Data Hazards: Solution - II

Solution II (hardware)

• Detect problem and stall the pipeline
  • Freeze IF, RF stages for 2 cycles and insert NOPs into IRALU for 2 cycles

i

i + 1

i + 5

i + 6

ADD

CMP

MUL

ADD

CMP

CMP

ADD

NOP1

NOP2

ADD

NOP1

NOP2

IF

RF

WB

MUL

CMP

CMP

CMP

MUL

SUB

MUL

SUB

MUL

ALU

ADD(r1, r2, r3)

CMPLEC(r3, 5, r0)

r3 written

r3 read

i + 2

i + 3

i + 4

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