Abstract: Systems and methods are disclosed for handling dynamic and static data for a system having non-volatile memory (“NVM”). By determining whether data being written to the NVM is dynamic or not, a NVM interface of a system can determine where to initially place the data on the NVM (e.g., place the data on either a dynamic stream block or a static stream block). Moreover, this information can allow the NVM interface to improve the efficiencies of both garbage collection (“GC”) and wear leveling.

Abstract: Systems and methods are disclosed for trim token journaling. A device can monitor the order in which trim commands and write commands are applied to an indirection system stored in a volatile memory of the device. In some embodiments, the device can directly write to a page of an NVM with a trim token that indicates that a LBA range stored in the page has been trimmed. In other embodiments, a device can add pending trim commands to a trim buffer stored in the volatile memory. Then, when the trim buffer reaches a pre-determined threshold or a particular trigger is detected, trim tokens associated with all of the trim commands stored in the trim buffer can be written to the NVM. Using these approaches, the same sequence of events that was applied to the indirection system during run-time can be applied during device boot-up.

Abstract: Systems and methods are disclosed for handling read disturbs based on one or more characteristics of read operations performed on a non-volatile memory (“NVM”). In some embodiments, a control circuitry of a system can generate a variable damage value determined based on one or more characteristics of a read operation. Using the damage value, the control circuitry can update a score associated with the block. If the control circuitry determines that the score exceeds a pre-determined threshold, at least a portion of the block can be relocated to a different memory location in the NVM. In some embodiments, portions of the block may be relocated over a period of time.

Abstract: Systems and methods are provided for handling uncorrectable errors in a non-volatile memory (“NVM”), such as flash memory, during a garbage collection operation.

Abstract: Systems and methods are disclosed for mount-time reconciliation of data availability. During system boot-up, a non-volatile memory (“NVM”) driver can be enumerated, and an NVM driver mapping can be obtained. The NVM driver mapping can include the actual availability of LBAs in the NVM. A file system can then be mounted, and a file system allocation state can be generated. The file system allocation state can indicate the file system's view of the availability of LBAs. Subsequently, data availability reconciliation can be performed. That is, the file system allocation state and the NVM driver mapping can be overlaid and compared with one another in order to expose any discrepancies.

Abstract: Systems and methods are disclosed for logical block address (“LBA) bitmap usage for a system having non-volatile memory (“NVM”). A bitmap can be stored in volatile memory of the system, where the bitmap can store the mapping statuses of one or more logical addresses. By using the bitmap, the system can determine the mapping status of a LBA without having to access the NVM. In addition, the system can update the mapping status of a LBA with minimal NVM accesses. By reducing the number of NVM accesses, the system can avoid triggering a garbage collection process, which can improve overall system performance.

Abstract: Systems and methods are provided for performing incremental garbage collection for non-volatile memories (“NVMs”), such as flash memory. In some embodiments, an electronic device including the NVM may perform incremental garbage collection to free up and erase a programmed block of the NVM. The programmed block may include valid data and invalid data, and the electronic device may be configured to copy the valid data from the programmed block to an erased block in portions. In between programming each portion of the valid data to the erased block, the electronic device can program host data to the erased block. This way, the electronic device can stagger the garbage collection operations and prevent a user from having to experience one long garbage collection operation.

Abstract: Systems and methods for coordinating sync points between a non-volatile memory (“NVM”) and a file system are provided. In some embodiments, a file system can issue one or more commands to control circuitry of a NVM, which can indicate whether a transaction is journaled or non-journaled. This way, the control circuitry can maintain a list of journaled transactions and corresponding LBA(s). By keeping track of journaled transactions, the control circuitry can ensure that sync points are not prematurely erased during a garbage collection process. In addition, upon detecting device failure events, the control circuitry can roll back to sync points corresponding to one or more journaled transactions.

Abstract: Systems and methods are disclosed for managing a non-volatile memory (“NVM”), such as a flash memory. To prevent data errors due to leakage effects, the NVM may be refreshed. For example, a reserved portion of the NVM may be selected, and a predetermined pattern can be stored into the reserved portion. The reserved portion can then be monitored for storage deterioration over time. After determining that storage deterioration of the reserved portion has occurred, the NVM can be refreshed. In some embodiments, a controller can attempt to distinguish data errors due to leakage effects from data errors due to disturb issues.

Abstract: Systems and methods are provided for selectively retiring blocks based on refresh events of those blocks. In addition to refresh events, other criteria may be applied in making a decision whether to retire a block. By applying the criteria, the system is able to selectively retire blocks that may otherwise continue to be refreshed.

Abstract: Systems and methods are disclosed for efficient buffering for a system having non-volatile memory (“NVM”). A tree can be stored in volatile memory that includes a logical-to-physical mapping between a logical space and physical addresses of the NVM. When the amount of memory available for the tree is below a pre-determined threshold, a system can attempt to reduce the number of data fragments in the NVM, and consequently flatten a portion of the tree. The NVM interface may select an optimal set of entries of the tree to combine. Any suitable approach can be used such as, for example, moving one or more sliding windows across the tree, expanding a sliding window when a condition has been satisfied, using a priority queue while scanning the tree, and/or maintaining a priority queue while the tree is being updated.

Abstract: Systems and methods are disclosed for providing a weave sequence counter (“WSC”) for non-volatile memory (“NVM”) systems. The WSC can identify the sequence in which each page of the NVM is programmed. The “weave” aspect can refer to the fact that multiple blocks can be open for programming at once, thus allowing the pages of these blocks to be programmed in a “woven” manner. Systems and methods are also disclosed for providing a host weave sequence counter (“HWSC”). Each time new data is initially programmed to the NVM, this data can be associated with a particular HWSC. The HWSC associated with the data may not change, even when the data is moved to a new page (e.g., for wear leveling purposes and the like). The WSC and HWSC may aid in, for example, performing rollback, building logical-to-physical mappings, determining static-versus-dynamic page statuses, and performing maintenance operations (e.g., wear leveling).

Abstract: Systems and methods are disclosed for configuring a non-volatile memory (“NVM”). In some embodiments, each block of the NVM can include a block table-of-contents (“TOC”), which can be encoded (e.g., run-length encoded) and dynamically-sized. Thus, as user data is being programmed to a block, the size of a block TOC can be concurrently recalculated and increased only if necessary. In some embodiments, the NVM interface can use a weave sequence stored in the context information and at least one weave sequence associated with each page of a block to determine whether to replay across the pages of the block after system boot-up.

Abstract: Systems and methods are disclosed for secure relocation of encrypted files for a system having non-volatile memory (“NVM”). A system can include an encryption module that is configured to use a temporary encryption seed (e.g., a randomly generated key and a corresponding initialization vector) to decrypt and encrypt data files in an NVM. These data files may have originally been encrypted with different encryption seeds. Using such an approach, data files can be securely relocated even if the system does not have access to the original encryption seeds. In addition, the temporary encryption seed allows the system to bypass a default key scheme.

Abstract: Systems and methods are provided for handling temporary data that is stored in a non-volatile memory, such as NAND flash memory. The temporary data may include hibernation data or any other data needed for only one boot cycle of an electronic device. When storing the temporary data in one or more pages of the non-volatile memory, the electronic device can store a temporary marker as part of the metadata in at least one of the pages. This way, on the next bootup of the electronic device, the electronic device can use the temporary marker to determine that the associated page contains unneeded data. The electronic device can therefore invalidate the page and omit the page from its metadata tables.

Abstract: Systems and methods are disclosed for partitioning data for storage in a non-volatile memory (“NVM”), such as flash memory. In some embodiments, a priority may be assigned to data being stored, and the data may be logically partitioned based on the priority. For example, a file system may identify a logical address within a first predetermined range for higher priority data and within a second predetermined range for lower priority data, such using a union file system. Using the logical address, a NVM driver can determine the priority of data being stored and can process (e.g., encode) the data based on the priority. The NVM driver can store an identifier in the NVM along with the data, and the identifier can indicate the processing techniques used on the associated data.

Abstract: Systems, apparatuses, and methods are provided for detecting corrupted data for a system having non-volatile memory, such as NAND Flash memory. In some embodiments, a non-volatile memory (“NVM”) package is provided, which can include a NVM controller and one or more NVM dies. Each NVM die can include one or more blocks, where each block can further include an array of memory cells. One or more of these memory cells can be configured as “multi-level cells” (“MLCs”). In some embodiments, in order to avoid transmitting data obtained from an improperly programmed page of a MLC, a NVM controller can be configured to detect if data obtained from the page is in fact data stored in a different page.

Abstract: Systems and methods are provided for unmapping unused logical addresses at mount-time of a file system. An electronic device, which includes a non-volatile memory (“NVM”), may implement a file system that, at mount-time of the NVM, identifies all of the logical addresses associated with the NVM that are unallocated. The file system may then pass this information on to a NVM manager, such as in one or more unmap requests. This can ensure that the NVM manager does not maintain data associated with a logical address that is no longer needed by the file system.

Abstract: Systems and methods are provided for storing and retrieving boot data (e.g., a first stage bootloader) in and from a non-volatile memory (“NVM”), such as a NAND flash memory. To increase storage reliability, the boot data may be stored in a subset of the pages in a boot data storage area, such as in only lower pages. The subset may be selected based on the specific operating specifications and characteristics of the NVM. To prevent a boot ROM from having to maintain a NVM-specific map of which pages are used to store boot data, the map may be maintained in the NVM itself. For example, the map may be in the form of a linked list, where each page storing boot data can include a pointer that points to the next page that stores boot data.

Abstract: Systems and methods are disclosed for stochastic block allocation for improved wear leveling for a system having non-volatile memory (“NVM”). The system can probabilistically allocate a block or super block for wear leveling based on statistics associated with the block or super block. In some embodiments, the system can select a set of blocks or super blocks based on a pre-determined threshold of a number of cycles (e.g., erase cycles and/or write cycles). The block or super block can then be selected from the set of super blocks. In other embodiments, the system can use a fully stochastic approach by selecting a block or super block based on a biased random variable. The biased random variable may be generated based in part on the number of cycles associated with each block or super block of the NVM.