Abstract: On a channel region enclosed by a pair of diffusion layers 13A, 13B, a first insulating layer 15, a charge accumulative layer 17, and a second insulating layer 19 are stacked up in this order, and on the second insulating layer 19, two control gate layers 21A, 21B spaced across a gap G1 are disposed in the middle of the channel width direction. The charge accumulative layer 17 has discrete charge traps, and, accordingly, movement of charge in the layer is limited. In the charge accumulative layer 17, the charges injected depend on the writing voltage applied in control gate layers 21A, 21B and can be localized beneath the control gate layers 21A, 21B through which a writing voltage is applied. The presence or absence of charges can be controlled in every charge accumulative region beneath the control gate layers 21A, 21B, so that multi-value storage in the memory cell can be realized.

Abstract: Circuits and methods to design and to fabricate said circuits to accomplish a two-level DRAM cell or a multilevel DRAM cell using a natural transistor have been achieved. The usage of a natural transistor, having a threshold voltage of close to zero, as a pass transistor reduces the amount of current required for a read operation significantly. The usage of a natural transistor in a multi-level DRAM is enabling to implement easily a high number of voltage levels, and thus more information, in one DRAM cell and is reducing the amount of output current required as well. The fabrication of said DRAM cells in an integrated circuit, comprising a natural transistor and standard transistors, include masking of the natural transistor during the ion implantation to avoid impurities increasing the threshold voltage.

Abstract: A software refreshed memory device comprises a plurality of memory cells that must be periodically refreshed to avoid losing data. Preferably, the memory cells can avoid losing data even though the time interval between successive memory refresh operations is relatively long, as compared to the time interval between successive memory refresh operations in a conventional volatile memory device, such as a DRAM. A processor can perform periodic memory refresh operations by executing a set of memory refresh instructions implemented in software, rather than in hardware. Accordingly, the memory device can advantageously be simplified, because the need for memory refresh circuitry and for a unique refresh control signal are advantageously eliminated. Moreover, the processor executing the memory refresh instructions can typically perform more sophisticated algorithms, as compared to memory refresh circuitry implemented in hardware, for determining when to perform a memory refresh operation.

Abstract: A high resistor SRAM memory cell to reduce soft error rate includes a first inverter having an output as a first memory node, and a second inverter having an output as a second memory node. The second memory node is coupled to an input of the first inverter through a first resistor. The first memory node is coupled to an input of the second inverter through a second resistor. A pair of access transistors are respectively coupled to a pair of bit lines, a split word line and one of the memory nodes. The resistors are prepared by coating a layer of silicide material on a selective portion of the gate structure of the transistors included in the first inverter, and connecting a portion of the gate structure that is substantially void of the silicide material to the drain of the transistors included in the second inverter.

Abstract: To allow a memory controller to synchronize strobe to clock relationship for a DRAM, a register, such as, a flip flop, is incorporated within the DRAM to facilitate the sampling of SCLK with DQS. Likewise, while the DRAM is in a test mode of operation, the memory controller advances or retards the clock to DQS at the memory controller hub (MCH) to achieve the proper DRAM relationship. In one embodiment, the memory controller advances DQS if a binary zero value is read. In contrast, the memory controller retards DQS if a binary one value is read.

Abstract: A memory cell with a charge storage structure is read by measuring current between the substrate region of the memory cell and one of the current carrying nodes of the memory cell. The read operation decreases the coupling between different parts of the charge storage structure when other parts of the charge storage structure store data that are not of interest. The sensing window of the memory cell can be greatly improved by this read operation. Example arrangements are a single memory cell, a column or NOR-connected memory cells, and a virtual ground array of memory cells.

Abstract: A method and apparatus for reducing power consumption in integrated memory devices is provided. Banks of memory cells may be individually put into “sleep” mode via respective “sleep” transistors.

Abstract: A high-voltage charge pump circuit includes a charge pump circuit. A first high-voltage output circuit is configured to set an output voltage of the charge pump at a first voltage level selected for regular programming and erasing memory cells. A second high-voltage output circuit is configured to set the output voltage of the charge pump at a second voltage level selected for walkout of device junctions, the second voltage level being higher than the first voltage level. A third high-voltage output circuit is configured to set the output voltage of the charge pump at a third voltage level selected for guardband programming and erasing, the third voltage level being lower than the second voltage level and higher than the first voltage level. Selection circuitry selectively couples one of the first, second, and third high-voltage output circuits to the output of the high-voltage charge pump circuit.

Abstract: A ferroelectric memory of the present invention comprises: a plurality of normal cells, each of which includes a first ferroelectric capacitor for holding data and a first transistor connected to a first electrode of the first ferroelectric capacitor; a first bit line connected to the first transistor; a first bit line precharge circuit which is a switch circuit provided between the first bit line and a ground; and a word line connected to a gate of the first transistor. The word line is deactivated to disconnect the first ferroelectric capacitor from the first bit line before the first bit line precharge circuit is driven to discharge a potential of the first bit line.

Abstract: A semiconductor memory is achieved which allows a reduction in the area of a memory array block without reducing the gate widths of floating gates. A plurality of select gates extend in straight lines in the X direction. Between the upper- and lower-side select gates, two rows' worth of floating gates are arranged. The plurality of floating gates are placed in a staggered arrangement (in other words, in a zigzag pattern). That is, looking at one floating gate in a specific column and another floating gate in a column adjacent to that specific column, those floating gates deviate from each other in the Y direction.

Abstract: An over-driven access method and device for ferroelectric memory. When accessing the data stored in a ferroelectric memory, the invention further provides an over-driven current to slightly reduce/raise the voltages in bit lines BL and BL? to further enlarge the voltage difference therebetween after having raised the plate-line/bit-line voltage using the plate-line/bit-line driven method.

Abstract: Systems and methods disclosed herein provide for variable data width memory. For example, in accordance with an embodiment of the present invention, a technique for doubling a width of a memory is disclosed, without having to increase a width of the internal data path or the number of input/output pads.

Abstract: A method for preventing generation of program disturbance incurred by hot electrons in a NAND flash memory device. A channel boosting disturb-prevention voltage lower than a program-prohibit voltage applied to other word lines is applied to edge word lines coupled to memory cells that are nearest to select transistors. As a result, an electric field between the memory cells coupled to the edge word lines and the select transistors is weakened, and the energy of the hot electrons is reduced.

Abstract: A non-volatile memory includes word lines providing access to memory cells, a word-line decoder applying an activation signal corresponding to an input address to a word line, a converter reproducing the activation signal on outputs by lowering its voltage level, and an encoding circuit that includes transistors with a switching threshold that is lower than the voltage level of the outputs and coupled so as to generate an output address specific to an activated word line if this word line is the only one activated, such that a test circuit generates an error signal if the input address differs from the output address. In such a configuration, the area of silicon occupied by a test circuit can be reduced.

Abstract: A multiple matchline sense circuit for detecting a single, more than one, or no match conditions during a search-and-compare operation of a content addressable memory is disclosed. The circuit compares the rising voltage rate of a multiple matchline to the rising voltage rate of a reference multiple matchline in order to generate a multibit result representing one of the three conditions. The circuit generates a self-timed control signal to end the search-and-compare operation, and to set the circuit to a precharge state.

Abstract: Disclosed is a non-volatile memory device and a method of erasing the non-volatile memory device. An erase voltage is simultaneously applied to a plurality of sectors contained in the non-volatile memory device. Then, erase validation is sequentially performed for each of the plurality sectors and results of the erase validation are stored in a plurality of pass information registers. According to the results stored in the pass information registers, sectors which were not successfully erased are simultaneously re-erased and then sequentially re-validated until no such “failed sectors” remain in the non-volatile memory device. Upon eliminating the “failed sectors” from the non-volatile memory device, a post-program operation is sequentially performed on each of the plurality of sectors.

Abstract: A page buffer is provided for an electrically programmable memory that includes multiple memory cells forming multiple memory pages. The page buffer includes a register for at least temporarily storing data read from or to be written to the memory cells of a selected memory page. The register includes multiple latches and multiple buffer elements. Each of the latches is coupled to at least one signal line for transferring the data bit that is stored in the latch. Each of the buffer elements decouples an output of a corresponding one of the latches from the signal line, with the buffer element driving the signal line according to the data bit stored in the corresponding latch. Also provided is a method of transferring data from a register to signal lines in an electrically programmable memory.

Abstract: A system for controlling the refresh cycles of a DRAM cell array based upon a temperature measurement. During active mode, a refresh request indication based on a measured temperature is provided to a DRAM controller (e.g. of another integrated circuit die), wherein the DRAM controller initiates a refresh cycle of the DRAM cell array in response thereto. In a self refreshing mode, the DRAM controller does not initiate refresh cycles, but refresh cycles are performed by a controller on the integrated circuit die of the array based upon a temperature measurement.

Abstract: A memory circuit includes a sense amplifier in which a single reference signal is compared to two data signals from two memory cells. The reference signal is generated from the combination of memory cells in opposite logic states. The data signal capacitance is matched to the reference signal capacitance. With reduced but matched capacitance both high speed and high sensitivity can be achieved.

Abstract: An end of a selected bit line in a selected column is electrically coupled to an end of a corresponding current return line by one of first and second write column select gates, which are selectively turned on in response to results of column selection. A data write circuit sets the other end of the selected bit line and the other end of the current return line to one and the other of a power supply voltage and a ground voltage in accordance with a level of write data via one of first and second data buses and an inverted data bus, respectively.