PRML detector having a viterbi decoder outputting temporary judgement results

A PRML detector including a waveform equalizer that equalizes a waveform of a reproduction signal obtained by reproducing marks and non-marks recorded on a recording medium, and a decoder that generates binary-coded data of the reproduction signal based on the waveform equalized by the waveform equalizer, said decoder outputting a temporary data string which is obtained before the binary-coded data is obtained, said decoder having a path memory having data paths and outputting binary data obtained through a converged data path of the data paths which is converged based on an output of the equalizer,

• said waveform equalizer comprising:
• an equalizer that includes a delay element that delays a propagation of the reproduction signal, a plurality of multipliers that multiply predetermined coefficients by the reproduction signal and the delayed signal from the delay element, and an adder that adds outputs from the plurality of multipliers;
• a target value judger that determines a target value for equalizing based on the temporary data string output from the decoder;
• and
• a coefficient adaptive controller that calculates the predetermined coefficients and adaptively updates the calculated predetermined coefficients for each of a plurality of multipliers, the PRML detector outputting a merge check signal indicating non-convergence of at least two of the data paths when no data path converges in a middle of the data path of path memory,
• wherein the coefficient adaptive controller stops updating of the predetermined coefficients based on the merge check signal output from the path memory.

A PRML detector including a waveform equalizer that equalizes a waveform of a reproduction signal obtained by reproducing marks and non-marks recorded on a recording medium, and a decoder that generates binary-coded data of the reproduction signal based on the waveform equalized by the waveform equalizer, said decoder outputting a temporary data string obtained before the binary-coded data is obtained, said waveform equalizer comprising:

• an equalizer, comprising:
• a delay element that delays propagation of the reproduction signal;
• a plurality of multipliers that multiply predetermined coefficients by the reproduction signal and the delayed signal from the delay element;
• and
• an adder that adds outputs from the plurality of multipliers;
• a target value judger that determines a target value for equalizing based on the temporary data string output from the decoder;
• and
• a coefficient adaptive controller that calculates the predetermined coefficients and adaptively updates the calculated predetermined coefficients for each of a plurality of multipliers,
• wherein said coefficient adaptive controller stops updating the predetermined coefficients based on a merge check signal output from a path memory.

A PRML detector including a waveform equalizer for equalizing a waveform of a reproduction signal obtained by reproducing marks and non-marks recorded on a recording medium, and a decoder for generating binary-coded data of the reproduction signal based on the waveform equalized by the waveform equalizer, said decoder outputting a temporary data string obtained before the binary-coded data is obtained, said waveform equalizer comprising:

• an equalizer, comprising:
• a delay element that delays propagation of the reproduction signal;
• a plurality of multipliers that multiply predetermined coefficients by the reproduction signal and the delayed signal from the delay element;
• and
• an adder that adds outputs from the plurality of multipliers;
• a target value judger that determines a target value for equalizing based on the temporary data string output from the decoder;
• and
• a coefficient adaptive controller that calculates the predetermined coefficients and adaptively updates the calculated predetermined coefficients for each of a plurality of multipliers, wherein said coefficient adaptive controller initializes and stops updating the predetermined coefficients based on a merge check signal output from a path memory.