Addressing Modes- Q6

+2 votes

X(Ri) represents an Index addressing mode.
The Effective address of operand is given by EA = X + [Ri]
X denotes signed integer and mentioned in the instruction itself. If the contents of the register Ri is always equal to zero then Index addressing mode will implement

(A) Immediate addressing mode
(B) Absolute addressing mode
(C) Indirect addressing mode
(D) Register addressing mode

asked Jun 4 in Computer Organization by gbmentor (54,290 points)
reshown Jun 5 by gbmentor

4 Answers

0 votes
Best answer
For example if the instruction is Load R1 X[Ri]

It would become Load R1 X , where X is a memory adderss of operand. Hence it is an absolute addressing mode
answered Jun 6 by getgatebook (31,090 points)
Sir how did you take an example for it ??
Without taking any reference to any instruction it seems it is immediate addressing mode
+1 vote
If content of X is zero,then this reduces to immediate addressing mode,hence option A is right answer
answered Jun 5 by soumyadeeppro20 (1,720 points)
0 votes
Immediate addressing mode
answered Jun 5 by tsnikhilsharmagate2018 (19,690 points)
+1 vote

Ri is always 0 so EA = X(Address) 

Why not Immediate Addressing mode

It is because instruction contains constant value instead address and this addressing mode doesn't have EA(Effective Address) and it is not considered as addressing mode on some computers 

In the given question, there is an effective address given so it must not be immediate

Hence option B


answered Jun 6 by 23rishiyadavpro20 (6,590 points)