Cadence Design Systems, Inc.

Other

Westinghouse Electric Corporation

Thomas Evan Wilson

Eric Harris Naviasky

Hari Anand Ravi

Vinod Kumar

Sachin Ramesh Gugwad

Aaron Willey

Ling Chen

Moo Sung Chae

Hajee Mohammed Shuaeb Fazeel

H Md Shuaeb Fazeel

Fuyue Wang

Jianyun Zhang

Jitendra Kumar Yadav

Balbeer Rathor

Nikhil Sawarkar

Scott David Huss

James Halvis

Tara Vishin

Raksha

Timothy F Henricks

Various embodiments described herein provide for a read data strobe (RDQS) path having variation compensation (e.g., voltage and temperature compensation), delay lines, or both, where the RDQS path can be included by a physical (PHY) interface for a memory device, such as a Double Data Rate (DDR) Dynamic Random-Access Memory (DRAM) memory device.

Read data strobe path having variation compensation and delay lines

The present disclosure relates to dynamically updating a delay line code. A method for updating the delay line code may include receiving a strobe input at a coarse delay line. The method may further include receiving a coarse delay cell code at the coarse delay line. The method may also include generating a first clock path based upon a first chain of interleaved logic gates included within the coarse delay line. The method may additionally include generating a second clock path based upon a second chain of interleaved logic gates included within the coarse delay line. The method may further include receiving the first clock path, and the second clock path, and a fine delay cell code at a fine delay cell. The method may also include generating a strobe delayed output based upon the first clock path, and the second clock path, and the fine delay code.

Dynamically updated delay line

Various embodiments provide for a data sampler with built-in decision feedback equalization (DFE) and offset cancellation. For some embodiments, two or more data samplers described herein can be used to implement a data signal receiver circuit, which can use those two or more data samplers to facilitate half-rate or quarter-rate data sampling.

Sampler with built-in DFE and offset cancellation

Various aspects of the subject technology relate to systems, methods, and machine-readable media for DDR reference voltage training. The method includes receiving a data stream, the data stream including pulses generated from a reference voltage in relation to a voltage input logic low and a voltage input logic high of an input stream. The method also includes receiving a clock signal, the clock signal including an in-phase signal and a quadrature-phase signal, the in-phase signal orthogonal to the quadrature-phase signal. The method also includes utilizing the in-phase signal and the quadrature-phase signal of the clock signal in relation to the data stream to obtain a stream of in-phase samples and a stream of quadrature-phase samples. The method also includes adjusting the reference voltage based on a relationship of the stream of in-phase samples to the stream of quadrature-phase samples.

Reference voltage training scheme

Various embodiments provide for active suppression circuitry. The active suppression circuitry can be used with a circuit for a memory system, such as a dual data rate (DDR) memory system. For example, some embodiments provide an active suppression integrated circuit. The active suppression integrated circuit can be used by a memory system to efficiently suppress power supply noise caused by resonance of a power delivery network (PDN) of the memory system, thereby improving power integrity of the memory system input/output.

Active suppression circuitry

Disclosed is an improved approach for a training approach to implement DFE for an electronic circuit. The inventive concept is particularity suitable to address, for example, circuits that implement high speed parallel data transmission protocols, such as GDDR6, that are used for graphics applications. The training scheme uses minimal hardware when compared to existing schemes by reusing calibration receiver in auto zeroing receiver as error receiver. Further it works for closed eyes by running the algorithm multiple times with gradual increase in complexity of training pattern, where DFE coefficients from previous iteration is used for the current iteration, thereby gradually opening the eye.

Hardware efficient decision feedback equalization training

This disclosure relates to slew rate boosting for communication interfaces. A circuit can include a driver circuit coupled to an output node and configured to provide a data signal to the output node based on an input signal. The data signal can a similar logical state as the input signal. The circuit can include a signal transition boosting circuit coupled to the output node and configured to provide a boosting signal to the output node based on the input signal and a charge pump delay adjustment signal. The charge pump delay adjustment signal can define an amount of time after which the boosting signal is provided to the output node. The boosting signal can be provided to the output node to signal boost the data signal for the amount of time defined by the charge pump delay adjustment signal to provide a boosted data signal at the output node.

Slew rate boosting for communication interfaces

The embodiments described herein provide for a method and system for training an optimal decision feedback equalization (DFE) coefficient for use in GDDR and DDR applications. The method includes determining a first expected bit pattern using a reference voltage. The method further includes determining a transition voltage value of the first expected bit pattern. The method further includes receiving a second expected bit pattern having a same first bit as the first expected bit pattern. The method further includes determining a transition voltage value of the second expected bit pattern using the reference voltage. The method further includes calculating an optimal reference voltage value by averaging the transition voltage values of the first expected bit pattern and the second-expected bit pattern and storing the optimal reference voltage value in a register corresponding to a logic value of the same first bit.

Decision feedback equalization training scheme for GDDR applications

In some examples, a time-based equalizer can be configured to receive an input signal from a channel. The input signal can be distorted by previously received input signals transmitted over the channel. The time-based equalizer can be configured to compensate for distortions in the input signal caused by at least one previously received input signal to provide an ISI compensated input signal. The time-based equalizer can be configured to compensate for the distortions by edge time shifting respective edges of the input signal in time over a time interval for detecting the input signal to new edge time locations based on a feedback signal and edge movement signals. The feedback signal can be generated based on at least one previously received input signal.

Time-based decision feedback equalizer

Embodiments relate to systems, methods, and computer-readable media to enable design and creation of receiver circuitry. One embodiment is a receiver apparatus comprising a plurality of receiver arrangements, each receiver arrangement having a sampling circuit and a multi-stage differential amplifier connected to the sampling circuit. Each receiver arrangement is configurable via switches between an amplifying mode and an autozero mode. Control circuitry may select output data from a sampling circuit of one or more receiver arrangements that are not in autozero mode. In various embodiments, settings for individual receiver arrangements may be set based on decision feedback equalization (DFE).

High-speed low VT drift receiver

Implementations described herein relate to circuits and techniques increasing transmitter output speed. In some implementations, a circuit is described using a pull-up data path comprising a first flying capacitor, a first buffer, a thin-oxide PMOS device, and a thick-oxide PMOS device, a pull-down data path comprising a second flying capacitor, a second buffer, a thin-oxide NMOS device, and a thick-oxide NMOS device, wherein the pull-up data path and the pull-down data path are operatively connected to a core data output signal line.

Protocol compliant high-speed DDR transmitter

Embodiments described herein relate to circuits and techniques for interfacing a microprocessor with memory devices, particularly memory devices such as DDR SDRAM in accordance with protocols such as DDR4 and DDR5. Some embodiments particularly relate to a receiver architecture for a DDR memory interface device that provides AC coupling to memory and includes auto-zeroing functionality. These and other embodiments incorporate equalization functionality such as decision feedback equalization and continuous time linear equalization.

Auto-zeroing receiver for memory interface devices

Embodiments relate to systems, methods, and computer-readable media to enable design and creation of receiver circuitry. One embodiment is a receiver apparatus comprising a plurality of receiver arrangements, each receiver arrangement having a sampling circuit and a multi-stage differential amplifier connected to the sampling circuit. Each receiver arrangement is configurable via switches between an amplifying mode and an autozero mode. Control circuitry may select output data from receiver arrangements that are not in autozero mode using multiplexer circuitry. In various embodiments, settings for individual receiver arrangements may be set based on decision feedback equalization (DFE).

Aspects of the present disclosure include a dual path phase locked loop (PLL) circuit with a switched capacitor filter topology along with systems, method, devices, and other circuits related thereto. The dual path PLL circuit includes an integral path and a proportional path. Both the integral path and proportional path include a charge pump and a loop filter. The outputs of a phase frequency detector (PFD) are sent to both charge pumps. The output of the integral path charge pump is connected to a capacitor, and the voltage on capacitor is used as the integral path control voltage for a voltage-controlled oscillator (VCO). A switched capacitor network is connected to the output of the proportional path charge pump and used to generate the proportional path control voltage for the VCO. Together, the two control voltages dictate the VCO's output frequency.

Dual path phase-locked loop circuit

Aspects of the present disclosure include systems, methods, devices, and circuits for fast settling of a bias node. Consistent with some embodiments, a bias circuit may include a successive-approximation-register-analog-to-digital converter (SAR-ADC) based settling loop configured to perform a fast settling process for a heavily loaded bias node. The SAR-ADC based loop performs a SAR-ADC process that includes measuring a reference signal to determine a number of cells in a capacitor array that are involved in a charge sharing process while simultaneously completing the settling process for the bias node.

Growing community of inventors

Laurel, MD, United States of America

Thomas Evan Wilson