first of all make a clear picture of problem. like
cache size = 4K word
cache block = 4K word / 64 word =64 blocks
no of sets = 64 / 4 = 16 sets each having 64 cache blocks and each cache block can contain 64 words
now same for the main memory.
main memory size = 32K word
main memory blocks = 32K word/ 64 word = 512 blocks each having 64 words
in 68 main memory blocks we can put all 4352 word
now you can apply set associative mapping eaisly
ans is :- 248
set0 0 16 32 48
set1 1 17 33 49
set2 2 18 34 50
set3 3 19 35 51
set4 4 20 36 52
: : : :
: : : :
: : : :
14 30 46 62
set15 15 31 47 63
it is using LRU so in set 0 block 0 replace by 64
set 1 block 1 replace by 65
set 2 block 2 replace by 66
set 3 block 3 replace by 67
hence 68 misses
now it will repeat again then 20 misses will occur each time
all the blocks are in cache except block 0, 1, 2, 3
in set 0 block 16 replace by 0
set 1 block 17 replace by 1
set 2 block 18 replace by 2
set 3 block 19 replace by 3
4 missing
and now block 16 17 18 19 are missing
so
in set 0 block 31 replace by 16
set 1 block 32 replace by 17
set 2 block 33 replace by 18
set 3 block 34 replace by 19
4 missing
and now block 31 32 33 34 are missing
so
in set 0 block 48 replace by 31
set 1 block 49 replace by 32
set 2 block 50replace by 33
set 3 block 51 replace by 34
4 missing
and now block 48 49 50 51 are missing
so
in set 0 block 64 replace by 48
set 1 block 65 replace by 49
set 2 block 66 replace by 50
set 3 block 67 replace by 51
4 missing
and now block 64 65 66 67 are missing
so
in set 0 block 0 replace by 64
set 1 block 1 replace by 65
set 2 block 2 replace by 66
set 3 block 3 replace by 67
4 missing
total = 4 + 4+ 4 + 4+ 4 =20 misses in second iteration
now it will repeat again then 20 misses will occur each time
so 20*9 = 180
total = 180+68 = 248
