Method and apparatus for servo data pattern detection
US6031672A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1996 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | Dec 17, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59633
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
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).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.