Abstract: The present disclosure generally relates to a XTS cache operation during a power down event. Upon detection of power loss, data that is waiting to be encrypted needs to be flushed to the memory device. For any unaligned data or data less than a flash management unit (FMU) size, the data is grouped together and, if necessary, padded to reach the FMU size and then encrypted, merged with other data FMUs, and written to the memory device. Grouping the unaligned data reduces the amount of padding necessary to reach FMU size and also reduces the amount of data to be encrypted. As such, data flushing can be accomplished using the limited amount of remaining power during the power loss event.

Abstract: Improved automation can be achieved using command-parts. Rather than using a command to determine which key to use, command partitioning will generate a task-ID based on a key index table to determine what key to use. Based on the task-ID, an encryption engine (XTS) will know which key to use. The command is split into partitions with the same attributes. The amount of task-IDs created will equal the amount of partitions. Automation will be based on the task-IDs to create a completion for a host. The controller will then return to the key index table to count the completed commands and send the completion to the host.

Abstract: A data storage device implements a Zoned Namespace (ZNS) storage architecture. The data storage device delays the execution of write commands that are received out of sequence instead of rejecting the write commands. The write commands that are received out of sequence are reordered according to a logical block address (LBA) associated with each write command. The data storage device also checks for deadlock conditions that may arise due to the execution of the write commands being delayed and/or due to the write commands being reordered.

Abstract: Instead of handling resources with one generic method, the controller can use a static method or dynamic method to handle the resources. The controller communicates to the host as to the number of resources the controller has for keeping doorbell times. The controller will also communicate with the host how those resources are used. The static method focuses on creating dedicated submission queues (SQ), while the dynamic method provides a hint during the doorbell execution. The static method further focuses on improving priority, while the dynamic method focuses on canceling commands that have timed out. The static method and the dynamic method can be combined to further support the hosts requirements.

Abstract: Adding a bypass module and a pattern detector module to a data path of a controller will increase the efficiency of both sanitize block erase audit and sanitize crypto erase audit operations. The sanitize crypto erase audit skips an end to end (E2E) protection module to provide decrypted data to a static random access memory (SRAM) buffer and ultimately a host device through a direct memory access (DMA) module. The sanitize block erase audit utilizes the pattern detector module to provide a known pattern to the SRAM buffer and host through the DMA module. The bypass module and pattern detector module feed into a multiplexer (Mux) prior to the SRAM buffer.

Abstract: Read commands and write commands are issued by a data storage device, but sometimes a read command can begin execution prior to the data for the write command having been written to the memory device (or HMB DRAM). In such a scenario, the data for the read command is not in the memory device, but rather, is in cache waiting to be written to the memory device in a write cache operation. In order to ensure the correct data is read, the cache write operation can be paused so that the data can be retrieved from cache rather than the memory device. Alternatively, a placeholder can be used for the read command until the write cache operation has occurred.

Abstract: Instead of entering lanes into an unused power state, enter unactive lanes into an unconnected power state to save more current during low power states. Using a small control logic will allow a controller to control unactive lanes in low power mode. When a lane is in an unactive power state or in an unused power state, an unactive lane controller (ULC) uses side-band signaling to place the unactive lane into either unused power state or unconnected power state. When a lane is in unused power state, then the ULC places the lane in unconnected power state. A single ULC is able to controller multiple lanes or you can have multiple ULC's, each controlling a single lane.

Abstract: Instead of using programmable block size aggregation, a lower multiple of page, and down to a page size aggregation is used. A bad block prediction unit in a controller is able to predict when a programmable block has a bad page. The bad block prediction unit can lower the aggregation size of a programmable block by monitoring the life cycle of the programmable block through bad block statistic collection. When the accumulation size passes a threshold, the bad block prediction unit lowers the aggregation size. The bad block prediction unit can also predict when to lower aggregation size based on the number of reconstructions. An aggregate size level is set at a page boundary, and once the number of reconstructions reaches that page boundary, the bad block prediction unit lowers the aggregation size to page aggregation. The bad block prediction unit is able to predict both life cycle threshold changes and reconstructions changes.

Abstract: Instead of using a bandwidth limiter for bandwidth allocation in an SSD, a dummy virtual function (VF) is used to transfer internal operations. A centralized logic such as the bandwidth limiter is incorporated in the device controller. This logic is responsible for controlling the bandwidth between the hosts. The logic is not just responsible for data transfers triggered by the hosts, but also for data transfers triggered by the device in internal operations such as garbage collection. In order to control the traffic trigged by internal operations, a dummy VF is created along with dummy submission queues. The internal operations are queued in the dummy submission queues, while the bandwidth limiter is responsible for the performance rate. Using this approach, bandwidth allocation is balanced between the hosts and SSD.

Abstract: Instead of handing each hot LBA separately, a hot LBA tracker is used to handle hot LBAs. As a command arrives, the controller classifies the command. If the command is classified as a hot LBA, then the hot LBA tracker will store the hot LBA in a separate location from where the executed commands are stored. In doing so, the hot LBA tracker will store completion information without executing the hot LBA. The hot LBAs that have a stored completion, but are not executed, are considered “skipped” hot LBAs. Once the controller determines that the hot LBA needs to be executed, the controller will execute the most recent hot LBA. After execution of the most recent hot LBA, the controller sends a completion for the most recent hot LBA and “skipped” hot LBAs.

Abstract: The present disclosure generally relates to improved fragment processing while command fetching is on-going. Rather than stopping command fetching, the controller uses a short fragment list, while command fetching can continue, to add a fragment. The controller first adds new fragments to the short list with the fragment information. The information is then checked for size. If the fragment information is smaller than the short fragment list, then the fragment list is updated during command fetching. As a command arrives, the controller does a binary search of a sorted fragment list. The results are stored and later scanned by the controller for matches with the short fragment list. If there are no matches in the short list, then the controller uses the stored results to update the search result. If there is a match in the short list then the controller uses the new results to update the search list.

Abstract: Adding a bypass module and a pattern detector module to a data path of a controller will increase the efficiency of both sanitize block erase audit and sanitize crypto erase audit operations. The sanitize crypto erase audit skips an end to end (E2E) protection module to provide decrypted data to a static random access memory (SRAM) buffer and ultimately a host device through a direct memory access (DMA) module. The sanitize block erase audit utilizes the pattern detector module to provide a known pattern to the SRAM buffer and host through the DMA module. The bypass module and pattern detector module feed into a multiplexer (Mux) prior to the SRAM buffer.

Abstract: In order to ensure that a bandwidth allocated to each tenant of a plurality of tenants of a data storage device is maintained, a controller of the data storage device may split a large read command, received from a host device, into a plurality of chunks, where each chunk corresponds to a distinct portion of the split large read command. Because the allocated bandwidth for a tenant is static, one or more chunks of the plurality of chunks, up to the allocated bandwidth, are executed, such that the bandwidth required to perform the one or more chunks does not exceed the allocated bandwidth for the particular tenant. Split information is added to the plurality of chunks in order to maintain coherency when executing the one or more chunks. Therefore, the agreed-upon allocated bandwidth for each tenant is maintained while performing large read commands requiring more bandwidth than allocated.

Abstract: A data storage device implements a Zoned Namespace (ZNS) storage architecture. The data storage device delays the execution of write commands that are received out of sequence instead of rejecting the write commands. The write commands that are received out of sequence are reordered according to a logical block address (LBA) associated with each write command. The data storage device also checks for deadlock conditions that may arise due to the execution of the write commands being delayed and/or due to the write commands being reordered.

Abstract: Improved automation can be achieved using command-parts. Rather than using a command to determine which key to use, command partitioning will generate a task-ID based on a key index table to determine what key to use. Based on the task-ID, an encryption engine (XTS) will know which key to use. The command is split into partitions with the same attributes. The amount of task-IDs created will equal the amount of partitions. Automation will be based on the task-IDs to create a completion for a host. The controller will then return to the key index table to count the completed commands and send the completion to the host.

Abstract: There is a tradeoff between the amount of power consumption decreased and the latency needed to return a data storage device back to an operational power mode. When the data storage device receives a wake up indication from a host device, a controller of the data storage device initiates a counter in order to determine a host exit latency. Based on the host exit latency, the controller determines a group of low power state entrance actions from a plurality of groups to perform during a next entrance into a firmware active idle state based on an associated completion wake up time and the host exit latency. The controller selects the group whose completion wake up time is closest to the host exit latency and less than or equal to the host exit latency. The controller performs the selected groups low power state entrance actions during a next entrance into the firmware active idle state.

Abstract: The present disclosure generally relates improved key-per IO (KIPO) processing for multiple tenants. Rather than when a tenant requests a key change to stop tenants from working, indirect-double-indexing can be used to prevent bandwidth loss in tenants during adaptions for other tenants. When a tenant requests to manipulate the key-index table, the system will keep working. The current key index list will be duplicated. While the duplicated key-index list is manipulated according to the request, all tenants may still work on their current key-index tables until the request is complete. Once the request is complete, the tenant with the request will switch to the new table, while the old table is updated. Once the old table is updated, the tenant will switch to the updated table for continued work. No tenant, including the tenant that makes the request, continues working as the request is completed.

Abstract: A data storage device includes a memory device and a controller coupled to the memory device. The controller is configured to create one or more thresholds for sending sideband information to a host device, determine that a link state is in a state other than L0, retain sideband information until the one or more thresholds is reached, and send the sideband information to the host device upon reaching the one or more thresholds for a corresponding link state. The one or more thresholds correspond to a link state between the host device and the data storage device. The thresholds are either based on an amount of sideband information retained, a time of retaining sideband information, or a combination of the amount of sideband information retained and the time of retaining sideband information. The sideband information is retained and sent in a first-in first-out order.

Abstract: The present disclosure generally relates to an efficient manner of fetching data for write commands. The data can be fetched prior to classification, which is a fetch before mode. The data can alternatively be fetched after classification, which is a fetch after mode. When the data is fetched after classification, the write commands are aggregated until sufficient data associated with any command is split between memory devices. When in fetch before mode, the data should properly align such that data associated with any command is not split between memory devices. Efficiently toggling between the fetch before and fetch after modes will shape how writes are performed without impacting latency and bandwidth without significantly increasing write buffer memory size.

Abstract: A data storage device includes a memory device and a controller coupled to the memory device. When a command is received by the controller from a host device, the controller determines whether the command size is greater than a threshold size. If the command is not greater than the threshold size, the command is sent to a first queue, otherwise, the command is sent to a second queue. Commands are executed from the first queue until a command size tracker value, which increases by a size representative of each command executed from the first queue, equals or exceeds a threshold value. When the command size tracker value equals or exceeds the threshold value, a command from the second queue is executed and the command size tracker value decreases by a size representative of the command from the second queue. Completion messages are sent at specific intervals based on the executing.