Abstract:
Domain bloom, also known as asymmetry, is a systematic imperfection caused by the writing process in optical discs. During disc read-out it causes signal transitions to shift with respect to their nominal positions. State-of-the-art equalization and detection methods suffer significant performance losses if directly applied to replay signals with asymmetry. A non-linear model for replay signals with asymmetry is used for new equalization and detection techniques that are applicable to signals in the presence of asymmetry. Modifications are described of the threshold bit-detector, the run-length pushback bit-detector, and the PRML sequence detector, which have significant performance benefits. These benefits come at almost no additional cost with respect to existing detectors.
Abstract:
Methods and apparatus are provided for determining the state of a phase-change memory cell. A plurality of measurements are made on the cell, the measurements being dependent on the sub-threshold current-versus-voltage characteristic of the cell. The measurements are processed to obtain a metric which is dependent on the slope of the sub- threshold current-versus-voltage characteristic. The state of the cell is then determined in dependence on this metric which, unlike absolute cell resistance,is substantially unaffected by drift.
Abstract:
A method is provided that comprises a step of programming the PCM cell to have a respective definite cell state by at least one current pulse flowing to the PCM cell, said respective definite cell state being defined at least by a respective definite resistance level, a step of controlling said respective current pulse by a respective bitline pulse and a respective wordline pulse, and a step of controlling said respective bitline pulse and said respective wordline pulse dependent on an actual resistance value of the PCM cell and a respective reference resistance value being defined for the definite resistance level.
Abstract:
A micro-electro mechanical device includes a first structure (104), a second structure (106) offset from the first structure by a gap. The first structure is configured to be electrostatically actuated to deflect relative to second structure. A pulse generator is configured to combine at least two different pulses (302, 304) to electrostatically drive at least one of the first structure and the second structure between an initial position and a final position.
Abstract:
Disclosed is a method for manufacturing a resistive memory element (1) which comprises: providing a storage layer (2) comprising a resistance changeable material comprising carbon; providing contact layers (3, 4) for contacting the storage layer (2), wherein the storage layer (2) is disposed between a bottom contact layer (3) and a top contact layer (4); and doping the resistance changeable material with a dopant material, preferably hydrogen, nitrogen or a transition metal, and/or annealing the material. A corresponding resistive memory element (1) includes a bottom contact layer (3), a top contact layer (4) and a storage layer (2) disposed between the bottom contact layer (3) and the top contact layer (4), wherein the storage layer (2) comprises a resistance changeable material comprising carbon that is doped with a dopant material.
Abstract:
Domain bloom, also known as asymmetry, is a systematic imperfection caused by the writing process in optical discs. During disc read-out it causes signal transitions to shift with respect to their nominal positions. State-of-the-art equalization and detection methods suffer significant performance losses if directly applied to replay signals with asymmetry. A non-linear model for replay signals with asymmetry is used for new equalization and detection techniques that are applicable to signals in the presence of asymmetry. Modifications are described of the threshold bit-detector, the run-length pushback bit-detector, and the PRML sequence detector, which have significant performance benefits. These benefits come at almost no additional cost with respect to existing detectors.
Abstract:
Methods and apparatus are provided for determining the state of a phase-change memory cell (10). The cell (10) is biased with a time- varying read voltage (V read ) and a measurement (T M ) is then made. The measurement (T M ) is dependent on a predetermined condition being satisfied. This condition depends on cell current during application of the read voltage (V read ). The measurement (T M ) is then used to determine the state of the cell (10).
Abstract:
A method for manufacturing a resistive memory element (1) comprises: providing a storage layer (2) comprising a resistance changeable material; said resistance changeable material comprising carbon; providing contact layers (3, 4) for contacting the storage layer (2), wherein the storage layer (2) is disposed between a bottom contact layer (3) and a top contact layer (4); and doping the resistance changeable material with a dopant material. A resistive memory element (1) includes a bottom contact layer (3), a top contact layer (4) and a storage layer (2) disposed between the bottom contact layer (3) and the top contact layer (4), wherein the storage layer (2) comprises a resistance changeable material that is doped with a dopant material.
Abstract:
A servo control system micro-electromechanical systems (MEMS)-based motion control system (and method therefor), includes a motion generator having an inherent stiffness component.
Abstract:
Methods and apparatus are provided for detecting N-symbol codewords stored in multilevel-cell solid-state memory. Each codeword is a permutation of an N-symbol vector of a predefined set of N-symbol vectors. The symbols of each codeword, each of which has one of q symbol values, are stored in respective q-level cells of solid state memory (2), where N≥q>2. The memory cells storing a group of codewords are read to obtain respective read signals each comprising N signal components corresponding to respective symbols of a codeword. The components of each read signal are ordered according to signal level to produce an ordered read signal. Corresponding components of the ordered read signals are averaged to produce an average read signal. A reference signal level corresponding to each of the q levels of the memory cells is determined in dependence on the average read signal and predefined probabilities of occurrence of each symbol value at each symbol position in a said codeword whose symbols are ordered according to symbol value. The codeword corresponding to each read signal is then detected in dependence on the reference signal levels.