Abstract: The technology disclosed herein provides a method of verifying data read from a data block when the cell number of the data block does not match an ECC value stored in the data block. In particular, the method includes designating as unusable a data block in an indexed sequence of data blocks, wherein each data block is associated with a physical index; associating a cell number with a subsequent usable data block following the identified data block in the indexed sequence; and recording in an offset table accessible by an error detection and correction module an offset in association with the cell number of the subsequent usable data block, wherein the combination of the offset and the cell number represents a seed for the error detection and correction module.

Abstract: The technology disclosed herein provides a method of verifying data read from a data block when the cell number of the data block does not match an ECC value stored in the data block. In particular, the method includes accessing a data block in an indexed sequence of data blocks based on a cell number, wherein each data block in the indexed sequence includes a stored ECC value; retrieving an offset associated with the cell number of the data block; generating an ECC value based on the cell number and the offset; and determining whether the generated ECC value and the stored ECC value satisfy an integrity condition.

Abstract: An adaptive guard band for a ramp load/unload device is disclosed to provide extended data storage. In illustrated embodiments, an adaptive guard band algorithm is configured to format one or more discs or media having a lower capacity device with the adaptive guard band and extended data zone utilizing capacity measurements. The algorithm formats the media to provide a track zero at a first cylinder if the capacity is at or above the threshold capacity and a second cylinder if the capacity is below the threshold capacity to provide the extended data storage zone. A size or width of the extended data zone is variable to provide additional capacity to meet the threshold capacity.

Abstract: The technology disclosed herein provides a method of verifying data read from a data block when the cell number of the data block does not match an ECC value stored in the data block. In particular, the method includes accessing a data block in an indexed sequence of data blocks based on a cell number, wherein each data block in the indexed sequence includes a stored ECC value; retrieving an offset associated with the cell number of the data block; generating an ECC value based on the cell number and the offset; and determining whether the generated ECC value and the stored ECC value satisfy an integrity condition.

Abstract: The technology disclosed herein provides a method of verifying data read from a data block when the cell number of the data block does not match an ECC value stored in the data block. In particular, the method includes designating as unusable a data block in an indexed sequence of data blocks, wherein each data block is associated with a physical index; associating a cell number with a subsequent usable data block following the identified data block in the indexed sequence; and recording in an offset table accessible by an error detection and correction module an offset in association with the cell number of the subsequent usable data block, wherein the combination of the offset and the cell number represents a seed for the error detection and correction module.

Abstract: Methods and devices are provided for managing the transitions between operating modes in a data device. In an illustrative example, a method includes storing, in a control system for a device, a value for a first interval of time. The value indicates a minimum interval of time required for the device to remain in a lower power operating mode to provide energy savings at least equal to an energy cost associated with transitioning between the lower power operating mode and a higher power operating mode. The method further includes receiving a signal that instructs the device to transition from the lower power operating mode to the higher power operating mode. The method also includes ensuring that the device has remained in the lower power operating mode for at least as long as the first interval of time before it transitions to the higher power operating mode.

Abstract: Methods and devices are provided for managing the transitions between operating modes in a data device. In an illustrative example, a method includes storing, in a control system for a device, a value for a first interval of time. The value indicates a minimum interval of time required for the device to remain in a lower power operating mode to provide energy savings at least equal to an energy cost associated with transitioning between the lower power operating mode and a higher power operating mode. The method further includes receiving a signal that instructs the device to transition from the lower power operating mode to the higher power operating mode. The method also includes ensuring that the device has remained in the lower power operating mode for at least as long as the first interval of time before it transitions to the higher power operating mode.

Abstract: An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.

Abstract: An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.

Abstract: The method and apparatus herein identifies instability events occurring within a magneto-resistive head. The method commences by positioning magneto resistive head over a selected area of a disk that has no transitions, and then iteratively setting a read bias, and a thermal asperity threshold for counting and analysis of magneto resistive head instability events. The sensitivity of the thermal asperity detector is tuned to detect events that indicate magneto resistive head instability generated by the MR head over regions where magnetic transitions have been erased. The analyzed events are then used to determine the action taken related to the reliability of the head, that is, whether to reject or attempt to reduce the amount of instability related output. The apparatus includes without limitation a preamplifier, a read channel with a thermal asperity detector, and a comparator for counting and analyzing the resultant signals tested via biasing the magneto resistive head in a disc drive.