Data management for a data storage device with zone relocation

Information

  • Patent Grant
  • 9424864
  • Patent Number
    9,424,864
  • Date Filed
    Wednesday, July 2, 2014
    10 years ago
  • Date Issued
    Tuesday, August 23, 2016
    7 years ago
Abstract
Managing data stored on media of a Data Storage Device (DSD) using zone relocation. At least a portion of the media is logically divided into a plurality of zones and zones are identified with access counts greater than or equal to a threshold. The access count for each of the identified zones indicates a number of times data in the zone has been read or written. Data is relocated from at least one zone of the identified zones to at least one destination zone on the media to reduce a data access time between the identified zones.
Description
BACKGROUND

Data Storage Devices (DSDs) are often used to record data onto or to reproduce data from a storage media. One type of storage media includes a rotating magnetic disk where a magnetic head of the DSD can read and write data in tracks on a surface of the disk.


To access data from a surface of the disk, the head seeks to the location of the data on the disk during a seek operation. A long seek operation can result in a decreased performance of the DSD due to a longer time to access the data from the disk.





BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the embodiments of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the disclosure and not to limit the scope of what is claimed.



FIG. 1 is a block diagram depicting a Data Storage Device (DSD) according to an embodiment.



FIG. 2 illustrates an example histogram of access counts for a plurality of zones according to an embodiment.



FIG. 3 depicts initial zone locations on a disk media according to an embodiment.



FIG. 4 depicts the zones of FIG. 3 after relocation according to an embodiment.



FIG. 5 is a flowchart for a zone relocation process according to an embodiment.



FIG. 6A depicts blocks of zones with their respective access counts according to an embodiment.



FIG. 6B depicts a subdivision of the blocks of zones of FIG. 6A according to an embodiment.



FIG. 6C depicts the identification of zones with access counts greater than or equal to a threshold according to an embodiment.



FIG. 7A depicts an initial logical to physical mapping for the identified zones of FIG. 6C according to an embodiment.



FIG. 7B illustrates a logical to physical mapping for the identified zones of FIG. 6C after updating the mapping to account for the relocation of data according to an embodiment.





DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth to provide a full understanding of the present disclosure. It will be apparent, however, to one of ordinary skill in the art that the various embodiments disclosed may be practiced without some of these specific details. In other instances, well-known structures and techniques have not been shown in detail to avoid unnecessarily obscuring the various embodiments.



FIG. 1 shows system 100 according to an embodiment which includes host 101 and Data Storage Device (DSD) 106. System 100 can be, for example, a computer system (e.g., server, desktop, mobile/laptop, tablet, smartphone, etc.) or other electronic device such as a digital video recorder (DVR). In this regard, system 100 may be a stand-alone system or part of a network. Those of ordinary skill in the art will appreciate that system 100 and DSD 106 can include more or less than those elements shown in FIG. 1 and that the disclosed processes can be implemented in other environments.


In the example embodiment of FIG. 1, DSD 106 includes both solid-state memory 128 and disk 150 for storing data. In this regard, DSD 106 can be considered a Solid-state Hybrid Drive (SSHD) in that it includes both solid-state Non-Volatile Memory (NVM) media and disk NVM media. In other embodiments, each of disk 150 or solid-state memory 128 may be replaced by multiple Hard Disk Drives (HDDs) or multiple Solid-State Drives (SSDs), respectively, so that DSD 106 includes pools of HDDs or SSDs. In yet other embodiments, the NVM media of DSD 106 may only include disk 150 without solid-state memory 128.


DSD 106 includes controller 120 which includes circuitry such as one or more processors for executing instructions and can include a microcontroller, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), hard-wired logic, analog circuitry and/or a combination thereof. In one implementation, controller 120 can include a System on a Chip (SoC).


Host interface 126 is configured to interface DSD 106 with host 101 and may interface according to a standard such as, for example, PCI express (PCIe), Serial Advanced Technology Attachment (SATA), or Serial Attached SCSI (SAS). As will be appreciated by those of ordinary skill in the art, host interface 126 can be included as part of controller 120.


In the example of FIG. 1, disk 150 is rotated by a spindle motor (not shown). DSD 106 also includes head 136 connected to the distal end of actuator 130 which is rotated by Voice Coil Motor (VCM) 132 to position head 136 in relation to disk 150. Controller 120 can control the position of head 136 and the rotation of disk 150 using VCM control signal 30 and SM control signal 34, respectively.


As appreciated by those of ordinary skill in the art, disk 150 may form part of a disk pack with additional disks radially aligned below disk 150. In addition, head 136 may form part of a head stack assembly including additional heads with each head arranged to read data from and write data to a corresponding surface of a disk in a disk pack.


Disk 150 includes a number of radial spaced, concentric tracks (not shown) for storing data on a surface of disk 150 from an Inside Diameter (ID) portion to an Outside Diameter (OD) portion of disk 150. In the example of FIG. 1, the tracks on disk 150 are grouped together into zones 152 with each track divided into a number of sectors that are spaced circumferentially along the tracks. In other embodiments, zones 152 may include groups of sectors within a track rather than groups of tracks.


Disk 150 also includes a plurality of angularly spaced servo wedges 1540-154N, each of which may include embedded servo information that can be read by head 136 to determine a position of head 136 over disk 150. For example, each servo wedge 1540-154N may include a pattern of alternating magnetic transitions (servo burst), which may be read by head 136 and used to estimate the position of head 136 relative to disk 200.


In addition to disk 150, the NVM media of DSD 106 also includes solid-state memory 128 for storing data. While the description herein refers to solid-state memory generally, it is understood that solid-state memory may comprise one or more of various types of memory devices such as flash integrated circuits, Chalcogenide RAM (C-RAM), Phase Change Memory (PC-RAM or PRAM), Programmable Metallization Cell RAM (PMC-RAM or PMCm), Ovonic Unified Memory (OUM), Resistance RAM (RRAM), NAND memory (e.g., Single-Level Cell (SLC) memory, Multi-Level Cell (MLC) memory, or any combination thereof), NOR memory, EEPROM, Ferroelectric Memory (FeRAM), Magnetoresistive RAM (MRAM), other discrete NVM chips, or any combination thereof.


Volatile memory 140 can include, for example, a Dynamic Random Access Memory (DRAM) which can be used by DSD 106 to temporarily store data. Data stored in volatile memory 140 can include data read from NVM media (e.g., disk 150 or solid-state memory 128), data to be written to NVM media, instructions loaded from firmware of DSD 106 for execution by controller 120, or data used in executing firmware of DSD 106.


As shown in the embodiment of FIG. 1, volatile memory 140 stores translation table 22, which provides a mapping between Logical Block Addresses (LBAs) used by host 101 to address data and physical locations (e.g., Physical Block Addresses (PBAs)) indicating physical locations on disk 150 or in solid-state memory 128. In one implementation, a back-up copy of a translation table is stored on disk 150 which is updated to account for changes to translation table 22 stored in volatile memory 140. In other embodiments, translation table 22 may be stored in a different location such as in solid-state memory 128. Translation table 22 is described in more detail below with reference to FIGS. 7A and 7B.


In operation, host interface 126 receives read and write commands from host 101 via host interface 126 for reading data from and writing data to the NVM media of DSD 106. In response to a write command from host 101, controller 120 may buffer the data to be written for the write command in volatile memory 140.


For data to be stored in solid-state memory 128, controller 120 receives data from host interface 126 and may buffer the data in volatile memory 140. In one implementation, the data is then encoded into charge values for charging cells (not shown) of solid-state memory 128 to store the data.


In response to a read command for data stored in solid-state memory 128, controller 120 in one implementation reads current values for cells in solid-state memory 128 and decodes the current values into data that can be transferred to host 101. Such data may be buffered by controller 120 before transferring the data to host 101 via host interface 126.


For data to be written to disk 150, controller 120 can encode the buffered data into write signal 32 which is provided to head 136 for magnetically writing data to the surface of disk 150.


In response to a read command for data stored on disk 150, controller 120 positions head 136 via VCM control signal 30 to magnetically read the data stored on the surface of disk 150. Head 136 sends the read data as read signal 32 to controller 120 for decoding, and the data is buffered in volatile memory 140 for transferring to host 101.


As discussed in more detail below, particular zones 152 may be accessed for reading or writing more frequently than other zones 152 on disk 150. Often a workload from host 101 includes localized random activity spread across a stroke of actuator 130. This can reduce performance of DSD 106 in servicing read and write commands since it can take a relatively long time (e.g., 5 ms or longer) to position head 136 from one localized area of activity to another area of localized activity.



FIG. 2 illustrates an example of such localized activity across disk 150 according to an embodiment. Zones 152 on disk 150 are shown along the x-axis corresponding to their physical locations from an ID portion to an OD portion of disk 150. An access count indicating a number of times a particular zone has been accessed for reading or writing is shown in FIG. 2. Certain zones such as zones 208, 210, 212 and 214 have a relatively high frequency of access as compared to other zones. The zones with a high frequency of access can be separated by large distances across disk 150 such as areas 202 and 204 with little or no access activity. Performance of DSD 106 generally suffers by having zones with high access counts spread out across disk 150 since this can result in longer seek times when moving head 136 from one frequently accessed zone to the next.


The processes discussed below involve identifying zones with an access count greater than or equal to a threshold and relocating data from at least one of the identified zones to reduce a data access time between the identified zones. The data access time between identified zones can refer to the time it takes to read or write data in an identified zone after reading or writing data in another identified zone.


In some cases, relocating data from at least one identified zone can include moving frequently accessed zones so that they are in close physical proximity to each other on a surface of a disk either radially by relocating the data to adjacent tracks or circumferentially by relocating the data to adjacent sectors or groups of sectors within a track. In other cases, data from at least one identified high access zone can be relocated to a different disk or a different disk surface in a disk pack so that the zones are in closer radial proximity to each other in the disk pack. In such an example, DSD 106 can then quickly switch from one head to another head in a head stack assembly to change between accessing high frequency zones on different disk surfaces with little or no movement of actuator 130.


In some embodiments, the access count may be a random access count indicating a number of times data in a particular zone has been non-sequentially read or written. In contrast to sequential reads and writes, non-sequential or random reads and writes are typically isolated accesses of data from locations that are spread across the media. Sequential writes on the other hand include accesses of data from adjacent or nearly adjacent locations on the media. As a result, non-sequential reads and writes are generally more time consuming than sequential reads and writes since head 136 typically needs to reposition farther to complete a series of non-sequential reads or writes.


In other embodiments, the access count may indicate a number of times data in a particular zone has been sequentially read or written. Although the performance of a series of non-sequential reads or writes can be more time consuming, relocating zones that are frequently sequentially accessed can also improve a performance of DSD 106 in servicing read and write commands. In some embodiments, the access count can include both sequential and non-sequential reads and writes.


In FIG. 2, a threshold number of access counts has been set at 600 access counts as indicated by the dashed line. Zones 208, 210, 212, and 214 may be identified as candidate zones for relocation with access counts greater than or equal to the threshold. In some embodiments, the threshold may be adjusted based on a data access time between zones with high access counts relative to other zones. For example, the threshold for zone 208 may be lowered to 400 based on the greater data access time or distance between zone 208 and the other frequently accessed zones when compared to shorter data access times or distances between zones 210, 212, and 214.



FIG. 3 depicts initial locations for zones 208, 210, 212 and 214 on disk 150 according to an embodiment. As shown in FIG. 3, zones 208, 210, 212 and 214 are initially spread out across disk 150.


In addition, FIG. 3 depicts first staging area 224 and second staging area 226 for copying or relocating data from an identified zone to a destination zone. The location of staging areas 224 and 226 may differ in other embodiments and do not need to be located adjacent to each other. In this regard, one or both of staging areas 224 and 226 in other embodiments may be located on a different disk or different media such as solid-state memory 128 or volatile memory 140.


The area of disk 150 outside of dashed line 222 indicates an OD portion of disk 150 that is associated with a quicker data access rate than other portions of disk 150. In some implementations, destination zones for relocating frequently accessed data may be located at or beyond dashed line 222 to allow for quicker access of frequently accessed data.


Although zones 208, 210, 212 and 214 in FIG. 3 each include groups of tracks, the identified zones in other embodiments may only include a single track or a portion of a single track. In cases where identified zones include portions of a single track, data from the identified zones may be located adjacent to each other circumferentially by relocating data from the identified zones in close physical proximity to each other in the same track or in a radially adjacent track.



FIG. 4 depicts the relocation of data from the zones of FIG. 3 according to an embodiment. As shown in FIG. 4, data from each of zones 208, 210, and 212 has been relocated to destination zones 208′, 210′, and 212′, respectively. Zone 214 remains in its initial location. In other examples, data from a different number of identified zones may be relocated such that, for example, data from all of the identified zones (i.e., zones 208, 210, 212, 214) are relocated to destination zones or data from only half of the identified zones are relocated to destination zones.


In the example of FIG. 4, the data of zones 208, 210, 212 has been relocated to destination zones 208′, 210′, and 212′ using staging areas 224 and 226 to swap the data initially stored in a destination zone with the data initially stored in an identified zone. More specifically, data initially stored in a destination zone is copied to one of staging areas 224 or 226 to make room for data from an identified zone. The data initially stored in the identified zone is copied to the other staging area. The data initially stored in the destination zone can then be copied from its staging area to the initial location of the identified zone and the data initially stored in the identified zone can be copied from its staging area to the destination zone.


In other embodiments, the staging areas may not be located on disk 150 and may be located on a different disk in a disk pack or may be located in a different memory media such as solid-state memory 128 or volatile memory 140.



FIG. 5 is a flowchart for a zone relocation process that can be performed by controller 120 executing a firmware of DSD 106 or other computer-executable instructions according to an embodiment. In block 502, controller 120 logically divides at least a portion of a media such as disk 150 into a plurality of zones. The logical division of the media can be made by dividing LBAs into ranges or blocks of LBAs. As part of the division in block 502, controller 120 may first logically divide the media into a plurality of blocks with each block having a larger data capacity than the individual zones. Such large scale division followed by a finer subdivision of the blocks into zones can ordinarily allow for a more efficient use of resources (e.g., controller 120 and volatile memory 140) by not having to evaluate access counts for each zone individually. Instead, the process of FIG. 5 may only evaluate the access counts for zones in blocks with higher access counts. An example of such a logical division into blocks, sub-blocks, and zones is conceptually illustrated in FIGS. 6A to 6C.



FIG. 6A depicts blocks of zones with their respective access counts according to an embodiment. As shown in FIG. 6A, the media has been logically divided in terms of LBAs into four blocks A, B, C, and D. The blocks of FIG. 6A may represent a logical space for all of the media or for only a portion of the media. In addition, other embodiments may divide the media into a different number of blocks.


In the example of FIG. 6A, blocks A and D are identified as having a high access count relative to other blocks. This may be accomplished by comparing the access counts for each of the blocks or by determining whether the access counts for the blocks have reached or exceeded a threshold number of access counts.



FIG. 6B depicts a subdivision of the identified blocks of FIG. 6A according to an embodiment. As shown in FIG. 6B, each of blocks A and D are further divided into sub-blocks A1 to A4 and D1 to D4, respectively. Sub-blocks A2, A4, and D2 are identified as having a high access count relative to the other sub-blocks. As with the identification of blocks in FIG. 6A, the identification of sub-blocks with a high access count may be accomplished by comparing the access counts for each of the sub-blocks or by determining whether the access counts for the sub-blocks have reached or exceeded a threshold number of access counts.



FIG. 6C depicts the identification of zones with access counts greater than or equal to a threshold according to an embodiment. As shown in FIG. 6C, each of the identified sub-blocks of A2, A4, and D2 in FIG. 6B have been further subdivided into four zones. In addition, zones A2-1, A4-2, D2-1, and D2-4 have been identified as zones with access counts greater than or equal to a threshold number of access counts. As described in more detail below, these identified zones serve as candidates for relocating data from the zones to destination zones.


In other embodiments, the number and size of blocks, sub-blocks and zones can differ from the example provided above with FIGS. 6A to 6C based on available resources such as a processing speed of controller 120 or an available data capacity of volatile memory 140. Similarly, the number of iterations of subdividing can also differ so as to include more or less iterations of divisions. For example, other embodiments may only include a division of the media into blocks and zones without subdividing the blocks into sub-blocks. Other embodiments may include the subdivision of sub-blocks into smaller sub-blocks before subdividing the smaller sub-blocks into zones.


Returning to the relocation process of FIG. 5, controller 120 in block 504 identifies zones with access counts greater than or equal to a threshold. This may be performed along the lines as discussed for the example of FIG. 6C discussed above. Controller 120 may also optionally adjust the threshold based on a data access time between zones with high access counts relative to other zones. This adjustment can compensate for factors such as the distance between frequently accessed zones being greater so as to allow such zones to reach the adjusted threshold quicker than if such zones were in closer physical proximity to each other.


In block 506, data is relocated from at least one zone of the identified zones to at least one destination zone to reduce a data access time between the identified zones. As discussed above, this may include relocating data from an identified zone to a destination zone such that the data from the identified zones is in closer radial or circumferential proximity on a disk surface. The relocation of data in block 506 may also include relocating data from the identified zones so that the data is in closer radial proximity on different disk surfaces in a disk pack to reduce movement of actuator 130 when accessing data from the identified zones.


In block 508, controller 120 updates a mapping by offsetting physical addresses for the relocated data. The mapping can include, for example, a portion of translation table 22 where the mapping indicates physical locations in terms of PBAs for data stored on the media. FIGS. 7A and 7B depict example portions of translation table 22 to illustrate one implementation for updating the mapping in block 508 of FIG. 5.



FIG. 7A depicts an initial logical to physical mapping for the identified zones of FIG. 6C (i.e., zones A2-1, A4-2, D2-1, and D4-4) according to an embodiment. As shown in FIG. 7A, the LBAs for each of the identified zones are mapped to PBAs indicating a physical location on the media where data for the LBAs are stored. In the example of FIG. 7A, there is not an exact one-to-one correspondence between LBAs and PBAs as shown by the slightly higher physical addressing for zones A4-2, D2-1, and D4-4 as compared to the logical addressing for these zones. This difference can represent defects in the media such as defective sectors on disk 150 that have been mapped out or other reserved sectors that are not available for storing user data. Although the numerical ranges for LBAs in FIG. 7A generally correspond to approximately the same numerical ranges for PBAs for each zone, other embodiments may have PBA ranges that do not necessarily correspond to the ranges of LBAs.



FIG. 7B illustrates a logical to physical mapping for identified zones A2-1, A4-2, D2-1, and D4-4 after the mapping has been updated to account for the relocation of data according to an embodiment. When compared to FIG. 7A, the LBAs for the identified zones remains the same while the PBAs for some of the identified zones has been offset to account for the relocation of data from the zones. In particular, the PBAs for zones A2-1, D2-1, and D4-4 have been offset indicating that the data for these zones has been relocated.


After updating the mapping in block 508, the process of FIG. 5 ends. Controller 120 may repeat the process of FIG. 5 or portions of the process of FIG. 5 after a predetermined amount of time and/or after a predetermined a number of reads or writes on the media. In one embodiment, controller 120 may periodically check to determine if any zones should be relocated by performing block 504. If it is determined that a data access time can be reduced by relocating data from at least one identified zone, controller may proceed with performing blocks 506 and 508 to relocate the data. By periodically identifying zones with access counts greater than or equal to a threshold and relocating data, it is ordinarily possible to adapt to changing data access patterns and reduce an average or overall data access time for DSD 106.


Those of ordinary skill in the art will appreciate that the various illustrative logical blocks, modules, and processes described in connection with the examples disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. Furthermore, the foregoing processes can be embodied on a computer readable medium which causes a processor or computer to perform or execute certain functions.


To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, and modules have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Those of ordinary skill in the art may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.


The various illustrative logical blocks, units, modules, and controllers described in connection with the examples disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.


The activities of a method or process described in connection with the examples disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The steps of the method or algorithm may also be performed in an alternate order from those provided in the examples. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable media, an optical media, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an Application Specific Integrated Circuit (ASIC).


The foregoing description of the disclosed example embodiments is provided to enable any person of ordinary skill in the art to make or use the embodiments in the present disclosure. Various modifications to these examples will be readily apparent to those of ordinary skill in the art, and the principles disclosed herein may be applied to other examples without departing from the spirit or scope of the present disclosure. The described embodiments are to be considered in all respects only as illustrative and not restrictive and the scope of the disclosure is, therefore, indicated by the following claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims
  • 1. A Data Storage Device (DSD), comprising: at least one media for storing data; anda controller configured to: logically divide at least a portion of the at least one media into a plurality of zones by dividing logical block addresses for the at least one media into ranges of logical block addresses;identify zones of the plurality of zones with access counts greater than or equal to a threshold, wherein the access count for each of the identified zones indicates a number of times data in the zone has been read or written; andrelocate data from at least one of the identified zones to at least one destination zone on the at least one media so that the relocated data is in closer physical proximity to other data from at least one other identified zone.
  • 2. The DSD of claim 1, wherein the access count is a random access count indicating a number of times data in the zone has been non-sequentially read or written.
  • 3. The DSD of claim 1, wherein the access count is a sequential access count indicating a number of times data in the zone has been sequentially read or written.
  • 4. The DSD of claim 1, wherein the controller is further configured to update a mapping indicating physical locations for data stored on the at least one media by offsetting physical addresses in the mapping for the relocated data.
  • 5. The DSD of claim 1, wherein the controller is further configured to: logically divide the at least one media into a plurality of blocks with each block having a larger data capacity than individual zones of the plurality of zones;identify a block of the plurality of blocks with a high access count relative to other blocks, wherein the access count for the identified block indicates a number of times data in the identified block has been read or written; andsubdivide the identified block into zones of the plurality of zones to identify at least one zone of the identified zones with access counts greater than or equal to the threshold.
  • 6. The DSD of claim 1, wherein the controller is further configured to periodically identify zones with access counts greater than or equal to the threshold after at least one of a predetermined amount of time and a predetermined number of reads or writes of data on the at least one media.
  • 7. The DSD of claim 1, wherein the at least one media comprises at least one disk and the destination zone is located in an outer diameter portion of the at least one disk.
  • 8. The DSD of claim 1, wherein the controller is further configured to adjust the threshold based on a data access time between zones with high access counts relative to other zones of the plurality of zones.
  • 9. The DSD of claim 1, wherein the controller is further configured to relocate data from the at least one zone of the identified zones by at least: copying the data from the at least one zone of the identified zones to a first staging area on the at least one media;copying data from the at least one destination zone to a second staging area on the at least one media;copying the data from the first staging area to the at least one destination zone; andcopying the data from the second staging area to the at least one zone of the identified zones.
  • 10. The DSD of claim 1, wherein the at least one destination zone is located on a first disk surface of the at least one media so that the relocated data is radially in closer physical proximity to the other data from the at least one other identified zone on a second disk surface of the at least one media.
  • 11. A method for managing data stored on at least one media of a Data Storage Device (DSD), the method comprising: logically dividing at least a portion of the at least one media into a plurality of zones by dividing logical block addresses for the at least one media into ranges of logical block addresses;identifying zones of the plurality of zones with access counts greater than or equal to a threshold, wherein the access count for each of the identified zones indicates a number of times data in the zone has been read or written; andrelocating data from at least one zone of the identified zones to at least one destination zone on the at least one media so that the relocated data is in closer physical proximity to other data from at least one other identified zone.
  • 12. The method of claim 11, wherein the access count is a random access count indicating a number of times data in the zone has been non-sequentially read or written.
  • 13. The method of claim 11, wherein the access count is a sequential access count indicating a number of times data in the zone has been sequentially read or written.
  • 14. The method of claim 11, further comprising updating a mapping indicating physical locations for data stored on the at least one media by offsetting physical addresses in the mapping for the relocated data.
  • 15. The method of claim 11, further comprising: logically dividing the at least one media into a plurality of blocks with each block having a larger data capacity than individual zones of the plurality of zones;identifying a block of the plurality of blocks with a high access count relative to other blocks, wherein the access count for the identified block indicates a number of times data in the identified block has been read or written; andsubdividing the identified block into zones of the plurality of zones to identify at least one zone of the identified zones with access counts greater than or equal to the threshold.
  • 16. The method of claim 11, further comprising periodically identifying zones with access counts greater than or equal to the threshold after at least one of a predetermined amount of time and a predetermined number of reads or writes of data on the at least one media.
  • 17. The method of claim 11, wherein the at least one media comprises at least one disk and the destination zone is located in an outer diameter portion of the at least one disk.
  • 18. The method of claim 11, further comprising adjusting the threshold based on a data access time between zones with high access counts relative to other zones of the plurality of zones.
  • 19. The method of claim 11, further comprising relocating data from the at least one zone of the identified zones by at least: copying the data from the at least one zone of the identified zones to a first staging area on the at least one media;copying data from the at least one destination zone to a second staging area on the at least one media;copying the data from the first staging area to the at least one destination zone; andcopying the data from the second staging area to the at least one zone of the identified zones.
  • 20. The method of claim 11, wherein the at least one destination zone is located on a first disk surface of the at least one media so that the relocated data is radially in closer physical proximity to the other data from the at least one other identified zone on a second disk surface of the at least one media.
  • 21. A computer readable medium storing computer-executable instructions for managing data on at least one media of a Data Storage Device (DSD), wherein when the computer-executable instructions are executed by a controller or processor, the computer-executable instructions cause the controller or processor to: divide the at least one media into a plurality of zones by dividing logical block addresses for the at least one media into ranges of logical block addresses;identify zones of the plurality of zones with access counts greater than or equal to a threshold, wherein the access count for each of the identified zones indicates a number of times data in the zone has been read or written; andrelocate data from at least one zone of the identified zones to at least one destination zone on the at least one media so that the relocated data is in closer physical proximity to other data from at least one other identified zone.
  • 22. The computer readable medium of claim 21, wherein the access count is a random access count indicating a number of times data in the zone has been non-sequentially read or written.
  • 23. A Data Storage Device (DSD), comprising: at least one media for storing data; anda controller configured to: logically divide the at least one media into a plurality of blocks;identify at least one block of the plurality of blocks with a high access count relative to other blocks, wherein the access count for the at least one identified block indicates a number of times data in the at least one identified block has been read or written;subdivide the at least one identified block into a plurality of zones;identify zones of the plurality of zones with access counts greater than or equal to a threshold, wherein the access count for each of the identified zones indicates a number of times data in the zone has been read or written; andrelocate data from at least one of the identified zones to at least one destination zone on the at least one media to reduce a data access time between the identified zones.
  • 24. A method for managing data stored on at least one media of a Data Storage Device (DSD), the method comprising: logically dividing the at least one media into a plurality of blocks;identifying at least one block of the plurality of blocks with a high access count relative to other blocks, wherein the access count for the at least one identified block indicates a number of times data in the at least one identified block has been read or written;subdividing the at least one identified block into a plurality of zones;identifying zones of the plurality of zones with access counts greater than or equal to a threshold, wherein the access count for each of the identified zones indicates a number of times data in the zone has been read or written; andrelocating data from at least one of the identified zones to at least one destination zone on the at least one media to reduce a data access time between the identified zones.
US Referenced Citations (446)
Number Name Date Kind
5333311 Whipple, II Jul 1994 A
5619690 Matsumani Apr 1997 A
6018789 Sokolov et al. Jan 2000 A
6065095 Sokolov et al. May 2000 A
6078452 Kittilson et al. Jun 2000 A
6081447 Lofgren et al. Jun 2000 A
6088766 Bachmat Jul 2000 A
6092149 Hicken et al. Jul 2000 A
6092150 Sokolov et al. Jul 2000 A
6094707 Sokolov et al. Jul 2000 A
6105104 Guttmann et al. Aug 2000 A
6111717 Cloke et al. Aug 2000 A
6145052 Howe et al. Nov 2000 A
6175893 D'Souza et al. Jan 2001 B1
6178056 Cloke et al. Jan 2001 B1
6191909 Cloke et al. Feb 2001 B1
6195218 Guttmann et al. Feb 2001 B1
6205494 Williams Mar 2001 B1
6208477 Cloke et al. Mar 2001 B1
6223303 Billings et al. Apr 2001 B1
6230233 Lofgren et al. May 2001 B1
6246346 Cloke et al. Jun 2001 B1
6249393 Billings et al. Jun 2001 B1
6256695 Williams Jul 2001 B1
6262857 Hull et al. Jul 2001 B1
6263459 Schibilla Jul 2001 B1
6272694 Weaver et al. Aug 2001 B1
6278568 Cloke et al. Aug 2001 B1
6279089 Schibilla et al. Aug 2001 B1
6289484 Rothberg et al. Sep 2001 B1
6292912 Cloke et al. Sep 2001 B1
6310740 Dunbar et al. Oct 2001 B1
6317850 Rothberg Nov 2001 B1
6327106 Rothberg Dec 2001 B1
6337778 Gagne Jan 2002 B1
6369969 Christiansen et al. Apr 2002 B1
6384999 Schibilla May 2002 B1
6388833 Golowka et al. May 2002 B1
6405342 Lee Jun 2002 B1
6408357 Hanmann et al. Jun 2002 B1
6408406 Parris Jun 2002 B1
6411452 Cloke Jun 2002 B1
6411458 Billings et al. Jun 2002 B1
6412083 Rothberg et al. Jun 2002 B1
6415349 Hull et al. Jul 2002 B1
6425128 Krapf et al. Jul 2002 B1
6441981 Cloke et al. Aug 2002 B1
6442328 Elliott et al. Aug 2002 B1
6445524 Nazarian et al. Sep 2002 B1
6449767 Krapf et al. Sep 2002 B1
6453115 Boyle Sep 2002 B1
6470420 Hospodor Oct 2002 B1
6480020 Jung et al. Nov 2002 B1
6480349 Kim et al. Nov 2002 B1
6480932 Vallis et al. Nov 2002 B1
6483986 Krapf Nov 2002 B1
6487032 Cloke et al. Nov 2002 B1
6490635 Holmes Dec 2002 B1
6493173 Kim et al. Dec 2002 B1
6499083 Hamlin Dec 2002 B1
6519104 Cloke et al. Feb 2003 B1
6525892 Dunbar et al. Feb 2003 B1
6545830 Briggs et al. Apr 2003 B1
6546489 Frank, Jr. et al. Apr 2003 B1
6550021 Dalphy et al. Apr 2003 B1
6552880 Dunbar et al. Apr 2003 B1
6553457 Wilkins et al. Apr 2003 B1
6578106 Price Jun 2003 B1
6580573 Hull et al. Jun 2003 B1
6594183 Lofgren et al. Jul 2003 B1
6600620 Krounbi et al. Jul 2003 B1
6601137 Castro et al. Jul 2003 B1
6603622 Christiansen et al. Aug 2003 B1
6603625 Hospodor et al. Aug 2003 B1
6604220 Lee Aug 2003 B1
6606682 Dang et al. Aug 2003 B1
6606714 Thelin Aug 2003 B1
6606717 Yu et al. Aug 2003 B1
6611393 Nguyen et al. Aug 2003 B1
6615312 Hamlin et al. Sep 2003 B1
6639748 Christiansen et al. Oct 2003 B1
6647481 Luu et al. Nov 2003 B1
6654193 Thelin Nov 2003 B1
6657810 Kupferman Dec 2003 B1
6661591 Rothberg Dec 2003 B1
6665772 Hamlin Dec 2003 B1
6687073 Kupferman Feb 2004 B1
6687078 Kim Feb 2004 B1
6687850 Rothberg Feb 2004 B1
6690523 Nguyen et al. Feb 2004 B1
6690882 Hanmann et al. Feb 2004 B1
6691198 Hamlin Feb 2004 B1
6691213 Luu et al. Feb 2004 B1
6691255 Rothberg et al. Feb 2004 B1
6693760 Krounbi et al. Feb 2004 B1
6694477 Lee Feb 2004 B1
6697914 Hospodor et al. Feb 2004 B1
6704153 Rothberg et al. Mar 2004 B1
6708251 Boyle et al. Mar 2004 B1
6710951 Cloke Mar 2004 B1
6711628 Thelin Mar 2004 B1
6711635 Wang Mar 2004 B1
6711660 Milne et al. Mar 2004 B1
6715044 Lofgren et al. Mar 2004 B2
6724982 Hamlin Apr 2004 B1
6725329 Ng et al. Apr 2004 B1
6735650 Rothberg May 2004 B1
6735693 Hamlin May 2004 B1
6744772 Eneboe et al. Jun 2004 B1
6745283 Dang Jun 2004 B1
6751402 Elliott et al. Jun 2004 B1
6757481 Nazarian et al. Jun 2004 B1
6772281 Hamlin Aug 2004 B2
6781826 Goldstone et al. Aug 2004 B1
6782449 Codilian et al. Aug 2004 B1
6791779 Singh et al. Sep 2004 B1
6792486 Hanan et al. Sep 2004 B1
6799274 Hamlin Sep 2004 B1
6811427 Garrett et al. Nov 2004 B2
6826003 Subrahmanyam Nov 2004 B1
6826614 Hanmann et al. Nov 2004 B1
6832041 Boyle Dec 2004 B1
6832929 Garrett et al. Dec 2004 B2
6845405 Thelin Jan 2005 B1
6845427 Atai-Azimi Jan 2005 B1
6850443 Lofgren et al. Feb 2005 B2
6851055 Boyle et al. Feb 2005 B1
6851063 Boyle et al. Feb 2005 B1
6853731 Boyle et al. Feb 2005 B1
6854022 Thelin Feb 2005 B1
6862660 Wilkins et al. Mar 2005 B1
6880043 Castro et al. Apr 2005 B1
6882486 Kupferman Apr 2005 B1
6884085 Goldstone Apr 2005 B1
6888831 Hospodor et al. May 2005 B1
6892217 Hanmann et al. May 2005 B1
6892249 Codilian et al. May 2005 B1
6892313 Codilian et al. May 2005 B1
6895455 Rothberg May 2005 B1
6895500 Rothberg May 2005 B1
6898730 Hanan May 2005 B1
6910099 Wang et al. Jun 2005 B1
6928470 Hamlin Aug 2005 B1
6931439 Hanmann et al. Aug 2005 B1
6934104 Kupferman Aug 2005 B1
6934713 Schwartz et al. Aug 2005 B2
6940873 Boyle et al. Sep 2005 B2
6943978 Lee Sep 2005 B1
6948165 Luu et al. Sep 2005 B1
6950267 Liu et al. Sep 2005 B1
6954733 Ellis et al. Oct 2005 B1
6961814 Thelin et al. Nov 2005 B1
6965489 Lee et al. Nov 2005 B1
6965563 Hospodor et al. Nov 2005 B1
6965966 Rothberg et al. Nov 2005 B1
6967799 Lee Nov 2005 B1
6968422 Codilian et al. Nov 2005 B1
6968450 Rothberg et al. Nov 2005 B1
6973495 Milne et al. Dec 2005 B1
6973570 Hamlin Dec 2005 B1
6976190 Goldstone Dec 2005 B1
6983316 Milne et al. Jan 2006 B1
6986007 Procyk et al. Jan 2006 B1
6986154 Price et al. Jan 2006 B1
6995933 Codilian et al. Feb 2006 B1
6996501 Rothberg Feb 2006 B1
6996669 Dang et al. Feb 2006 B1
7002926 Eneboe et al. Feb 2006 B1
7003674 Hamlin Feb 2006 B1
7006316 Sargenti, Jr. et al. Feb 2006 B1
7009820 Hogg Mar 2006 B1
7023639 Kupferman Apr 2006 B1
7024491 Hanmann et al. Apr 2006 B1
7024549 Luu et al. Apr 2006 B1
7024614 Thelin et al. Apr 2006 B1
7027716 Boyle et al. Apr 2006 B1
7028174 Atai-Azimi et al. Apr 2006 B1
7031902 Catiller Apr 2006 B1
7046465 Kupferman May 2006 B1
7046488 Hogg May 2006 B1
7050252 Vallis May 2006 B1
7054937 Milne et al. May 2006 B1
7055000 Severtson May 2006 B1
7055167 Masters May 2006 B1
7057836 Kupferman Jun 2006 B1
7062398 Rothberg Jun 2006 B1
7075746 Kupferman Jul 2006 B1
7076604 Thelin Jul 2006 B1
7082494 Thelin et al. Jul 2006 B1
7088538 Codilian et al. Aug 2006 B1
7088545 Singh et al. Aug 2006 B1
7092186 Hogg Aug 2006 B1
7095577 Codilian et al. Aug 2006 B1
7099095 Subrahmanyam et al. Aug 2006 B1
7106537 Bennett Sep 2006 B1
7106947 Boyle et al. Sep 2006 B2
7110202 Vasquez Sep 2006 B1
7111116 Boyle et al. Sep 2006 B1
7114029 Thelin Sep 2006 B1
7120737 Thelin Oct 2006 B1
7120806 Codilian et al. Oct 2006 B1
7126776 Warren, Jr. et al. Oct 2006 B1
7129763 Bennett et al. Oct 2006 B1
7133600 Boyle Nov 2006 B1
7136244 Rothberg Nov 2006 B1
7146094 Boyle Dec 2006 B1
7149046 Coker et al. Dec 2006 B1
7150036 Milne et al. Dec 2006 B1
7155616 Hamlin Dec 2006 B1
7171108 Masters et al. Jan 2007 B1
7171110 Wilshire Jan 2007 B1
7194576 Boyle Mar 2007 B1
7200698 Rothberg Apr 2007 B1
7205805 Bennett Apr 2007 B1
7206497 Boyle et al. Apr 2007 B1
7215496 Kupferman et al. May 2007 B1
7215771 Hamlin May 2007 B1
7237054 Cain et al. Jun 2007 B1
7240161 Boyle Jul 2007 B1
7249365 Price et al. Jul 2007 B1
7263709 Krapf Aug 2007 B1
7274639 Codilian et al. Sep 2007 B1
7274659 Hospodor Sep 2007 B2
7275116 Hanmann et al. Sep 2007 B1
7280302 Masiewicz Oct 2007 B1
7292774 Masters et al. Nov 2007 B1
7292775 Boyle et al. Nov 2007 B1
7296284 Price et al. Nov 2007 B1
7302501 Cain et al. Nov 2007 B1
7302579 Cain et al. Nov 2007 B1
7318088 Mann Jan 2008 B1
7319806 Willner et al. Jan 2008 B1
7325244 Boyle et al. Jan 2008 B2
7330323 Singh et al. Feb 2008 B1
7346790 Klein Mar 2008 B1
7366641 Masiewicz et al. Apr 2008 B1
7369340 Dang et al. May 2008 B1
7369343 Yeo et al. May 2008 B1
7372650 Kupferman May 2008 B1
7380147 Sun May 2008 B1
7392340 Dang et al. Jun 2008 B1
7404013 Masiewicz Jul 2008 B1
7406545 Rothberg et al. Jul 2008 B1
7415571 Hanan Aug 2008 B1
7436610 Thelin Oct 2008 B1
7437502 Coker Oct 2008 B1
7440214 Ell et al. Oct 2008 B1
7451344 Rothberg Nov 2008 B1
7471483 Ferris et al. Dec 2008 B1
7471486 Coker et al. Dec 2008 B1
7486060 Bennett Feb 2009 B1
7496493 Stevens Feb 2009 B1
7518819 Yu et al. Apr 2009 B1
7526184 Parkinen et al. Apr 2009 B1
7539924 Vasquez et al. May 2009 B1
7543117 Hanan Jun 2009 B1
7551383 Kupferman Jun 2009 B1
7562282 Rothberg Jul 2009 B1
7577973 Kapner, III et al. Aug 2009 B1
7596797 Kapner, III et al. Sep 2009 B1
7599139 Bombet et al. Oct 2009 B1
7619841 Kupferman Nov 2009 B1
7647544 Masiewicz Jan 2010 B1
7649704 Bombet et al. Jan 2010 B1
7653927 Kapner, III et al. Jan 2010 B1
7656603 Xing Feb 2010 B1
7656763 Jin et al. Feb 2010 B1
7657149 Boyle Feb 2010 B2
7672072 Boyle et al. Mar 2010 B1
7673075 Masiewicz Mar 2010 B1
7688540 Mei et al. Mar 2010 B1
7724461 McFadyen et al. May 2010 B1
7725584 Hanmann et al. May 2010 B1
7730295 Lee Jun 2010 B1
7760458 Trinh Jul 2010 B1
7768776 Szeremeta et al. Aug 2010 B1
7804657 Hogg et al. Sep 2010 B1
7813954 Price et al. Oct 2010 B1
7827320 Stevens Nov 2010 B1
7839588 Dang et al. Nov 2010 B1
7843660 Yeo Nov 2010 B1
7852596 Boyle et al. Dec 2010 B2
7859782 Lee Dec 2010 B1
7872822 Rothberg Jan 2011 B1
7898756 Wang Mar 2011 B1
7898762 Guo et al. Mar 2011 B1
7900037 Fallone et al. Mar 2011 B1
7907364 Boyle et al. Mar 2011 B2
7929234 Boyle et al. Apr 2011 B1
7933087 Tsai et al. Apr 2011 B1
7933090 Jung et al. Apr 2011 B1
7934030 Sargenti, Jr. et al. Apr 2011 B1
7940491 Szeremeta et al. May 2011 B2
7944639 Wang May 2011 B1
7945727 Rothberg et al. May 2011 B2
7949564 Hughes et al. May 2011 B1
7974029 Tsai et al. Jul 2011 B2
7974039 Xu et al. Jul 2011 B1
7982993 Tsai et al. Jul 2011 B1
7984200 Bombet et al. Jul 2011 B1
7990648 Wang Aug 2011 B1
7992179 Kapner, III et al. Aug 2011 B1
8004785 Tsai et al. Aug 2011 B1
8006027 Stevens et al. Aug 2011 B1
8014094 Jin Sep 2011 B1
8014977 Masiewicz et al. Sep 2011 B1
8019914 Vasquez et al. Sep 2011 B1
8040625 Boyle et al. Oct 2011 B1
8078943 Lee Dec 2011 B1
8079045 Krapf et al. Dec 2011 B2
8082433 Fallone et al. Dec 2011 B1
8085487 Jung et al. Dec 2011 B1
8089719 Dakroub Jan 2012 B1
8090902 Bennett et al. Jan 2012 B1
8090906 Blaha et al. Jan 2012 B1
8091112 Elliott et al. Jan 2012 B1
8094396 Zhang et al. Jan 2012 B1
8094401 Peng et al. Jan 2012 B1
8112603 Dow Feb 2012 B2
8116020 Lee Feb 2012 B1
8116025 Chan et al. Feb 2012 B1
8134793 Vasquez et al. Mar 2012 B1
8134798 Thelin et al. Mar 2012 B1
8139301 Li et al. Mar 2012 B1
8139310 Hogg Mar 2012 B1
8144419 Liu Mar 2012 B1
8145452 Masiewicz et al. Mar 2012 B1
8149528 Suratman et al. Apr 2012 B1
8154812 Boyle et al. Apr 2012 B1
8159768 Miyamura Apr 2012 B1
8161328 Wilshire Apr 2012 B1
8164849 Szeremeta et al. Apr 2012 B1
8174780 Tsai et al. May 2012 B1
8190575 Ong et al. May 2012 B1
8194338 Zhang Jun 2012 B1
8194340 Boyle et al. Jun 2012 B1
8194341 Boyle Jun 2012 B1
8201066 Wang Jun 2012 B1
8271692 Dinh et al. Sep 2012 B1
8279550 Hogg Oct 2012 B1
8281218 Ybarra et al. Oct 2012 B1
8285923 Stevens Oct 2012 B2
8289656 Huber Oct 2012 B1
8305705 Roohr Nov 2012 B1
8307156 Codilian et al. Nov 2012 B1
8310775 Boguslawski et al. Nov 2012 B1
8315006 Chahwan et al. Nov 2012 B1
8316263 Gough et al. Nov 2012 B1
8320067 Tsai et al. Nov 2012 B1
8324974 Bennett Dec 2012 B1
8332695 Dalphy et al. Dec 2012 B2
8341337 Ong et al. Dec 2012 B1
8350628 Bennett Jan 2013 B1
8356184 Meyer et al. Jan 2013 B1
8370683 Ryan et al. Feb 2013 B1
8375225 Ybarra Feb 2013 B1
8375274 Bonke Feb 2013 B1
8380922 DeForest et al. Feb 2013 B1
8390948 Hogg Mar 2013 B2
8390952 Szeremeta Mar 2013 B1
8392689 Lott Mar 2013 B1
8407393 Yolar et al. Mar 2013 B1
8413010 Vasquez et al. Apr 2013 B1
8417566 Price et al. Apr 2013 B2
8421663 Bennett Apr 2013 B1
8422172 Dakroub et al. Apr 2013 B1
8427771 Tsai Apr 2013 B1
8429343 Tsai Apr 2013 B1
8433937 Wheelock et al. Apr 2013 B1
8433977 Vasquez et al. Apr 2013 B1
8458526 Dalphy et al. Jun 2013 B2
8462466 Huber Jun 2013 B2
8467151 Huber Jun 2013 B1
8489841 Strecke et al. Jul 2013 B1
8493679 Boguslawski et al. Jul 2013 B1
8498074 Mobley et al. Jul 2013 B1
8499198 Messenger et al. Jul 2013 B1
8512049 Huber et al. Aug 2013 B1
8514506 Li et al. Aug 2013 B1
8531791 Reid et al. Sep 2013 B1
8554741 Malina Oct 2013 B1
8560759 Boyle et al. Oct 2013 B1
8565053 Chung Oct 2013 B1
8576511 Coker et al. Nov 2013 B1
8578100 Huynh et al. Nov 2013 B1
8578242 Burton et al. Nov 2013 B1
8589773 Wang et al. Nov 2013 B1
8593753 Anderson Nov 2013 B1
8595432 Vinson et al. Nov 2013 B1
8599510 Fallone Dec 2013 B1
8601248 Thorsted Dec 2013 B2
8611032 Champion et al. Dec 2013 B2
8612650 Carrie et al. Dec 2013 B1
8612706 Madril et al. Dec 2013 B1
8612798 Tsai Dec 2013 B1
8619383 Jung et al. Dec 2013 B1
8621115 Bombet et al. Dec 2013 B1
8621133 Boyle Dec 2013 B1
8626463 Stevens et al. Jan 2014 B2
8630052 Jung et al. Jan 2014 B1
8630056 Ong Jan 2014 B1
8631188 Heath et al. Jan 2014 B1
8634158 Chahwan et al. Jan 2014 B1
8635412 Wilshire Jan 2014 B1
8640007 Schulze Jan 2014 B1
8654619 Cheng Feb 2014 B1
8661193 Cobos et al. Feb 2014 B1
8667248 Neppalli Mar 2014 B1
8670205 Malina et al. Mar 2014 B1
8683295 Syu et al. Mar 2014 B1
8683457 Hughes et al. Mar 2014 B1
8687306 Coker et al. Apr 2014 B1
8693133 Lee et al. Apr 2014 B1
8694841 Chung et al. Apr 2014 B1
8699159 Malina Apr 2014 B1
8699171 Boyle Apr 2014 B1
8699172 Gunderson et al. Apr 2014 B1
8699175 Olds et al. Apr 2014 B1
8699185 Teh et al. Apr 2014 B1
8700850 Lalouette Apr 2014 B1
8743502 Bonke et al. Jun 2014 B1
8749910 Dang et al. Jun 2014 B1
8751699 Tsai et al. Jun 2014 B1
8755141 Dang Jun 2014 B1
8755143 Wilson et al. Jun 2014 B2
8756361 Pruett et al. Jun 2014 B1
8756382 Carlson et al. Jun 2014 B1
8769593 Elliott et al. Jul 2014 B1
8773802 Anderson et al. Jul 2014 B1
8780478 Huynh et al. Jul 2014 B1
8782334 Boyle et al. Jul 2014 B1
8793532 Tsai et al. Jul 2014 B1
8797669 Burton et al. Aug 2014 B1
8799977 Kapner, III et al. Aug 2014 B1
8819375 Pruett et al. Aug 2014 B1
8825976 Jones Sep 2014 B1
8825977 Syu et al. Sep 2014 B1
20090113702 Hogg May 2009 A1
20100306551 Meyer et al. Dec 2010 A1
20110226729 Hogg Sep 2011 A1
20120159042 Lott et al. Jun 2012 A1
20120272038 Wei Oct 2012 A1
20120275050 Wilson et al. Nov 2012 A1
20120281963 Krapf et al. Nov 2012 A1
20120324980 Nguyen et al. Dec 2012 A1
20140201424 Chen et al. Jul 2014 A1
Related Publications (1)
Number Date Country
20160005423 A1 Jan 2016 US