Fujitsu Corporation

Tomoki Sugaya

Hiroyuki Tanaka

Masahide Kanegae

Masao Kondou

Hideki Ohmori

Masahito Iwatsubo

Yoshihiro Hashimura

Katutoshi Asai

Disclosed is a PRML regenerating apparatus for regenerating a signal read by a head from a storage medium. This PRML regenerating apparatus has a waveform equalizing circuit for waveform-equalizing the read signal, a maximum-likelihood decoder for maximum-likelihood-decoding, after obtaining a determination value by comparing the equalized output with upper and lower slice levels, this determination value and a control circuit for setting variable a distance between the upper slice level and the lower slice level of the maximum-likelihood decoder. The distance between the upper and lower slice levels can be thereby set variable in accordance with an equalization characteristic. A ternary determination circuit of the maximum-likelihood decoder is constructed of a memory for storing a correspondence table of the equalized output and the upper or lower slice level versus the determination result and the next upper or lower slice level. The ternary determination circuit can be thereby actualized with a simple configuration.

PRML regenerating apparatus having adjusted slice levels

PRML regenerating apparatus having reduced number of charge pump circuits

Growing community of inventors

Kawasaki, Japan

Tomoki Sugaya