Stmicroelectronics S.r.l.

Micron Technology Incorporated

Stmicroelectronics Pvt. Ltd.

Other

Skhynix Inc.

Stmicroelectronics International N.v.

Angelo Di Sena

Sudeep Biswas

Domenico Manna

Giuseppe Ferrari

Procolo Carannante

Anna Sorgente

Fabio Salvati

Agata Intini

A method includes responding to a wear-level operation request by copying data from a first portion of a first memory array to a second portion of the first memory array, and copying metadata associated with the data from a third portion of a second memory array to a fourth portion of the second memory array. The first memory array includes a NAND or NAND-based memory array, and the second memory array includes non-volatile memory including at least one of the group consisting of: phase-change memory, EEPROM, and NOR flash memory.

Metadata storage associated with wear-level operation requests

A restoring operation of a storage device based on a flash memory. In an embodiment, a storage device emulates a logical memory space (including a plurality of logical blocks each one having a plurality of logical sectors), which is mapped on a physical memory space of the flash memory (including a plurality of physical blocks each one having a plurality of physical sectors for storing different versions of the logical sectors). A method may detect a plurality of conflicting physical blocks for a corrupted logical block and determines a plurality of validity indexes. One or more of the conflicting physical blocks are selected according to the validity indexes. The selected conflicting physical blocks are then associated with the corrupted logical block. At the end, each one of the non-selected conflicting physical blocks is discarded.

Restoring storage devices based on flash memories and related circuit, system, and method

A solution for managing a storage device based on a flash memory is proposed. A corresponding method starts with the step for mapping a logical memory space of the storage device (including a plurality of logical blocks) on a physical memory space of the flash memory (including a plurality of physical blocks, which are adapted to be erased individually). The physical blocks include a set of first physical blocks (corresponding to the logical blocks) and a set of second&#x2014;or spare&#x2014;physical blocks (for replacing each bad physical block that is unusable). The method continues by detecting each bad physical block. Each bad physical block is then discarded, so to prevent using the bad physical block for mapping the logical memory space.

Garbage collection in storage devices based on flash memories

Subject matter disclosed herein relates to sub-block accessible cache memory.

Sub-block accessible nonvolatile memory cache

Apparatus and methods for caching data are disclosed. Data is stored in a non-sub-block accessible nonvolatile memory, such as a NAND flash. A portion of the stored data is cached in a cache implemented using phase change memory using a sub-block accessible address.

Systems and methods for caching data with a nonvolatile memory cache

A wear leveling solution is proposed for use in a storage device based on a flash memory. The flash memory includes a plurality of physical blocks, which are adapted to be erased individually. A corresponding method starts with the step for erasing one of the physical blocks. One of the physical blocks being allocated for storing data is selected; this operation is performed in response to the reaching of a threshold by an indication of a difference between a number of erasures of the erased physical block and a number of erasures of the selected physical block. At least the data of the selected physical block being valid is copied into the erased physical block. The selected physical block is then erased.

Wear leveling in storage devices based on flash memories and related circuit, system, and method

A solution for restoring operation of a storage device based on a flash memory is proposed. The storage device emulates a logical memory space (including a plurality of logical blocks each one having a plurality of logical sectors), which is mapped on a physical memory space of the flash memory (including a plurality of physical blocks each one having a plurality of physical sectors for storing different versions of the logical sectors). A corresponding method starts by detecting a plurality of conflicting physical blocks for a corrupted logical block (resulting from a breakdown of the storage device). The method continues by determining a plurality of validity indexes (indicative of the number of last versions of the logical sectors of the corrupted logical block that are stored in the conflicting physical blocks). One ore more of the conflicting physical blocks are selected according to the validity indexes. The selected conflicting physical blocks are then associated with the corrupted logical block. At the end, each one of the non-selected conflicting physical blocks is discarded.

Memory block compaction method, circuit, and system in storage devices based on flash memories

A method controls write/erase operations in a memory device, such as a NAND flash memory. The method includes dividing the memory device in physical blocks, wherein each physical block is comprised of a number of pages; considering the memory device as comprising consecutive virtual blocks, each virtual block including consecutive sectors; associating to each virtual block a virtual block number; selecting the size of the virtual blocks equal to a multiple of the size of the physical blocks; and creating a virtual-to-physical mapping table having entries. Each entry in the mapping table stores a pointer to a root node of a tree structure that links logically a set of physical blocks in the memory device.

Controlling operation of flash memories

A method controls write/erase operations in a memory device including memory blocks that are exposed to wear as a result of repeated erasures. The method includes: storing the erase counts of the memory blocks, creating a chain storing the erase counts of the memory blocks that are available for writing at a certain instant of time, and selecting for writing, out of the blocks in the memory device available for writing, the block having the lowest erase count in the chain.

Growing community of inventors

Castello di Cisterna, Italy

Angelo Di Sena