Sampling clock generation for BCA data decoding

摘要

A sampling clock generator (41) for BCA data decoding providing a sampling clock, which is proportional to the actual rotation speed of a disk. The sampling clock generator (41) includes a frequency counter (411), a divider (412) and a frequency divider (413). The frequency counter (411) counts the number of pulses of a reference clock for each period of a rotation speed indicating signal of a spindle motor and generates a counting value. The divider (412) divides the counting value by a predefined value and generates a divided value. The frequency divider (413) is used to generate the sampling clock. The frequency divider (413) receives the reference clock and divides the frequency of the reference clock by the divided value to generate the sampling clock. The frequency divider (413) also adjusts the phase of the sampling clock according to the BCA reproducing signal.