Abstract: An analog front-end having built-in equalization includes a control module and a tunable gain stage. The control module is operably coupled to provide a frequency response setting based on a channel response of a channel providing high-speed serial data to the analog front-end. The tunable gain stage includes a frequency dependent load and an amplifier input section. The frequency dependent load is adjusted based on the frequency response setting. The amplifier input section is operably coupled to the frequency dependent load and receives the high-speed serial data. In conjunction with the frequency dependent load, the amplifier input section amplifies and equalizes the high-speed serial data to produce an amplified and equalized serial data.

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 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: Adjustment circuitry in a phase-locked loop (PLL) adjusts a sampling point to any desired location within a bit period of each bit of received high-speed serial data. The adjustment circuitry, responsive to program control, selectively adds current portions to a charge pump error current output thereby adjusting a feedback signal frequency to shift the serial data sampling point. A plurality of current mirror devices is scaled, with respect to a reference current device, to provide ?I current portions. A current control module controls the current portions magnitude and a sign of the current portions. The adjustment circuitry further controls charge pump programmable current sources in order to set a desired operating point of the PLL. The programmable current sources are controlled by a bias voltage and a plurality of selectable serial and parallel coupled resistors.

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: 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: A programmable serial data path includes a programmable timing circuit and a parallel to serial module. The programmable timing circuit is operably coupled to generate a first plurality of timing signals when width of parallel input data is of a first multiple and to generate a second plurality of timing signals when the width of the parallel input data is of a second multiple. The parallel to serial module is operably coupled to convert the parallel input data into serial output data based on the first or second plurality of timing signals.

Abstract: A calibrated VCO for use in a phase-locked loop includes a low frequency calibration block for setting a bias signal for a ring oscillator to a center point to prompt the ring oscillator to generate an oscillation that is in the middle of its output frequency range and a high frequency VCO gm stage for generating an adjustment calibration signal that is added or subtracted to and from the bias signal created by the low frequency calibration block. A low pass filter coupled between the gates of a current mirror of the low frequency calibration block operates to filter noise and interference generated within the low frequency calibration block. Additionally, the magnitude of the bias signal produced by the low frequency calibration block is significantly greater than the adjustment bias signal generated by the high frequency VCO gm stage.

Abstract: Adjustment circuitry in a phase-locked loop (PLL) adjusts a sampling point to any desired location within a bit period of each bit of received high-speed serial data. The adjustment circuitry, responsive to program control, selectively adds current portions to a charge pump error current output thereby adjusting a feedback signal frequency to shift the serial data sampling point. A plurality of current mirror devices is scaled, with respect to a reference current device, to provide ?I current portions. A current control module controls the current portions magnitude and a sign of the current portions. The adjustment circuitry further controls charge pump programmable current sources in order to set a desired operating point of the PLL. The programmable current sources are controlled by a bias voltage and a plurality of selectable serial and parallel coupled resistors.

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: A programmable serial data path includes a programmable timing circuit and a parallel to serial module. The programmable timing circuit is operably coupled to generate a first plurality of timing signals when width of parallel input data is of a first multiple and to generate a second plurality of timing signals when the width of the parallel input data is of a second multiple. The parallel to serial module is operably coupled to convert the parallel input data into serial output data based on the first or second plurality of timing signals.

Abstract: A phase adjustment module in a voltage controlled oscillator (VCO) samples a VCO oscillation to detect changes in the oscillation frequency and produces a corresponding correction voltage that is feedback to the VCO input to correct the frequency change. A plurality of sampling modules, each formed to start sampling at a different point on the oscillation cycle, charge a sampling module capacitor over the period of a full oscillation cycle. The samples are coupled to a low pass filter to produce a running average of all the samples. The charge on each capacitor is coupled to a first input of a plurality of operational amplifiers and the running average is coupled to a second input. The summed output of the operational amplifiers is substantially equal to a difference between the running average and a voltage representing the instantaneous time change or phase change of the oscillation frequency.

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: 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 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: 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: 8b/10b encoding begins when an input running disparity is received. The processing then continues by receiving an 8-bit digital input that includes a 5-bit digital input portion and a 3-bit digital input portion. The processing then continues by determining, in parallel, a 6-bit running disparity and a 4-bit running disparity. The processing then continues by determining a 6-bit digital output based on the 6-bit running disparity and the 5-bit digital input portion. The processing then continues by determining a 4-bit digital output based on the 4-bit running disparity and the 3-bit digital input portion. The resulting 10-bit encoded digital output is the combination of the 6-bit digital output and the 4-bit digital output.

Abstract: A phase locked loop having a voltage-controlled oscillator is adjusted to compensate for process variations in the formation of the phase locked loop. In each instance of the phase locked loop, the center frequency of the voltage-controlled oscillator is adjusted using a bias signal while holding the control voltage of the voltage-controlled oscillator at zero. Then, the control voltage of the voltage-controlled oscillator is set to a different value and the gain of the voltage-controlled oscillator is adjusted.

Abstract: A phase controller is coupled to a voltage-controlled oscillator (VCO) in a feedback configuration, thereby reducing the phase noise introduced by the VCO. As a result, circuits using the VCO, such as phase-locked loops or delay locked loops, will exhibit reduced jitter in the resulting output signals. In one embodiment, the phase controller measures successive actual periods of the VCO output clock, and in response, generates a control voltage representative of deviations in the successive actual periods of the VCO output clock. The phase controller transmits the control voltage to the VCO as a feedback control voltage. The VCO adjusts the actual period of the VCO output clock in response to the control voltage. More specifically, the VCO adjusts the actual period of the VCO output clock such that deviations in the successive actual periods of the VCO output clock are reduced.