Pipelining: Avoiding Control Hazards

• A repeat instruction repeats one instruction or a block of instructions after repeat

• The pipeline is filled with repeated instruction (or block of instructions)

• Cost: one pipeline flush only

RPT COUNT

TBLR *+

A key factor in the numeric performance of DSPs is the provision of special hardware to perform looping.

D

E

F

rpt

X

X

X

X

X

X

X

X

F

D

R

E

Execute

Read

Decode

Fetch

C

D

E

F

rpt

-

-

X

X

X

X

X

B

CD

E

F

rpt

-

-

X

X

X

X

ABCD

E

F

rpt

-

-

X

X

X

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