retagged by
17,703 views
23 votes
23 votes

A certain processor uses a fully associative cache of size $16$ kB, The cache block size is $16$ bytes. Assume that the main memory is byte addressable and uses a $32$-bit address. How many bits are required for the Tag and the Index fields respectively in the addresses generated by the processor?

  1. $24$ bits and $0$ bits
  2. $28$ bits and $4$ bits
  3. $24$ bits and $4$ bits
  4. $28$ bits and $0$ bits
retagged by

8 Answers

1 votes
1 votes
In fully associative cache, search for a block is simultaneously done for all entries based on the Tag.

So no need for indexing ( neither set nor line no).

Total size, tag bits + block offset bits = 32

Block size = 16 B = $2^4$B

So we require 4 bits to address a block. Thus, tag bits = 32 - 4 = 28

Ans D) 28 and 0 bits
1 votes
1 votes

fully associative Cahe:  it contains 

                                        

tag block offset
   

block size =16Byte

no of bit required to represent block size is  4 bit [2^4]

and physical address size given is 32 bits

therefore, tag bit =32-4=28 bits 

                index field bit=0 bit bz there is no concept of index field in  fully associative cache.           

0 votes
0 votes
option D as fully associative block no = tag ; tag bits =  32 bits  – 4 bits for block offset and no index field as it is fully associative.
Answer:

Related questions

1 votes
1 votes
2 answers
2
21 votes
21 votes
7 answers
4
Arjun asked Feb 7, 2019
9,040 views
The expenditure on the project _____ as follows: equipment Rs.$20$ lakhs, salaries Rs.$12$ lakhs, and contingency Rs.$3$ lakhs.break downbreakbreaks downbreaks