Patent ID: 7573665
Filing Date: 2009-08-11
Classification: G11B

Abstract:
1. Sample logic configured to provide at least one sample value signal with respect to input samples of a magnetic read signal, said input samples provided at an input of a PRML Viterbi detector additionally having path metrics, a path memory, and an output, said path memory comprising bits representing the specific points of analysis in a time index of said input signals, by said path metrics and said path memory of the sequence of samples received at said input, said sample logic comprising: identification logic configured to identify a most likely path memory state of said PRML Viterbi detector from said path metrics of said PRML Viterbi detector; a selector configured to obtain from said path memory of said PRML Viterbi detector, an intermediate bit sequence from said specific points of analysis of said time index of said identified most likely path memory state, said intermediate bit sequence extending from an initiation point of said analysis by said path metrics and said path memory which is intermediate said sequence of samples at said output and received at said input of said PRML Viterbi detector, said initiation point corresponding to an input sample of said magnetic read signal; most likely sample logic configured to determine a sample value corresponding to said obtained intermediate bit sequence; wherein said selector is configured to programmably select said initiation point out of a plurality of initiation points; and an error term processor configured to process said sample value and an input sample from said input corresponding to said initiation point to provide at least one error signal.