NIELIT 2017 DEC Scientist B - Section B: 4

Question

In a cache memory if total number of sets are ‘$s$’, then the set offset is:

• A. $2^8$
• B. $\log_2s$
• C. $s^2$
• D. $s$

Answer 1

If $'s'$ is the number of sets in the cache, then the set  index has $\log_{2}s$ bits.

References:

• https://cseweb.ucsd.edu/classes/su07/cse141/cache-handout.pdf
• https://www.d.umn.edu/~gshute/arch/cache-addressing.xhtml
• https://courses.cs.washington.edu/courses/cse378/09wi/lectures/lec15.pdf

So, the correct answer is $(B).$ 

Comments

Which of those refreences has the term "set offset"?

Answer 2

If S is the number of sets in our cache, then the set index has s=log2 S bits.

Answer 3

Number of bits required to address s sets = log S  (base 2)

B is correct.

Answer 4

option B) If s is the number of sets in cache then set offset is log2(S)