$)$ A computer has a cache, main memory and a disk used for virtual memory.

Access to the cache takes $10$ ns$.$ Access to the main memory takes $100$ ns$.$

Access to the disk takes $1000$ ns$.$ Suppose the cache hit ratio is $0\mathrm{.}8$ and the

$(8)$

$1$

$-$

Stage S$2$

Delay $6$ ns

C

co

Oa

a$,$ at

Stage S$1$

Delay Sns

eRegister $($Delay ins$)$

Stage S$3$

Delay $11$ ns

$-00$ Stage $54$

Delay $8$ ns

Pipeline Register$($Delayins$)$

Pipel ine Register$($Delayins$)$

main memory hit ratio is $0\mathrm{.}9.$ The effective access time required to access a

referenced word on the system is wheni$)$ Simultaneous access memory organization is used.

ii$)$ Hierarchical access memory organization is used.