Abstract: Optical data controller (ODC) and Optical data encoder/decoder (ODE) functions are integrated on a common chip to carry out optical disk drive control. Programming and some circuit functions are shared by the ODC are ODE. Internal marks detection signals and developed by the ODC and ODE and ODE commands are made available on new output pins for external control functions and diagnostics.

Abstract: In a normal sector mark detection routine, using a wide open search window bits read from an optical data disk are searched for the presence of a sector mark pattern. Following detection of the pattern, using a search window of programmable width, a predefined region of the next sector is searched to locate a sector mark pattern. If the pattern is found, a sector mark found signal is generated. If the pattern is not found, a pseudo sector mark signal is generated. This sequence is repeated until either a subsequent sector mark pattern is detected, a predetermined number of pseudo sector mark signals generated or an exit command is received. Data is read from a sector in response to a sector mark found signal or pseudo sector mark signal. In a constant sector mark mode, the disk is searched, with the window wide open. Sector mark patterns are detected continuously to carry out media certification.

Abstract: A recovery routine enables data to be read from a sector of an optical data disk in the presence of damaged or missing syncs. If a sync is found, a "sync found" signal is generated to designate a normal read operation, and blocks of data read from the sector are aligned to resyncs distributed in the data stream. If a sync is not found, a pseudo sync is generated to designate a data recovery operation, and blocks of data are aligned to resyncs found in the data stream during a single pass or during separate passes through the sector at the user's option. The syncs and resyncs are searched using windows of programmably variable size for the read and recovery operations.

Abstract: The sector mark SM within a long burn data pattern recorded in each sector of an optical disk is detected asynchronously using a robust pattern detection algorithm. The terminal portion of the data pattern at the VFO field of the ANSI X3B11/ISO CCS Standard is ignored. The corner bits at the ends of the remaining pattern and between strings of one and zero bits are ignored, and the pattern that remains is stored in a register. A decoder compares adjacent strings of one and zero bits stored in the register to corresponding predetermined data. Voting circuitry uses a threshold value programmed by the user to determine the presence of a sector mark in the data pattern.