Disk drive selecting target response based on identified response

摘要

A disk drive is disclosed comprising a head actuated over a disk. A test pattern is written to the disk and read from the disk to generate a read signal. The read signal is sampled to generate signal samples, the signal samples are filtered with an equalizer filter to generate a first output, and the test pattern is filtered with a target filter to generate a second output. An error signal is generated based on a difference between the first output and the second output. Coefficients of the target filter are adapted in response to the error signal, and after adapting the coefficients of the target filter, a sequence detector is configured based on the coefficients of the target filter.

主权项

1. A disk drive comprising:
a disk; a head actuated over the disk; and control circuitry operable to:
write a test pattern to the disk;read the test pattern from the disk to generate a read signal;sample the read signal to generate signal samples;filter the signal samples with an equalizer filter to generate a first output;filter the test pattern with a target filter to generate a second output;generate an error signal based on a difference between the first output and the second output;adapt coefficients of the target filter in response to the error signal;after adapting the coefficients of the target filter, configure a sequence detector based on the coefficients of the target filter; andadapt the coefficients of the target filter in order to minimize the error signal by minimizing:∂∂h^i⁢∑n⁢(x⁡[n]-x^⁡[n])2 where:ĥi represents the coefficients of the target filter;x[n] represents the first output; and{circumflex over (x)}[n] represents the second output.