Patent ID: 6031672
Filing Date: 2000-02-29
Classification: G11B

Abstract:
Apparatus for detecting servo information in a direct access storage device comprising:transducer means for reading a plurality of servo data symbols from a disk to produce a servo readback signal, each servo data symbol and each sequence of servo data symbols containing servo information;correlation filter means for providing a matched filter function of an expected servo readback signal of said plurality of servo data symbols to produce a correlated servo readback signal;threshold detector means coupled to said correlation filter means for identifying a threshold signal representative of said servo data symbol; andservo data separator means receiving a start signal and responsive to said threshold detector means for windowing said threshold signal and providing servo clock and servo data signals; said servo data separator means including an initial phase setup block and a variable frequency oscillator (VFO) block; said initial phase setup block being clocked responsive to said start signal and enabling said variable frequency oscillator (VFO) block responsive to detecting predetermined servo data symbols; said variable frequency oscillator (VFO) block providing said servo clock and servo data signals.