Patent ID: 6639748
Filing Date: 2003-10-28
Classification: G11B

Abstract:
A disk drive comprising:(a) a disk comprising a plurality of data tracks, each data track comprising a plurality of sectors, each sector comprising: a preamble field for storing a predetermined periodic data sequence; a sync field for storing a predetermined sync mark pattern; and a data field for storing data; (b) a head actuated radially over the disk for generating a read signal comprising a plurality of polarity alternating pulses; (c) a sync mark detector for detecting the sync mark pattern in the read signal, wherein when the sync mark pattern is detected the sync mark detector generates a sync mark detect signal and a polarity signal, the polarity signal indicative of an expected polarity of the pulses in the read signal representing the data stored in the data field; (d) a data detector for detecting an estimated data sequence from the read signal using the polarity signal to enhance performance; and (e) a data decoder, responsive to the sync mark detect signal, for decoding the estimated data sequence into a decoded data sequence.