What is Clock Domain Crossing?

Clock Domain Crossing (CDC) refers to the transfer of data between different clock domains in a digital system. Since signals are synchronized to a specific clock, transferring data between domains with asynchronous clocks can lead to metastability and data corruption. CDC methodologies employ techniques like synchronizers, FIFOs, and handshake protocols to ensure reliable data transfer between these domains. It's crucial in complex digital designs, such as SoCs, where different functional blocks operate at different clock frequencies or are driven by unrelated clock sources. Proper CDC design prevents system failures and ensures data integrity.