Concerning Caches

Cache Simulation

Initial cache status:

		Valid	Dirty	Tag	Data					Valid	Dirty	Tag	Data
Set Index	0	0								0
	1	0								0
	2	0								0
	3	0								0

Cache status after storing the value 5 at address 0. Compulsory miss, block is fetched from memory, dirty bit is set.

		Valid	Dirty	Tag	Data					Valid	Dirty	Tag	Data
Set Index	0	1	1	0	5	0	0	0		0
	1	0								0
	2	0								0
	3	0								0

Cache status after loading the value at address 64. Compulsory miss, block is fetched from memory, dirty bit is not set.

		Valid	Dirty	Tag	Data					Valid	Dirty	Tag	Data
Set Index	0	1	1	0	5	0	0	0		1	0	1	0	0	0	0
	1	0								0
	2	0								0
	3	0								0

Cache status after storing the value 7 at address 4. Hit.

		Valid	Dirty	Tag	Data					Valid	Dirty	Tag	Data
Set Index	0	1	1	0	5	7	0	0		1	0	1	0	0	0	0
	1	0								0
	2	0								0
	3	0								0

Cache status after storing the value 8 at address 40. Compulsory miss.

		Valid	Dirty	Tag	Data					Valid	Dirty	Tag	Data
Set Index	0	1	1	0	5	7	0	0		1	0	1	0	0	0	0
	1	0								0
	2	1	1	0	0	8	0	0		0
	3	0								0

Cache status after loading the value at address 68. Hit.

		Valid	Dirty	Tag	Data					Valid	Dirty	Tag	Data
Set Index	0	1	1	0	5	7	0	0		1	0	1	0	0	0	0
	1	0								0
	2	1	1	0	0	8	0	0		0
	3	0								0

Cache status after storing the value 9 at address 128. Conflict miss, leftmost block in set is evicted because it is the least recently used. It is written back because it is dirty.

		Valid	Dirty	Tag	Data					Valid	Dirty	Tag	Data
Set Index	0	1	1	2	10	0	0	0		1	0	1	0	0	0	0
	1	0								0
	2	1	1	0	0	8	0	0		0
	3	0								0

Cache status after loading the value at address 0. Conflict miss, rightmost block in set is evicted because it is the least recently used. It is not written back because it is not dirty.

		Valid	Dirty	Tag	Data					Valid	Dirty	Tag	Data
Set Index	0	1	1	2	10	0	0	0		1	0	0	5	7	0	0
	1	0								0
	2	1	1	0	0	8	0	0		0
	3	0								0