Sandisk Technologies Inc.

Western Digital Technologies, Inc.

Gautham Reddy

Nian Niles Yang

Alexandra Bauche

Zhenlei Shen

Niles Yang

Sahil Sharma

Rohit Sehgal

Philip David Reusswig

Nagdi Tafish

Michael Zhu

Satya Singamsetti

Embodiments of the present disclosure relate to physical secure erase (PSE) of solid state drives (SSDs). One embodiment of a method of PSE of a SSD includes receiving a PSE command, erasing the memory cells of the blocks, programming the memory cells, and programming the select gates to a portion of the blocks. One embodiment of a SSD includes a controller and a plurality of blocks having a plurality of NAND strings. Each NAND string includes connected in series a select gate drain, memory cells, and a select gate source. The SSD includes a memory erasing instruction that cause the controller to erase the memory cells of the block, program the memory cells, and increase the threshold voltage to the select gate drain and/or the select gate source of some of the NAND strings from the blocks.

Physical secure erase of solid state drives

A memory device and associated techniques avoid reading memory cells immediately after programming when uncorrectable errors may be present. In one aspect, data is copied from one block to another block and a timer is started after the copying is completed. If a read command is received before the timer has expired, the read operation proceeds by reading the one block. If the read command is received after the timer has expired, the read operation proceeds by reading the another block. This approach is particular suitable when data is copied from single-level cell (SLC) blocks to multi-level cell (MLC) blocks in a folding operation. The duration of the timer can be increased at lower temperatures.

Delayed data release after programming to reduce read errors in memory

A memory system or flash card may include a dynamic system-level process for the management of blocks in the different memory pools. There may be spare blocks available to the pools that are over provisioned to the pool which increases the efficiency of data compaction and helps reduce the average hot count for that pool and compensate for the grown defects. The block wear and grown defects in each memory pool may be tracked so that remaining spare blocks can be re-allocated.

Smart dynamic wear balancing between memory pools

A memory system or flash card may include memory maintenance scheduling that improves the endurance of memory. Certain parameters, such as temperature, are measured and used for scheduling maintenance. For example, memory maintenance may be performed or postponed depending on the ambient temperature of the card. The memory maintenance operations may be ranked or classified (e.g. in a memory maintenance queue based on priority) to correspond with threshold values of the parameters for a more efficient scheduling of memory maintenance. For example, at a low temperature threshold, only high priority maintenance operations are performed, while at a higher temperature threshold, any priority maintenance operation is performed.

Temperature based flash memory system maintenance

Data stored in a nonvolatile memory is selectively sampled based on write-erase cycle counts of blocks. Blocks with the lowest write-erase cycle counts are sampled to determine an error rate which is compared with a limit. If the error rate exceeds the limit then the sample is expanded to include blocks with the next lowest write-erase cycle counts.

Selective sampling of data stored in nonvolatile memory

A mobile device peripheral is provided comprising a wireless memory sub-system configured for carrying out wireless data communications with a mobile device. The mobile device peripheral also has a battery configured to provide power to the wireless memory sub-system and a housing configured to hold the wireless memory sub-system and battery. The housing is further configured to physically attach the mobile device peripheral to the mobile device so that the mobile device peripheral and mobile device are carryable together as a single unit. The mobile device peripheral can take the form of a mobile device case or cover, for example. In another embodiment, the mobile device peripheral has a power splitter configured to split power received from a power connector to charge both the battery of the mobile device peripheral and the battery of the mobile device.

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San Jose, CA, United States of America

Gautham Reddy