Patent attributes
Embodiments in accordance with the present invention provide a magnetic disk drive capable of achieving error recovery stably in a simple configuration in the event of thermal asperity (TA) and minimizing the error recovery time required, and a method for controlling the disk drive. According to one embodiment, if TA occurs, a cutoff frequency of a high-pass filter to which a data read signal is input is first increased and a loop gain of a low-order finite impulse response (FIR) filter connected in series to an FIR filter is also increased as high as possible. Next, a Viterbi decoder to which a signal is input from the low-order FIR filter provides feedback to the low-order FIR filter so that an input signal error becomes a minimum. Tap coefficients of the low-order FIR filter are thus optimized.
