Abstract: A memory system in an integrated circuit and a method of operation. The system includes multiple magnetic tunnel junction (MTJ) structures, each MTJ structure storing a logic value according to a resistive state. A selection switch device associated with a respective MTJ structure is activated to select one of the multiple MTJ structures at a time. An output circuit is configured to sense the resistive state of a selected MTJ structure, the output circuit having a selectable input reference resistance value according to a selected first reference resistance or a second reference resistance value, and outputting a first logic value of the selected MTJ structure responsive to a resistive state of the MTJ structure and a selected first resistance reference value, or alternately outputting a second logic value of the selected MTJ structure responsive to the resistive state of the MTJ structure and a selected second resistance reference value.

Abstract: There is disclosed an optical device for dispersion compensation of channels within a predetermined wavelength band, comprising: a waveguiding structure; and a grating structure formed in said waveguiding structure; characterized in that said grating structure has a Bragg frequency profile that is divided into contiguous periods, wherein the Bragg frequencies within each period vary between a lower Bragg frequency and an upper Bragg frequency, said lower and upper Bragg frequencies for each period both corresponding to wavelengths outside of said predetermined wavelength band.

Abstract: A waveguide includes a cladding region that has a refractive index that is substantially uniform and surrounds a wave-guiding region that has an average index that is close to the index of the cladding. The wave-guiding region also contains a thin ring or series of rings that have an index or indices that differ significantly from the index of the cladding. The ring or rings enable the structure to guide light.

Abstract: Information is read from a magnetic tunnel junction (MTJ) of a magnetic memory. An electromagnetic field is applied to the MTJ that is sufficient to cause a change in the electrical resistance of the MTJ. The change in the electrical resistance of the MTJ is at least substantially removed responsive to removal of the applied electromagnetic field. The change in the electrical resistance of the MTJ that associated with the application of the electromagnetic field is measured. The information in the MTJ is determined based on the measured change in the electrical resistance of the MTJ. The MTJ can be determined to store a representation of a first binary value when the electrical resistance of the MTJ decreases, and to store a representation of a second binary value when the electrical resistance increases.

Abstract: Disclosed is a method for testing a memory device with a long-term clock signal by automatically performing precharge only after activation. In this method, a signal for precharging the banks of the memory device is automatically generated only at the falling edge of an external signal when a signal for activating the banks is applied. Accordingly, the present invention ensures a stable test of the memory device, reducing the testing time.

Abstract: A memory circuit includes a delay circuit for generating a delay clock signal by delaying a reference clock signal, a temperature detection circuit, and a voltage detection circuit. The temperature detection circuit detects the temperature of part around a memory and the voltage detection circuit detects the power-supply voltage of the memory. The delay circuit determines the delay amount of the delay clock signal according to at least one of temperature data detected by the temperature detection circuit and voltage data detected by the voltage detection circuit, whereby a circuit accessing the memory can supply a clock signal without being affected by the temperature change and/or the power-supply voltage fluctuation.

Abstract: At the time of an operation of writing data to a specific memory cell in a memory block, a semiconductor memory device applies a write voltage for a predetermined period and, after that, performs a verifying operation by using a sense amplifier circuit and a comparator. When it is found as a result of the verifying operation that writing to the memory cell is insufficient, the writing operation is performed again by an instruction of a memory control circuit. At this time, the memory control circuit adjusts a write voltage.

Abstract: The present invention is based on the use of a plurality of gratings recorded in an optical waveguide, the gratings having different Bragg wavelengths selected to store individual bits of data. The invention has particular application to optical fiber communications networks.

Abstract: A correlation system providing the correlation function of two objects illuminated with coherent light by using the principle of double diffraction.The correlation system of the invention is essentially characterized in that it uses as recording medium a plate of recyclable material, i.e. inscribable and erasable at will, such as bismuth-silicon oxide. The recording provided in the plate by superimposition of the beams illuminating the objects is read by a beam undergoing angular sweeping so as to optimize the diffraction efficiency for all the correlation peaks in the observation plane.

Abstract: An acousto-optic modulator beam switching device for use in recording and display systems comprises a source of collimated light; an acousto-optic modulator; said source being capable of being beamed at said modulator; a radio-frequency oscillator capable of providing outputs at a plurality of frequencies; and a switching device coupled to said modulator and to said oscillator means; said switching device allowing each of said plurality of frequencies to be coupled to said modulator in succession, according to a predetermined sequence; the application to the modulator of each of said frequencies causing a corresponding deflection in the angle of the beam exiting from said modulator; said deflected beam having a predetermined power versus time characteristic; said predetermined sequence allowing a first frequency to be coupled to said modulator followed by a second frequency being coupled to said modulator at a time before the deflected beam exiting from said modulator, as a consequence of the application of s

Abstract: An apparatus and method for laser-beam modulation and deflection wherein stored information is recorded on a photosensitive or other recording medium with a laser or other light beam. A plurality of separate frequencies is induced by a transducer on an acoustooptic light-modulating cell which carries and develops every frequency separately. The light beam is passed through the acoustooptic cell which modulates the light by Bragg reflection in accordance with the frequencies impressed thereon. The modulated light beams transmitted from the cell are used to record by a plurality of simultaneous scans, characters, graphical data or other form of information which is representative of the stored information on the photosensitive medium.