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WAW HAZARDS

EXAMPLE 

MULF  R0, R2, R4
ADDF  R0, R6, R8

  • When MULF is issued the register R0 will be marked with the identifier of the multiply unit.

  • Ordinarily, any following instruction which uses R0 would get its operand from the multiply unit when it finishes, via the CDB.

  • However, when the ADDF is issued, register R0 is marked with the identifier tag of the adder.

  • When the multiply completes, it will broadcast on the CDB, but no register or FU will be interested.