Abstract: A programming method of a MOS electric fuse includes steps of preparing, as a fuse element, a MOS transistor which comprises second conductivity type first and second impurity regions formed to face with each other on an upper surface of a first conductivity type well on a semiconductor substrate, a gate dielectric film formed on the upper surface of the well at least between the first and second impurity regions, and a gate electrode formed through the gate dielectric film on the upper surface of the well between the first and second impurity regions and applying a first voltage to the gate electrode, and a second voltage different from the first voltage to the first impurity region, and short-circuiting the gate dielectric film only between the gate electrode and the first impurity region.

Abstract: A semiconductor memory device includes first and second CMOS (complementary metal oxide semiconductor) inverter circuits each having a latch structure and a control transistor which is connected between a storage node of the first CMOS inverter circuit and a bit line and whose gate is connected to a word line. The device further includes a selection circuit to apply one of a first voltage and a second voltage different from the first voltage to a power supply node of at least the second CMOS inverter circuit. The selection circuit applies the second voltage to the power supply node of the second CMOS inverter circuit at least in “1” data write mode.

Abstract: A semiconductor device is disclosed which includes a data memory which stores data and a code memory which stores an ECC code corresponding to the data. The semiconductor device includes an ECC unit which outputs, to the data memory as the data, a test pattern required to test the data memory, and which generates, from the test pattern, code information having an error checking function, and outputs the code information to the code memory as the ECC code.

Abstract: An output buffer circuit including a programmable impedance buffer configured to match a buffer size thereof with an external impedance, a buffer size decision circuit configured to generate a plurality of buffer size signals for determining the buffer size of the programmable impedance buffer synchronized with a first clock signal, and an impedance adjustment circuit configured to adjust the buffer size based on the buffer size signals in response to a level of an output data signal.

Abstract: A semiconductor memory comprises, a data memory having a plurality of memory regions to store data at addresses specified, a code memory having the same address space as the data memory to store error correction codes, an error correction code control circuit including an error correction code generation circuit, a syndrome generation circuit and an error correction code decoding circuit, generating an error correction code for correcting data before the data is written back into the memory region, and comparing the generated error correction code with corresponding error correction code, thereby to determine whether the data is erroneous, and an error correction code function invalidity control circuit invalidating an error correction function of the error correction code control circuit when the memory regions are accessed first after power application.

Abstract: A semiconductor memory device includes first and second CMOS (complementary metal oxide semiconductor) inverter circuits each having a latch structure and a control transistor which is connected between a storage node of the first CMOS inverter circuit and a bit line and whose gate is connected to a word line. The device further includes a selection circuit to apply one of a first voltage and a second voltage different from the first voltage to a power supply node of at least the second CMOS inverter circuit. The selection circuit applies the second voltage to the power supply node of the second CMOS inverter circuit at least in “1” data write mode.

Abstract: A semiconductor memory device includes first and second CMOS (complementary metal oxide semiconductor) inverter circuits each having a latch structure and a control transistor which is connected between a storage node of the first CMOS inverter circuit and a bit line and whose gate is connected to a word line. The device further includes a selection circuit to apply one of a first voltage and a second voltage different from the first voltage to a power supply node of at least the second CMOS inverter circuit. The selection circuit applies the second voltage to the power supply node of the second CMOS inverter circuit at least in “1” data write mode.

Abstract: A semiconductor memory device includes first and second CMOS (complementary metal oxide semiconductor) inverter circuits each having a latch structure and a control transistor which is connected between a storage node of the first CMOS inverter circuit and a bit line and whose gate is connected to a word line. The device further includes a selection circuit to apply one of a first voltage and a second voltage different from the first voltage to a power supply node of at least the second CMOS inverter circuit. The selection circuit applies the second voltage to the power supply node of the second CMOS inverter circuit at least in “1” data write mode.

Abstract: An output buffer circuit including a programmable impedance buffer configured to match a buffer size thereof with an external impedance, a buffer size decision circuit configured to generate a plurality of buffer size signals for determining the buffer size of the programmable impedance buffer synchronized with a first clock signal, and an impedance adjustment circuit configured to adjust the buffer size based on the buffer size signals in response to a level of an output data signal.