Servo Frame Format - Fujitsu MPC3096AT - Desktop 9.7 GB Hard Drive Product Manual

(2) Data area
This area is used as the user data area 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.
4.7.3

Servo frame format

As the servo information, the drive uses the two-phase servo generated from the gray code and
servo 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, servo A to
D and PAD. Figure 4.7 shows the servo frame format.
Write/read
recovery
2.34 s
(1) Write/read recovery
This area is used to absorb the write/read transient and to stabilize the AGC.
(2) Servo mark
This area generates a timing for demodulating the gray code and position-demodulating the
servo A to D by detecting the servo mark.
Servo
Gray code
mark
0.54 s 3.06 s 1.26 s
Figure 4.7

Servo frame format

C141-E055-03EN
Servo Servo
Servo
A B
C
1.32 s 1.32 s
Servo
PAD
D
1.32 s 0.54 s
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