5. Assume that each memory address of a computer system can address up to 16G bytes. The memory location is byte addressed. Suppose we use a 256K-byte cache to improve the performance. The cache is organized in a way that each block consists of 64 bytes.f (a) [7%] Suppose the cache is direct mapped. Which bit fields of the address indicate the tag, the cache index, and the offset, respectively? Give your derivation. (b) [7%] Suppose the cache is fully associative. Which bit fields of the address indicate the tag and the offset, respectively? Give your derivation.