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:
Aug. 18, 1998
Filed:
May. 12, 1995
Tyson Tuttle, Austin, TX (US);
Diwakar Vishakhadatta, Austin, TX (US);
Jerrel P Hein, Driftwood, TX (US);
David R Welland, Austin, TX (US);
David E Reed, Westminster, CO (US);
Richard T Behrens, Louisville, CO (US);
William G Bliss, Thornton, CO (US);
Paul M Romano, Boulder, CO (US);
Trent O Dudley, Littleton, CO (US);
Christopher P Zook, Longmont, CO (US);
Cirrus Logic, Inc., Fremont, CA (US);
Abstract
A sampled amplitude read channel incorporated within a magnetic disk storage system for reading data recorded in concentric tracks on a magnetic medium, where the data comprises user data sectors recorded at varying data rates across a plurality of predefined zones and embedded servo data sectors recorded at the same data rate across the zones. The sampled amplitude read channel comprises a timing recovery component for synchronous sampling of a read signal from a magnetic read head positioned over the magnetic medium, a gain control component for adjusting the amplitude of the read signal, and a DC offset component for cancelling a DC offset in the read signal. These components are dynamically configured to operate according to whether the read channel is processing user data or embedded servo data. A user data frequency synthesizer and a servo data frequency synthesizer lock the timing recovery component to a reference frequency and provide a coarse center frequency control signal corresponding to the user data or servo data mode. The read channel further employs pipelined reads to reduce the physical gap between sectors on the medium. In addition, an improved sync mark detector and an improved asynchronous servo address mark detector increase the accuracy and reliability of the read channel.