Sandisk Technologies Inc.

Dennis S Ea

Mrinal Kochar

Yew Yin Ng

Aaron Lee

Mikhail Palityka

Abhijeet Bhalerao

Ivan Baran

Jianmin Huang

Andrew John Tomlin

Gautam Ashok Dusija

Daniel Edward Tuers

Farookh Moogat

Alexander Kwok-Tung Mak

Steven S Cheng

Data that is initially stored in Single Level Cell (SLC) blocks is subsequently copied (folded) to a Multi Level Cell (MLC) block where the data is stored in MLC format, the data copied in a minimum unit of a fold-set, the MLC block including a plurality of separately-selectable sets of NAND strings, data of an individual fold-set copied exclusively to two or more word lines of an individual separately-selectable set of NAND strings in the MLC block.

Data folding in 3D nonvolatile memory

Partially-bad blocks are identified in a 3-D block-erasable nonvolatile memory, each partially-bad block having one or more inoperable separately-selectable sets of NAND strings and one or more operable separately-selectable sets of NAND strings. Operable sets of NAND strings within two or more partially-bad blocks are identified and are mapped to form one or more virtual blocks that are individually assigned virtual block addresses. The virtual block address are maintained in a list and used to access the virtual blocks.

Partially-bad block operation in 3-D nonvolatile memory

Non-volatile memory systems with multi-write direction memory units are disclosed. In one implementation an apparatus comprises a non-volatile memory and a controller in communication with the non-volatile memory. The controller is configured to select an empty memory block of the non-volatile memory for the storage of data; examine an identifier associated with the memory block to determine a write direction for the storage of data; and write data to the memory block beginning with an initial word line of the memory block or a last word line of the memory block dependent on the write direction. The controller is further configured to erase the memory unit and, in response to erasing the memory unit, modify the identifier to change the write direction for a subsequent write of data to the memory block.

Non-volatile memory systems with multi-write direction memory units

A method of searching for a boundary between a written portion and an unwritten portion of an open block may include performing a word line by word line binary search of a first physical area of the open block to identify a last written word line of the first physical area of the block, and subsequently, searching in at least a second physical area of the open block based on the last written word line of the first physical area of the block as identified by the binary search.

Efficient scanning of nonvolatile memory blocks

A method and system for phasing power-intensive operations is disclosed. A non-volatile storage device controller detects a power reset. The controller is in communication with non-volatile memories in the non-volatile storage device. In response to detecting a power reset, the controller determines a current consumption necessary to reset the non-volatile memories in the non-volatile storage device. The controller simultaneously resets all of the non-volatile memories when the determined current consumption is less than a current consumption threshold. If the determined current consumption is greater than the current consumption threshold, the controller resets a first subset of the plurality of non-volatile memories, and after a predetermined delay, resets a second subset of the non-volatile memories. Therefore, a power-intensive operation may be performed without exceeding a current consumption threshold by dividing the operation into a sequence of steps that do not exceed the threshold.

Phased NAND power-on reset

A memory device and method for performing a write-abort-safe firmware update are disclosed. In one embodiment, a location in a memory of a memory device for a firmware update is allocated. The firmware update is written into the allocated location in the memory. A pointer is written to the firmware update in a directory, and a pointer is written to the directory in a location in the memory that is read during boot-up. In another embodiment, a block in a memory of a memory device is allocated for updated file system data comprising a firmware update and a directory. The updated file system data is written into the allocated location in the memory. A pointer is written to the firmware update in the directory, and a pointer is written to the updated file system data in a boot block in the memory, wherein the boot block is read during boot-up.

Growing community of inventors

Hayward, CA, United States of America

Dennis S Ea