Method and apparatus for servo data pattern detection
摘要
Methods and apparatus are provided for detecting servo information in a direct access storage device. A plurality of data symbols are read from a disk to produce a readback signal. Each data symbol and each sequence of data symbols contains servo identification information. A correlation filter provides a matched filter function of an expected readback signal of the plurality of data symbols to produce a correlated readback signal. A threshold detector is coupled to the correlation filter for identifying a threshold signal representative of the data symbol. A data separator responsive to the threshold detector windows the threshold signal and provides clock and data signals. The data separator includes a digital variable frequency oscillator (VFO) which optimally centers incoming servo information from the disk in a timing window and provides standard clocked data for a servo processor. The threshold detector has a variable threshold voltage that is programmed using a trim digital-to-analog converter (DAC).
申请公布号
US6031672(A)
申请公布日期
2000.02.29
申请号
US19960767970
申请日期
1996.12.17
申请人
INTERNATIONAL BUSINESS MACHINES CORPORATION
发明人
BERGQUIST, MARK ANDREW;COKER, JONATHAN DARREL;GALBRAITH, RICHARD LEO;PHILPOTT, RICK ALLEN;STANEK, DAVID JAMES