International Business Machines Corporation

University of Minnesota

Lenovo (singapore) Pte. Ltd.

Roger John Gravrok

Todd Arthur Cannon

David Lawrence Pease

William James Csongradi, Jr

Ryan James Schlichting

Mark Kenneth Hoffmeyer

Mark Owen Maxson

Benjamin A Fox

Paul Eric Dahlen

Ronald Leroy Billau

David Howard Allen

Raymond M Warner, Jr

Brian Gerard Holthaus

Kenneth A Van Goor

Darryl Solie

David Loren Heckmann

Ryan J Schliehting

Patrick Evarist Sobotta

An electronic system having a high speed signaling bus requiring training (calibration) of a calibrated item in a driver circuitry or a receiver circuitry for reliable operation. At manufacturing or in a secure location, secure calibration coefficients are determined for the electronic system and are stored in a non-volatile storage. During operation, the high speed signaling bus may be re-calibrated, resulting in a new currently active calibration coefficient for the calibrated item. A coefficient watchdog checks a new coefficient value selected by the re-calibration at present environmental conditions such as voltage and temperature against the secure calibration coefficients. If the new calibration coefficient value is the same as a calibration coefficient value in an acceptably close secure calibration coefficient, the new calibration coefficient is accepted; if not, a potentially probed warning is created by the coefficient watchdog.

Snoop detection on calibrated bus

An integrated circuit includes a first clock island, a second clock island, a clock generator, and a first programmable delay element. The first clock island is configured to receive a first clock signal. The second clock island is configured to receive a second clock signal. The clock generator is configured to provide a generated clock signal and the first and second clock signals are based on the generated clock signal. The first programmable delay element is coupled between the clock generator and the first clock island. The first programmable delay element is configured to receive the generated clock signal and provide the first clock signal. The integrated circuit is configured to account for a clock skew between the first and second clock signals when information is transferred between the first and second clock islands. In this manner, a predetermined amount of the clock skew may be introduced between the first and second clock signals to smear out, over time, instantaneous power supply current demands of respective logic within the first and second clock islands.

Power supply current spike reduction techniques for an integrated circuit

Methods, systems, and computer program products are disclosed for acquiring test data from an electronic circuit by mounting a probe adjacent to a capture point on an electronic circuit board, capturing by the probe an electronic signal of the electronic circuit, digitizing by the probe the captured signal, and transmitting by the probe the digitized signal from the probe through a data communications connection to a remote device. Acquiring test data from an electronic circuit also includes storing by the probe the digitized signal in the probe. Acquiring test data from an electronic circuit may include processing by the probe the digitized signal. Acquiring test data from an electronic circuit also may include synchronizing acquisition of test data by the probe with acquisition of test data by one or more other probes.

Acquiring test data from an electronic circuit

A chip-to-chip digital transmission circuit includes a differential driver portion, a pair of differential signal transmission lines connected to the driver portion, and a receiver portion connected to the transmission lines, an output node of which reproduces a digital bit stream originally presented to a driver side input node, wherein the transmission lines carry both transmitted signal information and DC power for the receiver portion. The driver portion is configured to adjust both the transmitted signal magnitude and the DC power delivered to the receiver portion.

Chip-to-chip digital transmission circuit delivering power over signal lines

A method and structures are provided for implementing customizable dielectric printed circuit card traces. A void is defined near selected signal traces. The void is then filled with a dielectric material having a predefined dielectric property. The dielectric material is selected to alter at least one predefined electrical property of the selected signal traces, such as, coupling, propagation delay and attenuation. In one embodiment, an outer layer of a printed circuit card includes a plurality of signal traces and a mating circuit card layer including a plurality of matching signal traces is attached to the outer layer of the printed circuit card to create a cavity near selected signal traces. The cavity is filled with the selected dielectric material. In another embodiment, dielectric material is selectively removed near signal traces on an outer layer of the printed circuit card to define a void near selected signal traces.

Method and structures for implementing customizable dielectric printed circuit card traces

A method, apparatus and computer program product are provided for implementing automated detection of excess aggressor shape capacitance coupling in printed circuit board layouts. A PCB design file containing an electronic representation of a printed circuit board design is received. A list of candidate shapes is identified. The candidate shapes are disposed on layers adjacent to aggressor planes. A capacitance coupling the candidate shapes to adjacent aggressor planes is calculated. A ratio of the calculated capacitance and a decoupling capacitance connecting the candidate shapes to a reference plane is determined. The PCB design file containing an electronic representation of a printed circuit board design includes shape data and text data that are extracted to produce a list of shapes' names, areas, locations and planes; and includes data defining thickness and relative permittivity of the dielectric layers used for calculating the effective capacitance is an inter-layer parallel-plate effective capacitance.

Method, apparatus and computer program product for implementing automated detection excess aggressor shape capacitance coupling in printed circuit board layouts

Methods are disclosed for quantitatively characterizing the accuracy of a simulated electrical circuit model. In particular, available circuit simulation programs make use of 'black box' models of transmission lines used to carry high-speed electrical signals. Electrical transmission lines are characterized by resistance, inductance, capacitance, and dielectric conductance, all values of which may vary with frequency. The 'black box' model must accurately model the transmission line over a wide range of frequencies in a time-domain simulation. Algorithms used in the &#x201c;black box&#x201d; model may not accurately model the transmission line over the frequency range. Such inaccuracies must be quantified, and if excessive, must be corrected.

Method for characterizing the accuracy of a simulated electrical circuit model

A method, apparatus, system, and signal-bearing medium that in an embodiment select a subset of transmission line models based on bounding electrical criteria. The bounding electrical criteria may include combinations of maximum and minimum values and in an embodiment may also include nominal values. Models that meet the bounding electrical criteria may be used in modeling the transmission line while models that do not meet the bounding electrical criteria are not used.

Transmission line bounding models

A digital logic circuit having multiple inputs and a product-of-sums output uses multi input OR circuits with interacting constant-current and constant-voltage elements to improve voltage transfer characteristics. A second-level arbitration circuit connects to the OR circuits and provides mutually exclusive pull-up and pull-down control signals as a logical function of the states of the OR circuits. An output stage connects to the arbitration circuit. The output stage comprises pull-up and pull-down drivers responsive to the output of the second-level arbitration circuit. The digital logic circuit operates at high speed because its transistors are prevented from entering saturation. The logic circuit is easily expandable and provides a simple and direct method of implementing logic circuits which provide product-of-sums outputs.

Multi-input compound function complementary noise-immune logic

A new family of memory cells and digital-logic gates use an enhancement-mode driver, a voltage-level shifter, and a current regulator to provide improved noise margins and large logic swings. The voltage-level shifter and the current regulator are connected in series between an input and the control electrode of the driver. The voltage-level shifter establishes a voltage drop which is independent of current, while the current regulator establishes a constant current in the series path to the control electrode which is independent of voltage. The driver is an enhancement-mode device, such as a JFET, MESFET, or BJT.

Growing community of inventors

Eau Claire, WI, United States of America

Roger John Gravrok