a) A digital computer has the memory unit of 64K x 16 and a cache memory of 1K words. The cache uses the direct mapping along with a block size of 4 words. Explain how many bits are there in each word of cache, and how are they divided into the functions? Incorporate the valid bit.

b) Develop a sequential circuit which can detect two or more consecutive 1's in a stream of the input bits. Specifically, if last two bits in sequence were 1, the circuit must output 1. Otherwise, it must output 0.