The "valid" state means that the cache line is current.

This ensures that the three lookups stay within a cache line.

The cache line may be changed to the Modified state at any time in order to modify the data.

A cache line in the shared state holds the most recent, correct copy of the data.

Shared cache lines may not respond to a snoop request with data.

A cache line in the invalid state does not hold a valid copy of the data.

A store buffer is used when writing to an invalid cache line.

A 64-bit data bus allowed the cache line to be transferred in a 4-cycle burst.

Both caches are direct-mapped and have a 4-byte cache line.

If the starting offset within the cache line is zero, all of these modes reduce to the same order.