Hardware implemented method and apparatus for locating a target sector

Abstract

A header detect method and apparatus for an optical media decoder circuit includes one or more comparators which compare target header information to header information read from the optical media for a current sector and each subsequent sector until the header information read from the optical media matches the target header information. The target header information is programmed into one or more target header registers. The information stored in the target header registers is then compared to the header information read from the optical media. Multiple comparators are used, to compare the header information read from the optical media for the current sector and a number of previous sectors to the target header information programmed into each of the target header registers, in order to provide a redundancy within the system and allow the apparatus to locate the target header even if one or more of the registers contain errors. The comparators activate a match signal when the header information read from the optical disk matches the target header information. The control logic circuit will then output a sector found signal which notifies the optical media decoder that the target sector has been located. If multiple comparators are included, a system designer may program a predetermined threshold, specifying a number of match signals which must be activated before the control logic circuit outputs the sector found signal.