Method and apparatus for in situ detection of high-flying sliders over customer data

摘要

A method and apparatus are provided for in situ detection of high-flying sliders over customer data. A sampled and digitized readback sequence x(n) from a logical data block of customer data is received. Bandpass filtered data of the readback sequence x(n) is generated and processed for generating a predefined harmonic ratio. The generated predefined harmonic ratio is compared with a predefined threshold value to identify a high-flying slider. Bandpass filtered data of the readback sequence x(n) is generated with a digital comb filter and a digital resonator. The bandpass filtered data of the readback sequence x(n) is either squared or the absolute value is taken for a predefined number of samples and then accumulatively summed for the predefined number of samples and the harmonic ratio is calculated. The generated predefined harmonic ratio is compared with a predefined threshold value that is determined as a function of head and disk parameters. During a read operation, an equalizer high-frequency boost is generated responsive to identifying a high-flying slider. During a write operation to a selected write location, the write operation is aborted responsive to identifying a high-flying slider near the selected write location.