Fujitsu MH2060AH Manual/User Guide - Page 70

Theory of Device Operation

4-18

C141-E195-02EN

4.7.5 Spindle motor control

Hall-less three-phase twelve-pole motor is used for the spindle motor, and the 3-

phase full/half-wave analog current control circuit is used as the spindle motor

driver (called SVC hereafter).

The firmware operates on the MPU manufactured

by Fujitsu.

The spindle motor is controlled by sending several signals from the

MPU to the SVC.

There are three modes for the spindle control; start mode,

acceleration mode, and stable rotation mode.

(1) Start mode

When power is supplied, the spindle motor is started in the following sequence:

a)

After the power is turned on, the MPU sends a signal to the SVC to charge

the charge pump capacitor of the SVC.

The charged amount defines the

current that flows in the spindle motor.

b)

When the charge pump capacitor is charged enough, the MPU sets the SVC

to the motor start mode.

Then, a current (approx. 0.3 A) flows into the

spindle motor.

c)

A phase switching signal is generated and the phase of the current flowed in

the motor is changed in the order of (V-phase to U-phase),

(W-phase to U-

phase), (W-phase to V-phase), (U-phase to V-phase), (U-phase to W-phase),

and (V-phase to W-phase) (after that, repeating this order).

d)

During phase switching, the spindle motor starts rotating in low speed, and

generates a counter electromotive force.

The SVC detects this counter

electromotive force and reports to the MPU using a PHASE signal for speed

detection.

e)

The MPU is waiting for a PHASE signal.

When no phase signal is sent for a

specific period, the MPU resets the SVC and starts from the beginning.

When a PHASE signal is sent, the SVC enters the acceleration mode.

(2) Acceleration mode

In this mode, the MPU stops to send the phase switching signal to the SVC.

The

SVC starts a phase switching by itself based on the counter electromotive force.

Then, rotation of the spindle motor accelerates.

The MPU calculates a rotational

speed of the spindle motor based on the PHASE signal from the SVC, and waits

till the rotational speed reaches 5,400 rpm.

When the rotational speed reaches

5,400 rpm, the SVC enters the stable rotation mode.

(3) Stable rotation mode

The PLL (FLL) circuit is contained in the SVC that is used for this hard disk

drive.

The circuit controls the hardware to keep the rotational state steady to

maintain the target rotational speed.

The firmware calculates the time for one rotation based on the PHASE signal

output from the SVC to monitor the rotational state.

The control of this mode

(charge/discharge) is performed every rotation

Section	Page
Front Cover	1
FOR SAFE OPERATION	2
Revision History	3
Preface	5
Important Alert Items	9
Manual Organization	11
Contents	13
Illustrations	18
Figures	18
Tables	20
CHAPTER 1 Device Overview	21
1.1 Features	22
1.1.1 Functions and performance	22
1.1.2 Adaptability	22
1.1.3 Interface	23
1.2 Device Specifications	24
1.2.1 Specifications summary	24
1.3 Power Requirements	25
1.4 Environmental Specifications	28
1.5 Acoustic Noise	29
1.6 Shock and Vibration	29
1.7 Reliability	30
1.8 Error Rate	31
1.9 Media Defects	31
1.10 Load/Unload Function	31
1.11 Advanced Power Management	32
CHAPTER 2 Device Configuration	35
2.1 Device Configuration	36
2.2 System Configuration	37
2.2.1 ATA interface	37
2.2.2 1 drive connection	37
2.2.3 2 drives connection	38
CHAPTER 3 Installation Conditions	39
3.1 Dimensions	40
3.2 Mounting	41
3.3 Cable Connections	47
3.3.1 Device connector	47
3.3.2 Cable connector specifications	48
3.3.3 Device connection	48
3.3.4 Power supply connector (CN1)	48
3.4 Jumper Settings	49
3.4.1 Location of setting jumpers	49
3.4.2 Factory default setting	50
3.4.3 Master drive-slave drive setting	50
3.4.4 CSEL setting	51
3.4.5 Power Up in Standby setting	52
CHAPTER 4 Theory of Device Operation	53
4.1 Outline	54
4.2 Subassemblies	54
4.2.1 Disk	54
4.2.2 Spindle	54
4.2.3 Actuator	54
4.2.4 Air filter	55
4.3 Circuit Configuration	55
4.4 Power-on Sequence	58
4.5 Self-calibration	59
4.5.1 Self-calibration contents	59
4.5.2 Execution timing of self-calibration	60
4.5.3 Command processing during self-calibration	60
4.6 Read/write Circuit	61
4.6.1 Read/write preamplifier (PreAMP)	61
4.6.2 Write circuit	61
4.6.3 Read circuit	62
4.6.4 Digital PLL circuit	63
4.7 Servo Control	64
4.7.1 Servo control circuit	64
4.7.2 Data-surface servo format	66
4.7.3 Servo frame format	68
4.7.4 Actuator motor control	69
4.7.5 Spindle motor control	70
CHAPTER 5 Interface	71
5.1 Physical Interface	72
5.1.1 Interface signals	72
5.1.2 Signal assignment on the connector	73
5.2 Logical Interface	76
5.2.1 I/O registers	77
5.2.2 Command block registers	78
5.2.3 Control block registers	83
5.3 Host Commands	84
5.3.1 Command code and parameters	84
5.3.2 Command descriptions	88
5.4 Command Protocol	179
5.4.1 PIO Data transferring commands from device to host	179
5.4.2 PIO Data transferring commands from host to device	182
5.4.3 Commands without data transfer	184
5.4.4 Other commands	185
5.4.5 DMA data transfer commands	185
5.5 Ultra DMA Feature Set	188
5.5.1 Overview	188
5.5.2 Phases of operation	189
5.5.3 Ultra DMA data in commands	189
5.5.4 Ultra DMA data out commands	194
5.5.5 Ultra DMA CRC rules	198
5.5.6 Series termination required for Ultra DMA	199
5.6 Timing	200
5.6.1 PIO data transfer	200
5.6.2 Multiword data transfer	201
5.6.3 Ultra DMA data transfer	202
5.6.4 Power-on and reset	215
CHAPTER 6 Operations	217
6.1 Device Response to the Reset	218
6.1.1 Response to power-on	218
6.1.2 Response to hardware reset	219
6.1.3 Response to software reset	221
6.1.4 Response to diagnostic command	222
6.2 Power Save	223
6.2.1 Power save mode	223
6.2.2 Power commands	225
6.3 Defect Processing	225
6.3.1 Spare area	225
6.3.2 Alternating processing for defective sectors	226
6.4 Read-ahead Cache	228
6.4.1 DATA buffer structure	228
6.4.2 Caching operation	229
6.4.3 Using the read segment buffer	231
6.5 Write Cache	235
6.5.1 Cache operation	235
Glossary	237
Acronyms and Abbreviations	241
Index	243
Comment Form	245

Fujitsu MH2060AH Manual/User Guide - Page 70

Spindle motor control, phase, W-phase to V-phase

Page 70 highlights