The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 15, 1994
Filed:
May. 18, 1993
Lih-Jyh Weng, Shrewsbury, MA (US);
Michael E Kastner, Broomfield, CO (US);
Bruce Leshay, West Boylston, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A method and apparatus for identifying and synchronizing to two different fields in a disk drive employs different synchronization or 'sync' patterns to reduce the chances of mis-identifying and false-identifying a field. Two very distinct synchronization patterns have been found that satisfy the d=1, k=7 run-length constraints of a data code used in the disk drive. During operation, one sync pattern is searched for to identify and synchronize to its associated field, then the field itself is read. This procedure is then repeated for the other sync pattern and its associated field. Also, the phase of a preamble preceding each sync character is established, so that the number of comparisons needed to find either sync character is reduced. A sync detector operates on cell pairs, and has a selector that selects which sync pattern to search for. The sync detector also has special features that enable it to find preamble and DC Erase fields in the disk cell stream.