$($a$)($i$)$ What is Principle of Locality for memory access?

$($ii$)$ Discuss if data access $($global and local variables$)$ satisfies this principle.

$[3]$

$($iii$)$ Explain why $2-$way set associative cache always has a smaller cache miss

rate. $[2]$

Why direct$-$mapped cache is still used?

$($b$)$ Consider a hypothetical machine with $1024$ words of cache memory. They are

in two$-$way set associative organization, with cache block size of $64$ words, using

FIFO replacement algorithm. The cache hit time is $9$ ns$.$ Suppose the machine

can access $2$ words of memory in parallel, and the time to transfer the first

$2$ words from main memory to cache is $60ns,$ while each subsequent $2$ words

require $11$ ns$.$

Consider the following read pattern $($in blocks of $64$ words, and block id starts

from $0$