Kabushiki Kaisha Toshiba

Toshiba Memory Corporation

Keiji Maruyama

Shigeo Ohshima

Noriyasu Kumazaki

Naokazu Miyawaki

Ryosuke Matsuo

Tetsuya Fujita

Kazuaki Kawaguchi

Yutaka Shirai

Hiromi Noro

Hisashi Ueno

Masaaki Kuwagata

According to one embodiment, a semiconductor memory device includes, a memory cell array, a first clock signal line, a second clock signal line to which first and second input/output buffer circuits are coupled in the order from one end toward the other end, a first buffer coupled to the one end of the second clock signal line, and a second buffer coupled to the other end of the second clock signal line. When a write operation is performed, a clock signal is input to the first and second input/output buffer circuits through the first buffer, and when a read operation is performed, a clock signal is input to the first and second input/output buffer circuits through the second buffer.

Semiconductor memory device

A data transfer method includes reading data from a NAND flash memory in pages into a first buffer, transferring a parity in the data read into the first buffer to a second buffer, after transferring the parity to the second buffer, transferring a main data in the data read into the first buffer to the second buffer, on the basis of the parity, correcting an error in the main data transferred to the second buffer, and transferring an error-corrected main data to a third buffer.

Memory system with semiconductor memory and its data transfer method

A semiconductor memory device includes a n-channel type MOSFET in which a drain and a gate are connected to an external power supply and a source and a back gate are connected each other. A node is connected to the source and the back gate of the n-channel type MOSFET, and a detector for detecting an input of the external power supply based on a potential of the node.

Semiconductor memory device, power supply detector and semiconductor device

A synchronous semiconductor memory device includes a memory cell array and a command decoder. In the memory cell array, dynamic memory cells are arranged in a matrix form. The command decoder decodes a plurality of commands in synchronism with an external clock signal. The plurality of commands are set by combinations of logical levels of a plurality of control pins at input timing of a first command and at input timing of a second command one cycle after the input timing of the first command. The command decoder includes a first decode section which determines a read operation, a second decode section which determines a write operation, and a third decode section which determines an auto-refresh operation. Setting of an auto-refresh command is determined only by a combination of the logical levels of the plurality of control pins at the input timing of the first command.

Synchronous semiconductor memory device having dynamic memory cells and operating method thereof

A semiconductor integrated circuit, comprising: a first output driving part which outputs a data signal in sync with a reference clock signal; a second output driving part which outputs a data strobe signal prescribing a timing of said data signal; and a driving control part which separately controls driving ability of said first and second output driving parts.

Semiconductor integrated circuit and memory system

A semiconductor integrated circuit includes a bias voltage regulation circuit having variable resistors which are provided between voltage output circuits of higher and lower potential sides and changes corresponding to a specified condition such as V.sub.CC and a temperature. The variable resistors and bias voltage output circuits form a V.sub.CC divider, and the variable resistors properly regulate a bias voltage supplied to an oscillation circuit corresponding to each of the specified conditions. Accordingly, if the oscillation circuit is used in an automatic refresh circuit of a PSRAM, an increase of a refresh operation frequency is suppressed regardless of an increase in V.sub.CC. Since a temperature depending variable resistor causes a resistance value to be reduced by the predetermined characteristics against the temperature increase, it is possible to set an oscillation frequency to provide a desired pause for guarantee of circuit operation. It is possible to provide a ring oscillator having a low dependency of the oscillation frequency on a power source voltage and a temperature characteristic, thereby decreasing its current consumption.

Semiconductor integrated circuit including ring oscillator of low

A substrate bias voltage generator circuit has a substrate bias voltage detector circuit, a substrate bias driver circuit, and a charge pump circuit. the substrate bias voltage detector circuit detects a substrate bias voltage applied to a semiconductor substrate and outputs a substrate bias voltage detection signal. The substrate bias detector circuit includes a P-channel transistor with a gate terminal and an N-channel transistor with a substrate terminal, both terminals being connected to the semiconductor substrate and the substrate bias voltage which is a back bias for the N-channel transistor. The substrate bias driver circuit is responsive to the substrate bias voltage detection signal outputted from the substrate bias voltage detector circuit, and outputs a drive signal when the absolute value of the substrate bias voltage is equal to or smaller than a predetermined value, and stops outputting the drive signal when the absolute value of the substrate bias voltage is larger than the predetermined value. The charge pump circuit is responsive to the drive signal from the substrate bias driver circuit, and generates the substrate bias voltage.

Substrate bias voltage generator circuit

A semiconductor memory comprises a semiconductor memory circuit, a counter section for causing at least a part of counters to operate in association with an operation of the semiconductor memory circuit, and a counter comparator for comparing the logic state outputs of two independent counters of the counter section with each other, the output of the counter comparator being used to control the semiconductor memory circuit.

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Kawasaki, Japan

Keiji Maruyama