4.7.2Data-surface servo format

Figure 4.5 describes the physical layout of the servo frame. The three areas indicated by (1) to

(3) in Figure 4.6 are described below.

(1)Inner guard band

The head is in contact with the disk in this space when the spindle starts turning or stops, and the rotational speed of the spindle can be controlled on this cylinder area for head moving.

(2)Data area

This area is used as the user data area and SA area.

(3)Outer guard band

This area is located at outer position of the user data area, and the rotational speed of the spindle can be controlled on this cylinder area for head moving.

4.7.3Servo frame format

As the servo information, the drive uses the two-phase servo generated from the gray code and Pos A to D. This servo information is used for positioning operation of radius direction and position detection of circumstance direction.

The servo frame consists of 5 blocks; write/read recovery, servo mark, gray code, Pos A to D and PAD. Figure 4.6 shows the servo frame format.

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Fujitsu MPF3XXXAH manual Data-surface servo format, Servo frame format