Data storage device with assistive bursts in servo sectors
Various illustrative aspects are directed to a data storage device, method, and one or more processing devices that are configured to: during a read operation, open a servo gate in the selected head in order to read the first servo bursts, the sync mark, and the second servo bursts in one of the servo sectors; and determine a position error signal for the selected head based on reading the first servo bursts and the second servo bursts.
1 . A data storage device, comprising:
one or more disks each comprising a plurality of servo sectors defining a plurality of data tracks, wherein each of the servo sectors comprises first servo bursts followed by a sync mark followed by second servo bursts;
an actuator mechanism configured to position a selected head among one or more heads proximate to a corresponding disk surface of a corresponding disk among the one or more disks; and
one or more processing devices, individually or in combination, configured to:
during a read operation, open a servo gate in the selected head to read the first servo bursts, the sync mark, and the second servo bursts in one of the servo sectors; and
determine a position error signal for the selected head based on reading the first servo bursts and the second servo bursts.
2 . The data storage device of claim 1 , wherein the read operation is configured to read data stored in a data sector immediately following the one of the servo sectors.
3 . The data storage device of claim 1 , wherein each of the servo sectors further comprises a track identifier (ID) between the first servo bursts and the second servo bursts.
4 . The data storage device of claim 1 , wherein each of the servo sectors is devoid of a preamble.
5 . The data storage device of claim 1 , wherein each of the servo sectors further comprises a preamble between the first servo bursts and the second servo bursts.
6 . The data storage device of claim 1 , wherein the position error signal comprises an average of a first position error signal determined using the first servo bursts and a second position error signal determined using the second servo bursts.
7 . The data storage device of claim 6 , wherein the average is a weighted average based on a first number of burst cycles associated with reading the first servo bursts and a second number of burst cycles associated with reading the second servo bursts.
8 . The data storage device of claim 1 , wherein:
the first servo bursts comprise a first burst and a second burst;
the second servo bursts comprise a third burst and a fourth burst;
the first burst and the third burst are a first burst type; and
the second burst and the fourth burst are a second burst type different than the first burst type.
9 . The data storage device of claim 8 , wherein the position error signal is determined using a sum of values obtained by reading the first burst and the third burst and a sum of values obtained by reading the second burst and the fourth burst.
10 . The data storage device of claim 8 , wherein the determining the position error signal comprises:
performing a first asynchronous position error signal calculation using the first burst and the second burst;
performing a second asynchronous position error signal calculation using the third burst and the fourth burst; and
determining the position error signal based on the first asynchronous position error signal calculation and the second asynchronous position error signal calculation.
11 . The data storage device of claim 1 , wherein each of the servo sectors further comprises repeatable runout (RRO) correction data.
12 . The data storage device of claim 11 , wherein the RRO correction data is followed by the sync mark.
13 . The data storage device of claim 1 , wherein the one or more processing devices, individually or in combination, are further configured to control a position of the selected head using the position error signal.
14 . The data storage device of claim 1 , wherein:
the first servo bursts comprise a first split burst servo pattern; and
the second servo bursts comprise a second split burst servo pattern.
15 . A method comprising:
during a read operation, opening a servo gate in a selected head to read first servo bursts followed by second servo bursts in a servo sector that is devoid of a preamble and devoid of a sync mark;
determining a position error signal for the selected head based on reading the first servo bursts and the second servo bursts; and
controlling a position of the selected head using the position error signal,
wherein the opening the servo gate, the determining the position error signal, and the controlling the position of the selected head are performed by one or more processing devices individually or in combination.
16 . The method of claim 15 , wherein:
the first servo bursts comprise a first burst and a second burst;
the second servo bursts comprise a third burst and a fourth burst;
the first burst and the third burst are a first burst type; and
the second burst and the fourth burst are a second burst type different than the first burst type.
17 . One or more processing devices comprising, individually or in combination:
means for opening a servo gate in a selected head, during a read operation, to read repeatable runout (RRO) correction data followed by a sync mark followed by servo bursts in a servo sector;
means for generating a control signal for the selected head based on reading the RRO correction data and the servo bursts; and
means for controlling a position of the selected head using the control signal.
18 . The one or more processing devices of claim 17 , wherein:
the servo sector comprises first servo bursts preceding the sync mark;
the servo bursts following the sync mark comprise second servo bursts; and
the control signal is generated based on reading the RRO correction data, the first servo bursts, and the second servo bursts.
19 . The one or more processing devices of claim 18 , further comprising, individually or in combination, means for determining a position error signal using respective values obtained by reading the first servo bursts and the second servo bursts.
20 . The one or more processing devices of claim 17 , wherein the servo sector comprises a preamble between the RRO correction data and the sync mark.