Common Data Questions: 48 & 49

A computer system has an L1 cache, an L2 cache, and a main memory unit connected as shown below. The block size in L1 cache is 4 words.
The block size in L2 cache is 16 words.The memory access times are 2 nanoseconds. 20 nanoseconds and 200 nanoseconds for L1 cache,
L2 cache and main memory unit respectively.

Q. When there is a miss in L1 cache and a hit in L2 cache, a block is transferred from L2 cache to L1 cache. What is the time taken for this transfer?
Option (A)
2 nanoseconds
Option (B)
20 nanoseconds
22 nanoseconds
88 nanoseconds
Correct Option:
Question Solution:
A block to access in L2 cache requires 20 nanoseconds, and 2 sec to place in L1 – cache, so is total 22 nanoseconds