Kabushiki Kaisha Toshiba

Kazuko Inuzuka

Kazuaki Kawaguchi

Shigeo Ohshima

Katsushi Nagaba

An FCRAM includes first to third circuits. The first circuit generates a first signal based on a command detection signal. The second circuit is configured to receive the command detection signal, an operation mode specifying signal and a selection signal and generate a second signal which causes the start timing of the operation of a row-system circuit to be synchronized with the input timing of a second command. The third circuit is configured to select the first signal when a normal operation mode is specified by the operation mode specifying signal, select the second signal when a test mode is specified, and generate a third signal used to activate at least part of the memory cells in a memory cell array based on a selected one of the first and second signals and the selection signal.

Synchronous semiconductor memory device of fast random cycle system and test method thereof

The data output circuit in a clock synchronous DRAM comprises a first data transfer circuit to which the data read from a memory is input and which transfers the input data to the output side in synchronization with an internal clock, an equalizing circuit to which the output of the first data transfer circuit is input during a read operation by a burst operation and to which high-impedance data is input after the read operation, a second data transfer circuit connected to the equalizing circuit, and an output buffer to which the output of the second data transfer circuit is input. The second data transfer circuit transfers all the data to the output buffer in synchronization with an output clock. This eliminates the dependence of the data access time and data hold time on data item and/or cycle and facilitates the timing control of the output control signal.

Semiconductor integrated circuit device

The present invention provides a semiconductor memory circuit capable of high-speed access to a predetermined column portion by a simplified high-speed addressing circuit. The memory circuit in a DRAM is such that a portion of a column addressing circuit normally comprising a counter constitutes a shift register in a column addressing circuit at a preceding stage of a column address buffer so that a plurality of address signal wrappings are realized for accessing the predetermined column portion.

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Yokohama, Japan

Kazuko Inuzuka