Glossary

A.2 Pipeline

Normally, each instruction only remains in each stage for a single cycle, and each stage begins executing a new instruction as previous instructions are being completed in later stages. Thus, a new instruction can often begin during every cycle.

Pipelines greatly improve the rate at which instructions can be executed, as long as there are no dependencies. The efficient use of a pipeline requires that several instructions be executed in parallel, however the result of any instruction is not available for several cycles after that instruction has entered the pipeline. Thus, new instructions must not depend on the results of instructions which are still in the pipeline.