Abstract: An adaptive search scheme leads to threshold voltages that have lower bit error rates over initial values. An initial reference voltage is used and data is measured for set steps in voltage about the initial value sufficient to fit a polynomial curve. A minimum is used to determine the lowest bit error rate and corresponding optimum threshold voltage. This voltage is adopted as the new threshold voltage for reading the given data.

Abstract: A data storage system having a read channel configured to function in a normal operation mode and a test mode. In the normal operation mode, the read channel is configured to decode a readback signal to obtain data bits. In the test mode, the read channel is configured to extract gain control loop data and/or timing control loop data from the readback signal.

Abstract: An adaptive search scheme leads to threshold voltages that have lower bit error rates over initial values. An initial reference voltage is used and data is measured for set steps in voltage about the initial value sufficient to fit a polynomial curve. A minimum is used to determine the lowest bit error rate and corresponding optimum threshold voltage. This voltage is adopted as the new threshold voltage for reading the given data.

Abstract: A predictive failure control circuit and associated method are provided in a data storing and retrieving apparatus. The circuit is configured to schedule a data integrity operation on data associated with a subportion of a data storage space, in relation to a comparison of an accumulated plurality of executed host access commands associated with the subportion. The subportion can comprise a sector or a single track or a band of tracks. A table preferably stores accumulated number of host access commands for each of a plurality of subportions of the data storage space. The data integrity operation can comprise reading the data on to detect degradation and restoring the recovered data to the same or to new, different tracks. The data subportions can also be reallocated to a new location.

Abstract: A data storage system having a read channel configured to function in a normal operation mode and a test mode. In the normal operation mode, the read channel is configured to decode a readback signal to obtain data bits. In the test mode, the read channel is configured to extract gain control loop data and/or timing control loop data from the readback signal.