Zeal Test

Question

Question :

Consider a system with 20 bit physical address and direct mapped cache with 64 blocks and block size of 16 bytes To what block number does byte address 1200 mapped??

Comments

https://gateoverflow.in/366685/nptel-assignment

Answer 1

It will be mapped to block number 11 .

PA is divided as : 10 | 6 | 4

Division of PA : Tag = 10 bits , index =  6 bits , offset = 4 bits .

So for address 1200 take the 6 bits of index from PA i.e bits from block index and find the block number.

PA : Tag  | Index | wo

0000000001    |     001011   |   0000

So, 001011 = 11

 

Alternative way is:

 

As one block has 16 addresses so address 1200 will be in 1200/16 =75 block number.

Now this block number will be mapped to 75%64 = 11.