Elpida Memory, Inc.

Tomonori Hayashi

Yuji Sugiyama

Akihiko Kagami

A semiconductor memory device includes a mask information storage circuit that stores therein mask information indicating an area for which the self refresh operation is not performed among a plurality of areas in a memory cell array, a mask determining circuit that is activated by a self refresh command and generates a match signal in response to a detection of a match between a refresh address and the mask information, and a refresh operation control circuit that disables the self refresh operation in response to an activation of the match signal. When a test mode signal is activated, the mask determining circuit is also activated by the auto refresh command. With this configuration, it is possible to perform a test of a partial array self refresh function without actually entering a self refresh mode.

Semiconductor memory device performing refresh operation and method of testing the same

A semiconductor device comprises a plurality of terminals, a plurality of drive units corresponding to the plurality of terminals, and a data control unit. The data control unit outputs parallel data applied to the plurality of terminals to the plurality of drive unit in a normal operation mode, and converts serial data applied to a particular terminal, which is one of the plurality of terminals, to parallel data, and outputs the parallel data to which the serial data applied to the particular terminal is converted to the plurality of drive units in a test mode.

Semiconductor device

A semiconductor integrated circuit including a nonvolatile memory cell is provided with a detection/word line voltage control circuit for sequentially supplying two or more mutually different unstable bit detecting voltages to a control gate of the nonvolatile memory cell to cause the nonvolatile memory cell to output a plurality of pieces of readout data, and an OK/NG determination circuit for comparing the plurality of pieces of readout data to determine whether the nonvolatile memory cell is stable or not.

Semiconductor integrated circuit and unstable bit detection method for the same

In a semiconductor integrated circuit, a device identification-code-information circuit includes an internal circuit which can set device identification code information and which can selectively read the same. This structure enables reduction in size of an LSI chip and improvement in reliability.

Device identification-code-information circuit and semiconductor integrated circuit having the device identification-code-information circuit

A semiconductor device includes a plurality of package terminals included in a package, a plurality of chips provided on the package, each of the chips including a memory cell array and a plurality of data input/output terminals, and a plurality of data line control switch disposed between the plurality of package terminals and the plurality of data input/output terminals. The plurality of data line control switches of each of the chips connects the data input/output terminals of each of the chips to corresponding ones of the plurality of package terminals in a normal mode. The plurality of data line control switches connects different groups of the data input/output terminals in different ones of the chips to respective groups of the package terminals in a test mode. The respective groups of the data input/output terminals belong to the plurality of data input/output terminals. The respective groups of the package terminals are different between different ones of the chips.

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Tokyo, Japan

Tomonori Hayashi