METHOD AND STRUCTURE FOR LOCAL STALL CONTROL IN A MICROPROCESSOR

摘要

A processor implements a local stall functionality in which small, independent circuit units are stalled locally with the condition causing a stall being first detected locally, then propagated to other small independent circuit units. Stall conditions for a functional unit is detected locally with reduced logic circuitry and also without waiting to receive condition information from other functional units that is transmitted over long wires. Local stall logic circuits are distributed over diverse areas of an integrated circuit so that stall conditions are detected locally. A local stall is expanded into a global stall by propagation to logic circuits beyond a local region in subsequent cycles. Local detection of stall conditions and local stalling eliminates many critical paths in the processor.