Pipeline

Pipeline:Pipeline is a technique that decompose a sequential process into sub operations, with each sub operations being executed in a special delicate segment that operates concurrently with all other segment. A pipeline can be visualised as a collection of processing segments through which binary information flows. Each segment performs partial processing dictated by the way the last is petition. The result obtained from the computation in each segment is transferred to the next segment in the pipeline. The name pipeline implies a flow of information analogous to an industrial assembly line. Let us consider this example:Ai*Bi+Ci for i=1,2,3,…,5 1) 2) 3) 4) 5) R1 Ai R2 Bi R3 R1*R2 R4 Ci R5 R3+R4

Ai R1

Bi R2

Ci

Multiplier

R3

R4

ADDER

R5

Clock pulse no. 1 2 3 4 5 6 7 R1 A1 A2 A3 A4 A5 -----

Segment 1 R2 B1 B2 B3 B4 B5 -----

Segment 2 R3 --A1*B1 A2*B2 A3*B3 A4*B4 A5*B5 ---

R4 --C1 C2 C3 C4 C5 ---

Segment 3 R5 ------A1*B1+C1 A2*B2+C2 A3*B3+C3 A4*B4+C4 A5*B5+C5

If there be a k segment pipeline with a clock cycle timeline Tp is used to n task, and Tn be the time to complete each task in a non-pipeline unite then speed up ratio S=(n*Tn)/(K+n-1*Tp).