What is clock and data recovery?

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Retimers are a key building block in communication systems involving
high-speed data transmission. The use of clock and data recovery, or CDR,
provides improved clock and data synchronization and also reduces timing
uncertainty. In addition, CDRs are valuable as a means of jitter mitigation
for a variety of applications. In this video, we’re going to discuss the
clock and data recovery function and key metrics used to evaluate a CDR in
retimer products.
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[@olegs8922]

How do we know where to sample if CDR is bypassed? We may end up sampling right at the transition and see no signal.

[@eshabyalcn2747]

Yes, that is possible if we mentioned the type of a receiver that using clock recovery process from data straem. However, this is just retimer, which means that's role is just improve signal integrity on the communication channel.