Multi-phase-locked loop (PLL) solution for multi-link multi-rate line card applications

摘要

A multi-phase-locked loop (PLL) solution is described for multi-link multi-rate line cards. A reconfigurable enhanced phase-locked loop (EPLL) associated with a particular port in a line card is cascaded with an fast phase-locked loop (FPLL) and their combined output is used to provide a sampling clock to a data handler such as a serializer/deserializer (SERDES). The enhanced phase-locked loop (EPLL) is operable to take a multi-rate clock input and scale it accordingly to provide a fixed rate clock to the fast phase-locked loop (FPLL) input. The enhanced phase-locked loop (EPLL) can be dynamically reconfigured without affecting operation of other ports in the line card. The fast phase-locked loop (FPLL) and serializer/deserializer (SERDES) sample link data at a fixed rate and pass the data down through the communication system.