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• Structural hazards
  • A good example of a structural hazard occurs in machine with only one memory port.

  • The instruction fetch stage needs to read from memory in every cycle.

  • The memory access stage needs to read or write in those cycles where it is processing a load or store instruction.

  • Thus, the IF stage is stalled if the MEM stage is using the memory port.

  • Therefore we lose a clock cycle for every load or store instruction executed.