Crossing pipelined data between circuitry in different clock domains

Abstract

An integrated circuit implements a multistage processing pipeline, where control is passed in the pipeline with data to be processed according to the control. At least some of the different pipeline stages can be implemented by different circuits, being clocked at different frequencies. These frequencies may change dynamically during operation of the integrated circuit. Control and data to be processed according to such control can be offset from each other in the pipeline; e.g., control can precede data by a pre-set number of clock events. To cross a clock domain, control and data can be temporarily stored in respective FIFOs. Reading of control by the destination domain is delayed by a delay amount determined so that reading of control and data can be offset from each other by a minimum number of clock events of the destination domain clock, and control is read before data is available for reading.