Abstract: A programmable logic device includes a plurality of programmable multi-gigabit transceivers, programmable logic fabric, and a control module. Each of the plurality of programmable multi-gigabit transceivers is individually programmed to a desired transceiving mode of operation in accordance with a plurality of transceiver settings. The programmable logic fabric is operably coupled to the plurality of programmable multi-gigabit transceivers and is configured to process at least a portion of the data being transceived via the multi-gigabit transceivers. The control module is operably coupled to produce the plurality of transceiver settings based on a desired mode of operation for the programmable logic device.

Abstract: A method and apparatus are provided that allow exploitation of the common mode characteristics of a differential transmission network to provide an additional data signal. Signal (MODE) represents either a binary signal or a multi-valued signal to allow signaling of one or more bits of information. The signaling occurs through the variation of the common mode voltage in transmitters (300 and 400) and is detected using differential receiver (600). One embodiment is presented that achieves signaling of an extended run length data sequence to allow continued transmitter/receiver synchronization throughout the transmission of the sequence. In an alternate embodiment, a separate data path is provided to signal the extended run length sequence when a common mode signaling path is not available.

Abstract: A distributed buffering system includes at least one input buffer, at least one serializing module, a at least one deserializing module, at least one output buffer, and a programmable logic device. The input buffer is operably coupled to store at least one data block of incoming data. The serializing module serializes the data block as it is retrieved from the input buffer to produce a serial stream of data. The programmable logic device receives the serial stream of data and distributes it to one or more of the at least one deserializing modules. The at least one deserializing module converts the serial stream back into the data block. The recaptured data block is then provided to the corresponding output buffer, which stores the recaptured data.

Abstract: A system, device, and method for compensation of distortion caused by transmission line effects are disclosed herein. An output port including a feed-forward circuit parallel to the output impedance of an output driver compensates for distortion introduced by transmitting data over a transmission medium. The compensated output driver is utilized to transmit data between devices or circuits connected using conductive traces on printed circuit boards.

Abstract: A receiver termination network is included in a high-speed receiver that also includes a receiver analog front-end and a data recovery module. The receiver termination network includes a DC matched termination circuit and an AC coupled bias circuit. The DC matched termination circuit is operably coupled to provide a termination of a transmission line coupling the high-speed receiver to a transmission source and to receive high-speed data via the transmission line. The AC coupled bias circuit is operably coupled to provide a common mode reference and to high-pass filter the high-speed data to produce filtered high-speed data. The receiver analog front-end is biased in accordance with the common mode reference and is operably coupled to amplify the filtered high-speed data to produce amplified high-speed data.

Abstract: A Transmit line driver with selectable pre-emphasis and driver signal magnitudes comprises a primary current driver for setting a primary current level and a pre-emphasis current driver that provides an additional amount of current that is superimposed with or added to the primary current level produced by the primary current driver. The pre-emphasis current has either negative or positive magnitude based upon a pre-emphasis signal logic state. A first current selection module defines a reference signal that is used to select the primary current driver output signal magnitude in a first current mirror, while a second current selection module is used to define a second reference signal that selects a pre-emphasis current driver signal magnitude in a second current mirror. Logic generates a binary signal to both the first and second current selection modules to select the current levels as well as the pre-emphasis signal.

Abstract: A device and a method for processing high data rate serial data includes circuitry for recovering a clock based on the high data rate input data stream. A transceiver includes a coarse loop of a phase-locked loop that selectively provides a clock having accuracy that is within a specified amount. In a sample mode of operation, only the coarse loop PLL is coupled to provide an error signal from which an oscillation signal and clock may be derived. In a second mode (lock) of operation, the transceiver may lock to the received serial data stream by coupling the fine loop PLL to provide an adjusted error signal. In a third mode of operation, (automatic) the transceiver initially performs coarse loop calibration by de-coupling the fine loop PLL and coupling the coarse loop PLL until a steady state has been reached.

Abstract: A high frequency latch comprising a latch and a plurality of buffers coupled to peak load circuitry produces a peak response at a desired frequency of operation as well as isolating each high frequency latch output of a plurality of outputs to substantially reduce the effects of a kickback signal coupled into the latch output. The peaked load circuitry comprises selectable resistive elements and selectable capacitive elements coupled as a high pass filter to change the bias on a saturation region MOSFET configured as an active load. The high pass filter produces positive feedback on the saturation region MOSFET to increase the bias at high frequencies thereby producing an increased response at a desired operating frequency.

Abstract: Method and apparatus for configuring a programmable logic device to perform testing on a signal channel is described. Configurable logic of the programmable logic device is configured for a test mode. Configurable interconnects are configured for communication from or to the configurable logic to or from transceivers coupled to the configurable input/output interconnect to communicate test signals.

Abstract: An apparatus and method of the present invention includes a high frequency exclusive OR (XOR) with a peaked load stage. The peaked load stage coupled to the XOR produces a peaked response at a specified frequency of operation. The high frequency XOR comprises a mixer stage comprising first and second transconductance stages coupled to produce a differential output current. The peaked load stage receives the differential output current from the mixer stage and provides increasing impedance at a specified frequency of operation. The peaked load stage includes a pair of peaked load blocks comprising a saturation region peaked load MOSFET and a resistive load. The gate-to-source capacitance of the peaked load MOSFET is coupled to the resistive load to form a high pass filter that provides additional bias to a gate of the peaked load MOSFET that increases the resistance of the peaked load MOSFET at the specified frequency.

Abstract: Method and apparatus for a bidirectional transceiver cell is described. Each bidirectional transceiver cell has a transmitter and a receiver, where the transmitter and the receiver share a phase-locked loop. The bidirectional transceiver cell is configured to act as either a transmitter or a receiver. The bidirectional transceiver cell is for multi-gigabit data rates.

Abstract: A method for testing a multi-gigabit transceiver begins by configuring the multi-gigabit transceiver for testing. The processing continues by varying a performance aspect of the multi-gigabit transceiver to produce a varied multi-gigabit transceiver. The processing continues by providing an input test signal to the varied multi-gigabit transceiver. The processing further continues by monitoring an output of the varied multi-gigabit transceiver with respect to the input test signal to determine a level of signal integrity. The processing continues by determining when the level of signal integrity provides a desired performance margin. The processing continues by adjusting a programmable operational setting of the multi-gigabit transceiver when the level of signal integrity does not provide the desired performance margin.

Abstract: Method and apparatus for auto-negotiation of a programmable logic device for any of a plurality of communication protocols is described. The programmable logic device is programmed for auto negotiation to establish a communication session. The programmable logic device has access to transceiver attributes. A portion of the transceiver attributes are selected in response to session information from the auto negotiation. The portion of the transceiver attributes selected are for configuring at least one transceiver for a communication protocol.

Abstract: A Transmit line driver with selectable pre-emphasis and driver signal magnitudes comprises a primary current driver for setting a primary current level and a pre-emphasis current driver that provides an additional amount of current that is superimposed with or added to the primary current level produced by the primary current driver. The pre-emphasis current has either negative or positive magnitude based upon a pre-emphasis signal logic state. A first current selection module defines a reference signal that is used to select the primary current driver output signal magnitude in a first current mirror, while a second current selection module is used to define a second reference signal that selects a pre-emphasis current driver signal magnitude in a second current mirror. Logic generates a binary signal to both the first and second current selection modules to select the current levels as well as the pre-emphasis signal.

Abstract: A ring oscillator with a plurality of delay stages having selectable active loads for selecting an R-C time constant that defines a delay through the delay stage. The ring oscillator oscillation frequency is a function of the selected R-C time constant, a selectable bias level, and the number of delay stages in the ring oscillator. In one embodiment, a MOSFET device gate-to-source capacitance is used with at least one selectable resistive device to form the R-C time constant. In an alternate embodiment, a plurality of parallel coupled resistive devices and parallel coupled capacitive devices are selectively coupled to the active load circuit to set the delay through the delay stage. The resistive devices are formed to be one of a resistor configured MOSFET device and a traditional resistive element. The capacitive devices are formed to be one of a capacitor configure MOSFET device and a traditional capacitive element.

Abstract: Method and apparatus for a nonlinear current circuit element are described, and method and apparatus using the nonlinear current circuit element in current-source self-biasing circuits are described. In one embodiment, a transistor is provided having source and drain terminals coupled together. This transistor has a significant gate tunneling current used beneficially to provide a nonlinear current circuit element. This nonlinear current circuit element is used in a plurality of current-source self-biasing circuits.

Abstract: A transmit line driver with selectable slew rates and a common mode idle state comprises a capacitor array of selectable capacitors coupled between a line driver and a pre-driver wherein a slew rate may be selected by the selectable capacitors. A common mode idle state is provided by coupling a selectable switch (MOSFET in the described embodiment) to a mirror device that provides a bias current to the pre-driver wherein, when the bias current is removed by the switch, the pre-driver produces an output signal that is equal to the supply voltage for the circuit. Accordingly, a differential pair of the line driver are both biased on and provide a common mode idle state. The common mode idle state is equal to one half of an output signal magnitude for a logic one.

Abstract: In accordance with a preferred embodiment, a time-interleaved (or multi-phase) architecture is provided having individual control of a plurality of output signals or phases. The time-interleaved architecture may be implemented using a first set of delay cells such as those in a ring oscillator or a delay line device receiving overall control of its output signals by a global control signal. The global control signal may be issued by a phase-locked loop, delay-locked loop, or other like structure. A second set of delay cells is provided to further delay the output signals produced by the first set of delay cells. The second set of delay cells are controlled by individual control signals uniquely calibrated in accordance with a preferred embodiment of the invention to provide uniform (or substantially) uniform time spacing between output signals.

Abstract: A method and apparatus for characterizing and sensing the stability of a magnetic memory element. The method comprises setting a reference threshold, reading the state signal of the memory element, and comparing the magnitude of the state signal to the reference threshold, such that a state signal exceeding the reference threshold is considered stable. The apparatus comprises a reference generator having an output that is compared, in a windowed comparator, to the state signal magnitude, such that an output signal of the windowed comparator can be used to characterize the stability of the memory element.

Abstract: In this invention, three schemes of nonvolatile FPLD structures are proposed using a latch that has been disclosed herein. In the first proposed scheme the latches, which can be designed using either GMR or SDT devices, will work as interconnects in a conventional Programmable Logic Array (PLA). In the second proposed scheme, the latches will constitute the look-up table for a standard PLA. In the third proposed scheme, the latch itself will work as a nonvolatile Programmable Logic Device (PLD) structure. This FPLD latch will have 2n GMR or SDT resistors, instead of just 2, for an n-input logic gate. By programming the resistors differently, in each scheme, numerous different logic functions from the same logic gate can be achieved.