Abstract: An apparatus and method are disclosed for improving data recovery operations in a disc drive employing a redundant sync data block format. The disc drive includes a rotatable disc and a controllably positionable head which is used to store user data in a plurality of data blocks on tracks of the disc. Each data block includes a user data field to store user data, a first sync field and a redundant, second sync field, the sync fields storing first and second sync words, respectively, which establish symbol boundaries used by a read channel of the disc drive. User data are recovered from a selected data block by initiating a delay of selected duration during which a first portion of the selected data block passes proximate the head, allowing the second, remaining portion of the selected data block to be read at the completion of the delay.

Abstract: The present invention uses temperature readings obtained aperiodically, on demand. Rather than merely obtaining temperature readings on each expiration of a fixed timer, operating parameters are updated in response to a fault detected in the data path. Data handling systems of the present invention each include at least one data path having a thermal range within which it operates best. Applicant notes that some “key” operating parameters typically have a substantial effect on this thermal range. Temperature sensors positioned near the transducers provide a temperature reading to control circuits, which update “key” operating parameter values in response to indications of faults in a primary data path. This reduces the need for more frequent temperature monitoring and calculation-intensive recalibration.

Abstract: A method and system for providing adaptive threshold levels for detecting thermal asperities where a unique threshold level is determined for each head. In addition, a unique threshold level is also set for each head at various locations on a disc. In particular, a threshold level for a first head in a first track is determined wherein the threshold level is initially set at a minimum threshold level and is subsequently increased by a threshold level increment until a detection is not made. These steps can be repeated for the first head in a second track and a second head in a first and second track. A memory saves the determined threshold levels.

Abstract: A method and system for providing adaptive threshold levels for detecting thermal asperities where a unique threshold level is determined for each head. In addition, a unique threshold level is also set for each head at various locations on a disc. In particular, a threshold level for a first head in a first track is determined wherein the threshold level is initially set at a minimum threshold level and is subsequently increased by a threshold level increment until a detection is not made. These steps can be repeated for the first head in a second track and a second head in a first and second track. A memory saves the determined threshold levels.

Abstract: An apparatus and method are disclosed for optimizing the operational performance of a disc drive having a head adjacent a rotatable disc, a servo circuit which controls the position of the head and a read channel for decoding read signals from the head to reconstruct data previously stored on the disc. The read channel includes a channel quality monitor which generates a channel quality measurement indicative of read channel quality, the channel quality measurement determined from error values associated with the data reconstructed by the read channel from the read signal. An optimum value for a selected parameter affecting disc drive performance is selected by determining an associated quality measurement value for each of a plurality of parameter values, and selecting the optimum value for the parameter in relation to the associated quality measurement values. Preferably, each associated quality measurement value is determined in less than one revolution of the disc.

Abstract: An apparatus and method are disclosed for improving data recovery operations in a disc drive employing a redundant sync data block format. The disc drive includes a rotatable disc and a controllably positionable head which is used to store user data in a plurality of data blocks on tracks of the disc. Each data block includes a user data field to store user data, a first sync field and a redundant, second sync field, the sync fields storing first and second sync words, respectively, which establish symbol boundaries used by a read channel of the disc drive. User data are recovered from a selected data block by initiating a delay of selected duration during which a first portion of the selected data block passes proximate the head, allowing the second, remaining portion of the selected data block to be read at the completion of the delay.