Question

Assuming a direct-mapped cache with 4 four-word blocks that is initially empty, label each reference in the list as a hit or a miss and show the final contents of the cache.

The following is a sequence of address references given as word addresses.

1, 5, 8, 4, 17, 19, 20, 6, 9, 8, 43, 5, 6, 21, 9, 17

Reference Hit or Miss Miss 17 19 20 43 Wordo Wordi Word2 Word 3 Block

Answer 1

I hope the below method may fulfill your query. ihave solved it to the best of my knowledge.

reference	hit/miss	comments
1	miss	Hence fetch words 0, 1, 2, 3 (cache block 0).
5	miss	Hence fetch words 4, 5, 6, 7 (cache block 1).
8	miss	Hence fetch words 8, 9, 10, 11 (cache block 2).
4	hit	Already in cache: word 4 (in cache block 1).
17	miss	Hence fetch words 17, 18, 19, 20 (cache block 1), replaces words 4, 5, 6, 7.
19	hit	Already in cache: word 19 (in cache block 1).
20	hit	already in cache: word 20 (in cache block 1).
6	miss	hence fetch word 6,7,8,9 in cache block 0
9	hit	already in cache block 0
8	hit	already in cache block 0
43	miss	hence fetch words 43,44,45,46 in cache block 2
5	miss	hence fetch 5,6,7,8 in cache block 0
6	hit	already in cache block 0
21	miss	hence fetch words 18,19,20,21 in cache block 1
9	hit	in cache block 0
17	miss	hence fetch 17,18,19,20 in cache block 1

Block	Word0	Word1	Word2	Word3
0	5	6	7	8
1	17	18	19	20
2	43	44	45	46
3	Empty	Empty	Empty	Empty