Fujitsu Corporation

Fujitsu Microelectronics Limited

Fujitsu Semiconductor Limited

Kotoku Sato

Shinya Fujioka

Takaaki Suzuki

Koichi Nishimura

Tomohiro Kawakubo

Hitoshi Ikeda

Masao Taguchi

Akihiro Funyu

Kimiaki Satoh

Toshiya Uchida

Yasuharu Sato

Jun Ohno

Hiroyoshi Tomita

Shinichi Yamada

Yasurou Matsuzaki

Masao Nakano

Yoshihiro Takemae

Hajime Sato

Satoru Kawamoto

Tatsuya Kanda

Yoshiaki Okuyama

Yoshimasa Yagishita

Nobutaka Taniguchi

Shinya Fujijoka

A semiconductor device includes a memory core with a plurality of memory cells, an internal voltage generator and a low power entry circuit. The low power entry circuit receives a plurality of control signals which are provided to a command decoder, and generates a low power signal indicating a low power consumption mode where a refresh operation is prohibited. The internal voltage generator includes a detector and at least one of booster circuits. The internal voltage generator, coupled to the memory core via an internal power supply line, generates a boosted internal voltage based on an external voltage and supplies the boosted internal voltage to the memory core via the internal power supply line. The internal voltage generator stops supplying the boosted internal voltage to the internal power supply line in response to the low power signal while the external voltage is supplied to the semiconductor device.

Semiconductor memory device and method of controlling the same

An internal voltage generator when activated, generates an internal voltage to be supplied to an internal circuit. Operating the internal voltage generator consumes a predetermined amount of the power. In response to a control signal from the exterior, an entry circuit inactivates the internal voltage generator. When the internal voltage generator is inactivated, the internal voltage is not generated, thereby reducing the power consumption. By the control signal from the exterior, therefore, a chip can easily enter a low power consumption mode. The internal voltage generator is exemplified by a booster for generating the boost voltage of a word line connected with memory cells, a substrate voltage generator for generating a substrate voltage, or a precharging voltage generator for generating the precharging voltage of bit lines to be connected with the memory cells.

Semiconductor memory device, and method of controlling the same

A data transfer method and system are provided that prevent the length of a time required for writing to a flash memory from appearing on the surface as a system operation when the flash memory is used in place of an SRAM. The method of transferring data includes the steps of writing data from a controller to a volatile memory, placing the volatile memory in a transfer state, transferring the data from the volatile memory in the transfer state to a nonvolatile memory, and releasing the volatile memory from the transfer state in response to confirming completion of the transfer of the data.

Data transfer method and system

To perform mask control of data signals without increasing the number of external terminals even when the number of bits in a data mask signal is large, an address input circuit sequentially receives a first address signal, a second address signal, and a first data mask signal supplied to an address terminal in synchronization with transition edges of a clock signal. Namely, the first data mask signal is supplied to the address terminal at a different timing from timing at which the first and second address signals are received. The first address signal, second address signal, and first data mask signal are output, for example, from a controller accessing a semiconductor memory. A data input/output circuit inputs/outputs data via a data terminal and masks at least either of write data to memory cells and read data from the memory cells in accordance with logic of the first data mask signal.

Semiconductor memory and controller with time-shared mode for row address, column address and data mask signals inputted via address terminals

A command register holding a decoded result of information relating to an access request supplied from an outside and an address register are provided, and decode of the information relating to an access request from the outside in a processing circuit, namely, a chip control circuit and an address decoder, and an operation corresponding to the external access request in a memory cell array by an access control circuit are made executable independently in parallel, whereby access requests from the outside can be inputted in multiple, and a pipelined operation can be realized for decode and an operation corresponding to the external access request in the memory cell array, thus making it possible to speed up the access operation to a semiconductor memory device without causing any problem.

Semiconductor memory device and memory system

A method for controlling a semiconductor memory in which a mode register can be set in a burst mode. To set an operation mode in the burst mode, the semiconductor memory is changed first from the burst mode, through a power-down mode, to a standby mode of non-burst mode. Then the semiconductor memory is changed to a mode register set mode to set the mode register when commands are input in the same predetermined sequence that is used in the non-burst mode.

Semiconductor memory having mode register access in burst mode

A semiconductor memory device has a burst write mode in which predetermined plural command signals are input through a plurality of command pads and a mask control operation in the burst write mode is performed in response to the command signals. Therefore, the mask control in burst write mode is increased in speed to give an improved data transfer rate.

Semiconductor memory device with fast masking process in burst write mode

A method for controlling a semiconductor memory in which mode register can be set in burst mode. To set an operation mode in burst mode, the semiconductor memory is changed first from the burst mode, through power-down mode, to standby mode of non-burst mode. Then the semiconductor memory is changed to mode register set mode to set the mode register when commands are input in the same predetermined sequence that is used in the non-burst mode.

Semiconductor memory of a dynamic random access memory (DRAM) type having a static random access memory (SRAM) interface

A semiconductor memory device includes an SRAM provided on a chip, the SRAM including an SRAM cell array. A DRAM is provided on the chip, the DRAM including a DRAM cell array. An address input circuit receives an address signal, the address signal having a first portion and a second portion, the first portion carrying a unique value of row-column address information provided to access one of memory locations in one of the SRAM and DRAM cell arrays, the second portion carrying a unique value of SRAM/DRAM address information provided to select one of the SRAM and the DRAM.

Semiconductor memory device having an SRAM and a DRAM on a single chip

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Kawasaki, Japan

Kotoku Sato