SYNCHRONOUS DETECTION OF WIDE BI-PHASE CODED SERVO INFORMATION FOR DISK DRIVE

摘要

A magnetic disk drive (10) data storage disk (16) defines recording tracks divided into data sectors by narrow servo spokes. A data sector lying between servo spokes is recorded with user data encoded in accordance with a code having a predetermined distance and user data code rate. Each servo spoke of the recording area has at least one servo information field encoded in a wide bi-phase code pattern. The disk drive (10) further includes a synchronous sampling data detection channel having a data transducer head (26) positioned by a servo-controlled actuator (67) over the recording track, a preamplifier (28) for receiving electrical analog signals magnetically induced by the data transducer head (26) from flux transitions present in at least the servo information field, a digital sampler (46) for synchronously sampling the electrical analog signals to produce digital samples, and wide bi-phase decoding circuitry (52) coupled to receive digital samples from the synchronous sampling data detection channel for decoding the wide bi-phase code pattern.