Fujitsu MHS2020AT, Product Manual

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4.4 Power-on Sequence
C141-E171-03EN 4-7
4.4 Power-on Sequence
Figure 4.4 describes the operation sequence of the disk drive at power-on. The
outline is described below.
a) After the power is turned on, the disk drive executes the MPU bus test,
internal register read/write test, and work RAM read/write test. When the
self-diagnosis terminates successfully, the disk drive starts the spindle motor.
b) The disk drive executes self-diagnosis (data buffer read/write test) after
enabling response to the ATA bus.
c) After confirming that the spindle motor has reached rated speed, the head
assembly is loaded on the disk.
d) The disk drive positions the heads onto the SA area and reads out the system
information.
e) The disk drive sets up a requirement for execution of self-seek-calibration.
This collects data for VCM torque and mechanical external forces applied to
the actuator, and updates the calibrating value.
f) The drive becomes ready. The host can issue commands.