Addressing Modes- Q13

–1 vote
In A RISC machine if following addressing modes are implemented.
Match the following addressing modes to their main advantages

I.Immediate           P. No memory reference
II.Register Indirect address  Q. Larger address space 
III.Direct       R. Simple 
A. I - P, II - R, III - P 
B. I - R, II - Q, III - R 
C. I - P, II - Q, III - R 
D. I - R, II - Q, III - R
asked Jun 4 in Computer Organization by gbmentor (6,810 points)
reshown Jun 5 by gbmentor

4 Answers

0 votes
 
Best answer
1)in Immediate  mode no memory reference.

2)If large address space than we used register indirect mode in register we save the address of operand and give register number in instructions so instructions size might be small.

Here give large address space not large instructions size.

3)direct addressing mode simple comp to other because here we used direct address of the operand no need or finding address but here May be size of the instructions long because of size of address space.

So c is only correct options.
answered Jun 5 by tsnikhilsharmagate2018 (5,940 points)
selected Jun 5 by vinayakjhapro18
0 votes
Direct fact based question
answered Jun 5 by soumyadeeppro20 (1,640 points)
What is the answer?
I checked Option C
But how come register indirect have a larger address space because we are just specifying the address of the register which might take some bits but if we specify the address of the memory it will take a lot of space.
For III selecting simple might be okay but for II i am confused
And even options are not properly given
Even two options are same.
If large address space than we used register indirect mode in register we save the address of operand and give register number in instructions so instructions size might be small.

Here give large address space not large instructions size.
So c is only correct options.
See you are thinking in such a  way that because of register indirect there will not be a larger address space that's right..
But I am guessing according to options which are implying that because of register indirect there will be larger address space so that become a disadvantage.
Really don't know what might be the ans.
But even if question seems to be right options are not framed properly.
0 votes
@getgatebook

Sir, you intensionally given options like that or there is a mistake while framing the options.
answered Jun 5 by tskushagra-guptacse (8,650 points)
Option C is the answer. Larger address space can be addressed if we use register indirect addressing mode as the effective memory reference can be kept in register or memory and can be specified through less no of bits in the instruction through register address. In direct memory access you need to specify the address of the memory in the instruction through fewer no of bits, for example if you have 32 bits in instructions and if opcode consumes 10 bits and one operand consumes 5 bits then only we will end with 17 bits and with that only 2^17 different addresses we can refer.
Okay. Got it sir.
0 votes
I think c is the answer
answered Jun 5 by tsnikhilsharmagate2018 (5,940 points)
Answer:
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