Western Digital Technologies, Inc.

Sandisk Technologies Inc.

Westem Digital Technologies, Inc.

Shay Benisty

Ariel Navon

Yehuda Hahn

Alexander Bazarsky

Amir Segev

Tal Sharifie

Alon Marcu

Eran Sharon

Elkana Richter

Karin Inbar

Yair Baram

Alex Bazarsky

Ran Zamir

Yoav Weinberg

Leonid Minz

Amir Rozen

Dudy David Avraham

Ishai Ilani

Avichay Haim Hodes

Rajesh Koul

Noga Harari Shechter

Idan Alrod

William Bernard Boyle

Daniel Joseph Linnen

Opher Lieber

Nissim Elmaleh

Vitali Linkovsky

Yoseph Hassan

Julian Vlaiko

Eran Erez

Yuri Ryabinin

Itshak Afriat

Michael James

Erez Frank

Klod Assulin

Tomer Geron

Stephen Gold

Chinnakrishnan Ballapuram

Tomer Tzvi Eliash

Dmitry Vaysman

Tomer Eliash

Scheheresade Virani

Ofir Pele

James J Walsh

Yan Dumchin

Girish Desai

David Meyer

Marcus A Carlson

Eran Moshe

Rotem Sela

William Guthrie

Kan Lip Vui

Aki Bleyer

Yuval Yoskovits

Ilya Gusev

Simon Bass

Eran Banani

Yossi Yoseph Hassan

Guruswamy Ganesh

Beniamin Kantor

Yevgeny Zagalsky

Oded Karni

Amit Alon

Moshe Karni

Alexey Martynenko

Adi Blum

Klod Ausslin

Amir Turjeman

Gennady Burdo

Yevgeny Lazarev

A system and method are disclosed for flexible emergency power fail management for multiple persistent memory regions. In one embodiment, a method is provided that is performed in a host in communication with a plurality of data storage devices, each data storage device having a persistent memory region, wherein the host comprises a capacitor shared by the plurality of data storage devices. The method comprises determining an allocation of power from the capacitor to each of the plurality of data storage devices; and dynamically changing the allocation of power from the capacitor to at least one data storage device of the plurality of data storage devices. Other embodiments are disclosed.

System and method for flexible emergency power fail management for multiple persistent memory regions

Logical to physical (L2P) tables are implemented in solid state drives (SSDs) to hold L2P address translations. In a thin provisioning or thin storage system, the L2P table is sized to support the total amount of memory that is available to be allocated on a per client or per host basis. During thin provisioning, the total amount of memory is not typically utilized. As such, the L2P table, which is sized to accommodate full usage of the memory allocated, is not fully utilized resulting in unused portions of the L2P table. The unused portions of the L2P table can be reallocated to use as temporal buffers until needed for write commands. Due to the reallocation, less buffers are needed.

Thin provisioning L2P resource sharing

When entering low power mode, any commands that are fetched and waiting to be executed are completed. When the data storage device exits low power mode, new commands are fetched. The completing and fetching takes time. Rather than completing all of the commands, some selected commands can be stored in a persistent memory region (PMR) when entering low power mode. The storing in PMR is faster than completing the commands. Furthermore, retrieving the commands from PMR is faster than retrieving new commands from a host device on exiting low power mode. Thus, using PMR results in more efficient use of data storage device bandwidth.

Pipeline optimization in low power mode using PMR

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.

PHY lanes disabling for power efficiency

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.

Write completion pacing for unbalanced command length

Instead of maximizing the possible bandwidth of device, utilize time slice credits (TSC), to ensure bandwidth average over a sliding window. When the average is ensured over a sliding window, the device should not care when the host decides to sample a 100 mSec for example, as the average will always be correct. By utilizing set percentage of predetermined allotment for the average bandwidth requirement, the system can give out credit on a predetermined interval. The credit is given out based on usage and once credit is depleted, data cannot be sent until more credit is accumulated. When data is not sent, the system is given a chance to accumulate credit to increase the amount of data sent. Once credit is at a level high enough to send data the device will send the data, but not at a speed that will surpass the average bandwidth requirement.

Bandwidth averaging in a stochastic system

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.

Key-per-IO multiple tenant isolation

Instead of using address translation cache (ATC) to translate addresses for host queues, bypass the ATC and directly use translated addresses. When creating the submission queues (SQ) or completion queues (CQ), the controller receives the untranslated addresses from the host, and the device is responsible for translating the untranslated addresses before accessing the host queues. The host queue pointers will directly use the translated addresses while bypassing the ATC. When bypassing the ATC, different flows can be used such as create queue command flow and invalidate operations. In a create queue command flow, the firmware (FW) performs address translation by interacting with a translation agent (TA) to receive the translated addresses. With an invalidate flow, the controller scans all untranslated addresses provided by the host at the queue creation time and compares the untranslated addresses against the invalidated address.

Address translation service for host queues

A data storage device includes a memory device and a controller coupled to the memory device. When a copy command is received by the controller from a host device, the controller reads the relevant data from one or more first locations of the memory device. The data is the processed by an Rx path, where the data is decoded, decrypted, and verified. Rather than providing the data back to the host device or being made available to the host device, a copy accelerator loops the data from the Rx path to a Tx path, where protection information is generated and added to the data and the data is encrypted and encoded. The data is then programmed back to the memory device in a second location. By using the copy accelerator, a latency associated with performing copy command operations and other data management operations may be decreased.

NVMe copy command acceleration

Instead of the firmware (FW) monitoring for both an overlap read command and a write protected (WP) overlapped write command, the FW can monitor the overlap table only. The controller will receive a read command or an overlap read command. If the command is not an overlap read command, then the controller will process the command normally. If the command is an overlap read command, then the controller will look for the write command that is being overlapped. When passing the write overlap of write protect (WP) into the data path instead of the exception queue, the FW is limited to monitoring the overlap table. As such, when the WP command is completed the entry is removed by the data path. As a result, the FW can limit monitoring to when the data path clears the overlap table.

Write protect HW acceleration

The disclosure relates in some aspects to managing the fetching and execution of commands stored in submission queues. For example, execution of a command may be blocked at a data storage apparatus due to an internal blocking condition (e.g., a large number of commands of a particular type are pending for execution at the data storage device). As another example, execution of a command may be blocked at a data storage apparatus due to an external blocking condition (e.g., a host device may specify that certain commands are to be executed immediately one after another). The disclosure relates in some aspects to controlling how commands are fetched and executed so that commands that cannot be executed by the data storage apparatus in the near future do not prevent other commands (that are not subject to the same blocking condition) from being executed.

Managed fetching and execution of commands from submission queues

In addition to transmitting over the ASIC-NAND bus the legacy long command format, a data storage device will be able to use also a compressed/improved command format. The alternate command's format is hidden from most parts of the NAND. The NAND can have a layer that will translate compressed/non standard commands to the legacy (standard) format for use by the rest of the NAND device's logic, as currently implemented. According to selected command format, the Low Level Flow Sequencer (LLFS) sequence generator and the flash interface module (FIM) will know which format to use in order to encode the command's content for transmission to the NAND by the FIM/ASIC/controller. The command is then executed on the NAND side according to the selected command scheme. Changes will be applied in the device controller on the ASIC side—to encode the command, and on the NAND side—to decode the command according to the selected format. The controller on the ASIC side decides on the desired format and is responsible to sync any format change with the NAND before sending a command in a different format than currently agreed between the controller and the NAND.

Multiple command format interpretation for SSD

The present disclosure generally relates to improved host memory buffer (HMB) segment selection at the initialization phase. Rather than selecting an HMB segment strictly on one parameter, the selection process will consider multiple factors of the HMB segments. Instead of just selecting a HMB segments based on the size of the HMB segment, the data storage device will perform some basic performance measurements on the provided HMB segments before selecting HMB segments. The selection will be based also on the performance results from the various experiments. The experiments are performed in the initialization phase so the performance of the solid state drive (SSD) will not be impacted. The basic experiments include read, write, and mixed operations toward the HMB segments while measuring the performance and QoS.

HMB multi-segment optimal selection

Splitting an address translation cache (ATC) into two portions can reduce costs and maintain efficient retrieval of data. One portion can be disposed in a first location while a second portion can be disposed in a second location distinct from the first location. The first location can be in the controller. The second location can be in a host memory buffer (HMB) or in a memory device separate from the controller. To obtain translated addresses, untranslated addresses can be searched in the first portion and the corresponding translated addresses can be retrieved from the second portion. When invalidating untranslated addresses, the untranslated addresses of the first portion can be deleted without a need to delete corresponding translated addresses in the second portion. To improve ATC storage capacity, grouping of untranslated addresses is possible using most significant bytes (MSBs).

Hybrid address translation cache using DRAM

Instead of an arbitration over the link not considering bursts, a smart scheduler in a solid state drive (SSD) host interface is burst aware. The scheduler considers the type of transactions that are going to be sent over the interface. The scheduler sends the transactions in the most efficient way while maximizing the efficiency over the host DRAM. The schedulers may be calibrated from time to time on-the-fly to find the optimal configurations adapted to the current workload. The scheduler will organize the packets selected by the arbitration module so that the data transfers are sent in a burst of a predetermined sized to the host for optimum performance. For further optimization other packet types are sent in bursts as well.

Burst awareness scheduler over host interface

Growing community of inventors

Beer Sheva, Israel

Shay Benisty