MIPS

Inst/Cyclel 1 2 ID 6 4 MEM WB EX ID 5 EX ID IF IF MEM WB EX pipeline support MEM |WB Table 3 Instruction Execution with There are, though, situations in the pipelining when the next instruction cannot execute in the following clock cycle. These events are called Hazards and there are three different types [1] A. Structural Hazard. When a planned instruction cannot execute in the proper clock cycle because the hardware does not support the combination of instructions that are set to execute [1] B. Data Hazard or Pipeline Data Hazard. When a planned instruction cannot execute in the proper clock cycle because data that is needed to execute the instruction is not yet available [1] C. Control Hazard or Branch Hazard. When the proper instruction cannot execute in the proper pipeline clock cycle because the instruction that was fetched is not the one that is needed; that is, the flow of instruction addresses is not what the pipeline expected [1]