Caching 5) Here is a series of address references given as words addresses: 3, 7
ID: 3908473 • Letter: C
Question
Caching
5) Here is a series of address references given as words addresses: 3, 7, 10, 13, 64, 48, 19, 2, 3, 11, 16, 21, 11, 3, 22, 4, 27, 6,12, 3, 16, 17, 44, 21, and 12. a) Assuming a direct-mapped cache with 16 one-word blocks that is initially empty, label each reference in the list as a hit or a miss and show the contents of the cache (including previous, overwritten values). You do not need to show the tag field. When done, include the hit ratio [7 pts] Cache v Address Set 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 b) Show the hits and misses and cache contents (including previous, overwritten values) fora direct-mapped cache with four-word blocks and a total size of 16 words. You do not need [7 pts] to show the tag field. When done, include the hit ratio. Cache v Address Set 01 10Explanation / Answer
a)
3mod16=3 Miss
7mod16=7 miss
10mod16=10 miss
13mod16=13 miss
64mod16=0 miss
48mod16=0 miss
19mod16=3 miss
2mod16=2 miss
3mod16=3 miss
11mod16=11 miss
16mod16=0 miss
21mod16=5 miss
11mod16=11 hit
3mod16=3 hit
22mod16=6 miss
4mod16=4 miss
27mod16=11 miss
6mod16=6 miss
12mod16=12 miss
3mod16=3 hit
16mod16=0 hit
17mod16=1 miss
44mod16=12 miss
21mod16=5 hit
12mod16=12 miss
hit ratio = 5/25 =1/5 = 20%
b)
3=0000 00 11 = 0th set miss
7=0000 01 11 =1st set miss
10=0000 10 10 = 2nd set miss
13 = 0000 11 01= 3rd set miss
64=0100 00 00= 0th set miss
48= 0011 00 00 = 0th set miss
19=0001 00 11 =0th set miss
2=0000 00 10 = 0 th set miss
3 =0000 00 11= 0 th set hit
11=0000 10 11 = 2nd hit
16= 0001 00 00= 0 th set miss
21 = 0001 01 01= 1st set miss
11 = 0000 10 11=2nd set hit
3 = 0000 00 11=0th set miss
22 = 0001 01 00 =1st set hit
4 = 0000 01 00= 1 st set miss
27 = 0001 10 11=2nd set miss
6=0000 01 10 = 1 st set miss
12 = 0000 11 00 = 3 rd set hit
3= 0000 00 11=0th set hit
16 = 0001 00 00= 0 set miss
17 = 0001 00 01= 0th set hit
44 = 0010 11 00= 3 rd set miss
21 = 0001 01 01= 1 set miss
12 = 0000 11 00= 3 set miss
hit ratio 7/25=28%
Cache Set v Address 0000 64,48,16 0001 17 0010 2 0011 3,19,3 0100 4 0101 21 0110 22,6 0111 7 1000 1001 1010 10 1011 11,27 1100 44,12 1101 13 1110 1111