Theory of Device Operation
4-6 C141-E239
4.4 Power-on Sequence
Figure 4.3 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 SATA interface.
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 drive becomes ready. The host can issue commands.
f) The disk drive executes self -calibration. This collects data for VCM torque
and mechanical external forces applied to the actuator, and updates the
calibrating value.
Figure 4.3 Power-on operation sequence
Star
t
Sel
f
-diagnosis 1
- MPU bus test
- Internal register
write/read test
- Work RAM write/read
test
Power-on
a)
The spindle motor starts.
Sel
f
-diagnosis 2
- Data buffer write/read
test
b)
Confirming spindle moto
r
speed
c)
Load the head assembl
y
Drive ready state
(command waiting state)
f)
Execute sel
f
-calibration
e)
Initial on-track and
r
ead
out of system information
d)
End