Rambus Inc.

Intel Corporation

Lsi Corporation

Yikui Jen Dong

Masum Hossain

Nhat M Nguyen

Arash Zargaran-Yazd

Wendemagegnehu Beyene

Shenggao Li

Freeman Yingquan Zhong

Amaresh Virupanagouda Malipatil

Chaitanya Palusa

Tai Jing

Hollis H Poche, Jr

Venkata Naga Jyothi Madhavapeddy

Some embodiments include an encoder to convert a thermometer code into a binary code output information or a Gray code output information. The encoder supports blind input swapping, such that it provides correct output information without prior knowledge of the input swapping. Some embodiments also include a truth table that has additional rows to describe output information when input information at inputs of the encoder is swapped. The encoder includes symmetrical logic functions with respect to information at its inputs as building blocks.

Self-organized encoder architectures including blind input swapping support

Decision feedback equalization (DFE) is used to help reduce inter-symbol interference (ISI) from a data signal received via a band-limited (or otherwise non-ideal) channel. A first PAM-4 DFE architecture has low latency from the output of the samplers to the application of the first DFE tap feedback to the input signal. This is accomplished by not decoding the sampler outputs in order to generate the feedback signal for the first DFE tap. Rather, weighted versions of the raw sampler outputs are applied directly to the input signal without further analog or digital processing. Additional PAM-4 DFE architectures use the current symbol in addition to previous symbol(s) to determine the DFE feedback signal. Another architecture transmits PAM-4 signaling using non-uniform pre-emphasis. The non-uniform pre-emphasis allows a speculative DFE receiver to resolve the transmitted PAM-4 signals with fewer comparators/samplers.

PAM-4 DFE architectures with symbol-transition dependent DFE tap values

Some embodiments include apparatus having multiple samplers in a decision feedback equalizer (DFE). The multiple samplers include at least two samplers and are configured to be activated in a first mode of the DFE to receive first input information from a summing circuit. At least one of the samplers is configured to be deactivated in a second mode of the DFE. At least one of the samplers is configured to be activated in the second mode of the DFE to receive second input information from the summing circuit.

Multi pulse amplitude modulation signaling decision feedback equalizer having power differentiating modes and tap-weight re-configuration

A transmitting device includes an output node, at least one driver circuit and transition equalization circuitry. The driver circuit drives an output data signal including a data transition onto the output node. The output of the transition equalization circuitry is coupled to the output node. The transition equalization circuitry begins to drive the output node at the data transition and ends driving of the output node a pre-determined delay after beginning to drive the output node. The transition equalization circuitry drives the output node by injecting current onto the output node if the data transition is a positive transition, and sinking current from the output node if the data transition is a negative transition.

Transmitter with self-triggered transition equalizer

Embodiments include apparatuses, methods, and systems including a decision feedback equalizer (DFE). The DFE includes a first summer circuit, a second summer circuit, a decision circuit, and a tap-delay line including a number of delay elements. The first summer circuit is to add together an analog signal and a first set of weighted feedback taps {h(j+1), . . . h(m)} of time delayed signals of a detected symbol to generate a first summand. The second summer circuit is to add together a second set of weighted feedback taps {h(k+1), h(n)} of time delayed signals of the detected symbol to generate a second summand. The decision circuit is to receive at least the first summand and the second summand, to generate the detected symbol based on a sum including the first summand and the second summand. Other embodiments may also be described and claimed.

Multi-tap decision feedback equalizer (DFE) architecture with split-path summer circuits

A receiver serial data streams generates a local timing reference clock from an approximate frequency reference clock by phase-aligning the local clock to transitions in the data stream. This process is commonly known as clock and data recovery (CDR). Certain transitions of the data signals are selected for use in phase-aligning the local clock, and certain transitions are ignored. Phase-error signals from multiple receivers receiving the multiple serial data streams are combined and used to make common phase adjustments to the frequency reference clock. These common adjustments track jitter that is common to the received data streams. Local adjustments that better align each respective local clock to the transitions of its respective serial data stream are made using a local phase-error signal. These local adjustments track jitter that is more unique to each of the respective serial data streams.

Collaborative clock and data recovery

An on-chip AC coupled receiver with offset calibration. The receiver includes AC coupling circuitry to couple a differential input signal into a coupled differential signal having a first signal and a second signal. The receiver includes a first comparator to generate a first error signal indicative of whether a first reference signal is greater or smaller than a signal derived from the coupled differential signal. The receiver includes a second comparator to generate a second error signal indicative of whether a second reference signal is greater or smaller than the signal derived from the coupled differential signal. The receiver further includes feedback circuitry to adjust a voltage offset between the first signal and the second signal of the coupled differential signal based on the first error signal and the second error signal.

Receiver with offset calibration

An on-chip AC coupled receiver with baseline wander compensation. The receiver may be used for either single ended or differential signals. The receiver includes an input terminal to receive an input signal. AC coupling circuitry is between the input terminal and a node and couples the input signal into a coupled signal at the node. A control loop senses low frequency signal content at the node and uses a linear buffer in adjusting the coupled signal at the node based on the low frequency signal content. The operation of the control loop compensates for potential baseline wander in the coupled signal. An input stage to recovers data from the coupled signal at the node.

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Cupertino, CA, United States of America

Yikui Jen Dong