Abstract: In a dynamic random access memory device, an auto-refresh method comprises receiving a command for the memory device to operate in a half-density mode. This causes a remapping circuit to remap a first memory address bit to an unused memory address location. Using the new addressing scheme, an auto-refresh operation is performed on the memory array operating in the half-density mode without skipping refresh commands.
Abstract: Disclosed is a page buffer for a nonvolatile semiconductor memory device and a related method of operation. The page buffer includes a unidirectional driver between a loading latch unit used for storing a data bit in the page buffer and a bitline used to program a memory cell connected to the page buffer.
Abstract: A circuit and method for generating a wordline voltage in a nonvolatile semiconductor memory device. The circuit comprises a switching unit to provide an external program voltage as the wordline voltage, together with a wordline voltage pump to generate the wordline voltage by pumping a power source voltage. After the wordline voltage is raised to a first level by the external program voltage, it is further increased by a pumping operation. According the circuit and method described herein, shortens the time required to reach a target voltage.
Abstract: The programming method of the present invention minimizes program disturb by initially programming cells on the same wordline with the logical state having the highest threshold voltage. The remaining cells on the wordline are programmed to their respective logical states in order of decreasing threshold voltage levels.
Abstract: An address latch circuit of a memory device is disclosed. A latch operation is disabled while an address signal makes a level transition in the memory device, and then enabled when the address signal is stabilized after the level transition. Therefore, it is possible to reduce power consumption caused during the level transition of the address signal.
Abstract: Flash memory cells are presented which comprise a dielectric material formed above a substrate channel region, a charge trapping material formed over the dielectric material, and a control gate formed over the charge trapping material. The cell may be programmed by directing electrons from the control gate into the charge trapping material to raise the cell threshold voltage. The electrons may be directed from the control gate to the charge trapping material by coupling a substrate to a substrate voltage potential, and coupling the control gate to a gate voltage potential, where the gate voltage potential is lower than the substrate voltage potential. The cell may be erased by directing electrons from the charge trapping material into the control gate to lower a threshold voltage of the flash memory cell, such as by coupling the substrate to a substrate voltage potential, and coupling the control gate to a gate voltage potential, where the gate voltage potential is higher than the substrate voltage potential.
Type:
Grant
Filed:
August 29, 2006
Date of Patent:
May 8, 2007
Assignee:
Spansion LLC
Inventors:
Zhizheng Liu, Zengtao Liu, Yi He, Mark Randolph
Abstract: A semiconductor storage device in which a pair of wiring lines extending in a first direction are arranged repeatedly with a predetermined pitch, comprising: a group of pair transistors in which a plurality of pair transistors is arranged according to a repetition unit with a predetermined pattern, the pair transistors composed of a MOS transistor of which a gate is connected to one line of the pair of wiring lines and of another MOS transistor of which a gate is connected to the other line of the pair of wiring lines, wherein the repetition unit of the group of pair transistors includes a plurality of the pair transistors such that two MOS transistors are adjacent to each other in the first direction, and at least one pair of pair transistors such that two MOS transistors are not adjacent to each other and diagonally opposite to each other.
Abstract: A ferroelectric memory has a plurality of memory cells respectively having a cell transistor and ferroelectric capacitor whose one terminal is connected with the cell transistor, a plurality of word lines respectively connected with said cell transistor, a plurality of plate lines connected with the other terminal of said ferroelectric capacitor and intersecting with said word lines, a plurality of local bit lines connected with said cell transistors, and a global bit line that is selectively connected with local bit lines. Furthermore, the ferroelectric memory has a sensing amplifier unit that detects the amount of charging of the local bit lines from said memory cells while maintaining the potential of the local bit lines at a potential equivalent to the non-selected plate lines, during reading.
Abstract: A selected wordline that is coupled to cells for programming is biased with a programming voltage. The unselected wordlines that are adjacent to the selected wordline are biased at a first predetermined voltage. The remaining wordlines are biased at a second predetermined voltage that is greater than the first predetermined voltage. The first predetermined voltage is selected by determining what unselected, adjacent wordline bias voltage produces a minimized Vpass disturb in response to the selected wordline programming voltage.
Type:
Grant
Filed:
June 30, 2004
Date of Patent:
May 1, 2007
Assignee:
Micron Technology, Inc.
Inventors:
Paul J. Rudeck, Andrei Mihnea, Andrew Bicksler
Abstract: An operation scheme for operating stably a semiconductor nonvolatile memory device is provided. When hot-hole injection is conducted in the semiconductor nonvolatile memory device of a split gate structure, the hot-hole injection is verified using a crossing point that does not change with time. Thus, an erased state can be verified without being aware of any time-varying changes. Also, programming or programming/erasure is conducted by repeating pulse voltage or multi-step voltage application to a gate section multiple times.
Abstract: This invention provides a semiconductor memory device and a corresponding method of operation. The semiconductor memory device comprises a semiconductor substrate having a first conductivity; a plurality of gate structures for storing charge in a non-volatile manner regularly arranged in above the surface of the semiconductor substrate and electrically isolated therefrom; a plurality of wordlines, each of the gate structures being connected to one of the wordlines and a group of the gate structures being connected to a common wordline; and a plurality of active regions, each of the active regions being individually connectable to at least one of the gate structures.
Abstract: A semiconductor memory device includes memory cell arrays, a redundancy cell array shared by the memory cell arrays, a correction capacitance, and switching circuits arranged in correspondence with the memory cell arrays. Each memory cell array includes ferroelectric cells arranged at the intersections between word lines and bit lines. The redundancy cell array includes spare ferroelectric cells arranged at the intersections between spare word lines and redundancy bit lines. The number of spare ferroelectric cells connected to the redundancy bit line is smaller than that of ferroelectric cells connected to the bit line in each memory cell array. The correction capacitance is connected to the redundancy bit line to make its capacitance equivalent to that of the bit line. When a replaced ferroelectric cell in the memory cell array is selected, the switching circuits select a corresponding spare ferroelectric cell in place of the replaced ferroelectric cell.
Abstract: Disclosed herein is a block switch of a flash memory device in which a voltage higher than a predetermined operating voltage is generated to drive path transistors in order to stably apply the predetermined operating voltage to a selected cell block of the flash memory device. The block switch generates a high voltage clock signal of a high voltage level according to a control signal and a clock signal, and raises the voltage level of an output terminal to a predetermined level according to the high voltage clock signal. Accordingly, a high voltage can be outputted even at a low power supply voltage. There is no need for a decoder for high voltage as in a precharge and self-boosting mode. A voltage can be directly applied to word lines without a precharge operation. It is thus possible to reduce an operating time.
Abstract: Methods and circuitry are present for improving performance in non-volatile memory devices by allowing the inter-phase pipelining of operations with the same memory, allowing, for example, a read operation to be interleaved between the pulse and verify phases of a write operation. In the exemplary embodiment, the two operations share data latches. In specific examples, at the data latches needed for verification in a multi-level write operation free up, they can be used to store data read from another location during a read performed between steps in the multi-level write. In the exemplary embodiment, the multi-level write need only pause, execute the read, and resume the write at the point where it paused.
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: The semiconductor device of the present invention includes at least one dummy cell of a programmed state proximately located to an edge of a reference cell array. Thus, the leak current does not flow when a data of the cell on the edge of the reference cell array is read out. The memory cell located around the center of the reference cell array has neighboring cells of the programmed state, and the leak current can be prevented when the data is read out from all the reference cells. Thus, the reference current can be supplied stably.
Abstract: A method for a read-before-write functionality for a memory within a programmable logic device (PLD) is provided. The method begins when a read operation and a write operation are initiated through two different ports of a memory simultaneously to access the same address in the memory. In order to prevent the write operation from proceeding prior to the read operation, a read-before-write control logic is provided to the control block of the port that supports the write operation. Thus, the write operation is paused until the control block of the port that supports the write operation receives a signal from a read sense amplifier indicating that the read operation is complete. The read sense amplifier is capable of detecting the completion of a read operation by monitoring the voltage difference of the read bitline. When this voltage difference reaches a threshold value, the read sense amplifier triggers a write wordline signal.
Abstract: A semiconductor memory includes a converter configured to convert each read-data of plural bits read from a memory core into serial data, respectively, in synchronization with a read clock to generate converted read-data. An output register holds the converted read-data in synchronization with the read clock. A selector selects one bit from each plural bits of the converted read-data, in accordance with a control data, and to supply the selected bit to the output register.
Abstract: Disclosed are a precharge circuit employing an inactive weak precharging and equalizing scheme, a memory device including the same and a precharging method. The inactive weak precharging and equalizing scheme equalizes a non-selected bit line and complementary bit line while sensing and amplifying memory cell data delivered to a selected bit line and complementary bit line to evaluate the voltage difference between the selected bit line and complementary bit line. Then, the scheme precharges the selected bit line and complementary bit line and the non-selected bit line and complementary bit line. This does not require high precharge driving capability for inactivated bit line and complementary bit line equalized to a predetermined voltage level so that precharge current and operating current can be reduced.