Lapis Semiconductor Co., Ltd.

Shuhei Kamano

Teruhiro Harada

A semiconductor memory device includes: a memory cell including a first cell that stores data, and a second cell that stores complementary data that is complementary to the data; a redundant memory cell including a third cell that stores margined complementary data in which a margin is added to the complementary data, and a fourth cell that stores margined data in which a margin is added to the data; and a controller that causes the data and the margined complementary data to be compared and a test of the first cell to be executed, and the complementary data and the margined data to be compared and a test of the second cell to be executed.

Semiconductor memory device and method for testing semiconductor memory device

A semiconductor device includes an output driver having a variable current driving ability, for outputting an amplified data signal to the outside through a transmission line; a nonvolatile memory having a specific area for storing output adjustment data to adjust the current driving ability of the output driver; an output adjustment data readout unit for reading out the output adjustment data from the specific area of the memory in response to powering on; and a current driving ability adjustment unit for adjusting the current driving ability of the output driver on the basis of the output adjustment data read out from the memory.

Semiconductor device and semiconductor memory device

A nonvolatile semiconductor memory device of the charge trap type is initialized by reading the memory cells in the device to determine which charge traps hold less than a predetermined minimum charge and injecting charge into these charge traps until all of the charge traps in the device hold at least the predetermined minimum charge. The charge traps are then programmed selectively with data. The initialization procedure shortens the programming procedure by narrowing the initial distribution of charge in the charge traps, and leads to more reliable reading of the programmed data.

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Kanagawa, Japan

Shuhei Kamano