Method and apparatus for generating absolute time in pregroove data

Abstract

An apparatus and a method for generating an ATIP data are provided. The apparatus, based on a wobble signal generated by reading a re-writable compact disc, generates an ATIP data; the apparatus includes: a frequency demodulator for demodulating the wobble signal to generate an original ATIP data signal; an ATIP clock generating circuit for generating an ATIP clock signal based on the wobble signal; and a data generating circuit, coupled to the frequency demodulator and the ATIP clock generating circuit, for generating the ATIP data based on the number of the original ATIP data signal at a first logic level during one period of the ATIP clock signal. This apparatus uses the number of the original ATIP data signal at a first logic level during one period of the ATIP clock signal and the bi-phase rule to precisely generate the ATIP data.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the priority benefit of Taiwan application Ser. No. 93108817, filed on Mar. 31, 2005. All disclosure of the Taiwan application is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention generally relates to a method of generating absolute time in pregroove (ATIP) data, and more particularly to a method of generating ATIP data based on an original ATIP data signal generated by a wobble signal and an ATIP clock signal. [0004] 2. Description of Related Art [0005] During the manufacture of the re-writable compact disk (CD), a shallow groove will be made from the center of the CD toward the outer circumference in spiral way. This groove is so-called pregroove. This pregroove is not a perfect spiral but a little wobbling. Generally, in a CD made by die-casting, each sector includes the timing-related data to control the spin speed of the CD-ROM drive in order ...

AI Technical Summary

Benefits of technology

[0026] In light of the above, the present invention uses the status of the ATIPORG signal corresponding to the ATIPCLK signal and the bi-phase rule to precisely generate the ATIP data.

Problems solved by technology

Therefore, how to effectively read the wobble signal from the CD-RW and to effectively obtain the ATIP data from the wobble signal is an important issue in CD-RW application.

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