Patent ID: 6604220
Filing Date: 2003-08-05
Classification: G11B,H03M

Abstract:
A disk drive comprising:(a) a disk for storing data; (b) a head for reading the data stored on the disk to generate an analog read signal; (c) a sampler for sampling the analog read signal to generate a sequence of read signal sample values; (d) a multiple-input sequence detector, responsive to the read signal sample values, for detecting a first estimated data sequence during a first time interval, a second estimated data sequence during a second time interval, and a third estimated data sequence during a third time interval, the multiple-input sequence detector comprising: i. a first iterative detector, responsive to the read signal sample values and biased by selected reliability metrics, for generating first reliability metrics; and ii. a second iterative detector, responsive to the read signal sample values and biased by the first reliability metrics, for generating second reliability metrics; (e) an ECC decoder for decoding the first estimated data sequence into at least one decoded codeword comprising a plurality of bits concurrent with the multiple-input sequence detector detecting the second estimated data sequence; (f) a local memory for storing bits of the decoded codeword; and (g) a means for selecting between the second reliability metrics and bits of the decoded codeword stored in the local memory as the selected reliability metrics for use in biasing the first iterative detector, whereby the bits of the decoded codeword assist the multiple-input sequence detector in detecting the third estimated data sequence.