Clock and Data Recovery / Retiming

Clock and data recovery (CDR) is a technique used in digital circuits to recover the clock signal and data from an incoming data stream. This is often necessary when transmitting data over long distances or through noisy channels, where the clock and data signals can become distorted or lose synchronization. In a CDR circuit, the incoming data stream is sampled using a phase-locked loop (PLL) or other clock recovery technique, and then passed through a retiming circuit that regenerates the clock and data signals. This ensures that the recovered clock and data signals are clean and properly synchronized, allowing the data to be accurately received and processed.