Invention Grant
- Patent Title: Method of detecting frequency of digital phase locked loop
- Patent Title (中): 数字锁相环频率检测方法
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Application No.: US09449735Application Date: 1999-11-26
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Publication No.: US06580775B1Publication Date: 2003-06-17
- Inventor: Hyun-Soo Park , Jae-Seong Shim , Yong-Kwang Won
- Applicant: Hyun-Soo Park , Jae-Seong Shim , Yong-Kwang Won
- Priority: KR98-50947 19981126
- Main IPC: H03D324
- IPC: H03D324

Abstract:
A method of detecting a frequency of a digital phase locked loop in an optical disc reproduction and/or recording apparatus, which includes (a) detecting an edge point of an input signal, (b) sampling a previous and following input signal on the basis of the detected edge point into a predetermined frequency, (c) counting a number of reference clock signals between the detected edge point and a sample which is positioned previously, adding a count value and an interval of time corresponding to the count value to obtain a frequency count value at the edge point, and (e) comparing the obtained frequency count value with a predetermined reference value, to enhance the frequency according to the comparison result can detect frequency having high resolution with only a reference clock frequency without heightening a frequency of a reference clock signal, to thereby enhance the quality of data. The frequency having the high resolution with only the reference clock frequency without heightening the frequency of the reference clock signal is detected, to thereby enhance the quality of data.
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