Finding Effective Access Time

Question

Do you find the answer in the options? I didnt. Or I am plain understanding this question wrong:

Consider the following data with respect to a paging system with the page table stored in the memory:
Associative look up = $x \mu sec$
Memory cycle time = $1 \mu sec$
Hit ratio (percentage of time that a page number is found in the associative register) = y
Determine the effective access time.
(A) (1+x+y)$\mu$s
(B) (2+x+y)$\mu$s
(C) (x+y-1)$\mu$s
(D) (2+x-y)$\mu$s

Answer 1

Given details are

Associative look up =$x \mu sec$ xμsec
Memory cycle time =$1 \mu sec$

Hit ratio (percentage of time that a page number is found in the associative register) = y

SO Effective Memory Access Time=$y\times \left ( hit\ time \right )+ (1-y)\times \left ( miss\ time \right )$

                                                     =$y\times \left ( x+ 1\right )+ (1-y)\times \left ( x+2 \right )$

                                                     =$xy+ y+x + 2 -xy-2y$

                                                     =$x -y+ 2$

                                               

xμsec 1μsec

Comments

use latex

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well...I mean its normal addition right? then whats up with dot on the top of plus sign?

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ya its normal dear.Bright eyes