Sandisk Corporation

Sundisk Corporation

Other

Sandisk Technologies Inc.

Zilog, Inc.

Western Digital Corporation

Sanjay Mehrotra

Robert D Norman

Eli Harari

Douglas J Lee

Raul-Adrian Cernea

Mehrdad Mofidi

Daniel C Guterman

John S Mangan

Anil K Gupta

Jeffrey G Craig

Daniel L Auclair

Jeffrey Donald Stai

Stephen Jeffrey Gross

Winston Lee

Karl M J Lofgren

Karl M Lofgren

George Samachisa

Khandker N Quader

Raul-Ardian Cernea

A memory system includes an array of solid state memory devices which are in communication with and under the control of a controller module via a device bus with very few lines. This forms an integrated-circuit mass storage system which is contemplated to replace a mass storage system such as a disk drive memory in a computer system. Command, address and data information are serialized into component strings and multiplexed before being transferred between the controller module and the array of memory devices. The serialized information are is accompanied by a control signal to help sort out the multiplexed components. Each memory device in the array is mounted on a multi-bit mount and assigned an array address by it an array mount. An A memory device is selected by an appropriate address broadcast over the device bus, without requiring the usual dedicated select signal. A reserved array particular mount multi-bit configuration is used to unconditionally select the device mounted thereon. A reserved predefined address broadcast over the device bus deselects all previously selected memory devices. Read performance is enhanced by a read streaming technique in which while a current chunk of data is being serialized and shifted out of the memory subsystem devices to the controller module, the controller module is also setting up the address for the next chunk of data to begin to address the memory system.

Device and method for controlling solid-state memory system

An EEPROM system includes flash EEPROM cells organized into subarrays. Pairs of subarrays share row address decoders by sharing word lines, and individual subarrays have dedicated column address decoders and data registers. Each row decoder has an associated row address latch, and each column decoder has an associated column address latch. Multiple data chunks are concurrently written into the subarrays by first latching chunk addresses into the row and column address latches, and corresponding chunks of data into the data registers, then activating a programming signal to initiate concurrent programming and verifying the programming of the data chunks.

Latched address multi-chunk write to EEPROM

Soft errors occur during normal use of a solid-state memory such as EEPROM or Flash EEPROM. A soft error results from the programmed threshold voltage of a memory cell being drifted from its originally intended level. The error is initially not readily detected during normal read until the cumulative drift becomes so severe that it develops into a hard error. Data could be lost if enough of these hard errors swamps available error correction codes in the memory. A memory device and techniques therefor are capable of detecting these drifts and substantially maintaining the threshold voltage of each memory cell to its intended level throughout the use of the memory device, thereby resisting the development of soft errors into hard errors.

Soft errors handling in EEPROM devices

A memory system includes an array of solidstate memory devices which are in communication with and under the control of a controller module via a device bus with very few lines. This forms an integrated-circuit mass storage system which is contemplated to replace a mass storage system such as a disk drive memory in a computer system. Command, address and data information are serialized into component strings and multiplexed before being transferred between the controller module and the array of memory devices. The serialized information are is accompanied by a control signal to help sort out the multiplexed components. Each memory device in the array is mounted on a multi-bit mount and assigned an array address by it an array mount. An A memory device is selected by an appropriate address broadcast over the device bus, without requiring the usual dedicated select signal. A reserved array particular mount multi-bit configuration is used to unconditionally select the device mounted thereon. A reserved predefined address broadcast over the device bus deselects all previously selected memory devices. Read performance is enhanced by a read streaming technique in which while a current chunk of data is being serialized and shifted out of the memory subsystem devices to the controller module, the controller module is also setting up the address for the next chunk of data to begin to address the memory system.

A system of Flash EEprom memory chips with controlling circuits serves as non-volatile memory such as that provided by magnetic disk drives. Improvements include selective multiple sector erase, in which any combinations of Flash sectors may be erased together. Selective sectors among the selected combination may also be de-selected during the erase operation. Another improvement is the ability to remap and replace defective cells with substitute cells. The remapping is performed automatically as soon as a defective cell is detected. When the number of defects in a Flash sector becomes large, the whole sector is remapped. Yet another improvement is the use of a write cache to reduce the number of writes to the Flash EEprom memory, thereby minimizing the stress to the device from undergoing too many write/erase cycling.

Flash EEprom system

A system of Flash EEprom memory chips with controlling circuits serves as non-volatile memory such as that provided by magnetic disk drives. A chunk of user data is programmed into a group of memory cells in parallel, the programming of individual memory cells being terminated when they are determined to have reached desired threshold level ranges while the programming of other memory cells continues. Other improvements include selective multiple sector erase, in which any combinations of Flash sectors may be erased together. Selective sectors among the selected combination may also be de-selected during the erase operation. Another improvement is the ability to remap and replace defective cells with substitute cells. The remapping is performed automatically as soon as a defective cell is detected. When the number of defects in a Flash sector becomes large, the whole sector is remapped. Yet another improvement is the use of a write cache to reduce the number of writes to the Flash EEprom memory, thereby minimizing the stress to the device from undergoing too many write/erase cycling.

Flash EEprom system capable of selective erasing and parallel programming/verifying memory cell blocks

Method for selective erasing and parallel programming/verifying of cell blocks in a flash EEprom system

A system of Flash EEprom chips with controlling circuits serves as non-volatile memory such as that provided by magnetic disk drives. Improvements include selective multiple sector erase, in which any combinations of Flash sectors may be erased together. Selective sectors among the selected combination may also be de-selected during the erase operation. Another improvement is the ability to remap and replace defective cells with substitute cells. The remapping is performed automatically as soon as a defective cell is detected. When the number of defects in a Flash sector becomes large, the whole sector is remapped. Yet another improvement is the use of a write cache to reduce the number of writes to the Flash EEprom memory, thereby minimizing the stress to the device from undergoing too many write/erase cycling.

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Milpitas, CA, United States of America

Sanjay Mehrotra