect: EA = 20
Immediate: EA = 701
PC-­‐Relative: EA = 150 + 702 = 852
Register indirect: EA = 120
Autoincrement(pre): EA = 121
Index with R1 as the index register: EA = 150 + 120 = 270
So, option (C) is correct.
 

Quiz of this Question