Abstract: Protection for the transmission of higher amplitude outputs required of differential amplifiers formed by thin oxide transistors with limited maximum voltage tolerance used where compliance with communication protocol standards requires handling voltages which may, in transition, exceed desirable levels is provided by limiting the voltage across any two device terminals under power down conditions.

Abstract: Jitter method and control circuit for a circuit block in a transceiver system having a phase lock loop circuit which includes an oscillator, a charge pump connected to the oscillator to add or subtract charge to or from said oscillator, and a low pass filter connected to said charge pump are provided. Circuitry is connected to the output of the oscillator and the input of the charge pump to control the amount of charge added to or subtracted from the charge pump to control the bandwidth output by the oscillator and thereby reduce jitter in the phase lock circuit.

Abstract: A method for determining data signal jitter via asynchronous sampling provides a low cost and production-integrable mechanism for measuring data signal jitter. The data signal is edge-detected and sampled by a sampling clock of unrelated frequency the sampled values are collected in a histogram according to a folding of the samples around a timebase. The timebase is determined by sweeping to detect a minimum jitter for the folded data. The histogram for the correct estimated timebase period is representative of the probability density function of the location of data signal edges and the jitter characteristics are determined by the width and shape of the density function peaks. Frequency drift can be corrected by adjusting the timebase used to fold the data across the sample set.

Abstract: A method a low cost and production-integrable technique for providing a signal diagram. The data signal is edge-detected and asynchronously sampled (or alternatively a clock signal is latched). The data signal or a second signal is compared to a settable threshold voltage and sampled. The edge and comparison data are folded according to a swept timebase to find a minimum jitter period. The crossing of the signal diagram edges is determined from a peak of a histogram of the folded edge data. A histogram of ratios of the sample values versus displacement from the position of the crossing location is generated for each threshold voltage. The technique is repeated over a range of settable threshold voltages. Then, the ratio counts are differentiated across the histograms with respect to threshold voltage, from which a signal diagram is populated.

Abstract: Substantially-accurate calibration of output impedance of a device-under-test (DUT) to within a predetermined range of allowable impedance. The DUT is part of a source series terminated (SST) serial link transmitter, in which two branches of parallel transistors each provide an impedance value when particular transistors of the parallel branch are turned on. The impedance value is added to a series-connected resistor to provide the output impedance. The DUT consists of one branch of parallel transistors in series with a resistor. Output impedance of the DUT is compared to the resistance of a reference resistor, and the comparator provides a control signal based on whether the output impedance falls within the pre-set percentage variance of the reference resistance. The control signal is processed by a FSM (finite state machine) that individually turns on or off the transistors within the parallel branch until the DUT impedance value falls within the desired range.

Abstract: A multimode circuit that is configured to operate in one of multiple operating modes is disclosed. In particular, an exemplary multimode circuit may be configured to operating in one of a full-swing mode, a limited-swing mode, a full-swing to limited-swing converter mode, and a limited-swing to full-swing converter mode. The operating modes of the multimode circuit may be dynamically selectable. One or more multimode circuits may be part of a configurable distribution path for controlling the performance of a signal distribution path or tree of an integrated circuit.

Abstract: A system and method is disclosed for evaluating a data group of oversampled bits to detect edge transitions and for improving use of information available from a sampled data while maintaining acceptable noise rejection. An edge detection system for receiving a serial data stream includes a sampler for collecting a sample pattern from the serial data stream, the sample pattern including a succession of a plurality of data samples from the data stream with the plurality of data samples including multiple samples during a bit time associated with the data stream; a memory, coupled to the sampler, for storing one or more successive sample patterns; and a correlator, coupled to the memory, for producing a sample condition signal using a set of predefined patterns by comparing the stored sampled patterns to the predefined patterns.

Abstract: A system and method is provided for transmitting data signals and additional information signals having partially overlapping frequency bands simultaneously within a wire based communication system over the same wired medium using a spread spectrum technique for modulating the additional information signals.

Abstract: A method and system for testing a high-speed circuit is disclosed. The method and system include obtaining a high-speed statistical signature of the high-speed circuit using a conventional tester. The method and system further include comparing the high-speed statistical signature of the high-speed circuit to an expected signature. Consequently, it can be determined whether the high-speed circuit functions within the desired parameters.

Abstract: A method of forming a differential amplifier on a substrate which has a greater tolerance for applied voltages and a chip so formed. The differential amplifier circuit on a substrate has additional transistors connected with resistors which form a voltage divider, thereby sharing the voltage stress which may be applied and accommodating enhanced capabilities for the differential amplifier.

Abstract: A system and method for tracking/adapting phase or frequency changes in an incoming serial data stream that may contain significant amounts of noise and/or jitter and may contain relatively long periods of successive univalue data bits. The method includes digitally sampling a received data stream at predefined intervals to produce a data set; estimating when logic transitions occur in the data set; detecting a timing trend represented by the estimated logic transitions; and adjusting a frequency of the first clock so that the timing trend averages approximately zero over a plurality of logic transitions.

Abstract: A method and apparatus for determining data signal jitter via asynchronous sampling provides a low cost and production-integrable mechanism for measuring data signal jitter. The data signal is edge-detected and sampled by a sampling clock of unrelated frequency the sampled values are collected in a histogram according to a folding of the samples around a timebase. The timebase is determined by sweeping to detect a minimum jitter for the folded data. The histogram for the correct estimated timebase period is representative of the probability density function of the location of data signal edges and the jitter characteristics are determined by the width and shape of the density function peaks. Frequency drift can be corrected by adjusting the timebase used to fold the data across the sample set.

Abstract: A circuit design method and transmitter that enables flexible control of amplitude, pre-emphasis, and slew rate utilizing a design of a segmented self-series terminated (SSST) transmitter having a parallel configuration of multiple, individually controllable segments of dual pull-up and pull-down transistors. Amplitude control, slew rate control and pre-emphasis control are enabled by manipulation/selection of normal or inverted inputs for the various segments. Also provided is a mechanism for providing/maintaining accurate output across a self-series terminated (SST) transmitter by regulating the supply voltage. Regulation of the supply voltage allows compatibility with conventional serial link receiver termination voltages and protects the transmitter output devices when those voltages are larger than the normal supply for the devices.

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: 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: 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: A system and method for a predriver and driver interface having scalable output drive capability with corresponding scalable power is disclosed.

Abstract: A method and apparatus for determining jitter and pulse width from clock signal comparisons provides a low cost and production-integrable mechanism for measuring a clock signal with a reference clock, both of unknown frequency. The measured clock signal is sampled at transitions of a reference clock and the sampled values are collected in a histogram according to a folding of the samples around a timebase which is either swept to detect a minimum jitter for the folded data or is obtained from direct frequency analysis for the sample set. The histogram for the correct estimated period is statistically analyzed to yield the pulse width, which is the difference between the peaks of the probability density function and jitter, which corresponds to width of the density function peaks. Frequency drift is corrected by adjusting the timebase used to fold the data across the sample set.

Abstract: A method and system for is disclosed for reducing intersymbol interference in a stream of data bits to be transmitted over a transmission medium. Aspects of the present invention include a phase delayed clock generated from a reference clock that produces an edge on sub-bit boundaries; and a digital filter coupled to the phase delayed clock for performing equalization on the data bits, wherein the phase delayed clock causes the digital filter to perform partial clock switching, such that equalization is performed on the data bits on-sub-bit boundaries.

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.