-Stall Conditions

3.4 Interlock and Exception Handling

Stall Conditions

Often, a stall condition is only detected after parts of the pipeline have advanced using incorrect data; this is called a pipeline overrun. When a stall condition is detected, all eight instructions--each different stage of the pipeline--are frozen at once. In this stalled state, no pipeline stages can advance until the interlock condition is resolved.

Once the interlock is removed, the restart sequence begins two cycles before the pipeline resumes execution. The restart sequence reverses the pipeline overrun by inserting the correct information into the pipeline.

Generated with CERN WebMaker