Synchronization servo mark detector and method having improved phase error immunity for use in mass data storage device, or the like

摘要

A detector (55) and method for detecting a synchronization servo mark (SSM) in a data stream of mass data storage device (10) has a matched filter (56) to receive the data stream. The filter (56) produces a maximum output when the SSM is applied. A delay element receives (64) the matched filter output to produce a delay element output (72). When the delay element output (72) is greater than a predetermined threshold value (Vth) and is larger than the output value (74), the (SSM) is in a current time location. When the "D" element output (72) is greater than the predetermined threshold value (Vth) and less than the output value, the SSM is in the next time location. The threshold may be established to be less than maximum if the phase of the SSM is within a predetermined phase range.