Abstract: A memory device has at least one pair of memory cell blocks, a spare row decoder, a data exchange control signal generator and a data exchange unit. When a defective memory cell in a first memory cell block is repaired with a spare memory cell in a second memory cell block that neighbors (or is adjacent) the first memory cell block, the data topology of the memory cell of the first memory cell may be matched to the memory cell of the second memory cell block.

Abstract: An optic switch for cross-connecting input light signals incoming from inlet fiber cables to outlet fiber cables is disclosed that makes use of a holographic filter (5) having a series of preformed different speckle patterns, each in the form of a hologram (H1, H2, . . . ). Associated with input light signals guided past respective inlet passages (4in) of a multimode waveguide (4), different speckle patterns are formed by applying different control voltages across respective electrode pairs (10, 10a) provided thereon. These speckle patterns past a single outlet passage (4out) of the multimode waveguide (4) into which the inlet passages (4in) converge are joined together and enter the holographic filter (5) in which an input light signal is selectively switched, addressed and cross-connected to an outlet waveguide (2) through a region thereof where a formed speckle pattern coincides with a preformed speckle pattern. The multi mode waveguides (4) is formed in, e.g., a LiNbO3 photorefractive substrate (3).

Abstract: A memory device has at least one pair of memory cell blocks, a spare row decoder, a data exchange control signal generator and a data exchange unit. When a defective memory cell in a first memory cell block is repaired with a spare memory cell in a second memory cell block that neighbors (or is adjacent) the first memory cell block, the data topology of the memory cell of the first memory cell may be matched to the memory cell of the second memory cell block.

Abstract: An optic switch for cross-connecting input light signals incoming from inlet fiber cables to outlet fiber cables is disclosed that makes use of a holographic filter (5) having a series of preformed different speckle patterns, each in the form of a hologram (H1, H2, . . . ). Associated with input light signals guided past respective inlet passages (4in) of a multimode waveguide (4), different speckle patterns are formed by applying different control voltages across respective electrode pairs (10, 10a) provided thereon. These speckle patterns past a single outlet passage (4out) of the multimode waveguide (4) into which the inlet passages (4in) converge are joined together and enter the holographic filter (5) in which an input light signal is selectively switched, addressed and cross-connected to an outlet waveguide (2) through a region thereof where a formed speckle pattern coincides with a preformed speckle pattern. The multi mode waveguides (4) is formed in, e.g., a LiNbO3 photorefractive substrate (3).

Abstract: A semiconductor memory device has a single input terminal to select a buffer and includes input-output terminals, input-output buffers, a memory core, and a buffer selecting unit. The input-output terminals include address input terminals, data input-output terminals and an input terminal to select a buffer. The input-output buffers are coupled to the data input-output terminals respectively. The memory core is coupled to the input-output buffers through input-output lines. The buffer selecting unit generates a parallel buffer select signal based on an expected signal having a pulse stream, wherein the expected signal is provided via the input terminal to select a buffer in a test mode, and applies the parallel buffer select signal to the plurality of input-output buffers to select a corresponding input-output buffer. Hence, The semiconductor memory device may increase efficiency of a pin in a test device.

Abstract: A data access circuit of a semiconductor memory device in which data is read and written via all multiple ports in the semiconductor memory device having a multi-port structure. The data access circuit device having a multi-port structure comprises a write controller, a plurality of ports to receive serial data to be written, a plurality of read/write data control units, a plurality of write buffer units, a read controller, an input/output sense amplifier, and a plurality of read buffer units. Test time for the semiconductor memory device can be shortened by doubling the number of ports even in low frequency equipment, thus improving the throughput, by allowing data to be simultaneously and divisionally accessed via all ports, instead of accessing the data via a specified port at a time.

Abstract: A holographic storage system implements both a rotational and an angular multiplexings in combination. The system comprises a light source, a pair of wedge prisms, a beam splitter, a first, a second, a third and a parabolic mirrors, a SLM(spatial light modulator) and a storage medium. In the system, a light beam emitted from the light source is split into a reference and a signal beams by the beam splitter. The signal beam reflected by the first mirror to the SLM which modulates data in the firm of pages. The modulated signal beam falls into the storage medium, while the reference beam is reflected by the second mirror to the wedge prisms which deflect the reference beam to an arbitrary position on the third mirror. The deflected reference beam is reflected onto the parabolic mirror by the third mirror. The deflected reference beam is converged onto the storage medium by the parabolic mirror.