Phase-locked loop, method of operating the same, and devices having the same

摘要

A method of operating a phase-locked loop (PLL) such as an all-digital PLL includes operations of comparing a reference clock signal with a feedback signal of the PLL and outputting a comparison signal according to a result of the comparison, and detecting whether the PLL is in a lock state by using a number of times the comparison signal is toggled.

主权项

1. A method operating a phase-locked loop (PLL), the method comprising:
comparing a reference clock signal with a feedback signal of the PLL, and outputting a comparison signal according to a result of the comparison; and detecting whether the PLL is in a lock state according to a number of times the comparison signal is toggled, wherein the detecting comprises comparing the number of times the comparison signal is toggled with a reference number of times, and detecting whether the PLL is in the lock state, according to the result of the comparison.