Patent ID: 6992963

Claim:
A semiconductor integrated circuit comprising: a synchronous detection circuit which is given a playback signal generated by reading both first data recorded before recording to an optical disk is interrupted and second data recorded after the interruption, detects synchronization of the playback signal, and outputs a playback sync signal; and a sync signal phase measurement unit which is given the playback signal and playback sync signal, and measures and outputs a phase difference between components corresponding to the first and second data, which are included in the playback sync signal, wherein said sync signal measurement unit comprises: a data playback unit which is given the playback signal output from a reading unit and the playback sync signal output from said synchronous detection circuit, and generates a first data playback period signal indicating a period corresponding to the first data in the playback sync signal, and a second data playback period signal indicating a period corresponding to the second data in the playback sync signal; a sync signal phase holding unit which is given the playback sync signal and first data playback period signal, extracts a component contained in the period corresponding to the first data in the playback sync signal, and outputs a first data phase holding sync signal which holds the phase of the extracted component from the period corresponding to the first data to the period corresponding to the second data; and a phase difference measurement unit which is given the playback sync signal, second data playback period signal, and first data phase holding sync signal, and measures and outputs a phase difference between the first data phase holding sync signal and a component of the period corresponding to the second data in the second data playback period signal.