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US-12619352-B2 - Storing multiple versions of preloaded content to mitigate cross-temperature impact

US12619352B2US 12619352 B2US12619352 B2US 12619352B2US-12619352-B2

Abstract

A data storage device includes a cross-temperature mitigation system that mitigates cross-temperature issues that arise when preloaded content is read from the data storage device. The data storage device stores different copies of preloaded content, and each copy of preloaded content is written to the data storage device when the data storage device is operating at different temperatures. When a request to read preloaded content is received, the cross-temperature mitigation system determines a current operating temperature of the data storage device and determines which copy of preloaded content has a write temperature that is closest to the current operating temperature of the data storage device. When a particular copy of preloaded content is identified, that particular copy of preloaded content is decoded in the storage controller and the decoded data is returned to a host device.

Inventors

  • Alexander Bazarsky
  • Ariel Navon
  • Eran Sharon

Assignees

  • SanDisk Technologies, Inc.

Dates

Publication Date
20260505
Application Date
20240318

Claims (20)

  1. 1 . A method, comprising: receiving a read command from a host device, the read command being associated with preloaded content that is stored by a data storage device; based, at least in part, on receiving the read command, determining an operating temperature of the data storage device; selecting, based at least in part, on the determined operating temperature, one of a first copy of the preloaded content that is associated with a first write temperature and a second copy of the preloaded content that is associated with a second write temperature that is different from the first write temperature; decoding the selected one of the first copy of the preloaded content and the second copy of the preloaded content; returning the decoded selected copy of the preloaded content to the host device; updating an access frequency of the selected one of the first copy of the preloaded content and the second copy of the preloaded content; updating a list of detected read temperatures based, at least in part, on the determined operating temperature of the data storage device; and selecting at least one of the first copy of preloaded content and the second copy of preloaded content to be deleted based, at least in part, on the access frequency of the selected one of the first copy of the preloaded content and the second copy of the preloaded content and the list of detected read temperatures.
  2. 2 . The method of claim 1 , wherein the first copy of the preloaded content is written to the data storage device at the first write temperature when the data storage device is operating at an operating temperature associated with the first write temperature.
  3. 3 . The method of claim 1 , wherein the first copy of the preloaded content is written to the data storage device using write parameters that simulate an operating temperature associated with the first write temperature.
  4. 4 . The method of claim 1 , further comprising determining whether to delete at least one of the first copy of the preloaded content and the second copy of the preloaded content from the data storage device.
  5. 5 . The method of claim 4 , wherein the determination is based, at least in part, on an amount of available storage space in the data storage device.
  6. 6 . The method of claim 1 , further comprising deleting the selected one of the first copy of the preloaded content and the second copy of the preloaded content from the data storage device during a background operation.
  7. 7 . The method of claim 1 , wherein the first copy of the preloaded content is a subset of the preloaded content.
  8. 8 . The method of claim 1 , wherein selecting the at least one of the first copy of preloaded content and the second copy of preloaded content to be deleted is further based, at least in part, on one or more performance metrics associated with each of the first copy of preloaded content and the second copy of preloaded content.
  9. 9 . The method of claim 1 , further comprising performing an error correction operation on a copy of preloaded content using the copy of preloaded content that is selected to be deleted.
  10. 10 . A data storage device, comprising: a cross-temperature mitigation system operable to: determine an operating temperature of the data storage device; select, based at least in part, on the determined operating temperature, one of a first copy of preloaded content that is associated with a first write temperature and a second copy of preloaded content that is associated with a second write temperature that is different from the first write temperature; return a decoded copy of the selected one of the first copy of preloaded content and the second copy of preloaded content to a requesting device; update a frequency order of the first copy of preloaded content and the second copy of preloaded content based, at least in part, on the selection of one of the first copy of preloaded content and the second copy of preloaded content and the determined operating temperature, wherein the frequency order indicates which copy of preloaded content will be erased in response to a triggering event associated with the data storage device; and in response to detecting the triggering event, erasing one of the first copy of preloaded content and the second copy of preloaded content in an order specified by the frequency order, the frequency order being based, at least in part, on the determined operating temperature.
  11. 11 . The data storage device of claim 10 , further comprising a temperature detection system operable to provide the operating temperature of the data storage device to the cross-temperature mitigation system.
  12. 12 . The data storage device of claim 10 , wherein the first copy of preloaded content and the second copy of preloaded content are stored on the data storage device during a factory setting.
  13. 13 . The data storage device of claim 12 , wherein the first copy of preloaded content is written to the data storage device at the first write temperature when the data storage device is operating at an operating temperature associated with the first write temperature.
  14. 14 . The data storage device of claim 12 , wherein the first copy of preloaded content is written to the data storage device using write parameters that simulate an operating temperature associated with the first write temperature.
  15. 15 . The data storage device of claim 10 , wherein the first copy of preloaded content is a subset of preloaded content.
  16. 16 . The data storage device of claim 10 , wherein the triggering event is the data storage device reaching a capacity threshold.
  17. 17 . The data storage device of claim 10 , wherein the data storage device is further configured to use the copy of preloaded content that will be erased as part of an error correction operation performed on another copy of preloaded content.
  18. 18 . A data storage device, comprising: means for determining an operating temperature of the data storage device; means for selecting one of a first copy of preloaded content that is associated with a first write temperature and a second copy of preloaded content that is associated with a second write temperature that is different from the first write temperature, wherein the selection is based, at least in part, on the determined operating temperature of the data storage device; means for decoding the selected one of the first copy of preloaded content and the second copy of preloaded content; means for returning the decoded selected copy of the preloaded content to a requesting device; and means for updating an access frequency of the selected one of the first copy of the preloaded content and the second copy of the preloaded content; means for updating a list of detected read temperatures associated with the operating temperature of the data storage device; and means for determining whether at least one of the first copy of the preloaded content and the second copy of preloaded content will be deleted in response to the data storage device reaching a capacity threshold, wherein the determination as to whether the at least one of the first copy of the preloaded content and the second copy of preloaded content will be deleted is based, at least in part, on the list of detected read temperatures.
  19. 19 . The data storage device of claim 18 , wherein the first copy of preloaded content and the second copy of preloaded content are stored on the data storage device during a factory setting.
  20. 20 . The data storage device of claim 18 , wherein the first copy of preloaded content is written to the data storage device at the first write temperature using write parameters that simulate an operating temperature associated with the first write temperature.

Description

BACKGROUND Cross-temperature issues arise in various embedded data storage devices and is particularly prevalent when preloaded content is stored in the data storage device. Cross-temperature issues are the result of data being read from the data storage device when the data storage device is operating at a temperature that is significantly different from a temperature at which the data storage device was operating when the data was initially written to the data storage device. Cross-temperature issues typically increase the bit error rate (BER) of data when the data is read. When the BER of data increases, the need for more robust error correction capabilities increases, as does the amount of time required to complete any error correction processes. Currently, cross-temperature issues may be mitigated using read threshold calibrations and different decoding optimizations (that may include reading soft bits) in the data storage device. However, these solutions require significant overhead, which reduces the overall performance of the data storage device. Accordingly, it would be beneficial for a data storage device to mitigate cross-temperature issues that affect preloaded content without negatively impacting the performance capabilities of the data storage device. SUMMARY The present disclosure describes a cross-temperature mitigation system that is associated with a data storage device. The cross-temperature mitigation system acts to mitigate cross-temperature issues that arise when preloaded content is read from a data storage device. Although the examples described herein relate to preloaded content, the cross-temperature mitigation system may be used to mitigate any cross-temperature issues. Preloaded content is data that is not written organically by a host device. Rather, the preloaded content is written to the data storage device in a factory setting before a customer receives the data storage device. As will be explained in greater detail herein, the data storage device stores different copies of preloaded content. In an example, each copy of preloaded content is written to the data storage device when the data storage device is operating at different temperatures. In another example, each copy of preloaded content is written to the data storage device using one or more write parameters that simulate the data storage device operating at different temperatures. When a request to read preloaded content is received (e.g., from a host device), the cross-temperature mitigation system determines a current operating temperature of the data storage device. The cross-temperature mitigation system determines which copy of preloaded content has a write temperature that is closest to the current operating temperature of the data storage device. When a particular copy of preloaded content is identified, that particular copy of preloaded content is decoded by the storage device and the decoded data returned to the host device. Accordingly, examples of the present disclosure describe a method that includes receiving a read command from a host device. In an example, the read command is associated with preloaded content that is stored by a data storage device. Based, at least in part, on receiving the read command, an operating temperature of the data storage device is determined. A first copy of the preloaded content that is associated with a first write temperature or a second copy of the preloaded content that is associated with a second write temperature that is different than the first write temperature is identified and/or selected. In an example, the copy of the preloaded content is selected based, at least in part, on the determined operating temperature. The selected first copy of the preloaded content or the selected second copy of the preloaded content is decoded by the storage device, and the decoded data provided to the host device. Other examples describe a data storage device that includes a controller and a cross-temperature mitigation system. In an example, the cross-temperature mitigation system is operable to determine an operating temperature of the data storage device. The cross-temperature mitigation system also selects one of a first copy of preloaded content that is associated with a first write temperature and a second copy of preloaded content that is associated with a second write temperature that is different than the first write temperature. In an example, the selection is based, at least in part, on the determined operating temperature. The cross-temperature mitigation system also decodes and returns the decoded selected first copy of preloaded content or the selected second copy of preloaded content to a host device. In another example, the present disclosure describes a data storage device having a controller means and a means for determining an operating temperature of the data storage device. In an example, the data storage device also includes a means for selecting one of a first