Matrix Semiconductor, Inc.

Sandisk 3d LLC

Daniel C Steere

Christopher S Moore

J James Tringali

Derek Bosch

James E Schneider

Roy E Scheuerlein

Roger March

David Russell Friedman

A digital storage system is coupled to a write-once memory array. File delete commands are implemented by over-writing a destructive digital pattern to at least a portion of the memory cells associated with the file to be deleted. One disclosed system alters the manner in which a file delete command is implemented, depending upon whether the file is stored in a write-once memory or in a re-writable memory.

Method for deleting stored digital data from write-once memory device

The preferred embodiments described herein provide a method for reading data in a write-once memory device using a write-many file system. In one preferred embodiment, data traffic between a data storage device and a write-once memory device is redirected so that file system structures of a write-many file system do not overwrite previously-stored file system structures. Data traffic between the write-once storage device and a data reading device is also redirected so that a current file system structure of the write-many file system is provided to the data reading device instead of an out-of- date file system structure. In another preferred embodiment, a non-volatile write-many memory array is provided in the write-once memory device to store file system structures of a write-many file system. With these preferred embodiments, data stored during multiple sessions using a write-once file system can be read by a write-many file system, thereby increasing the memory device's interoperability among existing data reading devices. Other preferred embodiments are provided, and each of the preferred embodiments described herein can be used alone or in combination with one another.

Method for reading data in a write-once memory device using a write-many file system

The preferred embodiments described herein provide a three-dimensional memory cache system. In one preferred embodiment, a modular memory device removably connectable to a host device is provided. The modular memory device comprises a substrate, a cache memory array, a three-dimensional primary memory array, and a modular housing. The cache memory array and the three-dimensional primary memory array can be on the same or separate substrates in the modular housing. In another preferred embodiment, an integrated circuit is provided comprising a substrate, a cache memory array in the substrate, and a three-dimensional primary memory array above the substrate. Other preferred embodiments are provided, and each of the preferred embodiments can be used alone or in combination with one another.

Three-dimensional memory cache system

A write-once memory device includes a memory array controller and an electronically resetable flag. The memory array controller prevents writing and erasing from a write-once memory array unless the flag is in a selected state. The memory device is used with a data storage system that automatically determines whether a memory device installed in the data storage system is a write-once memory, and then automatically sends a recognition signal to the memory device once it has been determined to be a write-once memory. The memory device (1) automatically sets the flag in response to the recognition signal, (2) automatically refuses to implement write and erase commands prior to receipt of the recognition signal and setting of the flag, and (3) implements write and erase commands subsequent to receipt of the recognition signal and setting of the flag. The memory device implements nondestructive commands such as read and status commands regardless of the state of the flag.

Growing community of inventors

Menlo Park, CA, United States of America

Daniel C Steere