JPS6441343A - Timing recovery circuit - Google Patents

Abstract

PURPOSE:To accurately detect an error of a frequency through the decision of the convergence of a frequency error detection period by applying sufficient initial pull-in at first, confirming the convergence, applying initial setting of frequency error detection by the convergence decision at the self-traveling start point of time afterward, setting a detection criterion so as to apply convergence decision corresponding to the sequence. CONSTITUTION:An initial convergence deciding means 44 applies correction so as to match the phase of a recovered clock RC with that of a reception signal by the pull-in of the reception signal and decides it to be the initial convergence depending on the repetition of the consecutive phase inversion of the phase comparison result A. A self-traveling deciding means 45 decides it as the start of self-traveling by the initial phase inversion of the phase comparison result by using a reception signal at an optional point of time of self-traveling start decision after the initial convergence. Then a convergence deciding means 46 applies the convergence decision when the phase comparison result A represents the phase inversion by the repulling-in of the reception signal after the self-traveling of prescribed time. Thus, the convergence decision according to the sequence is applied and accurate frequency error detection is attained by the convergence decision for the frequency error detection period.