Patent ID: 8773793

Claim:
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; and adapt the coefficients of the target filter in order to minimize the error signal by minimizing: ∂ ∂ h ^ i ⁢ ∑ n ⁢ ( x ⁡ [ n ] - x ^ ⁡ [ n ] ) 2 where: ĥ i represents the coefficients of the target filter; x[n] represents the first output; and {circumflex over (x)}[n] represents the second output.