Fixed disc servo head control circuitry

摘要

The disc drive has a servo region where servo information and phase steps for each cylinder are located, a leader region where clock data are recorded and an indicator region showing the angular position of the servo region. A servo head (18) reads servo data. A read impulse capture circuit generates a read impulse. A clock generator section generates a phase synchronised clock signal w.r.t. the read pulse. A main clock generator (10) generates phase synchronised clock signals to access the desired cylinder in which the servo head (18) locates a track. A sampling pulse generates a clock signal of mark/space ratio corresponding to the phase difference in a region of the main clock reference phase, and an integrator generates a servo head positioning signal.