GATE 2017 Set 2 - COA

Question

In Gate 2017 Afternoon session there was a que where they asked for Tag Size in bit.

So in this que tag bit was 18 .

But to calculate tag size i think we should multiply it with number of Lines i.e 18*2⁹ 

Note : No. of Lines was given in que.

Is my approach is right?

Comments

as i remeber it was like size of tag field in bits .....

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Are you going to challenge the answer key of gate for this question?

Answer 1

You mean tag memory size?
Yes . It is : tagbits * |cache_lines|

Comments

in que they asked only about tag size ..... and i think tag size means same as tag memory size

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Tag size or Tag Bits....???

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I think that was size of Tag field in bits but recommend you to wait till release of question paper. May be i am wrong.

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yup.....it will be better to wait.....:-)

Answer 2

I think the question was:

32 bit logical address. 32 bytes page size and 512 Cachle lines.

That will give 18 bit tag size.

Please correct me if I am wrong.

Comments

Hello   sandeep007734 : 

Tag Size means tag directory size that would be Tag Field bit*Number of Lines = 18*2⁹ =9216

Note : 9216 would be answer if they ask for Tag size and 18 would be answer if they ask for Tag field bits.

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I see. Thanks