Abstract: A differential clock signal gating method and system is provided, wherein a clock buffer circuit control path develops a clock gating signal with a timing relationship to a clock signal. The clock gating signal gates a buffer on the clock buffer circuit controlled path in communication with the clock signal responsive to a first clock signal pulse negative half. The buffer provides second and successive clock signal pulses occurring immediately and sequentially after the first clock signal pulse as a buffer clock signal output to a second buffer stage in a second stage clock path, each having the nominal clock amplitude and the nominal clock pulse width of the clock signal without jitter.

Abstract: The forward error correction based clock and data recovery system according to the invention comprises a data latch (16) for intermediately storing received data, which is triggered by a sampling clock (sclk). The system further comprises an error determination unit (20, 21) for determining whether and which of the sampled received data is wrong, and for generating out of it a phase/frequency correction signal (ctrl). Furthermore, the system comprises a clock generator (23, 24, 25) for generating the sampling clock (sclk) depending on the correction signal (ctrl).

Abstract: Systems and methods for controlling electro-migration, and reducing the deleterious effects thereof, are disclosed. Embodiments provide for reversal of an applied voltage to an integrated circuit when a measurement indicative of an extent of electro-migration indicates that a healing cycle of operation is warranted. During the healing cycle, circuits of the integrated circuit function normally, but electro-migration effects are reversed. In one embodiment, micro-electro-mechanical switches are provided at a lowest level of metallization to switch the direction of current through the levels of metallization of the integrated circuit. In another embodiment, if the measurement indicative of the extent of electro-migration exceeds a reference level by a specifiable amount, then the voltage applied to the integrated circuit is reversed in polarity to cause current to switch directions to counter electro-migration.

Abstract: A high speed serial link structure and method are provided, comprising a data driver and a replica driver structure, the replica driver structure comprising a replica driver, a calibration engine and a peak level detector. The calibration engine compares a peak level detector output to a reference value and responsively performs a data driver adjustment, wherein the data driver adjustment comprises at least one of a driver biasing adjustment, a driver intermediate stage bandwidth adjustment and a driver equalization setting adjustment. In some embodiments, the calibration engine incorporates a comparator and a digital state machine; in other embodiments, it incorporates an analog operational amplifier.

Abstract: A high speed serial data communication system includes provisions for the correction of equalization errors, particularly those errors introduced by equalizer non-idealities. The equalization is achieved at the data transmitter, and is based on dynamic current subtraction at the output of a differential pair. When bit time>0, the error current is removed or subtracted from the total driver current, thereby maintaining a constant total current from bit time 0 to bit time>0. The same result can also be achieved by subtracting current when bit time>0 using field effect transistors of the opposite gender. The error current can be determined empirically from simulation or through feedback using a replica of the driver. The circuits for achieving equalization error correction and the resulting electrical network analysis are shown and described.

Abstract: A method, circuit and system for altering the power consumption in communication links. A type of noise and an amount of jitter in a signal transmitted across a communication link is measured. Upon determining the contribution of the measured noise to the measured jitter in the signal, the measured noise is classified based on such contribution and the intensity of the measured jitter. The power consumption in a component(s) of the communication link may be adjusted based on the classification of the measured noise. For example, if the measured noise is classified as being a low amount of noise, then the power consumption of the component(s) may be reduced such as by lowering the voltage of the power supply and/or reducing the complexity of the circuitry. By reducing the power consumption when the communication link is not subject to the worst-case condition, a savings in power consumption may be made.

Abstract: A body-biased enhanced current mirror reference circuit is disclosed wherein the body bias voltage of a current mirror device is varied to adjust its threshold voltage. Both the drain and body potentials of a replica mirror transistor are controlled to selected values. The drain is set to an expected DC voltage output of an NFET current mirror device. The body potential is set to a maximum desired value to prevent forward biasing of the body-to-diffusion junction(s) of one or more current mirror devices, which is accomplished by a feedback control circuit. A low-frequency, low-precision op amp drives the gate of a replica load device so that the body of the replica NFET current mirror device is set to a maximum bias voltage. The maximum bias voltage is also used to bias the body of a diode connected NMOS reference transistor, so that the current in the NFET current mirror device will be approximately equal to the current in the diode-connected NMOS reference.

Abstract: A method of balancing signal interconnect path delays between an analog domain and a digital domain of an integrated circuit includes applying a test signal to a selected one of a plurality of communication paths between the analog domain and the digital domain. A rising edge delay and a falling edge delay of the test signal is equalized by adjusting a body bias voltage of a delay element configured within the selected communication path. A rising edge delay and a falling edge delay for each of the remaining communication paths is compared with the equalized rising edge delay and falling edge delay of the selected communication path, and a body bias voltage for one or more of a plurality of delay elements configured within each of the remaining communication paths is adjusted until corresponding rising and falling edge delays thereof match the equalized rising edge delay and falling edge delay of the selected communication path.

Abstract: A structure and method for power distribution to a network for an integrated circuit chip complex are provided. The chip complex has at least two sectors, each having at least one power providing connection with at least one of said connections beings individually addressable by, and isolatable from, a given power source. At least one MEMS is positioned to selectively connect and disconnect said at least one connection to and from said given power source.

Abstract: Methods and arrangements to determine phase adjustments for a sampling clock of a clock and data recovery (CDR) loop based upon subsets of data samples, or values, derived from an incoming data signal are disclosed. In particular, embodiments extend the CDR loop by slowing the clock rate with respect to the sampling clock. For instance, the slower clock rate may be implemented by dividing the frequency of the sampling clock by a number such as 128, slowing a sampling clock frequency designed to handle multiple gigabits per second (Gbps) to a frequency of less than one kilohertz (Khz). In addition to the reduced power consumption realized by operating at a lower frequency, the slower clock rate allows components of the CDR loop circuitry to operate a lower operating voltage reducing power consumption by the CDR loop even more.

Abstract: A unified, unidirectional serial link is described for providing data across wired media, such as a chip-to chip or a card-to-card interconnect. It consists of a transmit section and a receive section that are operated as pairs to allow the serial data communication. The serial link is implemented as part of a VLSI ASIC module and derives its power, data and clocking requirements from the host modules. The logic transmitter portion contains a phase locked loop (PLL), a dibit data register, a finite impulse response (FIR) filter and a transmit data register. The phase locked loop comprises both a digital coarse loop and an analog fine loop. The digital receiver portion contains a PLL, an FIR phase rotator, a phase rotator control state machine, and a clock buffer. The transmitter and the receiver each preferably utilize a pseudo-random bit stream (PRBS) generator and checker.

Abstract: A method for controlling the common-mode output voltage in a fully differential amplifier includes comparing a sensed common-mode output voltage of the fully differential amplifier to a reference voltage, and generating an error signal representing the difference between the sensed common-mode output voltage and the reference voltage. The error signal is utilized to control the body voltage of one or more FET devices included within the fully differential amplifier until the sensed common-mode output voltage is in agreement with said reference voltage.

Abstract: The present analog invention is related to a unified digital architecture comprising logic transmitter portions and logic receiver portions. A unified serial link system and method for transmitting digital data across wired media including a transmitter and a receiver portion is provided, one of the transmitter portion and receiver portion comprising a phase locked loop (PLL) circuit. The PLL circuit comprises a voltage control oscillator, a frequency divider, a phase-frequency detector, a charge pump and a multi-pole loop filter. One embodiment comprises a dual loop PLL having a digital coarse loop and an analog fine loop.

Abstract: Methods, systems, and media to time-share the signal detection between reference voltages for a data transmission are contemplated. Embodiments include a time-sharing detector that is designed to enable comparison of a first reference voltage and a second reference voltage against the serial data transmission in a specified pattern. In many embodiments, the pattern is pre-defined and, in some embodiments, the pattern includes an overlap period. During the overlap period both the first and the second reference voltages are compared with the data transmission to determine if valid data can be detected. Upon detecting a valid bit based upon one of the reference voltages, an output signal is generated to indicate that the data transmission includes a valid data signal. Advantageously, alternating between the comparisons can reduce power consumption. In many embodiments, the power reduction can be, for example, 50%, depending upon the specified pattern.

Abstract: A circuit having a precision passive circuit element, such as a resistor or a capacitor, with a target value of an electrical parameter is fabricated on a substrate with a plurality of independent parallel-connected passive circuit elements. The plurality of passive circuit elements are designed to have a plurality of values of the electrical parameter which are spaced or offset at or around the target value of the electrical parameter, such as three circuit elements with one having a value at the target value, one having a value above the target value, and one having a value below the target value. Each passive circuit element also has a fuse in series therewith. A reference calibration structure is also fabricated, which can be a passive circuit element having the target value of the electrical parameter, in a reference area of the substrate under the same conditions and at the same time as fabrication of the plurality of passive circuit elements.

Abstract: Aspects of providing automatic adaptation to frequency offsets in high speed serial links are described. First signals for phase adjusts in a receiver link are adjusted by detecting trends in the first signals to generate second signals, the second signals improving a rate of compensation for the frequency offsets by the phase adjusts. An up/down counter is included for counting signals for phase adjustments by a clock-data-recovery loop of a serial receiver. An adder is coupled to the up/down counter and outputs accumulated data indicative of a trend in the phase adjustments. Combinatorial logic coupled to the adder adapts the signals based on the accumulated data.

Abstract: Aspects for increased noise immunity for clocking signals in high speed digital systems are described. The aspects include buffering a differential clock signal with a single buffer circuit for a plurality of load circuits and configuring the single buffer circuit to adjust to alterations in the number of load circuits receiving the differential clock signal. The configuring achieves a constant bandwidth and voltage level for the clock signal output while adjusting to alterations in the number of load circuits.

Abstract: Described is a system for trimming the value of an electronic component. The system comprises: at least one trimming component, each trimming component having an associated switch for selectively connecting that trimming component to the electronic component in response to a corresponding bit in a control vector. A comparator is included for generating an output bit having a first value if a net value of the electronic component and any connected trimming components differs from a desired value. A controller connected to the switches and the comparator generates the control vector in dependence on the output of comparator, the controller comprising a shift register for sequentially receiving successive output bits from the comparator; wherein the control vector comprises the contents of the shift register and wherein a bit of said first value in control vector effects switching of the corresponding switch.

Abstract: The method for determining jitter of a signal in a serial link according to the invention comprising the following steps: First, a section of the signal transmitted via a transmission channel is sampled at different sampling times. The total number of edges in the section is determined. The neighboring sample values are analyzed and from that a statistical value is formed. From the statistical value and the total number of edges a figure of merit is determined. Finally, by means of a look-up table or a jitter-versus-figure of merit curve, the total jitter corresponding to the figure of merit is derived.

Abstract: Aspects of saving power in a serial link transmitter are described. The aspects include providing a parallel arrangement of segments, each segment comprising prebuffer and output stage circuitry of the serial link transmitter and each segment enabled independently to achieve multiple power levels and multiple levels of pre-emphasis while maintaining a substantially constant propagation delay in a signal path of the serial link transmitter. Further aspects include providing a bypass path in the prebuffer stage circuitry to implement a controllable idle state in the segments and tail current and resistive load elements in the prebuffer circuitry as sectioned portions for slew rate control capability. Also included is provision of a control element with pre-emphasis delay circuitry in the transmitter signal path to allow inversion of a last delayed bit of the pre-emphasis delay circuitry to achieve a polarity change of a pre-emphasis weight.