Clock data recovery in serdes

1. How clock data recovery works?
2. What is a clock recovery circuit?
3. What is cdr in SerDes?

How clock data recovery works?

How does CDR work? It locks on a frequency that is retrieved from incoming data stream. To do so, it detects the data transitions and locks an VCO (Voltage Controlled Oscillator) to that frequency. This frequency is then used when generating the transmitted data bit stream.

What is a clock recovery circuit?

A clock recovery circuit supplies timing to a phase locked loop (PLL), which in turn controls a clock for the recovered upstream information, as we describe shortly. From: Modern Cable Television Technology (Second Edition), 2004.

What is cdr in SerDes?

High-speed analog SerDes systems use clock and data recovery (CDR) circuitry to extract the proper time to correctly sample the incoming waveform. The CDR circuitry creates a clock signal that is aligned to the phase and to some extent the frequency of the transmitted signal.