Basic of Caches:

• Two issues:

-How do we know if a data item is in the cache? (Is it a hit or a miss?)
_ If it is there (a hit), how do we find it?

• Our first example

_ block size is one byte of data
_ we will consider the "direct mapped" approach

Direct Mapped Cache:

- (Block address) modulo (Number of blocks in the cache)

- Problem: Multiple words share 1 location in the upper level