Patent ID: 6392830
Filing Date: 2002-05-21
Classification: G11B

Abstract:
A sync byte detection system for use in a disk drive, comprising:a rotatable disk comprising at least one track for storing data in blocks of a predefined format, the data block format comprising a primary sync byte field including a primary sync byte pattern, a secondary sync byte field including a secondary sync byte pattern, at least one VFO field for producing an electrical signal of predetermined frequency, and a data field, the primary and secondary sync byte fields being separated by an isolating region comprising at lease one byte; a transducer; means for selectably positioning the transducer in close proximity to the disk; a data channel coupled to the transducer and including a sync byte detection circuit for detecting a sync byte pattern in an electrical signal received from the transducer, the data channel further including a VFO circuit coupled between the transducer and the sync byte detection circuit for receiving the electrical signal of predetermined frequency and producing therefrom a clock signal having the same predetermined frequency; and mode selccfing means for conditioning the sync byte detection circuit to detect the primary sync byte pattern in a first mode of operation and the secondary sync byte pattern in a second mode of operation, wherein the primary sync byte pattern and the secondary sync byte pattern are detected prior to accessing of said data field.