Abstract: A method for counting a number of tracks of an optical disc in an optical disc system. The optical disc system includes an optical pickup, a light source, and a plurality of optical sensors. The method includes emitting a light beam to the optical disc from the light source, detecting light reflected from the optical disc by the optical sensors, and generating a tracking error signal according to detected signals of the optical sensors while the optical pickup moves along a radial direction of the optical disc. The method further includes generating a tracking error zero crossing signal according to the tracking error signal, generating a peak detecting signal according to the tracking error signal, generating a pseudo radio frequency zero crossing signal according to the peak detecting signal, and generating a track count signal according to the pseudo frequency crossing signal.

Abstract: A pre-pit signal decoder includes a shift register, a pattern comparator, a counting unit, an in-sync signal generating unit and a protection unit. The register receives serial pre-pit bits and converts them into a parallel pre-pit byte. The comparator generates an odd sync bit, an even sync bit, a low bit, and a high bit according to the pre-pit byte and receives a disable signal to operate when the disable signal is not enabled. The counting unit generates a counting value, which marks oddness/evenness of frames of the pre-pit bits and sequence of wobble signals in the frames, according to the odd sync, even sync, low and high bits. The signal generating unit generates an in-sync signal according to the odd sync, even sync, low, and high bits. The protection unit receives the counting value and the in-sync signal to thereby enable the disable signal at positions where the pre-pit bits impossibly exist according to the counting value.

Abstract: An ADIP demodulation method and apparatus, which are used in an optical disk driver to generate the ADIP information according to a wobble signal. The apparatus includes a slicing unit for receiving the wobble signal and generating a wobble pulse, a phase locked loop for generating a reference wobble signal with the same frequency and phase as the wobble pulse and a reference clock with frequency higher than the wobble pulse, a channel bit generator for generating a channel bit signal according to the reference wobble signal and the wobble pulse, and a decoder for decoding to ADIP information according to the channel bit signal. The channel bit generator generates a difference signal between the wobble pulse and the reference wobble signal, and outputs the channel bit signal according to the difference signal.

Abstract: A method for counting a number of tracks of an optical disc in an optical disc system. The optical disc system includes an optical pickup, a light source, and a plurality of optical sensors. The method includes emitting a light beam to the optical disc from the light source, detecting light reflected from the optical disc by the optical sensors, and generating a tracking error signal according to detected signals of the optical sensors while the optical pickup moves along a radial direction of the optical disc. The method further includes generating a tracking error zero crossing signal according to the tracking error signal, generating a peak detecting signal according to the tracking error signal, generating a pseudo radio frequency zero crossing signal according to the peak detecting signal, and generating a track count signal according to the pseudo frequency crossing signal.