Patent ID: 7423948
Filing Date: 2008-09-09
Classification: G11B,H03L,H04L

Abstract:
1. A phase error detecting circuit for use in extracting, based on reproduced data that has been reproduced from a record reproducing apparatus and quantized, a synchronous clock which is synchronized with the reproduced data, the reproduced data being data sampled and quantized by a not-yet-synchronized clock which is not yet adjusted to have a frequency of the synchronous clock, the phase error detecting circuit comprising: a cross detector for receiving the reproduced data sampled by the not-yet-synchronized clock and a specified reference value and detecting a cross timing at which the reproduced data sampled by the not-yet-synchronized clock the reference value; a phase error calculator for receiving the reproduced data sampled by the not-yet-synchronized clock and a cross timing signal from the cross detector and calculating a difference between the value of the reproduced data sampled by the not-yet-synchronized clock and a zero value at the cross timing as phase error data including a phase error amount resulted from a frequency error between the synchronous clock and the not-yet-synchronized clock; and a cross reference value generator for receiving the phase error data from the phase error calculator and updating the reference value of the cross detector based on the phase error data.