Western Digital Technologies, Inc.

Sandisk Technologies Inc.

Nissim Elmaleh

Shay Benisty

Julian Vlaiko

Amir Segev

Dmitry Vaysman

Elkana Richter

Roni Ankonina

Asaf Heller

Ishai Asa

During operation of a data storage device, a controller of the data storage device may initiate read/write operations based on workloads provided by a host device. When initiating the read/write operations, power consumption and the data rate of the data storage device are generally high. Over time, the data rate corresponding to the workload decreases. Thus, the power consumption may be decreased to correspond with the decreased data rate. In order to maintain a high efficiency while decreasing an amount of power utilized, the controller may duty cycle the data storage device to operate between performance states to maintain a high data rate while decreasing power consumption.

Highly efficient SSD power management through PCIe data rate modulation

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.

Low power optimization based upon host exit latency

The present disclosure generally relates to reducing exit latency when transitioning from non-operational power states. Before entering a non-operational power state, specific data in databases and/or tables can be identified as being recently utilized by the host device. In addition to saving the databases and/or tables, a recovery code is also stored to identify that specific data. Upon transitioning back to an operational power state, the recovery code is detected and the specific data can be recovered rather than recovering the entire database and/or table. Data not identified in the recovery code need not be recovered from always-on memory. In so doing, when transitioning back to an operational power state, the latency will be reduced compared to a situation where all data is stored in always-on memory.

Selective device power state recovery method

A method and apparatus for data storage devices, or other devices that are L1 sub-state capable, to enter these sub-states while on the same network or bus as a device not enabled for transition to an L1 power sub-state. According to certain embodiments, a PCI FW register is configured to place a CLKREQ de-assert signal to a MAC of the data storage device, independent of the power state of the host. The CLKREQ de-assert signal causes the MAC to place the data storage device in an L1 power substate such as L1.2. A sensor of the controller remains active to detect a wakeup signal from the host that causes the data storage device to transition to a higher power state.

Systems and methods for power management in a data storage device

The present disclosure describes methods and systems for data storage or other devices that are L1 sub-state capable, to be able to enter these sub-states while on the same network or bus as a device not enabled for transition to an L1 sub-state. In some embodiments, when an LTSSM circuit in a MAC of a PCIe device indicates an L1 idle state, an L1 sub-state (L1SS) timer is initiated in a CLKREQ on the device. Upon expiration of the timer, a CLKREQ_in emulator de-asserts its signal on the MAC, causing the MAC to enter an L1SS.

Growing community of inventors

Meitar, Israel

Nissim Elmaleh