Caches

Direct Mapped with One Word Blocks

Each data item has a unique place in the cache.

LSBs of address index into cache.

MSBs of address are tage field to indicate whether we have a hit.

Each data item has a limited number of places in the cache.

LSBs of address index into cache.

MSBs of address are tage field to indicate whether we have a hit.

Middle bits of address indicate which word in block we want.

Each data item has a limited number of places in the cache.

LSBs of address index into cache.

MSBs of address are tag field to indicate whether we have a hit.

Must compare tag against multiple entries in index.

Any data item can be anywhere in the cache.

MSBs of address are tag field to indicate whether we have a hit.

Must compare tag against all entries in cache.

A := 7
B := [1,2,3,4,5]
C := [6,7,8,9,10]

for i := 2 to 5
  C[i] := B[i]
  B[i] := A + B[i-1]
end