Abstract: Methods, systems and computer program products for performing hybrid defect detection are disclosed. A hybrid defect detection mechanism may be used to detect various classes of defects (e.g., long and shallow defects, and short and deep defects) while reducing the probability of a miss or false alarm. In some implementations, the hybrid defect detection mechanism may utilize a defect detector that includes one or more defect sub-detectors. Each defect sub-detector may be associated with an individual threshold and sliding window length to enhance the hybrid defect detection process that maximizes the detection of a specific type or class of defects.

Abstract: Unfolded adaptive/decision-directed loops and correction circuits therefor, architectures, apparatuses and systems including the same, and methods, algorithms and software for reducing latency in an adaptive and/or decision-directed loop. Disclosed embodiments advantageously reduce effects of loop latency, improve the accuracy of corrections in an adaptive loop, and minimize overhead and delays associated with such improvements.

Abstract: A system comprising: a read/write head configured to generate signals in response to the read/write head being at a particular fly height over a storage medium during a read operation; a weighting function module configured to i) determine time domain samples in response to the signals generated by the read/write head, and ii) multiply each of the time domain samples by a corresponding coefficient of a window function to generate weighted samples; a first harmonic sensor module configured to estimate a magnitude of a first frequency in response to the weighted samples; and a head height control module configured to i) determine an estimated height of the read/write head over the storage medium in response to the magnitude of the first frequency, and ii) selectively adjust, during the read operation, the particular fly height of the read/write head over the storage medium based on the estimated height.

Abstract: Methods, apparatuses, and systems implementing analog techniques to decode signals extracted from servo wedges of computer-readable storage media. A digital signal representing a repeatable runout (RRO) signal included in an analog signal of a computer-readable storage medium is obtained. The RRO signal includes a preamble that represents a magnitude of the RRO signal, and data. The digital signal includes a digital representation of the preamble. An estimate of the magnitude of the RRO signal is determined based on the digital representation. The estimate is compared with a specified level to generate an error signal based on a difference between the two. The provision of the error signal, for application to a subsequent RRO signal of the computer-readable storage medium, is delayed. The RRO signal is amplified prior to being represented as the digital signal to match a value established to decode the RRO signal.

Abstract: Apparatus and methods are disclosed for decoding data stored on a data storage medium. A disclosed decoding method and decoder include a radial incoherence (RI) detector that increases the probability of detecting RI and improves the decoding performance in terms of the bit error rate of the decoded signal. RI is detected by comparing an input signal to the decoder against a RI threshold value and generating a RI-type signal. The RI detector may include a filter for filtering out noise and error in the RI-type signal, an adaptive threshold unit that adjusts the RI threshold value based upon the RI-type signal, a transition-based threshold unit that adjusts the RI threshold value based upon each transition in the input signal, or a path-based threshold unit that adjusts the RI threshold value based upon a best surviving path corresponding to the input signal, in combination or alone.

Abstract: Methods and apparatus are provided for performing interpolated timing recovery using a frequency and phase estimate. An analog signal representing a sector is asynchronously sampled and stored in a storage device. A retiming circuit reads the stored samples and, based on first portions of first and second timing portions of the sector, determines phase adjustments. The retiming circuit generates a signal representing the samples at the adjusted phase and determines sample shift adjustments based on the generated signal and second portions of the first and second timing portions. The retiming circuit computes start and end indices of the sector in the buffer based on the sample shift adjustment and phase adjustment. The start and end indices may be used to compute a frequency estimate. The frequency estimate and a phase adjustment is used to interpolate the asynchronous samples at the appropriate frequency and phase.

Abstract: The present disclosure includes apparatus, systems and techniques relating to detecting sync marks. In some implementations, an apparatus includes phase locking circuitry that includes a phase calculator to identify a phase of sampled data, and a phase-locked loop to generate an output signal and phase-lock the generated output signal with the calculated phase of the sampled data to produce a phase-locked signal. The apparatus includes detector circuitry to receive phase information of the phase-locked output signal. The detector circuitry includes a detector to generate a stream of decision bits for the sampled data with each bit in the stream being associated with a different phase. The detector circuitry includes an output selector to select at least one bit from the stream based on the received phase information of the phase-locked output signal.

Abstract: The invention is a networked system of devices positioned in a hazardous environment to monitor/control process conditions. The devices include sensors and controls such as valves. The sensors detect process conditions/control device settings and are monitored by a slave devices having, generally microprocessor controlled and having associated memory to receive and record the sensor/control device data. The network includes master devices, each master device may be associated with one or more slaved devices and associated sensors, where the master device communicates to is associated slave devices through a digital communication bus. The master device can automatically detect its associated slave devices and detect the communication and data characteristics of the slave devices. The master may also set parameters for detected slave devices, such as needed for computations performed by the master (using its own microprocessor) using data received form the slave device(s).

Abstract: A frequency adjustment system comprises an offset estimation module and a frequency adjustment module. The offset estimation module estimates a distance between data written to a rotating storage medium and a first center location about which the rotating storage medium rotates, the data having been previously written to the rotating storage medium relative to a second center location that is different than the first center location. The frequency adjustment module adjusts a sampling frequency at which the data is read from the rotating storage medium based on the distance between the data and the first center location.

Abstract: A fly height control system includes a weighting function module. The weighting function module applies coefficients from a window function in a time domain to digital samples to provide weighted samples. A first of the coefficients is applied to a first of the digital samples and a second of the coefficients is applied to a second of the digital samples. The first of the coefficients has a first magnitude that is different than a second magnitude of the second of the coefficients. The system also includes a harmonic sensor module that estimates a magnitude of a frequency in a frequency domain based on the weighted samples. The system also includes a head height control module that determines a height of a read/write head over a storage medium based on the magnitude of the frequency.

Abstract: Methods, apparatuses, and systems describing digital techniques to decode signals extracted from computer-readable storage media. A digital signal that includes a digital representation of a repeatable runout signal having a magnitude and included in an analog signal is obtained. An estimate of the magnitude of the RRO signal based on the digital signal is determined. The estimate is provided for decoding the digital signal to extract the included data by adapting a detector gain target in accordance with the estimate. The detector gain target is a function of a desired amplitude of the RRO signal.

Abstract: A system for identifying and compensating for non-linear transition shift in a magnetic medium data storage device is disclosed. The non-linear transition shift compensation system includes a non-linear transition shift estimation module adapted to generate non-linear transition shift estimates for specific bit patterns. The system further includes a pre-compensation module adapted to adjust the temporal spacing of binary transitions written to the magnetic medium based on the non-linear transition shift estimates generated by the non-linear transition shift estimation module for specific bit patterns corresponding to bit patterns appearing in the data being written to the magnetic medium.

Abstract: Systems and methods for detecting and designing enhanced disk sync marks using correlation detection are disclosed. The enhanced sync marks provide better noise immunity and higher detection rates over traditional Viterbi-based detection schemes even with a shorter sync mark length. The disk sync mark may provide optimal noise immunity for a particular target polynomial or a plurality of common target polynomials. The minimum Euclidean distance between a candidate sync mark and a plurality of right-shifted versions of the candidate sync mark is computed and compared with other candidate sync marks. The sync mark with the largest minimum Euclidean distance is then selected as the optimal mark. Systems and methods are also disclosed for detecting and designing a disk sync mark using correlation detection when the polarity of the disk is unknown or time-varying.

Abstract: Media menu items are generated within a media interface environment. Media menu item abstractions are generated, one of the media menu item abstractions arranged in a foreground position, and one or more of the media menu item abstractions arranged in background positions in the media interface environment. Selection of a media menu items transitions to a corresponding content menu interface.

Abstract: In a method for providing an estimate of a head position for a disk drive, a readback signal is filtered. The readback signal includes a first position signal component corresponding to a first position pattern on a disk, and includes a second position signal component corresponding to a second position pattern on the disk. Filtering the readback signal includes using a filter determined based on statistical information regarding a noise component of the readback signal. An estimate of an amplitude of the first position signal component is generated based on the filtered readback signal, and an estimate of an amplitude of the second position signal component is generated based on the filtered readback signal. An estimate of a head position with respect to a track on the disk is generated based on the estimate of the amplitude of the first position signal component and the estimate of the amplitude of the second position signal component.

Abstract: Media menu items are generated within a media interface environment. Media menu item abstractions are generated, one of the media menu item abstractions arranged in a foreground position, and one or more of the media menu item abstractions arranged in background positions in the media interface environment. Selection of a media menu items transitions to a corresponding content menu interface.

Abstract: Audio files and video files are selected for playback. One or more unassociated video items are selected for presentation during a playback of a selected audio file and presented during the playback of the selected audio file.

Abstract: Content abstractions are emerged in to an ingress terminus of a multidimensional path and depth transitioned through the multidimensional path to an egress terminus. The content abstractions are eliminated at the egress terminus.

Abstract: Playing a media file can include receiving input from a user identifying a playback location associated with a media file; downloading media content corresponding to the identified playback location from the media file; displaying a status bar to the user on a display device; and presenting a download indicator associated with the status bar showing an amount of downloaded media content, wherein the downloaded media content comprises a contiguous portion of the media file that includes the identified playback location. Further, playing the media file can include receiving additional input from a user identifying a new playback location associated with a media file; downloading media content corresponding to the new playback location; and presenting a new download indicator associated with the status bar showing an amount of downloaded media content, wherein the downloaded media content comprises a contiguous portion of the media file that includes the new playback location.

Abstract: Icons are arranged in foreground background positions in an interface environment to define a multidimensional path extending from a terminus. The icons transition between the foreground position and the background positions along the multidimensional path. Each icon corresponds to a content-specific menu item.