CIRCUIT AND METHOD FOR REPRODUCING DIGITAL SIGNAL

PROBLEM TO BE SOLVED: To quickly and automatically perform equalization and restrict a final equalization error to a minimum when characteristics of an equalizer to which reproduced digital signals are supplied are to be automatically adjusted. SOLUTION: A CPU 11 generates an equalization parameter for an equalizer 4 (an amplitude equalizer 4a and a phase equalizer 4b), thereby to automatically adjust characteristics of the equalizer 4. The CPU 11, reading a detected count of sinks from a sink detection circuit 8 and a corrected count of C1 errors by an error-correcting code, determines the equalization parameter to make an equalization error minimum according to a 'hill-climbing control method'. An equalization state is divided into three levels according to the control method and a using evaluation value is switched in the levels. In other words, when the equalization state is worst, the detected count of sinks is used. When the equalization state is best, the count of sole C1 errors is used. In the middle equalization state, the count of all C1 errors is used. The evaluation value shows the highest sensitivity to a change of the equalization error in each level.