Question

If I have 9 address bits, how many sets are there in a direct mapped cache?
If I have 10 address bits, how many sets are there in a direct mapped cache?

Is there a general formula for this question?

Answer 1

For direct mapped, each address only maps to one location in the cache, thus the number of sets in a direct mapped cache is just the size of the cache.

There would be 0 bits for the tag, and you don’t provide enough information to determine the index or displacement bits.

Assuming you are using word addressing and you meant there are 9 or 10 bits for the index + tag:

9 bits -> 2^9 sets

10 bits -> 2^10 sets