A high speed Viterbi detector for an optical disk system, includes a
frequency dividing unit for generating an auxiliary clock at one-third of
the main clock frequency, a branch metric calculation unit for calculating
each of a plurality of branch metrics, a serial-to-parallel converting
unit for outputting each of the branch metrics at the main clock frequency
in units of 3 state bits, an addition/comparison/selection unit for adding
the branch metrics and previously stored state metrics and for comparing
the addition results to select and output the minimum of the addition
results as a new state metric, and for outputting a corresponding path
selection signal, at the auxiliary clock frequency, a path memory for
storing the path selection signal and for outputting parallel data
corresponding to the path selection signal, at the auxiliary clock
frequency, and a parallel-to-serial converting unit for converting the
path memory output into serial data.
