Signal processing apparatus, signal processing method, and magnetic disk apparatus

摘要

According to at least one embodiment, a signal processor apparatus includes a Viterbi decoder, a processor, and an adjustment module. The Viterbi decoder calculates a branch metric based on an input signal. The processor outputs a processing result correlated with a processing result of the Viterbi decoder. A latency of the processor for the input signal is lower than a latency of the Viterbi decoder. The adjustment module adjusts a first parameter for calculating the branch metric based on the processing result of the processor.

主权项

1. A signal processing apparatus to receive an input signal and to output a first processing result, the signal processing apparatus comprising:
a Viterbi decoder configured to calculate a branch metric based on the input signal and a first parameter; a processor comprising at least one of an automatic gain control circuit, a phase locked loop, and an asymmetry correction circuit and configured to output a second processing result based on the input signal, the input signal being supplied to the Viterbi decoder through the processor, and the second processing result being correlated with the first processing result, wherein a latency of the processor is lower than a latency of the Viterbi decoder; and an adjuster configured to adjust the first parameter for the Viterbi decoder based on the second processing result and to supply the adjusted first parameter to the Viterbi decoder, wherein the second processing result comprises at least one of:
a gain correction amount of the automatic gain control circuit,an error estimation amount of the phase locked loop, andan asymmetry correction amount of the asymmetry correction circuit, and the adjuster is further configured to adjust the first parameter for data sectors comprising encoded data, adjust a second parameter for calculating the branch metric before the branch metric is calculated for a first data sector of the data sectors, and adjust the first parameter for the first data sector based on the second processing result.