Nvidia Corporation

Sunil Rao Sudhakaran

Gautam Bhatia

Rohit Rathi

Russell R Newcomb

Robert Bloemer

Yaping Zhou

Kyutaeg Oh

Don Templeton

Wenjun Shi

Russ Newcomb

Sheetal Jain

Jim Dobbins

John M Wilson

Vishnu Balan

Seema Kumar

Santhosh Kumar Gude

Daehyun Chung

Seunghyun Hwang

Baal Yang

Daniel Lin

First symbols are generated on a plurality of data channels by applying PAM-N encoding on a first subset of bits of a data burst, the first symbols generated without maximum transitions; second symbols are generated on at least one optionally-activated additional data channel, the second symbols generated by applying the PAM-N encoding on a second subset of bits of the data burst, the second symbols generated without maximum transitions; and third symbols are generated on a channel for communicating error correction bits for the first bits and second bits, the third symbols generated by applying hybrid PAM-N encoding on the error correction bits and a third subset of bits of the data burst, the hybrid PAM-N encoding comprising an interleaving of symbols with N voltage levels and symbols with less than N voltage levels.

Error detection pin encoding scheme to avoid maximum transitions and further improve signal integrity on high speed graphic memory interfaces

A transceiver configured to communicate a burst of data bits and meta-data bits for the data bits includes data channels, auxiliary data channels, and at least one error correction channel. The transceiver includes an encoder that applies 11b7s encoding to a first number of the data bits to generate first PAM-3 symbols on some or all of the communication channels, and that applies 3b2s encoding to a second number of the data bits to generate second PAM-3 symbols on at least some of the communication channels.

Hardware-efficient PAM-3 encoder and decoder

Data bits are encoded in one or both of an eleven bit seven pulse amplitude modulated three-level (PAM-3) symbol (11b7s) format and a three bit two symbol (3b2s) format on a plurality of data channels and on an error correction channel. One or more of a cyclic redundancy check (CRC) value, a poison value, and a severity value are encoded as 11b7s and/or 3b2s PAM-3 symbols on the error correction channel.

Data bits are encoded in one or both of an eleven bit seven pulse amplitude modulated three-level (PAM-3) symbol (11b7s) format and a three bit two symbol (3b2s) format on a plurality of data channels, one or more auxiliary data channels, and an error correction channel. One or more of a cyclic redundancy check (CRC) value, a poison value, and a severity value are encoded as 11b7s and/or 3b2s PAM-3 symbols on an error correction channel.

A system includes a transmitter to transmit a set of bits associated with signaling having one or more levels. The system includes a receiver coupled to the transmitter, the receiver to receive the set of bits and generate a first plurality of digital values, each digital value generated at a first timing value and a plurality of reference voltages, the reference voltage incremented based at least in part on generating a digital value of the first plurality of digital values. The receiver is to generate a second plurality of digital values at a second timing value and the plurality of reference voltages, the first timing value incremented to the second timing value based at least in part on generating the first plurality of digital values. The system includes a controller to determine an amplitude associated with each the first and second plurality of digital values.

On-chip virtual oscilloscope using high-speed receiver sampler readback

Various embodiments include a memory device that recovers from write errors and read errors more quickly relative to prior memory devices. Certain patterns of write data and read data may result on poor signal quality on the memory interface between memory controllers and memory devices. The disclosed memory device, synchronously with the memory controller, scrambles read data before transmitting the data to the memory controller and descrambles received from the memory controller. The scrambling and descrambling results in a different pattern on the memory interface even for the same read data or write data. Therefore, when a write operation or a read operation fails, and the operation is replayed, the pattern transmitted on the memory interface is different when the operation is replayed. As a result, the memory device more easily recovers from data patterns that cause poor signal quality on the memory interface.

Techniques for data scrambling on a memory interface

This disclosure provides a multi-layered printed circuit board (PC) that has signal array region. The signal array region has a width and circumscribes a power core region and has signal vias connected to respective signal ball pads, and ground vias connected to respective ground ball pads within the signal array region that have an associated ball pad pitch. The PCB also has an inner current power layer. The signal and ground vias are arranged on the component layer in a pattern and extend into the inner current layer. The pattern forms current power paths across the width of the signal array region, such that the current power paths have a width that is at least about 50% as wide as the ball pad pitch.

Via pattern for framebuffer interfaces

Techniques for limiting the growth of errors in decoded data words that arise from bit errors incurred during transmission. The growth of 3+ bit errors in the decoded data word is limited at the expense of a higher number of two bit errors, which are correctable using practical error correcting codes.

Codebook to reduce error growth arising from channel errors

Embodiments of the present invention reconstruct a waveform at a receiver-end of a channel from an observed waveform physically measured at a probe point near the middle of the channel, where the channel is corrupted by reflections. The channel may be a memory channel of a high-speed I/O interface, for example. Equations to derive the waveform may be created using linear network analysis and/or signal processing, for example. S-parameters may be derived from simulated models representing components from the probe point to the load. The s-parameters together with the load impedance are used to recreate the desired waveform free from corruption due to reflections.

Systematic methodology to remove reflections from I/O measurements

Systems and methods that facilitate resistance and capacitance balancing are presented. In one embodiment, a system comprises: a plurality of ground lines configured to ground components; and a plurality of signal bus lines interleaved with the plurality of ground lines, wherein the interleaving is configured so that plurality of signal bus lines and plurality of ground lines are substantially evenly spaced and the plurality of signal bus lines convey a respective plurality of signals have similar resistance and capacitance constants that are balanced. The plurality of signals can see a substantially equal amount ground surface and have similar amounts of capacitance. The plurality of signal bus lines can have similar cross sections and lengths with similar resistances. The plurality of signal bus lines interleaved with the plurality of ground lines can be included in a two copper layer interposer design with one redistribution layer (RDL).

Resistance and capacitance balancing systems and methods

An encoding process for bus data utilizes data from multiple data line groups on a multi-byte wide bus where each group has an associated DBI line. The process leverages the expanded encoding space for the multiple groups and associated multiple DBI bits. This process may be expanded to four bytes, eight bytes, etc.

Bus-invert coding with restricted hamming distance for multi-byte interfaces

In one embodiment, a system comprises: a plurality of aggressor bus lines; and a plurality of differential pair bus lines that are located in relatively parallel close proximity to the plurality of aggressor bus lines, wherein at least two of the plurality of differential pair bus lines change location with respect to each other at a point that has a cancelling affect on cross talk from the plurality of aggressor bus lines, wherein the change includes cross over routing. The plurality of differential pair bus lines can convey differential clock signals. The routing of the plurality of differential pair bus lines is substantially parallel to one another before and after the change.

Cross talk reduction differential cross over routing systems and methods

A circuit includes a splitter to extract L bits from each of a plurality of N-bit transmissions on a data bus, a decoder to generate output data comprising N-L bits of each N-bit transmission, and a delay circuit to apply the L bits for a previous transmission to control the inversion of a current transmission at the decoder.

Maximum transition avoidance (MTA) encoding

A PAM-4 communication process divides a full burst of raw data into two half bursts, extracts a bit from each half burst and communicating the extracted bit on a DBI line, and encodes the remaining bits of the half burst to avoid maximum transitions between PAM-4 symbols on a data line.

A memory driver, a method of driving a command bus for a synchronous dual data rate (sDDR) memory and a memory controller for controlling dynamic random-access memory (DRAM). In one embodiment, the memory driver includes: (1) pull-up and pull-down transistors couplable to a command bus of a memory controller and operable in 1N and 2N timing modes and (2) gear down offset circuitry coupled to the pull-up transistor and operable to offset the command bus when transitioning out of the 1N timing mode and increase an extent and duration of 1-0-1 transitions on the command bus.

Growing community of inventors

Brisbane, CA, United States of America

Sunil Rao Sudhakaran