Question

A 4 - stage pipeline has the stage delays as 150, 120, 160 and 140 nanoseconds respectively. Registers that are used between the stages have a delay of 5 nanoseconds each. Assuming constant clocking rate, the total time taken to process 1000 data items on this pipeline will be

• A. $160.5microseconds$
• B. $120.4microseconds$
• C. $590.0microseconds$
• D. $165.5microseconds$

Answer 1

The correct option is D $165.5microseconds$

$Kstagepipelinecanprocessntasks$
$in{T}_{K}time$

$T_K=[K+(n-1\left)\right]\tau$

$When\tau ={\tau }_m+dwhere{\tau }_{m}isthe$
$maximumstagedelayso$
$max(150,120,160,140)$

$=160$


$\tau =160+5=165ns$

$\tau =165\times {10}^{-3}ms$

$K=4,n=1000$

$T=[4+(1000-1\left)\right]\tau$

$=1003\times 165\times {10}^{-3}$

$=165.5ms$