$5\mathrm{.}4[15]<5\mathrm{.}3>$ Section $5\mathrm{.}3$ shows the typical method to index a direct$-$mapped cache, specifically $($Block address$)$ modulo $($Number of blocks in the cache$).$ Assuming a $32-$bit address and $1024$ blocks in the cache, consider a different indexing function, specifically $($Block address$[63$:$54]$ XOR Block address$[53$:$44]).$ Is it possible to use this to index a direct$-$mapped cache? If so$,$ explain why and discuss any changes that might need to be made to the cache. If it is not possible, explain why.

$5\mathrm{.}3\mathrm{.}1[10]<5\mathrm{.}3>$ Calculate the total number of bits required to implement a $32$ KiB cache with two$-$word blocks.