Kabushiki Kaisha Toshiba

Yoshiharu Hirata

Takuya Fujimoto

Akira Umezawa

Shinji Takeda

Yoshiaki Hashiba

Seiichi Mori

Kazushige Kanda

Hideki Takeuchi

Masataka Takebuchi

Kazuaki Isobe

Takamichi Kasai

Kazuhiko Kakizoe

Naokazu Kuzuno

Nozomi Kasai

A semiconductor integrated circuit according to an embodiment includes an oscillator that generates and outputs an oscillation signal in an active state and generates no oscillation signal in an inactive state. The semiconductor integrated circuit includes a negative charge pump that generates an output voltage that is a negative voltage in response to the oscillation signal and outputs the output voltage to an output pad. The semiconductor integrated circuit includes a negative voltage detecting circuit that detects the output voltage and controls the oscillator to be in the active state or inactive state so as to bring the output voltage close to a target voltage.

Semiconductor integrated circuit and nonvolatile semiconductor storage device

According to one embodiment, a nonvolatile semiconductor storage device includes a first well region of a first conductivity type, a second well region of the first conductivity type, a third well region of a second conductivity type, a bit line and a column decoder. A first cell array including a plurality of memory cells is formed in the first well region. A second cell array including a plurality of memory cells is formed in the second well region. The third well region includes the first and second well regions. The bit line is connected to the memory cells included in the first cell array and the memory cells included in the second cell array. The column decoder is connected to the bit line.

Nonvolatile semiconductor storage device with multiple well regions and a shared bit line

A semiconductor memory device comprises: a write circuit including a latch circuit configured by two inverters having a positive side power supply terminal supplied with a first voltage and a negative side power supply terminal supplied with a second voltage; and a write state machine controlling the first and second voltages. When writing data to a memory cell, the first voltage is changed to a second value that is lower than a first value. When writing data to a memory cell, the second voltage is changed to a third value that is lower than the second value. The write state machine lowers the second voltage to an intermediate value between the second value and the third value and, while maintaining this intermediate value, lowers the first voltage from the first value to the second value.

Nonvolatile semiconductor memory device

A semiconductor memory device includes a memory cell array, word lines, and a row decoder. The memory cell array includes memory cells arranged in a matrix. The memory cell includes a first MOS transistor having a charge accumulation layer and a control gate and a second MOS transistor. The word line connects the control gates of the first MOS transistors. The row decoder includes a first address decode circuit, a second address decode circuit, and a transfer gate. The first address decode circuit decodes m bits in a n-bit row address signal (m and n are a natural number satisfying the expression m&#x3c;n). The second address decode circuit decodes (n&#x2212;m) bits in the row address signal. The transfer gate supplies the output of the first address decode circuit to the word line according to the output of the second address decoded circuit.

Semiconductor memory device with MOS transistors each having floating gate and control gate

A semiconductor integrated circuit device comprises a semiconductor memory circuit including a memory cell array in which normal cells are integrated and a fuse circuit in which fuse cells that store operation information of the semiconductor memory circuit are integrated. The fuse cell is of a 2-transistor type memory cell which comprises a cell transistor having a charge storage layer and a selection transistor which selects the cell transistor.

Semiconductor integrated circuit device

A semiconductor memory device includes memory cells, a memory cell array, word lines, a first charge pump circuit, and a discharge circuit. The memory cell has a first MOS transistor with a stacked gate including a floating gate and a control gate. The memory cell array includes the memory cells arranged in a matrix. The word line connects commonly the control gates of the first MOS transistors in a same row. The first charge pump circuit is activated and generates a first voltage in a write operation and erase operation. The first voltage is supplied with either the well region or the word lines. The discharge circuit, when the first charge pump circuit is deactivated, discharges the charge generated by the first charge pump circuit to ground or to a power-supply potential, while causing current to flow to an output node of the first voltage.

Semiconductor memory device including floating gates and control gates, control method for the same, and memory card including the same

A semiconductor memory device includes memory cells, write bit lines, read bit lines, latch circuits, a n-channel MOS transistor, and voltage setting circuits. The memory cell includes a first MOS transistor having a charge accumulation layer and a control gate. The first MOS transistors are connected commonly to the write bit lines and read bit lines. The latch circuits are provided for the write bit lines and hold write data for the memory cells. The n-channel MOS transistor transfer '1' data to the latch circuits in a data latch operation. The voltage setting circuits supply a potential corresponding to '0' data to the write bit lines in a read operation. In a data latch operation, the latch circuit corresponding to the write bit line connected to the memory cell into which &#x201c;0&#x201d; data is to be written latches the potential supplied to the write bit lines in a read operation.

Semiconductor memory device with MOS transistors, each including a floating gate and a control gate, a control method thereof, and a memory card including the same

Data read out from each memory cell in a memory cell array is compared with an expected value by a comparator, and the quality of a memory cell is determined by performing program verify and erase verify. Based on the comparison result of the comparator, a detected defective cell is repaired by replacing it with a spare cell. Every time a defective cell is replaced with a spare cell, information on the defective cell is stored in a register, and whether a defective cell exists and whether the repair is possible are determined on the basis of the information. When the repair is possible, a control circuit is caused to execute control, and a detected defective cell is repaired by replacing it with a spare cell. When the repair is impossible, the defect repair stops.

Semiconductor device and test method thereof

An n-type diffused layer is formed in a p-type semiconductor substrate. A control gate electrode of a memory cell MC is connected with a metal interconnect of a first layer and the metal interconnect is connected with the diffused layer. Moreover, a metal interconnect of the first layer is connected with a metal interconnect of a second layer. An interconnect of the second layer is connected with the output node of a row decoder.

Semiconductor device having multilayer metal interconnection

A voltage stepup circuit having a plurality of setup circuit units connected in stages between an input voltage node and a stepup voltage node. Each circuit unit comprises at least two first and second MOS transistor T1 and T2. Each of first stepup capacitors is connected between a first clock signal supply node and a first connection node at which the drain and gate of a corresponding one of odd-numbered MOS transistors, of a plurality of MOS transistors connected in series through the plurality of stepup circuit units, are connected together. Each of second stepup capacitors is connected between a second connection node at which the drain and gate of a corresponding one of even-numbered MOS transistors of the plurality of MOS transistors connected together and a second clock signal supply node for supplying said second connection node with a second clock signal whose pulse width does not overlap in time with that of the first clock signal. A first clock amplitude control circuit limits the amplitude of the first clock signal to be supplied to the first clock signal supply node to a predetermined level and applies the first amplitude-limited clock signal to the first clock signal supply node. A second clock amplitude control circuit limits the amplitude of the second clock signal to be supplied to the second clock signal supply node to a predetermined level and applies the second amplitude-limited clock signal to the second clock signal supply node.

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Yokohama, Japan

Yoshiharu Hirata