A processor issues 24-bit addresses. Memory is byte-addressable. The memory system comprises of the main memory and a 128K bytes 8-way set associative write-back cache, the block size is 16 bytes. The access time to cache is 30 nanoseconds. The access time to memory is 120 nanoseconds. The data bus between cache and main memory is 128 bits wide. The hit rate on cache is 95%. 25% of the cache blocks are dirty.
a) Specify the size, in bits, of tags in mapping part of the cache? Explain your answer.
b) Specify the average access time of memory system (as obseverd by the processor)? Describe your answer.