What is reclocking?

Answer 1

Reclocking can be thought of as "refreshing" or "regenerating" a signal. When a clock signal, typically some variation on a square wave that is pulse-width modulated, is run over a long length of cable it can suffer significant degradation. This can take the form of noise and interference, decrease in amplitude, and most significantly "rounded edges" (essentially low-pass filtering of the signal due to the capacitance of the cable). If this degradation becomes too severe the clock signal can be rendered unusable. To prevent this a reclocking device can be inserted in the signal chain. This device uses the incoming signal as a template to regenerate a new signal with the same characteristics. Just as you are still able to read the sentence "Th q ick br n f x umped ov r the l zy dog." and re-write it as "The quick brown fox jumped over the lazy dog.", a reclocking device can "read" incoming clock signals with missing information and "rewrite" them in their originally intended form.