DATA STORAGE DEVICE WITH SUPPORTING BURSTS IN SERVO SECTORS

Abstract

Various illustrative appearances relate to a data storage device, a method, and one or more processing devices configured to: open a servo gate in the selected head during a read operation 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.

Description

BACKGROUND

[0001] Data storage devices such as disk drives consist of a disk and a head connected to the distal end of an actuating arm. A voice coil motor (VCM) rotates the head around a pivot point to position it radially above the disk. The disk has a multitude of radially spaced, concentric tracks for recording user data sectors and servo sectors. The servo sectors contain head positioning information (such as a track address) that is read by the head and processed by a servo control system to control the actuating arm as it searches from track to track.

[0002] Fig. Figure 1 shows a prior art plate format 2 having a number of radially spaced concentric servo tracks 4, which are separated by servo sectors 60-6 Nare defined, recorded around the circumference of each servo track. A multitude of concentric data tracks are defined relative to the servo tracks 4, the data tracks having the same or a different radial density (e.g., tracks per inch (TPI)) than the servo tracks 4. Each servo sector 6 iIt features a preamble 8 for storing a periodic pattern, which enables appropriate gain adjustment and time synchronization of the read signal, as well as a sync marker 10 for storing a special pattern used for symbol synchronization with a servo data field 12. The servo data field 12 stores coarse head positioning information, such as a servo track address, which is used to position the head over a target data track during a search operation. Each servo sector (e.g., servo sector 64) further features groups of phase-based servo bursts 14 (e.g., N- and Q-servo bursts) that are recorded with a predetermined phase relative to each other and relative to the servo track centerlines.

[0003] The coarse head position information is processed to position a head over a target data track during a search operation, and the servobursts 14 provide precise head position information used for centerline tracking when accessing a data track during read / write operations. A position error signal (PES) is generated by reading the servobursts 14, where the PES represents a measured position of the head relative to a centerline of a target servo track. A servo controller processes the PES to generate a control signal that is applied to one or more head actuators to actuate the head radially across the disk in a direction that reduces the PES.In some examples, the one or more head actuators may include a voice coil motor as well as one or more fine control actuators such as milli actuators or micro actuators. SUMMARY

[0004] Several examples disclosed herein provide data storage devices, such as hard disk drives, with control circuits configured to perform a novel and inventive position error signal determination using values ​​obtained by reading respective first and second servo bursts in a servo sector without a preamble. In several examples, the servo sector has the first servo bursts, followed by a sync marker, followed by the second servo bursts in the longitudinal direction of a track containing the servo sector. Since the servo sector lacks a preamble, in some embodiments the first servo bursts can be written to the initial region of the servo sector, where the preamble would normally be written.In some embodiments, the first servobursts written to this region of the servo sector provide the servo sector with additional servobursts compared to servo sectors that have a preamble in this region. In some embodiments, the additional servobursts increase the amount of servoburst information available for determining the PES, thereby advantageously reducing the repeatable runout (RRO) component of the PES associated with read operations.

[0005] Various exemplary appearances relate to a data storage device comprising: one or more disks, each having a plurality of servo sectors defining a plurality of data tracks, each servo sector having first servo bursts followed by a sync mark followed by second servo bursts; an actuation mechanism configured to position a selected head from one or more heads near a corresponding disk surface of a corresponding disk from the one or more disks; and one or more processing devices.The one or more processing devices are set up individually or in combination to: open a servo gate in the selected head during a read operation 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.

[0006] Several exemplary manifestations relate to a method which includes: opening a servo gate in a selected head during a read operation to read first servo bursts followed by second servo bursts in a servo sector that has no preamble; determining a position error signal for the selected head based on reading the first and second servo bursts; and controlling a position of the selected head using the position error signal, wherein the opening of the servo gate, the determination of the position error signal, and the control of the position of the selected head are performed by one or more processing devices individually or in combination.

[0007] Various exemplary manifestations relate to one or more processing devices which include: means for opening a servo gate in a selected head during a read operation to read Repeatable Runout Correction Data (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.

[0008] Various other manifestations are depicted in the accompanying figures and described below, and become more apparent on this basis. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Several features and advantages of the technology of the present disclosure will become apparent from the following description of certain examples of this technology and their representation in the accompanying drawings. The drawings are not necessarily to scale; rather, the emphasis is on illustrating the principles of the technological concepts. In the drawings, the same reference numerals may refer to the same parts in different views. The drawings merely represent illustrative examples of the present disclosure and are not limiting in scope. Fig. Figure 1 shows a prior art plate format having a number of radially spaced concentric servo tracks defined by servo sectors recorded around the circumference of each servo track. Fig. 2A and Fig. 2B illustrate conceptual block diagrams of a top view and a side view of a data storage device in the form of a disk drive according to manifestations of the present disclosure. Fig. 2C shows a flowchart for an exemplary procedure which can perform or execute the control switching logic of a disk drive when controlling the operations of the disk drive, according to manifestations of the present disclosure. Fig. Figures 3A to 3E show exemplary servo sectors according to manifestations of the present disclosure. Fig. Figures 4A to 4E show the control of a servo gate relative to servo sectors according to manifestations of the present disclosure. Fig. Figures 5A to 5B show exemplary realizations of first servobursts and second servobursts in a servo sector according to manifestations of the present disclosure. Fig. Figure 6 shows a flowchart for an exemplary procedure which can perform or execute the control switching logic of a disk drive when controlling the operations of the disk drive, according to manifestations of the present disclosure. Fig. Figure 7 shows a flowchart for an exemplary procedure which can perform or execute the control switching logic of a disk drive when controlling the operations of the disk drive, according to manifestations of the present disclosure. DETAILED DESCRIPTION

[0010] Fig. 2A and Fig. Figure 2B illustrates conceptual block diagrams of a top view and a side view of a data storage device in the form of a disk drive 15 according to manifestations of the present disclosure. The disk drive 15 comprises a control switching logic 22, an actuating arm assembly 19 and several hard disks 16A, 16B, 16C, 16D (“hard disks 16”). Fig. 2C shows a flow chart for an exemplary method 80 which can perform or execute the servo control 24 of the control switching logic 22 when controlling the operations of the disk drive 15 according to manifestations of the present disclosure, including determining a position error signal for a head according to manifestations of the present disclosure.

[0011] The actuating arm assembly 19 comprises a primary actuating element 20 (e.g., a voice coil motor (“VCM”)) and a number of actuating arms 40 (e.g., the uppermost actuating arm 40A, as shown in the perspective view of the Fig. 2A and Fig. 2B). Each of the actuating arms 40 has a suspension assembly 42 at its distal end (e.g., the exemplary uppermost suspension assembly 42A, which is shown in the view of the Fig. 2A and Fig. 2B is included in the uppermost actuating arm 40A). Each suspension assembly 42 may, in some examples, have one or more additional fine actuating elements.

[0012] Each of the actuating arms 40 is configured to suspend a read / write head 18 in close proximity above a corresponding disk surface 17 (e.g., the read / write head 18A is suspended from the uppermost actuating arm 40A above the uppermost corresponding disk surface 17A, the read / write head 18H is suspended from the lowermost actuating arm 40H above the lowermost corresponding disk surface 17H). Further examples can include a wide variety of other numbers of disks and disk surfaces, as well as other numbers of actuating arm assemblies, primary actuators, and fine actuators besides the single actuating arm assembly 19 and the single actuator, for example, in the form of the VCM in the example of the Fig. 2A and Fig. 2B, exhibit.

[0013] In various examples, it can be assumed that the disk drive 15 performs or executes functions, tasks, processes, procedures and / or techniques, including manifestations of exemplary procedure 80 relating to the performance or execution of such functions, tasks, processes, procedures and / or techniques by its control circuit 22. The control circuit logic 22 may comprise and / or take the form of one or more driver devices and / or one or more other processing devices of any kind and may, in various examples, realize or execute functions, tasks, processes, procedures or techniques by executing computer-readable instructions of software code or firmware code on a hardware structure configured to execute such software code or firmware code.The control switching logic 22 can, in various examples, also realize or execute functions, tasks, processes, procedures, or techniques through its hardware switching logic, by realizing or executing such functions, tasks, processes, procedures, or techniques through the hardware structure itself, without any software operation. The control switching logic 22 can be operationally in communication and / or control connection or coupling with a host 44, which, in various examples, can be any external processing, data processing, and / or data management unit, such as a data processing device, a storage area network, a data center, a cloud computing resource of any type, and / or any other type of host.

[0014] The control logic 22 can comprise one or more processing devices, which represent device drivers specifically configured for controlling and operating certain devices, and one or more modules. Such device drivers can include one or more head drivers configured for controlling and operating the heads 18. Device drivers can be configured in various examples as one or more integrated components of one or more larger circuits, such as one or more PLSI (Power Large-Scale Integrated Circuit) chips or circuits, and / or as part of the control logic 22.Device drivers can also be set up in various examples as one or more components in other large integrated circuits, such as system-on-chip (SoC) circuits, or as more or less independent circuits which can be operationally coupled with other components of the control switching logic 22.

[0015] The primary actuating element 20 can perform a primary, macroscopic actuation of a plurality of actuating arms 40, each of which can suspend one of the heads 18 above and near the corresponding plate surfaces 17 of the plates 16. The positions of the heads 18, e.g., heads 18A and 18H, are shown in Fig. 2A is specified, although the heads 18 are generally positioned very close to the plate surfaces and are too small to be visible when in Fig. 2A and Fig. 2B is shown to scale.

[0016] The exemplary 15-inch disk drive of the Fig. 2A and Fig. Example 2B has four disks 16. Other examples may have any number of disks, such as one, two, three, five or more, ten, eleven, or more. Disks 16 are also referred to as disks, and their disk surfaces are also referred to as media or media surfaces. The four disks 16 have eight disk surfaces 17A, 17B, 17C, 17D, 17E, 17F, 17G, and 17H (“disk surfaces 17”), with one disk surface 17 on each side of each disk 16 in this illustrative example. The actuator assembly 19 suspends the heads 18 of each actuator arm 40 above and near a corresponding disk surface 17, enabling each head 18 to write control features and data to and from the respective adjacent disk surface 17.In this sense, each head 18 of each actuating arm 40 interacts with a corresponding plate surface 17. In the sense used here, it can be said that a head 18 works “over” a corresponding plate surface 17, such that the local reference frame is defined accordingly.

[0017] The term "disk surface" has the usual meaning it holds for experts in the respective technical fields. The term "disk surface" refers both to the outermost surface layer of a disk and to the volume of disk material beneath this outer surface layer, which can be understood as an atomic depth or (in a simplified model) as the number of atoms deep below the surface layer where the material can physically interact with the read / write heads. The term "disk surface" can encompass the portion of the disk's material that can interact with a read / write head during disk drive operations such as write control operations, read control operations, data write operations, and data read operations.

[0018] In the embodiment of the Fig. 2A and Fig. 2B represents each plate surface, e.g., plate surface 17A, as shown in Fig. Figure 2A shows a variety of control features. These control features include servo sectors 321 to 32. N on, which define a plurality of servo tracks 34, wherein data tracks which define a plurality of servo tracks 34, wherein data tracks are defined relative to the servo tracks 34, and which may have the same or different radial densities. The control switching logic 22, comprising the servo control 24, processes head signals 36 (e.g., one or more read signals) originating from the respective head, e.g., head 18A, to read from the disk surface 17A, the servo sectors 321-32 Nto demodulate and generate a position error signal (PES), which represents an error between the actual position of the head and a target position relative to a target track. The servo controller 24 in the control switching logic 22 filters the PES from the servo sectors using a suitable compensation filter to generate a control signal 38, which is applied to the actuating arm assembly 19, comprising the primary actuating element 20, which acts as a control actuating element, and rotates the actuating arm assembly 19 about an axial pivot point to perform primary actuation of the corresponding heads 18 radially above the plate surfaces 17 in a direction that reduces the PES, and in various examples to control any fine actuating elements.In various examples, the control switching logic 22 can also apply control signals to the heads 18 and / or to any of the different components of the disk drive 15 and receive sensor signals from them.

[0019] In the example of the Fig. 2A and Fig. In 2B, the actuator arm assembly 19 rotates the actuator arms 40 about a common pivot point. In another example, a first actuator arm assembly and / or a VCM and a second actuator arm assembly and / or a VCM, or other types of primary actuators, can each be configured to actuate respective actuator arm assemblies or groups of multiple actuator arms about separate pivot points, which are mounted, for example, at different circumferential positions around the plates. In some examples, each of the two actuator arm assemblies can control half of the heads and write to and read from half of the plate surfaces. In some examples, each of the actuator arm assemblies can be addressed by the host 44 as a separate logical data storage unit.In other examples, more than two actuating arm assemblies or primary actuating elements or multiple actuating elements can be used, which can be actuated around a common pivot point or can consist of several multiple actuating elements mounted at different positions on the circumference of the plates. The actuating arm assembly 19 and / or each of these other examples can thus represent and / or include an actuating mechanism in various examples. An actuating mechanism, such as the actuating arm assembly 19, can thus be configured to position heads 18, comprising a selected head from one or more heads 18, near a corresponding plate surface 17 from the one or more plates 16.

[0020] When performing the exemplary procedure 80 of the Fig. 2C (whose manifestations are also explained in more detail below with reference to the other figures) allows the control switching logic 22 to issue one or more commands to other components of the disk drive 15, receive information from one or more other components of the disk drive 15, and / or perform one or more internal operations, such as generating one or more driver currents for output to system components of the disk drive 15. In a specific example, during a read operation, the servo control 24 of the control switching logic 22 can open a servo gate in a selected head to read first servo bursts, followed by a sync marker, followed by second servo bursts in a servo sector (82). The servo control 24 can further determine a position error signal for the selected head based on the reading of the first servo bursts and the second servo bursts (84).The servo controller 24 can further control the position of the selected head using the position error signal (86). The control switching logic 22, comprising the servo controller 24, can further perform additional actions, procedures, and techniques according to various manifestations described in more detail herein.

[0021] The term “servo controller 24”, as used herein, may refer to any hardware, firmware, software, and / or combinations thereof contained in the control logic 22 of the disk drive 15, and which implement, embody, or operate any of the structures or functions attributed herein to the servo controller 24 or any other novel and inventive manifestation of the present disclosure. The servo controller 24 may consist of any hardware, firmware, software, and / or any other elements of the control logic 22 to determine a position error signal for a selected head based on the reading of first servo bursts and second servo bursts, and to perform other techniques and procedures as described herein.

[0022] Fig. Figure 3A shows an exemplary servo sector 300 according to various manifestations of the present disclosure. The servo sector 300 can represent one of many respective servo sectors located in respective tracks on respective disks 16 in the disk drive 15 of the Fig. 2A are included. In embodiments, the servo sector 300 has the first servobursts 305, the Gray code 310, the sync mark 315, and the second servobursts 320, which are arranged sequentially (i.e., one after the other) along the length of a track containing the servo sector 300. The Gray code 310 may have an address of the track (also called track ID or TID) and an address of the servo sector 300 in the track. The sync mark 315 may have a pattern such as a servo address mark (SAM) or a servo index mark (SIM) used for symbol synchronization with a servo data field, such as with respect to Fig. 1 described. In embodiments, the first servobursts 305 and the second servobursts 320 each have a corresponding group of phase-based servobursts (e.g., a periodic sequence of magnetic transitions) which are recorded with a predetermined phase relative to each other and relative to a center line of the track containing the servo sector 300.

[0023] Further referring to Fig. 3A, according to the manifestations of the present disclosure, the servo sector 300 is compared to the one in Fig. The servo sector format shown in Figure 1 is written to the disk without a preamble. In this way, servo sector 300 is free of a preamble (i.e., it has none). In embodiments, writing servo sectors without preambles improves disk formatting efficiency by reserving more space for user data. In one embodiment, writing servo sectors without preambles means that gain control and time synchronization can be implemented without the benefit of reading a preamble at the beginning of each servo sector. Because servo sector 300 has no preamble, the first servo bursts can be written to the beginning region of the servo sector, where the preamble would normally be written.

[0024] According to embodiments of the present disclosure, the servo controller 24 determines the PES for the head during a read operation based on the respective readouts of the first servobursts 305 and the second servobursts 320. In embodiments, first servobursts 305 supply the servo sector 300 with additional servobursts compared to the one in Fig. 1 servo sector format shown. In embodiments, these additional servo bursts increase the amount of servo burst information that can be used in determining the PES, compared to the servo sector format shown in Fig. Figure 1 is shown. In embodiments, this increased amount of servo burst information reduces the repeatable runout (RRO) component of the PES associated with read operations compared to when the PES uses the information shown in Figure 1. Fig. The servo sector format shown in Figure 1 is determined. By reducing the RRO component of the PES in this way, the amount of RRO correction data used with the disk is advantageously reduced, which advantageously reduces the time required to determine the RRO correction data and the amount of memory used to store the RRO correction data.

[0025] Fig. Figure 3B shows an embodiment of a servo sector 300' which includes the RRO data 325 and a preamble 330. In various embodiments, the RRO data 325 includes RRO correction data used to correct the RRO component of the PES associated with read operations. Such data can be determined during the manufacture and testing of the disk drive and written to the disk in the servo sector 300'. Due to the reduction in the amount of RRO correction data resulting from the use of the additional servo bursts, in embodiments the RRO correction data can advantageously be stored in the servo sector 300' instead of being stored in a separate memory such as a NAND flash memory or a dynamic random-access memory (DRAM). According to manifestations of the present disclosure, the RRO data 325 precedes the Gray code 310 and the sync mark 315 in the servo sector 300'.In one example, the RRO data 325 precedes the first servo bursts 305 to accommodate write transients associated with the RRO data 325. In another example, the RRO data 325, the first servo bursts 305, the preamble 310, the sync marker 315, the Gray code 310, and the second servo bursts 320 are arranged sequentially (i.e., one after the other) along the length of a track containing the servo sector 300'.

[0026] Since the write head is located a few micrometers behind the read head in the down-track direction, and the read head is configured to detect at least two servobursts 320 before completing the writing of user data in write mode, more space remains in the servo sector for fields such as the first servobursts 305 and the RRO data 325 between the user data and the other parts of the servo pattern, provided that the Gray code 310 and the sync mark 315 are kept as short as possible, as described in U.S. Patent 11,417,362 entitled "DATA STORAGE DEVICE ELIMINATING PREAMBLE FROM SERVO SECTORS." Therefore, although the absence of a preamble is permissible for some embodiments (e.g., Fig. 3B and Fig. 3E) is not a requirement in some other embodiments (e.g. Fig. 3A and Fig. 3D) The preamble is eliminated to free up more space in the servo sector for fields such as the first servo bursts 305 and / or the RRO data 325, making these embodiments more effective at reducing the RRO during servo operations in user data read mode. In some embodiments, a zone-divided servo pattern layout can be used, where the outer diameter side of each zone provides less space for the first servo bursts 305 and / or the RRO data 325. Consequently, in some embodiments, more servo zones and a continuous zone servo are used to allow more space for the first servo burst 305 and / or the RRO data 325.

[0027] Fig. Figure 3C shows an embodiment of a servo sector 300", which has first servo bursts 305 followed by second servo bursts 320, arranged sequentially (i.e., one after the other) along the length of a track containing the servo sector 300". In this embodiment, the servo sector 300" has no Gray code, no preamble, no RRO data, and no sync mark. In various examples, the control switching logic 22 in servo sectors of the disk uses only the second servo bursts 320 for all write operations, so that in these servo sectors there is more space for the first servo bursts 305.Consequently, for these servo sectors, the read mode PES determined using the relatively longer first servo bursts 305 is more effective when reducing the RRO during a read operation, thus eliminating the need for RRO calibration for the read mode in the manufacturing process and the need to store the corresponding RRO data, either written to the servo sector on the disk itself or stored in memory, as well as the subsequent operations of reading and using this data during the servo operation.

[0028] Fig. Figure 3D shows an embodiment of a servo sector 300''' which has the RRO data 325 before the first servo bursts 305, followed by the sync mark 315, followed by the second servo bursts 320 in the longitudinal direction of a track containing the servo sector 300'''. In this embodiment, the servo sector 300''' has neither a Gray code nor a preamble.

[0029] Fig. Figure 3E shows an embodiment of a servo sector 300'''' which includes the RRO data 325, the preamble 330, the sync mark 315, the Gray code 310, and the second servo bursts 320, arranged sequentially (i.e., one after the other) along the longitudinal direction of a track containing the servo sector 300''''. In this embodiment, the space in the servo sector 300'''' before the preamble is allocated for writing the RRO data 325, for example, when the length is insufficient for an effective, i.e., sufficiently long, group of first servo bursts 305.

[0030] Fig. Figure 4A shows exemplary states of a servo gate relative to the servo sector 300 according to manifestations of the present disclosure. In various embodiments, the servo controller 24 generates the Fig. 2A a servo time window which has a servo gate window which allows reading servo information in servo sector 300 using a read element in a head (e.g. in head 18A of the Fig. 2A) enables, which is guided via the servo sector 300. In embodiments, the servo controller 24 demodulates the servo information read by means of the read element, processes the demodulated servo information to determine the PES, and generates a control signal based on the PES. In embodiments, the control signal is configured to be sent to the VCM (e.g., the VCM of the Fig. 2A) to be used to control the position of the head, e.g., relative to a target position such as the center line of a track over which the head is moving. As in Fig. As shown in Figure 4A, arrow “D” represents the direction of movement of the head across the surface of the plate containing servo sector 300 (i.e., along the length of a track containing servo sector 300), so that the head moves across data sector N-1, then across servo sector 300, and then across data sector N. In the example shown in Fig. As shown in 4A, data sector N follows servo sector 300 and is the data sector that is assigned to servo sector 300.

[0031] In some embodiments, when performing a read operation on the data sector associated with servo sector 300, the servo controller 24 opens the servo gate to allow the read element to read the first servo bursts 305, the Gray code 310, the sync mark 315, and the second servo bursts 320 of servo sector 300. However, during a write operation, the servo gate can be opened in a way that reduces a write gap that would otherwise precede each servo sector. In one example, during a write operation, the servo gate is opened to allow the read element to read the sync mark 315 and the second servo bursts 320 without reading the first servo bursts 305 and the Gray code 310. In another example, during a write operation, the servo gate is opened to allow the read element to read part of the Gray code 310 (e.g.,to read the least significant bits of the track ID), the sync marker 315 and the second servo bursts 320, without reading the first servo bursts 305.

[0032] Fig. 4B, Fig. 4C, Fig. 4D and Fig. Figure 4E shows exemplary states of a servo gate relative to the servo sectors 300', 300'', 300'''' and 300'''' according to manifestations of the present disclosure. Fig. 4B, Fig. 4C, Fig. 4D and Fig. Figure 4E illustrates how the servo control 24 is configured in embodiments to control the servo gate relative to the servo sectors 300', 300'', 300''' and 300'''' differently during read operations than during write operations, e.g., in a manner similar to that of the Fig. 4A, or various write-gate operating modes that differ from Fig. 4A differ. In all configurations, different sectors, for example the odd and even sectors, can have different write gate configurations.

[0033] Fig. Figure 5A shows an exemplary implementation of first servobursts 305 and second servobursts 320 of the servo sector 300 according to embodiments of the present disclosure. In various embodiments, the first servobursts 305 have the first burst 501 and the second burst 502, and the second servobursts 320 have the third burst 503 and the fourth burst 504. In some embodiments, the first burst 501 and the third burst 503 are of a first burst type, and the second burst 502 and the fourth burst 504 are of a second burst type, which differs from the first burst type. In one example, the first burst 501 and the second burst 502 each correspond to a first A-burst and a first B-burst of a first null-burst servo pattern, and the third burst 503 and the fourth burst 504 each correspond to a second A-burst and a second B-burst of a second null-burst servo pattern.In this example, the A-bursts (which can also be called N-bursts) have a first pattern polarity, and the B-bursts (which can also be called Q-bursts) have a second pattern polarity that differs from the first. In various embodiments, the first and second pattern polarities are selected such that, when the first burst A and the second burst B are read back, their amplitudes are offset by half a track relative to the track deviation.

[0034] Fig. Figure 5A shows another exemplary realization of first servobursts 305 and second servobursts 320 of the servo sector 300 according to manifestations of the present disclosure. In various embodiments, the first servobursts 305 have a first servo pattern with split bursts, and the second servobursts 320 have a second servo pattern with split bursts. Servo patterns with split bursts are described in U.S. Patent No. 11,830,524 entitled "DATA STORAGE DEVICE WITH SPLIT BURST SERVO PATTERN" and U.S. Patent No. 12,100,431 entitled "DATA STORAGE DEVICE WITH SYMMETRIC SPLIT BURST SERVO PATTERN," the disclosures of both of which are incorporated herein by reference in their entirety. In various embodiments, and as shown in Fig. As shown in Figure 5B, the first burst 501 and the third burst 503 (or the second burst 502 and the fourth burst 504) can be split into two or more bursts (e.g. 501A, 501B, 503A, 503B), and a respective PES can be determined using the respective servo patterns with split bursts in the manner described in the aforementioned patent specifications.

[0035] Fig. 5A and Fig. 5B shows examples of first servobursts 305 and second servobursts 320 in the context of servo sector 300 of the Fig. 3A. The teachings of Fig. 5A and Fig. However, 5B are not limited to servo sector 300 and can instead be applied with any of the disclosed servo sectors that have first servo bursts 305 and second servo bursts 320, such as servo sector 300' of the Fig. 3B, the servo sector 300'' of the Fig. 3C and the servo sector 300''' of the Fig. 3D. Further reference to Fig. 5A und Fig. 5B, and according to various manifestations of the present disclosure, the servo controller 24 determines the PES for the head using values ​​obtained by reading each of the first servo bursts 305 and second servo bursts 320. In one example, the servo controller 24 determines a first PES using the first servo bursts 305, determines a second PES using the second servo bursts 320, and determines the PES for the head based on a function of the first PES and the second PES. For example, the servo controller 24 can determine the first PES based on values ​​obtained by reading the first burst 501 and the second burst 502, and determine the second PES based on values ​​obtained by reading the third burst 503 and the fourth burst 504. In embodiments, the function can be an average value, such that the PES for the head is an average of the first PES and the second PES.In one example, the function is a weighted average based on a first number of burst cycles associated with reading the first servo bursts 305, and a second number of burst cycles associated with reading the second servo bursts 320.

[0036] In another example, the servo controller 24 determines the PES for the head by calculating a first sum of values ​​obtained by reading the first burst 501 and the third burst 503, calculating a second sum of values ​​obtained by reading the second burst 502 and the fourth burst 504, and calculating the PES using the first sum and the second sum. In this example, the servo controller 24 can be configured to set the values ​​obtained by reading the first burst 501 and the third burst 503 and the values ​​obtained by reading the second burst 502 and the fourth burst 504 to synchronous amplitudes before the respective values ​​are added.

[0037] In another example, the servo controller 24 determines the PES for the head by performing a first asynchronous PES calculation using the first burst 501 and the second burst 502, performing a second asynchronous PES calculation using the third burst 503 and the fourth burst 504, and determining the PES based on the first and second asynchronous PES calculations. In this example, the respective asynchronous PES calculations can be performed in the manner described in U.S. Patent No. 12,046,256 entitled "DATA STORAGE DEVICE READ / WRITE CHANNEL WITH DIRECT RADIAL POSITION DEMODULATION IN ASYNCHRONOUS POSITION ERROR SIGNAL DEMODULATION," the disclosure of which is incorporated herein by reference in its entirety. In this example, the PES can be an average of the first asynchronous PES calculation and the second asynchronous PES calculation.In some embodiments, such as those where the servo sector is 300'''' of the . Fig. When 3E is used, the PES is determined from the second servobursts 320 using a synchronous PES calculation without the first servobursts 305. In embodiments that include the RRO data 325 (such as Fig. 3B, Fig. 3D and Fig. 3E), the control signal is determined based on the PES and the RRO correction data contained in the RRO data 325.

[0038] Fig. Figure 6 shows a flowchart for an exemplary method 680, which the servo control 24 of the control switching logic 22 can perform or execute when controlling the operations of the disk drive 15, according to embodiments of the present disclosure. In embodiments, the method 680 comprises: 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 without a preamble (682); determining a position error signal for the selected head based on reading the first servo bursts and the second servo bursts (684); and controlling a position of the selected head using the position error signal (686).

[0039] Fig.Figure 7 shows a flowchart for an exemplary method 780, which can perform or execute the servo control 24 of the control switching logic 22 when controlling the operations of the disk drive 15, according to manifestations of the present disclosure. In embodiments, the method 780 comprises: opening a servo gate in a selected head during a read operation to read repeatable runout correction data (RRO correction data) in a servo sector, followed by a sync mark, followed by servo bursts (782); generating a control signal for the selected head based on reading the RRO correction data and the servo bursts (784); and controlling a position of the selected head using the control signal (786). Generating the control signal may include determining a PES using one or more servo burst patterns and determining the control signal based on the PES and the RRO correction data.

[0040] Any suitable control logic can be used to implement the flowcharts in the embodiments described above, such as any suitable integrated circuit(s). For example, the control logic can be implemented in an integrated read channel circuit or in a component separate from the read channel, such as a data storage controller. Alternatively, certain operations described above can be performed by one read channel and others by a data storage controller. In some examples, the read channel and the data storage controller can be implemented as separate integrated circuits, and in some examples, the read channel and the data storage controller can be manufactured in a single integrated circuit or system-on-a-chip (SoC).In some examples, the control switching logic may include a suitable preamplifier circuit, which is implemented as a separate integrated circuit, integrated into the read channel or data storage control circuit, or integrated into a SOC.

[0041] In some examples, the control logic may include a microprocessor that executes instructions, the instructions being designed to cause the microprocessor to perform one or more manifestations of the procedures, processes, or techniques shown in the flowcharts and described herein with reference. Executable instructions of this disclosure may be stored on any computer-readable medium. In some examples, executable instructions of this disclosure may be stored on a non-volatile semiconductor storage device, a component, or a system outside of a microprocessor, or integrated with a microprocessor in a system-on-a-chip (SoC). In some examples, executable instructions of this disclosure may be stored on one or more disks and read into a volatile semiconductor memory when the disk drive is powered on.In some examples, the control logic can employ logic switching logic, such as state machine switching logic. In some examples, at least some of the sequence blocks can be implemented using analog switching logic (e.g., analog comparators, timers, etc.). In some examples, at least some of the sequence blocks can be implemented using digital switching logic or a combination of analog and digital switching logic.

[0042] In various examples, one or more processing devices can incorporate or form the control switching logic as described herein and / or perform one or more of the functions of the control switching logic as described herein. In various examples, the physical proximity of the control switching logic or one or more other processing devices performing one or more of the functions of the control switching logic as described herein can be abstracted from the disks and the disk surfaces.The control logic and / or one or more of its device drivers and / or one or more processing devices of any other type, performing one or more of the functions of the control logic as described herein, may, in various examples, be part of or located near a rack containing multiple data storage devices or a single-unit product containing multiple data storage devices, or may be part of or located near one or more physical or virtual servers, or may be part of or located near one or more local area networks or one or more storage area networks, or may be part of or located near a data center, or may be hosted in one or more cloud services.

[0043] In various examples, a disk drive may be a magnetic disk drive, an optical disk drive, a hybrid disk drive, or other types of disk drives. Some examples may include electronic devices, such as data processing devices, data server devices, media content storage devices, or other devices, components, or systems that incorporate the storage media and / or the control switching logic as described above.

[0044] The various features and processes described above can be used independently or combined in various ways. All possible combinations and subcombinations fall within the scope of this disclosure. Certain procedure, event, or process blocks may be omitted in some realizations. The procedures and processes described herein are not restricted to a specific sequence, and the blocks or states relating thereto may be performed in other sequences. For example, described tasks or events may be performed in a different order than the one specifically disclosed, or several may be combined in a single block or state. The exemplary tasks or events may be performed serially, in parallel, or otherwise.Tasks or events can be added to or removed from the disclosed exemplary manifestations. The exemplary systems and components described herein can be configured differently than described. For example, elements can be added, removed, or rearranged compared to the disclosed examples.

[0045] Although certain exemplary embodiments are described, these embodiments are presented merely as examples and do not limit the scope of protection of the inventions disclosed herein. Thus, nothing in the foregoing description is intended to imply that any particular feature, property, step, module, or block is necessary or indispensable. The new methods and systems described herein may be embodied in many other forms. Various omissions, substitutions, and modifications to the form of the methods and systems described herein may be made without departing from the idea and scope of this disclosure.

[0046] Method 80 and other methods of the present disclosure may have different steps or variations in various other embodiments. Some or all of Method 80 and other methods of the present disclosure may be performed by or embodied in hardware and / or by a controller, a CPU, an FPGA, a SoC, a measurement and control multiprocessor system on a chip (MPSoC), which may include both a CPU and an FPGA, and other elements together in an integrated SoC or other processing or data processing device that processes executable instructions, while controlling other associated hardware, devices, systems, or products in carrying out, realizing, or embodying various aspects of the method.The steps of Method 80 and other methods of the present disclosure can be performed individually or in combination by one or more processing devices. For example, in some implementations, the one or more processing devices may comprise a single processing device that performs all the steps of such a method. In some implementations, different processing devices may each perform different steps of such a method. For example, in some implementations, the one or more processing devices may comprise at least one first processing device that performs a first subset of the steps of such a method, and at least one second processing device that performs a second subset of the steps of the method.In some implementations, one or more steps of such a process can be performed by two or more of the one or more processing devices working together.

[0047] Therefore, data storage systems, devices, and methods are presented and described herein in various fundamental forms and in various selected exemplary applications, architectures, techniques, and methods for realizing and embodying new advantages of the present disclosure. These systems and methods are realized by the present disclosure and embody new advantages thereof. Those skilled in the art in the relevant fields will be well equipped by this disclosure to understand and implement a wide range of further applications, architectures, techniques, and methods for novel advantages, techniques, methods, processes, devices, and systems encompassed by the present disclosure and the claims listed below.

[0048] As used herein, the reference to "at least one of A, B, and C" shall mean "either A, B, C, or any combination of A, B, and C." The descriptions of the disclosed examples are intended to enable the person skilled in the art in the relevant field to understand how to manufacture or use the subject matter of this disclosure. Based on this disclosure, it will be readily apparent to the person skilled in the art various modifications to these embodiments, and the principles defined herein can be applied to other examples without departing from the idea or scope of this disclosure. Therefore, this disclosure is not limited to the embodiments presented herein but is intended to provide the broadest scope of protection consistent with the principles and novel features disclosed herein.

[0049] The present disclosure and many of its associated advantages are made clear by the foregoing description, and various modifications to the shape, construction, and arrangement of the components can be made without departing from the disclosed subject matter or without losing all or some of its essential advantages. The described shape serves only for illustration, and the following claims encompass and include a wide range of embodiments, including a wide range of examples, all of which include such modifications to the shape, construction, and arrangement of the components as described herein.

[0050] Although the present revelation has been described with reference to various examples, it is understood that these examples serve only for illustration and that the scope of the revelation is not limited to them. All the objects described herein are presented as illustrative, non-limiting examples and not as exclusive realizations, regardless of whether they are expressly designated as examples in the description or not. Many variations, modifications, and additions are possible within the framework of the examples of revelation. More generally, examples have been described according to the present revelation in the context of specific realizations.The functionality may be described differently in various examples of the disclosure, either separated into blocks or combined, or using different terminology, without deviating from the idea and scope of protection of the present disclosure and the following claims. These and other variations, modifications, additions, and improvements may fall within the scope of protection of the disclosure as defined in the following claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 11 417 362

[0026] US 11 830 524

[0034] US 12 100 431

[0034] US 12 046 256

[0037]

Claims

[1] Data storage device comprising: one or more disks, each having a plurality of servo sectors defining a plurality of data tracks, each servo sector having first servo bursts, followed by a sync marker, followed by second servo bursts; an actuating mechanism designed to position a selected head from one or more heads near a corresponding plate surface of a corresponding plate from the one or more plates; and one or more processing units, which are set up individually or in combination for: Opening a servo gate in the selected head during a read operation to read the first servo bursts, the sync mark, and the second servo bursts in one of the servo sectors; and Determining a position error signal for the selected head based on reading the first servo bursts and the second servo bursts. [2] Data storage device according to claim 1, wherein the read operation is configured to read data stored in a data sector immediately following one of the servo sectors. [3] Data storage device according to claim 1, wherein each of the servo sectors further comprises a track ID between the first servo bursts and the second servo bursts. [4] Data storage device according to claim 1, wherein none of the servo sectors has a preamble. [5] Data storage device according to claim 1, wherein each of the servo sectors further comprises a preamble between the first servo bursts and the second servo bursts. [6] Data storage device according to claim 1, wherein the position error signal has an average value 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] Data storage device according to claim 6, wherein the mean value is a weighted mean value 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] Data storage device according to claim 1, wherein: the first servobursts exhibit a first burst and a second burst; the second servobursts exhibit a third burst and a fourth burst; the first burst and the third burst, which are of a first burst type; and the second and fourth bursts are of a second burst type, which differs from the first burst type. [9] Data storage device according to 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] Data storage device according to claim 8, comprising determining the position error signal: Performing an initial asynchronous position error signal calculation using the first burst and the second burst; Perform a second asynchronous position error signal calculation using the third and fourth bursts; and Determining the position error signal based on the first asynchronous position error signal calculation and the second asynchronous position error signal calculation. [11] Data storage device according to claim 1, wherein each of the servo sectors further comprises Repeatable Runout Correction Data (RRO Correction Data). [12] Data storage device according to claim 11, wherein the sync mark follows the RRO correction data. [13] Data storage device according to claim 1, wherein the one or more processing units, individually or in combination, are further configured to control a position of the selected head using the position error signal. [14] Data storage device according to claim 1, wherein: the first servo bursts exhibit an initial servo pattern with split bursts; and The second servo bursts exhibit a second servo pattern with split bursts. [15] Methods 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 without a preamble; Determining a position error signal for the selected head based on reading the first servo bursts and the second servo bursts; and Controlling the position of the selected head using the position error signal, including opening the servo gate, determining the position error signal and The control of the position of the selected head can be carried out by one or more processing devices individually or in combination. [16] Method according to claim 15, wherein: the first servobursts exhibit a first burst and a second burst; the second servobursts exhibit a third burst and a fourth burst; the first burst and the third burst, which are of a first burst type; and the second and fourth bursts are of a second burst type, which differs from the first burst type. [17] One or more processing devices comprising: Means of opening a servo gate in a selected head during a read operation to read repeatable runout correction data (RRO correction data) in a servo sector, followed by a sync mark, followed by servo bursts; Means of generating a control signal for the selected head based on reading the RRO correction data and servo bursts; and Means of controlling the position of the selected head using the control signal. [18] One or more processing devices according to claim 17, wherein: the servo sector shows the first servo bursts before the sync mark; the servo bursts that follow the sync mark exhibit 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] One or more processing devices according to claim 18, further comprising means for determining a position error signal using respective values ​​obtained by reading the first servobursts and the second servobursts. [20] One or more processing devices according to claim 17, wherein the servo sector has a preamble between the RRO correction data and the sync mark.

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