Method and apparatus for accelerating a motor from an intermediate
velocity to a final operational velocity. The motor is accelerated from
rest to the intermediate velocity through application of fixed duration
drive pulses to the spindle motor. Once the motor reaches the
intermediate velocity, commutation circuitry and back electromotive force
(bemf) detection circuitry use detected bemf from the motor to
electronically commutate the motor to accelerate to the final operational
speed. A phase lock oscillator (PLO) attempts to acquire frequency lock
for the motor. A control circuit measures the current in the motor to
evaluate the effectiveness of the phase lock. If the measured current is
found to be above a threshold value, the motor is restarted.