摘要:
Perpendicular spin transfer torque memory (STTM) devices with enhanced stability and damping are described. For example, a material layer stack for a magnetic tunneling junction includes a fixed magnetic layer. A dielectric layer is disposed above the fixed magnetic layer. A first free magnetic layer is disposed above the dielectric layer. A second free magnetic layer is magnetically coupled with the first free magnetic layer.
摘要:
A memory system includes a memory controller coupled to at least one memory device via high-speed data and request links. The timing and voltage margins of the links are periodically calibrated to reduce bit error. The high-speed request links complicate calibration because commands issued over the uncalibrated request links can be erroneously interpreted by the memory device. Misinterpreted commands can disrupt the calibration procedure (e.g., a write command might be misinterpreted as a power-down command). The memory controller addresses this problem using a separate, low-speed control interface to issue a filter command that instructs the memory device to decline potentially disruptive requests when in a calibration mode.
摘要:
A system and apparatus generates a time-stamp to identify and record the time of an event such as an edge received in a data signal or clock signal. A set of strobe pulses can be generated by routing an external clock signal to delay elements with incrementally increasing delay values. A data signal or device under test clock signal can be applied to the input to each of a set of latches which are clocked by the strobe pulses. The set of latches can thereby capture a series of samples of the data signal or clock signal. The series of samples can be encoded as an edge time within a clock cycle. A clock cycle counter can be added to the edge time to generate the time stamp.
摘要:
A delay circuit for delaying an input signal with a desired delay and outputting the delayed signal. The delay circuit includes a light emitting element for emitting light according to an input signal and outputting a delay signal, a bias current source for supplying in advance a first light emitting element with a bias current smaller than a light emission threshold current of the first light emitting element, a bias current controller for controlling the bias current according to a desired delay time, a modulation current source for supplying the light emitting element with a modulation current for making the light emitting element emit light in accordance with the input signal, and a modulation current controller for controlling the modulation current in accordance with a delay resolution in the delay circuit. The modulation current controller controls the modulation current further according to a variable delay range in the delay circuit.
摘要:
The invention relates to a tester head which interfaces with high speed protocol memories such as RAMBUS devices. A head in a memory test system conditions the signals applied to the Device Under Test (DUT). A memory of this type further comprises a base providing all the algorithmic funcionality. A high speed protocol memory test head according to the invention comprises a test generator connector for receivong the test signals form the test generator, a control packet generator for generating row and column control packets basing on control signals (including address) from the test generator connector, a data packet generator for generating data packets from data streams from the test generator connector, the inputs of the control packet generator and the data packet generator being connected to the test generator connector, serialisers respectively connected to the outputs of the control packet generator for transforming wide and slow packets into high-speed and narrow packets, pin electronics for interfacing to a high speed protocol memory DUT, deserialiers for transforming high-speed and narrow DUT-output packets back to wide and slow packets, a data comparator for comparing the deserialised DUT-output data with the refence data from the data packet generator and a fault logger connector for feeding the comparison results from the data comparator to the fault logger.
摘要:
A method and apparatus using a non-intrusive probe for testing double data rate interfaces is provided. The method begins with the generation of at least one component parameter model, which is then cascaded to form a full system parameter model of the double data rate interface being tested. Transfer functions are generated using the full system parameter model. A target transfer function is calculated between the test equipment and a decision point. The calculated target transfer function is applied and testing is completed. The apparatus includes a device to be tested, mounted on a circuit board. A probe card is attached to the backside of the circuit board and is in communication with a high-speed connector. At least one connector in communication with the high-speed connector and at least one small footprint RF connector on an accessible side of the circuit board are also part of the non-intrusive probing apparatus.
摘要:
A tapped transmission line structure (1) for providing an electrical connection between a driver terminal (110) and a plurality of device connections (120a, 120b) comprises a main transmission line (130) and a plurality of branching structures (142a, 142b). The branching structures couple the main transmission line (130) with the device connections at different distances (I1, I2) from the driver terminal (110) and have associated therewith signal transmission portions. Different of the signal transmission portions are designed to have different signal transmission characteristics in order to counteract differences of signal characteristics at different device connections.