Stmicroelectronics S.r.l.

Other

Micron Technology Incorporated

Hynix Semiconductor Inc.

Roberto Ravasio

Rino Micheloni

Angelo Bovino

Alessia Marelli

Luca Crippa

Massimiliano Lunelli

Valeria Intini

Vincenzo Altieri

Giovanni Campardo

Federico Pio

Osama Khouri

Stefano Zanardi

Massimiliano Picca

Ilaria Motta

Chiara Missiroli

Salvatrice Scommegna

Mario De Matteis

A method and system for making error corrections on digital information coded as symbol sequences, for example digital information stored in electronic memory systems or transmitted from and to these systems is described, provides the 5 transmission of sequences incorporating a portion of error corrector code allowing the sequence which is more probably the original transmitted through the calculation of an error syndrome using a parity matrix to be restored when received. Advantageously according to embodiments of the invention, the error code incorporated in the original sequence belongs to a non Boolean group.

Method for performing error corrections of digital information codified as a symbol sequence

A method and system for making error corrections on digital information coded as symbol sequences, for example digital information stored in electronic memory systems or transmitted from and to these systems is described, provides the transmission of sequences incorporating a portion of error corrector code allowing the sequence which is more probably the original transmitted through the calculation of an error syndrome using a parity matrix to be restored when received. Advantageously according to embodiments of the invention, the error code incorporated in the original sequence belongs to a non Boolean group.

A multi-level flash memory device allows for a faster and more effective configuration of the operating parameters of the memory device for performing the different functioning algorithms of the memory. The identification of an optimal configuration of the operating parameters of the memory device during testing is simplified by allowing for a one-time processing of configuration bits into algorithm-friendly data that are stored in an embedded ancillary random access memory at every power-on of the memory device. This is done by executing a specific power-on algorithm code stored in the ancillary read only memory of the embedded microprocessor.

Configuration of a multilevel flash memory device

A reading method for a memory device with error-correcting encoding envisages the steps of: carrying out a first reading of a plurality of memory locations (A, A, . . . , ALS-) to generate a first recovered string (S), and performing a first decoding attempt using the first recovered string (S). When the first decoding attempt fails, the memory locations are read at least one second time, and at least one second recovered string (S-SN) is generated. On the basis of a comparison between the first recovered string (S) and the second recovered string (S-SN), a modified string (SM) is generated, in which erasures (X) are located, and at least one second decoding attempt is carried out using the modified string (SM).

Reading method of a memory device with embedded error-correcting code and memory device with embedded error-correcting code

A solid state mass storage device having a first storage area portion and a second storage area portion. The mass storage device including accessing means adapted to cause data to be stored in the first storage area portion in one of: only in memory cells belonging to columns of a first collection or only to columns of a second collection such that memory cells of the first storage area portion belonging to the first or second collection are left unprogrammed; or only in memory cells of even rows or only memory cells of odd row such that the memory cells of the first storage area belonging to the even or to the odd rows are left unprogrammed; or only in memory cells such that memory cells that are immediately adjacent to said memory cells in said row and column are left unprogrammed.

Non-volatile, electrically-programmable memory

A multi-level flash memory device allows for a faster and more effective configuration of the operating parameters of the memory device for performing the different functioning algorithms of the memory The identification of an optimal configuration of the operating parameters of the memory device during testing is simplified by allowing for a one-time processing of configuration bits into algorithm-friendly data that are stored in an embedded ancillary random access memory at every power-on of the memory device This is done by executing a specific power-on algorithm code stored in the ancillary read only memory of the embedded microprocessor.

Configuration of a multi-level flash memory device

A reading method for a memory device with error-correcting encoding envisages the steps of: carrying out a first reading of a plurality of memory locations (A, A, . . . , ALS&#x2212;) to generate a first recovered string (S), and performing a first decoding attempt using the first recovered string (S). When the first decoding attempt fails, the memory locations are read at least one second time, and at least one second recovered string (S-SN) is generated. On the basis of a comparison between the first recovered string (S) and the second recovered string (S-SN), a modified string (SM) is generated, in which erasures (X) are located, and at least one second decoding attempt is carried out using the modified string (SM).

An embodiment of the present invention relates to an integrated memory system comprising at least a non-volatile memory and an automatic storage error corrector, and wherein the memory is connected to a controller by means of an interface bus. Advantageously, the system comprises in the memory circuit means, functionally independent, each being responsible for the correction of a predetermined storage error; at least one of said means generating a signal to ask a correction being external to the memory.

Integrated memory system

The capacitive coupling between two adjacent bitlines of a NAND memory device may be exploited for boosting the voltage of bitlines that are not to be programmed in order to inhibit program operations on them. The even (odd) bitlines that include cells not to be programmed are biased with a first voltage for inhibiting them from being programmed while the even (odd) bitlines that include cells to be programmed are grounded. The adjacent odd (even) bitlines are biased at the supply voltage or at an auxiliary voltage for boosting the bias voltage of the even (odd) bitlines above the supply voltage. The bias voltage of the even (odd) bitlines that include cells not to be programmed is boosted because of the relevant parasitic coupling capacitances between adjacent bitlines.

Method of programming cells of a NAND memory device

A memory has one bus for data, addresses, and commands. A data register is coupled to the bus to store the data written to and read from the memory, a command register is coupled to the bus for receiving memory commands, and an address register is coupled to the bus to address the memory. The memory also includes an Error Correction Code circuit for calculating an ECC. The memory is configured to be responsive to external commands for controlling the operation of the ECC circuit for reading or writing of the ECC that are separate from external commands controlling reads or writes of the memory data. The memory may also include a status register that stores information regarding the passing or failing of the ECC.

Memory with embedded error correction codes

A method for operating a flash memory device. The memory device includes a matrix of memory cells each one having a programmable threshold voltage defining a value stored in the memory cell. The method includes the steps of erasing a block of memory cells, and compacting the threshold voltages of the memory cells of the block within a predefined compacting range, wherein the step of compacting includes: selecting at least one first memory cell of the block for writing a target value; restoring the threshold voltage of a subset of the memory cells of the block to the compacting range, the subset including the at least one first memory cell and/or at least one second memory cell of the block being adjacent to the at least one first memory cell; and at least partially writing the target value into the at least one first memory cell.

Method for compacting the erased threshold voltage distribution of flash memory devices during writing operations

A NAND flash memory device includes a matrix of memory cells each having a threshold voltage. The matrix includes an individually erasable sector and is arranged in plural rows and columns with the cells of each column arranged in plural strings of cells connected in series. The memory device includes logic that erases the cells of a selected sector, and restoring logic that restores the threshold voltage of the erased cells. The restoring logic acts in succession on each of plural blocks of the sector, each block including groups of one or more cells. The restoring logic reads each group with respect to a limit value exceeding a reading reference value, programs only each group wherein the threshold voltage of at least one cell does not reach the limit value, and stops the restoring in response to reaching the limit value by at least one set of the groups.

Flash memory device with NAND architecture with reduced capacitive coupling effect

Multi-level programming allows for writing a first and a second bit in selected cells by separately programming the first bit from the second bit. Programming of the first bit determines a shifting from a first threshold level to a second threshold level. Programming of the second bit requires a preliminary reading to detect whether the first bit has been modified, performing a first writing step to bring the cell to a third threshold voltage if the first bit has been modified and performing a second writing step to bring the selected cell to a fourth threshold voltage different from the third threshold level if the first bit has not been modified. For increasing reading and program reliability, during preliminary reading of the second portion a reading result is forced to correspond to the first threshold level.

Method for accessing a multilevel nonvolatile memory device of the flash NAND type

A method for programming an electrically programmable memory including a plurality of memory cells arranged in individually-selectable memory cell sets each including at least one memory cell. The programming method includes causing the memory cells of a selected memory cells set to be brought into a predetermined, starting programming state. Receiving a target value for the first data bits groups of the memory cells of the selected memory cells set. Receiving a target value for the second data bits groups of the memory cells of the selected memory cells set. After having received the target values of both the first and the second data bits groups, applying to the memory cells of the selected memory cells set a programming sequence adapted to cause the memory cells of the selected memory cells sets to be brought into a target programming state jointly determined by the target values of the first and second data bits groups.

Double page programming system and method

A non-volatile memory device is proposed. The non-volatile memory device includes a plurality of memory cells each one having a programmable threshold voltage, and means for reading a set of selected memory cells with respect to a plurality of reference voltages, for each selected memory cell the means for reading including means for charging a reading node associated with the selected memory cell with a charging voltage, means for biasing the selected memory cell with a biasing voltage, means for connecting the charged reading node with the biased selected memory cell, and means for sensing a voltage at the reading node after a predefined delay from the connection, for at least a first one of the reference voltages the biasing voltage being a first biasing voltage equal to the first reference voltage and the delay being a common first delay, wherein for at least a second one of the reference voltages the biasing voltage is a second biasing voltage different from the second reference voltage, and the delay is a second delay different from the first delay.

Growing community of inventors

Ponte San Pietro, Italy

Roberto Ravasio