3.6.8.7.1 FPU Structural Hazards

When a requested FPU resource is unavailable, a structural hazard will be detected. This may result in the coprocessor stalling the CPU until the hazard is resolved.

Hazards that arise from actions within the FPU are referred to as “internal” hazards. Those that arise due to actions between the CPU and FPU are referred to as “external” hazards. Depending upon how the CPU/FPU pipeline is viewed (separate or conjoined), some of these hazards may be viewed as either structural (i.e., a resource is unavailable) or data related.