Fujitsu MPG3XXXAH manual Synthesizer circuit, 1 Transfer rate of each zone, Servo Control

Models: MPG3XXXAH

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4.6.4Synthesizer circuit

The drive uses constant density recording to increase total capacity. This is different from the conventional method of recording data with a fixed data transfer rate at all data area. In the constant density recording method, data area is divided into zones by radius and the data transfer rate is set so that the recording density of the inner cylinder of each zone is nearly constant. The drive divides data area into 15 zones to set the data transfer rate. Table 4.1 describes the data transfer rate and recording density (BPI) of each zone.

Table 4.1 Transfer rate of each zone

Zone

0

1

2

3

4

5

6

7

 

 

 

 

 

 

 

 

 

Cylinder

0

1216

2432

3744

4832

5824

7744

9632

 

to

to

to

to

to

to

to

to

 

1215

2431

3743

4831

5823

7743

9631

10815

 

 

 

 

 

 

 

 

 

Transfer rate

50.82

50.82

50.82

50.20

49.41

47.45

45.49

43.92

[MB/s]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Zone

8

9

10

11

12

13

14

 

 

 

 

 

 

 

 

 

 

Cylinder

10816

12352

13952

15232

16288

17824

19072

 

 

to

to

to

to

to

to

to

 

 

12351

13951

15231

16287

17823

19071

19423

 

 

 

 

 

 

 

 

 

 

Transfer rate

41.76

39.53

37.65

36.08

33.73

31.76

29.65

 

[MB/s]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The MPU transfers the data transfer rate setup data to the RDC that includes the time base generator circuit to change the data transfer rate.

4.7Servo Control

The actuator motor and the spindle motor are submitted to servo control. The actuator motor is controlled for moving and positioning the head to the track containing the desired data. To turn the disk at a constant velocity, the actuator motor is controlled according to the servo data that is written on the data side beforehand.

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C141-E112-01EN

Page 59
Image 59
Fujitsu MPG3XXXAH manual Synthesizer circuit, 1 Transfer rate of each zone, Servo Control