4. Consider a 2-way set associative cache with 8 sets, two blocks per set, 4 bytes per block and the size of a memory address is 13 bits. Fig. 3 shows the content of the cache memory. Note that invalid cache lines are left blank. (1) (3 marks) Show the format of the memory address in terms of tag, set and byte fields. (2) (3 marks) Consider an access to the address 0x08A7. Does this access hit or miss in the cache? What value is returned if it is a hit? Justify your answer. (3) (3 marks) Consider an access to the address 0x1D68. Does this access hit or miss in the cache? What value is returned if it is a hit? Justify your answer. (b) (4 marks) A testing program is executed to evaluate the performance of the cache system. The program consists of 4000 read instructions and 2000 write instructions. Their corresponding hit rates are, respectively, 0.82 and 0.88 . In read (write) operations, the access time of the cache memory is 100ns ( 200ns) and that of the main memory is 1s(2s). Estimate the overall hit rate and the effective access time of the system. Fig. 3 (Note that invalid cache lines are left blank.)