Patent ID: 8300342
Filing Date: 2012-10-30
Classification: G11B

Abstract:
1. A method of detecting a synchronization mark, the method comprising: reading a stream of bits from a storage medium, wherein the stream of bits is read as output from a matched filter upstream of a primary data detector; performing pattern matching to determine whether a pattern of bits read from the storage medium, matches at least a portion of a synchronization mark; recognizing in the stream of bits, a phase of a repeated pattern of N bits indicative of a synchronization field; performing phase alignment to determine whether a location of the first bit of the pattern, is consistent with an expected location of the synchronization mark based upon the phase; wherein the phase alignment is performed by comparing a number of the first bit with a modulo N counter reading; wherein N=4; wherein the phase alignment indicates the synchronization mark if, the phase is 0 and the reading of the modulo counter 4 is zero, the phase is 1 and the reading of the modulo 4 counter is zero, the phase is 1 and the reading of the modulo 4 counter is 1, the phase is 2 and the reading of modulo 4 counter is 2, or the phase is 3 and the reading of the modulo 4 counter is 3; and indicating an existence of a synchronization mark only where the pattern matching and phase alignment are satisfied.