Abstract: A memory device comprises a memory cell and a sense amplifier which has a sensing interval. An output circuit is coupled to the sense amplifier and responsive to a clock signal to accept the signal from the sense amplifier. A first source of timing signals generates a first timing signal in response to an enable signal which is asynchronous relative to the clock signal. A second source of timing signals generates a second timing signal based on the clock signal. A switch selects one of the first and second timing signals at the timing signals for use to define pre-charge and sensing intervals for the sense amplifier. The first source of timing signals is selected during an interval of time corresponding to a clock latency, so that the timing signals define a sensing interval where transitions in the clock signal are outside of the sensing interval.
Type:
Grant
Filed:
May 3, 2006
Date of Patent:
August 3, 2010
Assignee:
Macronix International Co., Ltd.
Inventors:
Ti Wen Chen, Yi Te Shih, Pei Hsun Liao, Ho Hsuan Liu
Abstract: An internal voltage generation device includes a plurality of output nodes; a bit line precharge voltage generation unit for generating a bit line precharge voltage; a first voltage drop unit for transferring the bit line precharge voltage to a first output node after decreasing the bit line precharge voltage by a first voltage drop amount in response to a test mode signal; and a second voltage drop unit for transferring the bit line precharge voltage to a second output node after decreasing the bit line precharge voltage by a second voltage drop amount in response to the test mode signal, wherein the second voltage drop amount is greater than the first voltage drop amount.
Abstract: A semiconductor memory device includes a memory cell array and a sense amp circuit. The memory cell array includes bit lines connected to memory cells operative to store first logic data and second logic data smaller in cell current than the first logic. The sense amp circuit has a clamp transistor operative to clamp a bit line voltage. The sense amp circuit is operative to detect data in a selected memory cell via the clamp transistor and the bit line. The sense amp circuit is operative to read data from the selected memory cell in at least the two of first and second read cycles while a control voltage is applied to a gate of the clamp transistor. Different control voltages are applied to the gate of the clamp transistor in the first and second read cycles.
Abstract: A refresh method for a semiconductor memory device features high noise resistance, lower power consumption, and lower cost. All word lines of one or more memory cell blocks that have not been selected in a self refresh mode are controlled to have a floating potential substantially at ground level. Even when a word line and a bit line are short-circuited, this control prevents destruction of memory cell information, which may be caused by noise, and also prevents generation of leakage current. A fuse, etc., for preventing generation of leakage current is unnecessary, so that lower cost is realized.
Abstract: An object is to realize high-capacity of a memory while reducing power consumption and making the power consumption even throughout the memory. A memory includes a plurality of memory block arranged to be symmetrically to each other. Also, a specific combination of signals among address signals supplied to the memory, a memory block including a memory cell to be read from or written to is specified. Further, signals supplied to other memory blocks than the above memory block is maintained at a constant value. Consequently, a wiring length of a bit line in a memory array can be shortened, and current consumption can be made to be even among data reading or writing from/to memory cells of a variety of addresses within the memory, at the same time as reducing load capacitance.
Type:
Grant
Filed:
May 23, 2007
Date of Patent:
March 9, 2010
Assignee:
Semiconductor Energy Laboratory Co., Ltd.
Abstract: A memory circuit includes a global read bit line, a global read bit line latch, and a plurality of sub-arrays, each of which includes first and second local read bit lines, first and second local write bit lines, and first and second pluralities of memory cells interconnected, respectively, with the first and second local read bit lines and the first and second local write bit lines. The local read bit lines are decoupled from the local write bit lines. A local multiplexing block is interconnected with the first and second local read bit lines and is configured to ground the first and second local read bit lines upon assertion of a SLEEP signal, and to selectively interconnect the local read bit lines to the global read bit line. A global multiplexing block is interconnected with the global read bit line and is configured to maintain the global read bit line in a substantially discharged state upon assertion of the SLEEP signal and to interconnect the global read bit line to the global read bit line latch.
Type:
Grant
Filed:
April 7, 2008
Date of Patent:
February 23, 2010
Assignee:
International Business Machines Corporation
Inventors:
Sam Gat-Shang Chu, Saiful Islam, Jae-Joon Kim, Stephen V. Kosonocky
Abstract: A control apparatus of a GIO line includes a plurality of GIO line termination units, and a GIO control unit for generating a control signal to activate an operation of a specific one of the plurality of GIO termination units according to a data transmission method. Further, a method of controlling a GIO line through GIO termination includes the step of generating a control signal to activate an operation of a specific one of a plurality of GIO termination units according to a data transmission method.
Abstract: One embodiment of the present invention relates to a method by which the imprint of a ferroelectric random access memory (FRAM) array is reduced. The method begins when an event that will cause imprint to the memory array is anticipated by an external agent to the device comprising the chip. The external agent sends a command to the control circuitry that the data states are to be written to a particular data state. Upon receiving a signal the control circuitry writes all of the ferroelectric memory cells in the FRAM array to a preferred memory data state. The memory data states are held in the preferred data state for the entire duration of the event to minimize imprint of the FRAM memory cells. When the event ends the external agent sends a command to the control circuitry to resume normal memory operation. Other methods and circuits are also disclosed.
Abstract: A non-volatile semiconductor memory device includes a page buffer comprising a lower latch block and an upper latch block, and a memory array that is connected to the lower latch block via a lower common bit line and that is connected to the upper latch block via an upper common bit line. The memory array includes a plurality of non-volatile memory cells, a lower even bit line and a lower odd bit line that are selectively connectable to the lower common bit line, an upper even bit line and an upper odd bit line that are selectively connectable to the upper common bit line, a first switch that electrically connects the lower even bit line to the upper even bit line in response to a first connection control signal and a second switch that electrically connects the lower odd bit line to the upper odd bit line in response to a second connection control signal.
Abstract: An object of the present invention is to provide a memory system that offers enhanced security of ROM code that is data whose contents can be utilized for a given purpose in its intact form. In a memory system, data is read from a memory according to at least two or more addresses outputted from an address generator, from individual pages uniquely specified respectively by the addresses. A data generator generates one piece of data on the basis of the at least two or more pieces of data read from the individual pages.
Abstract: This invention provides a semiconductor memory device in which standby current is suppressed to a small level. A ROM device includes memory cells for reading data corresponding to impedance between a terminal connected to bit lines and a source terminal and source power lines connected to the source terminal. In this ROM device, bias voltage is applied between the terminals of selected memory cells.
Abstract: A ferroelectric memory device includes a memory cell, read circuit, temperature sensing circuit, and read controller. The memory cell includes a ferroelectric capacitor. The read circuit is configured to read data from the memory cell. The temperature sensing circuit is configured to sense the ambient temperature of the memory cell. The read controller is configured to receive a temperature sensing signal from the temperature sensing circuit, and inhibit a data read operation by the read circuit when the temperature sensed by the temperature sensing circuit is higher than a preset temperature.
Abstract: The invention concerns a ROM comprising a set of memory points arranged in rows and columns, each memory point capable of storing two bits of data and comprising a single switch controllable to connect together first and second terminals of said switch, each of said first and second terminals being connected to one of first, second and third conductive lines, wherein said switch is connected via said first and second terminals between said first and second lines to encode a first data value, between said first and third lines to encode a second data value, between said second and third lines to encode a third data value, and both of said first and second terminals being connected to the same one of said first, second and third lines to encode a fourth data value.
Type:
Grant
Filed:
April 11, 2008
Date of Patent:
February 9, 2010
Assignee:
Dolphin Integration
Inventors:
Olivier Montfort, Sébastien Gaubert, Philippe Beliard
Abstract: This invention discloses a dual port static random access memory (SRAM) cell, which comprises at least one inverter coupled between a positive supply voltage (Vcc) and a complementary low supply voltage (Vss) and having an input and an output terminals, at least one PMOS transistor with its gate, source and drain connected to the output terminal, Vcc and input terminal, respectively, a write port connected to the input terminal and having a write-word-line, a write-enable and a write-bit-line, and a read port connected to either the input or output terminal and having a read-word-line and a read-bit-line.
Abstract: An apparatus includes a control unit for generating an input control signal to select a global input/output line to which data is transmitted. A repeater receives data from the global input/output line to output the data to a global input/output line corresponding to the input control signal. A plurality of input drivers receive the data from the repeater to transmit the data to a local input/output line connected to each memory bank.
Abstract: A voltage regulation circuit in a nonvolatile memory card accepts an input voltage from a host at two or more different voltage levels and provides an output voltage at a single level to components including a memory die. The voltage regulation circuit can provide an output voltage that is higher or lower than the input voltage.
Abstract: To program one or more non-volatile storage elements, a set of programming pulses are applied to at least one selected non-volatile storage element and one or more particular unselected non-volatile storage elements, for example, via a common word line. A boosting voltage is applied to other unselected non-volatile storage elements during the programming process in order to boost the channels of the unselected non-volatile storage elements so that programming will be inhibited. Each of the programming pulses has a first intermediate magnitude, a second intermediate magnitude and a third magnitude. In one embodiment, the first intermediate magnitude is similar to or the same as the boosting voltage. The second intermediate magnitude is greater than the first intermediate magnitude, but less then the third magnitude. Such an arrangement can reduce the effects of program disturb.
Type:
Grant
Filed:
May 25, 2007
Date of Patent:
February 2, 2010
Assignee:
SanDisk Corporation
Inventors:
Yingda Dong, Jeffrey W. Lutze, Dana Lee
Abstract: The NOR flash memory device according to the present invention is operated by a high voltage supplied from bitline selection transistors and includes a bitline bias circuit for supplying a bias voltage of a constant level to the bitline bias transistor. In accordance with the present invention, it is possible to stably supply a desired voltage closing to a power voltage to the bitline bias transistor.
Abstract: Adaptive write operations for non-volatile memories select programming parameters according to monitored programming performance of individual memory cells. In one embodiment of the invention, programming voltage for a memory cell increases by an amount that depends on the time required to reach a predetermined voltage and then a jump in the programming voltage is added to the programming voltage required to reach the next predetermined voltage. The adaptive programming method is applied to the gate voltage of memory cells; alternatively, it can be applied to the drain voltage of memory cells along a common word line. A circuit combines the function of a program switch and drain voltage regulator, allowing independent control of drain voltage of selected memory cells for parallel and adaptive programming. Verify and adaptive read operations use variable word line voltages to provide optimal biasing of memory and reference cells during sensing.
Abstract: A column access control apparatus comprises a column signal control unit for controlling a write CAS pulse signal and an internal CAS pulse signal in response to a first signal, and a column decoder for outputting a column decoding signal using an output signal of the column signal control unit and the first signal. The column signal control unit delays the internal CAS pulse signal and the write CAS pulse signal to output delayed signals when the first signal is activated.