Nvidia Corporation

Rambus Inc.

The University of North Carolina at Chapel Hill

Stephen G Tell

William James Dally

John Wood Poulton

Nikola Nedovic

Carl Thomas Gray

Sudhir Shrikantha Kudva

Robert E Palmer

John M Wilson

Sanquan Song

Thomas H Greer, Iii

Xi Chen

Scott C Best

Brucek Kurdo Khailany

Rangharajan Venkatesan

Matthew Rudolph Fojtik

A glitch detection device includes an oscillator to generate multiple local clocks of multiple different phases and a sampling circuit to oversample, using the multiple local clocks, a system clock to generate multiple samples of the system clock. The device further includes a glitch detector to monitor a variation in pulse width of the system clock based on counting the multiple samples and to report a glitch in response to detecting a variation in the pulse width that exceeds a threshold value.

Frequency-locked and phase-locked loop-based clock glitch detection for security

Neural networks, in many cases, include convolution layers that are configured to perform many convolution operations that require multiplication and addition operations. Compared with performing multiplication on integer, fixed-point, or floating-point format values, performing multiplication on logarithmic format values is straightforward and energy efficient as the exponents are simply added. However, performing addition on logarithmic format values is more complex. Conventionally, addition is performed by converting the logarithmic format values to integers, computing the sum, and then converting the sum back into the logarithmic format. Instead, logarithmic format values may be added by decomposing the exponents into separate quotient and remainder components, sorting the quotient components based on the remainder components, summing the sorted quotient components using an asynchronous accumulator to produce partial sums, and multiplying the partial sums by the remainder components to produce a sum. The sum may then be converted back into the logarithmic format.

Asynchronous accumulator using logarithmic-based arithmetic

A glitch detection device includes an oscillator to generate multiple local clocks of multiple different phases and a sampling circuit to oversample, using the multiple local clocks, a system clock to generate multiple samples of the system clock. The device further includes digital logic that in turn includes a glitch detector to monitor a variation in pulse width of the system clock based on counting the multiple samples and to report a glitch in response to detecting a variation in the pulse width that exceeds a threshold value. The digital logic further includes a loop filter coupled between the glitch detector and the oscillator. The loop filter variably adjusts the oscillator based on a frequency of each of the multiple samples to control an output frequency of each of the multiple different phases of the oscillator.

A circuit includes a set of multiple bit generating cells. One or more adjustable characterization circuits are coupled to inputs to the bit generating cells to affect the outputs of the bit generating cells. Based on the effect of the characterization circuit(s) on the outputs of the bit generating cells, a subset less than all of the bit generating cells is selected.

Detection and mitigation of unstable cells in unclonable cell array

A circuit interface includes one or more processors that generate opcodes, a plurality of interface control circuits, each including a respective processing element responsive to the opcodes generated by one or more processors. Each interface control circuit corresponds to a respective link of a plurality of links of a device-to-device interface (DDI), and each link of the plurality of links of the DDI is for transmitting or receiving signals from one or more sources or one or more destinations external to the circuit.

Memory controller with processor for generating interface adjustment signals

This disclosure relates to a circuit comprising a first, second, and third data latch, and an input for a data signal. The first data latch may be configured to sample a delayed version of the data signal in response to a first control signal. The second data latch may be configured to sample the delayed version of the data signal in response to a run clock signal. The run clock signal may be configured to run for a predefined number of clock cycles subsequent to the first control signal. The third data latch may be configured to sample either an output signal of the first data latch or an output signal of the second data latch in response to a second control signal received after the predefined number of clock cycles of the run clock signal.

Signal calibration circuit

A receiver circuit includes a clock lane propagating a clock signal. A self-sampled clock applies a delayed version of the clock signal to the clock signal and compensation logic controls an amount of delay of the delayed version of the clock, based on a reference voltage offset (difference) between the receiver and a transmitter. The delayed version of the clock is centered on one unit interval of the clock. An offset correction based on a clock duty cycle error is applied to data receiver front ends.

Reference noise compensation for single-ended signaling

A receiver circuit includes a clock lane propagating a clock signal. A self-sampled clock applies a delayed version of the clock signal to the clock signal and compensation logic controls an amount of delay of the delayed version of the clock, based on a reference voltage offset (difference) between the receiver and a transmitter. The delayed version of the clock is centered on one unit interval of the clock. An offset correction is computed as a global offset value based on a clock duty cycle error, combined with a local offset value for each data lane, and is applied to data receiver front ends.

Described are a system and method to control interface timing and/or voltage operations of signals transmitted between devices. A processor may be coupled through one or more bus interfaces of a bus to one or more corresponding interface timing and/or voltage comparison circuits and corresponding interface timing and/or voltage adjustment circuits.

A circuit, method, and system are disclosed for sampling a signal. The system includes a sampler circuit configured to sample input signals when a clock signal is at a first voltage level to produce sampled signals, a detection circuit that is coupled to the sampler circuit, and a feedback circuit that receives an output signal and generates the clock signal. The detection circuit pre-charges the sampled signals when the clock signal is at a second voltage level and, using threshold adjusted inverters, detects voltage levels of each sampled signal to produce detected voltage levels, where a threshold voltage of the threshold adjusted inverters is entirely outside of a transition voltage range of the sampler circuit. In response to one of the detected voltage levels transitioning from the second level to the first level, the detection circuit transitions the output signal from the first voltage level to the second voltage level.

Self-clocking sampler with reduced metastability

A circuit, method, and system are disclosed for sampling a signal. The system includes a sampler circuit configured to sample input signals when a clock signal is at a first level to produce sampled signals, a detection circuit that is coupled to the sampler circuit, and a feedback circuit that receives an output signal and generates the clock signal. The detection circuit pre-charges the sampled signals when the clock signal is at a second level and, using threshold adjusted inverters, detects voltage levels of each sampled signal to produce detected voltage level signals, where a threshold voltage of the threshold adjusted inverters is entirely outside of a transition voltage range of the sampler circuit. In response to one of the detected voltage level signals transitioning from the second level to the first level, the detection circuit transitions the output signal from the first level to the second level.

A method and a system are provided for speculative periodic synchronization. A phase value representing a measured phase of the second clock signal relative to the first clock signal measured at least one cycle earlier is received. A period value representing a period of the second clock signal relative to the first clock signal measured at least one cycle earlier is also received. A reduced timing margin is determined based on the phase value and the period value. A speculatively synchronized output signal is generated based on the reduced timing margin.

Periodic synchronizer using a reduced timing margin to generate a speculative synchronized output signal that is either validated or recalled

A method and a system are provided for clock phase detection. A set of delayed versions of a first clock signal is generated. The set of delayed versions of the first clock is used to sample a second clock signal, producing a sequence of samples in a domain corresponding to the first clock signal. At least one edge indication is located within the sequence of samples.

Growing community of inventors

Chapel Hill, NC, United States of America

Stephen G Tell