The Need to Make a Decision!
Direct Mapped Cache:
- Each memory location can only mapped to 1 cache location
- No need to make any decision :-)
- Current item replaced the previous item in that cache location
N-way Set Associative Cache:
- Each memory location have a choice of N cache locations
Fully Associative Cache:
- Each memory location can be placed in ANY cache location
Cache miss in a N-way Set Associative or Fully Associative Cache:
- Bring in new block from memory
- Throw out a cache block to make room for the new block
- We need to make a decision on which block to throw out!