Renesas Technology Corp.

Hitachi Ulsi Systems Co., Ltd.

Shinya Miyazaki

Tsukasa Ooishi

Tomohiro Uchiyama

Kei Katoh

Koudoh Yamauchi

For each memory block, a predecoder for predecoding an applied address signal, an address latch circuit for latching the output signal of the predecoder, and a decode circuit for decoding an output signal of the address latch circuit and performing a memory cell selecting operation in a corresponding memory block are provided. Propagation delay of latch predecode signals can be made smaller and the margin for the internal read timing can be enlarged. In addition, the internal state of the decoder and memory cell selection circuitry are reset to an initial state when a memory cell is selected and the internal data output circuitry is reset to an initial state in accordance with a state of internal data reading. Thus, a non-volatile semiconductor memory device that can decrease address skew and realize an operation with sufficient margin is provided.

Non-volatile semiconductor memory device and semiconductor memory device

A semiconductor integrated circuit has a nonvolatile memory and a logic circuit which uses information stored in the nonvolatile memory to perform logical operation. The nonvolatile memory comprises bit lines, word lines, and memory cells. The memory cell comprises MOS transistors whose gate electrodes are connected with a word line. Information storage is carried out according to whether one source/drain electrode of the MOS transistors is connected with a source line or floated. During other periods than a predetermined period in the operation of accessing the memory cell, the potential difference between the source/drain electrodes of the MOS transistors constituting the memory cell is zeroed. Subthreshold leakage current is prevented from passing through the memory cell on standby. During the predetermined period in accessing operation, a potential difference is produced between the source/drain electrodes of the MOS transistors. Therefore, the bit line potential can be varied by word line

Semiconductor integrated circuit

For each memory block, a predecoder for predecoding an applied address signal, an address latch circuit for latching the output signal of the predecoder, and a decode circuit for decoding an output signal of the address latch circuit and performing a memory cell selecting operation in a corresponding memory block are provided. Propagation delay of latch predecode signals can be made smaller and the margin for the internal read timing can be enlarged. In addition, the internal state of the decoder and memory cell selection circuitry are rest to an initial state when a memory cell is selected and the internal data output circuitry is reset to an initial state in accordance with a state of internal data reading. Thus, a non-volatile semiconductor memory device that can decrease address skew and realize an operation with sufficient margin is provided.

A semiconductor integrated circuit has nonvolatile memory and a logic circuit which uses information stored in the nonvolatile memory to perform logical operation. The nonvolatile memory comprises bit lines, word lines, and memory cells. The memory cell comprises MOS transistors whose gate electrodes are connected with a word line. Information storage is carried out according to whether one source/drain electrode of the MOS transistors is connected with a source line or floated. During other periods than a predetermined period in the operation of accessing the memory cell, the potential difference between the source/drain electrodes of the MOS transistors constituting the memory cell is zeroed. Subthreshold leakage current is prevented from passing through the memory cell on standby. During the predetermined period in accessing operation, a potential difference is produced between the source/drain electrodes of the MOS transistors. Therefore, the bit line potential can be varied by word line selection.

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Maebaru, Japan

Shinya Miyazaki