US Patent 7308593 Interlocked synchronous pipeline clock gating

An integrated circuit including a pipeline and a method of operating the pipeline. Each stage of the pipeline is triggered by one or more triggering events and are individually, and selectively, stalled by a stall signal. For each stage a stall signal, delayed with respect to the stall signal of a downstream stage, is generated and used to select whether the pipeline stage in question is triggered. A data valid signal propagating with valid data adds further selection, such that only stages with valid data are stalled.