Fujitsu Corporation

Winbond Electronics Corporation

Nec Corporation

Fujitsu Microelectronics Limited

Fujitsu Semiconductor Limited

Renesas Electronics Corporation

Cypress Semiconductor Corporation

Windbond Electronics Corp.

Spansion Llc.

Kaoru Mori

Shinichi Yamada

Masato Matsumiya

Ayako Kitamoto

Masato Takita

Yuki Ishii

Kuninori Kawabata

Hideki Kanou

Toshikazu Nakamura

Atsushi Kamijo

Yoshiaki Okuyama

Masatomo Hasegawa

Jun Ohno

Shinya Fujioka

Satoshi Eto

Tetsuhiro Suzuki

Toru Koga

Tadahiko Sugibayashi

Hitoshi Ikeda

Toshiya Uchida

Norikazu Ohshima

Yoshiyuki Fukumoto

Hironobu Tanigawa

Eiji Kariyada

Sadahiko Miura

Shigemasa Ito

Katuhiro Mori

Hiroyuki Kobayashi

Takashi Nakagawa

Nobuyuki Ishiwata

Atsushi Hatakeyama

Yoshitaka Takahashi

Noboru Sakimura

Kiyokazu Nagahara

Shunsuke Fukami

Koichi Nishimura

Takeshi Honda

Kenichi Shimura

Kota Hara

Masaki Okuda

Nobuyuki Ikarashi

Akihiro Funyu

Hisao Matsutera

Katsumi Suemitsu

Ken-ichi Shimura

Junichi Sasaki

Makiko Oshida

Yasuaki Ozaki

Yukihiro Nomura

Shuji Mabuchi

Shinichiro Suzuki

A semiconductor memory is provided to include an adjustment circuit. The adjustment circuit sets a second period longer than a first period and adjusts time at which the last read data is output. When a chip selection signal is set to be asserted, the semiconductor memory device performs a read operation on data according to an external clock signal. The first period begins at a rising edge or a falling edge of the external clock signal and ends when the output of the last read data begins. The second period begins when the chip selection signal goes from asserted to negated and ends when the output of the last read data is complete. The external clock signal is used to read the last read data during the read operation.

Semiconductor memory with adjustment circuit and method for controlling a semiconductor memory

A pseudo-static random-access memory is provided. A count-and-command decoder starts counting a clock signal when an internal enable signal changes from a disable state to an enable state, and outputs a column address strobe signal at a first level when the count reaches a first clock amount. During a period starting from when the column address strobe signal changes from a second level to the first level to when the internal enable signal changes from the enable state to the disable state, a burst-length counter counts the clock signal to provide a burst length accordingly. A delay control circuit outputs a first confirmation signal at the first level to a row-and-column control circuit, such that a length of a column select signal is equal to the burst length.

Pseudo-static random-access memory and reading method thereof

A semiconductor memory device includes a transmission circuit and a control circuit. The transmission circuit is configured to obtain write data and transmit that into a memory cell array according to the external clock signal when the chip selection signal is asserted. The control circuit is configured to control the transmission circuit to transmit first write data into the memory cell array when the chip selection signal changes from assertion to negation during the input period of the first write data, according to the external clock signal.

Semiconductor memory device operates asynchronously with external clock signal

A memory system includes memory chips connected to each other. Each of the memory chips includes a memory array, a read/write data strobe pin, a look-up table storage device, a chip number identification circuit, and a control logic circuit. The memory array stores data. The read/write data strobe pin is connected to read/write data strobe pins of other memory chips. The look-up table storage device stores a plurality of trimming shift values related to a number of chip connections in advance. The chip number identification circuit identifies a current number of chip connections according to a state information, and finds a selected trimming shift value from the look-up table storage device. The control logic circuit transmits a data signal in response to a clock signal, and adjusts a setup hold time between the clock signal and the data signal according to the selected trimming shift value.

Memory system and operation method thereof

A semiconductor memory device can appropriately control operation timing, based on changes in the environment (for example, power supply voltage and temperature, etc.) when in use. The semiconductor memory device includes a temperature sensorthat detects the temperature of the semiconductor memory device, a voltage detection portion (composed of a ring oscillatorand a counter) that detects the power supply voltage of the semiconductor memory device, and a control portionthat controls the operation timing in the semiconductor memory device to meet specific conditions, according to the temperature detected by the temperature sensorafter the power is applied and the voltage detected by the voltage detection portion after the power is applied.

Semiconductor memory device to control operating timing based on temperature of the memory device

A memory controller is provided. The memory controller is suitable for a pseudo static random access memory. The memory controller includes a mode register, a mode register write controller and a latency controller. The mode register is configured to generate a latency control signal according to a write instruction signal. The mode register write controller is configured to generate the write instruction signal during a mode register write operation and generate a write mask signal according to a chip selection signal. The latency controller generates a latency type control signal according to the latency control signal and the write mask signal.

Memory controller

A pseudo static random access memory including a plurality of memory chips and an information storing device is provided. The memory chips transmit a plurality of read/write data strobe signals to a memory controller by using a same bus. Regardless of whether a self refresh collision occurs in the memory chips, when the memory chips perform a read operation, read latency of the memory chips is set to be a fixed period that self refresh is allowed to be completed. The fixed period is greater than initial latency. The information storing device is configured to store information which defines the fixed period. The read/write data strobe signal indicates whether the self refresh collision occurs in the memory chips, and a level of the read/write data strobe signals is constant during the read latency. A method for operating a pseudo static random access memory is also provided.

Pseudo static random access memory and method for operating pseudo static random access memory

An efuse circuit adapted for a memory device is provided. The efuse circuit includes a plurality of efuse sets and a control circuit. Each of the plurality of efuse sets includes a plurality of efuses. When a power is turned on, the control circuit detects each of the plurality of efuse sets to generate a detection signal. The control circuit determines whether the efuses of each of the efuse sets are burned according to the detection signal to determine whether to perform a burn operation on the plurality of efuses. When the control circuit determines that at least one of the plurality of efuses is a burned efuse according to the detection signal, the control circuit latches a write data of at least one burned efuse and disables an overwrite operation on the efuse set to which the at least one burned efuse belongs.

Efuse circuit and operation method thereof

A control circuit and a control method thereof adapted to a pseudo static random access memory are provided. The control circuit includes a write data determining circuit and a clock generating circuit. The write data determining circuit counts and compares data input times and actual data write times of the pseudo static random access memory to generate a write matching signal, and generates a write counting clock signal according to counting operation of the data input times of the pseudo static random access memory. The clock generating circuit generates a preamble signal according to the write matching signal and the write counting clock signal, and generates a column address strobe clock signal and a control signal according to the preamble signal. The clock generating circuit determines whether to dynamically delay the preamble signal to delay or omit a pulse of a column selection line signal.

Control circuit and control method thereof for pseudo static random access memory

In a control method, external data input to the pseudo static random access memory with a reference clock signal in a write operation are counted to generate a first count value. Data written to a dynamic memory array of the pseudo static random access memory with a built-in clock signal in the write operation are counted to generate a second count value. An initial cycle of the built-in clock signal is smaller than a cycle of the reference clock signal. The first count value is compared with the second count value. When the first count value is equal to the second count value, a write match signal is enabled. When the enabled write match signal is received, the write operation is converted from an asynchronous mode to a synchronous mode to adjust the cycle of the built-in clock signal to be equal to the cycle of the reference clock signal.

Pseudo static random access memory and control method thereof

A bit line power supply apparatus including a bit line high voltage generator is provided. The bit line high voltage generator includes a first voltage generation circuit and a second voltage generation circuit. The first voltage generation circuit includes a first sensor and a first linear voltage regulator. The first sensor compares a first reference voltage with a bit line high voltage to generate a first sensing voltage according to a first control signal. The first linear regulator generates the bit line high voltage according the first sensing voltage. The second voltage generation circuit includes a second sensor and a switching voltage regulator. The second sensor compares the first reference voltage with the bit line high voltage to generate a second sensing voltage according to a second control signal. The switching regulator generates the bit line high voltage according the second sensing voltage.

Bit line power supply apparatus

A method for manufacturing a semiconductor device includes the steps of: determining a first design dimension of a gate electrode of a selection MISFET, a second design dimension of a sidewall insulating film, and initial setting conditions for ion implantation for a high-concentration semiconductor region; forming the gate electrode; measuring a first processed dimension of the gate electrode; implanting ions to form a low-concentration semiconductor region at each end of the gate electrode; forming the sidewall insulating film over a sidewall of the gate electrode; measuring a second processed dimension of the sidewall insulating film; and implanting ions to form a high-concentration semiconductor region. In the former implantation step, execution conditions to the initial setting conditions are reset according to a deviation of the first processed dimension from the first design dimension and a deviation of the second processed dimension from the second design dimension, and the step is executed.

Method for manufacturing semiconductor device

A magnetoresistive effect element of the present invention includes: a domain wall motion layer, a spacer layer and a reference layer. The domain wall motion layer is made of ferromagnetic material with perpendicular magnetic anisotropy. The spacer layer is formed on the domain wall motion layer and made of non-magnetic material. The reference layer is formed on the spacer layer and made of ferromagnetic material, magnetization of the reference layer being fixed. The domain wall motion layer includes at least one domain wall, and stores data corresponding to a position of the domain wall. An anisotropy magnetic field of the domain wall motion layer is larger than a value in which the domain wall motion layer can hold the perpendicular magnetic anisotropy, and smaller than an essential value of an anisotropy magnetic field of the ferromagnetic material of the domain wall motion layer.

Magnetoresistive effect element and magnetic random access memory using the same

A semiconductor device includes: a plurality of memory cells; a plurality of local bit lines connected to respective memory cells of the plurality of memory cells; and a first amplifier. The first amplifier receives read data from each local bit line of the plurality of local bit lines and determines a transition speed of an output level of the first amplifier in response to receiving a combination of at least two pieces of read data. The first amplifier transfers, based on the determined transition speed, multivalued data of the read data to a read global bit line.

Simultaneous programming of many bits in flash memory

A semiconductor memory includes a sense amplifier which operates in response to activation of a sense amplifier enable signal and determines logic held in a nonvolatile memory cell according to a voltage of a bit line, the voltage varying with a cell current flowing through a real cell transistor, a replica cell transistor coupled in series between a first node and a ground line, and a timing generation unit. The timing generation unit activates the sense amplifier enable signal when the first node coupled to the ground line via the replica cell transistor changes from a high level to a low level. The replica cell transistor includes a control gate receiving a constant voltage and a floating gate coupled to the control gate. Thus, the activation timing of the sense amplifier can be optimally set in accordance with the electric characteristic of the memory cell.

Semiconductor memory read and write access

Growing community of inventors

Kawasaki, Japan

Kaoru Mori