CLOCK/DATA REPRODUCTION UNIT, METHOD FOR CONTROLLING POWER THEREOF, AND PON SYSTEM

摘要

The purpose of the present invention is to reduce unnecessary power consumption when a clock/data reproduction unit in a terminal device of a PON system is booted from a power-saving state, and to make it possible to perform communication in a speedy and reliable manner. The clock/data reproduction unit is provided with a phase-locked loop for extracting a clock signal and a data signal from an input signal, the phase-locked loop being able to be set to normal mode or power-saving mode and including a voltage-controlled oscillator. The clock/data reproduction unit is further provided with a reference clock multiplication circuit for multiplying and outputting a reference clock signal, and with a frequency training loop that includes the same voltage-controlled oscillator and performs synchronous oscillation training by the voltage-controlled oscillator using the reference clock multiplication circuit before the phase-locked loop shifts from the power-saving mode to the normal mode.