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. 17, 1999
Filed:
Jan. 10, 1997
Daniel James Malone, Sr, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The present invention provides a system, method and data format wherein a redundant sync byte or group of sync bytes is provided in a data sector at a distance sufficient to isolate the redundant sync byte from the primary sync byte in the event of multiple byte defects. In a first embodiment, a redundant sync byte, or group of sync bytes, is provided in the AGC field preceding the primary sync region. Upon failure to detect the primary sync byte, an attempt is made on a subsequent revolution to read the secondary sync byte, either by holding the AGC gain prior to reaching the data block, or initiating an 'early read' just prior to reaching the data block. In a second embodiment of the invention, the redundant sync byte is provided within the data field subsequent to the primary sync region. On failing to detect the primary sync byte, the secondary sync byte can be read immediately or can be postponed until a subsequent revolution. The missed first data region is reconstructed using ECC information. In third and fourth alternative embodiments, a secondary sync byte is provided either between the primary sync byte and the start of data or between the primary sync byte and AGC field.