Optimized continuous time linear equalization (CTLE) circuit parameters for a received signal are found using an iterative search process. The received signal is repeatedly sampled by an analog-to-digital converter (ADC). Certain samples containing interference that cannot be cancelled by a CTLE in the sampled series are filtered out (discarded). The remaining samples are used to generate, over a selected evaluation window, a histogram of the sampled values. This histogram is used to calculate a figure of merit for the current CTLE parameter settings. The figures of merit for various CTLE parameter settings are compared to find the set of CTLE parameter settings that optimize the figure of merit and by extension, optimize the CTLE circuitry's performance at equalizing the received signal.

Embodiments provide a data sampling circuit and a data sampling device. The sampling circuit includes: a first sampling module configured to respond to a signal from a data signal terminal and a signal from a reference signal terminal and to act on a first node and a second node; a second sampling module configured to respond to a signal from the first node and a signal from the second node and to act on a third node and a fourth node; a latch module configured to input a high level signal to a first output terminal and input a low level signal to a second output terminal or input the low level signal to the first output terminal and input the high level signal to the second output terminal according to a signal from the third node and a signal from the fourth node; and a decision feedback equalization module.

An optical module configured to electrically connect to a host. A linear equalizer performs equalization on a host equalized signal to create a module equalized signal, and a driver configured to present the module equalized signal from the linear equalizer to an optical conversion device at a magnitude suitable for the optical conversion device. An optical conversion device receives the module equalized signal from the driver, converts the module equalized signal to an optical signal, and transmit the optical signal over an optical channel. Also part of the optical module is an interface which communicates supplemental equalizer settings to the host. A memory stores the supplemental equalizer settings which reflect the optical modules effect on a signal passing through the optical module. A controller oversees communication of the supplemental equalizer settings to the host such that the host uses the supplemental equalizer settings to modify host equalizer settings.

Methods and systems are described for generating a time-varying information signal at an output of a continuous time linear equalizer (CTLE), asynchronously sampling a data signal according to a sampling clock having a frequency less than a data rate of the data signal; generating corresponding pattern-verified samples for at least two data patterns, each of the at least two data patterns having a respective frequency content; determining corresponding frequency-specific voltage measurements associated with each of the at least two data patterns based on the corresponding pattern-verified samples of the at least two data patterns; and adjusting an equalization of the data signal based on a comparison of the corresponding frequency-specific voltage measurements.

A CTLE-based SERDES receiver circuit using ISI metering provides an improved SERDES I/O performance. The CTLE SERDES receiver circuit may include an analog receiver frontend to generate an analog-to-digital converter (ADC) digital signal and a reduced ISI signal, a data path circuit to generate a sliced data stream and sliced cursor error stream, a digital signal processing (DSP) circuit to generate a converged data stream, a multi-tap intersymbol interference (ISI) assessment circuit to generate a weighted ISI sum, and an ISI minimization circuit to generate a continuous time linear equalizer (CTLE) adaptation control signal based on the weighted ISI sum.

An Automatic Gain Control (AGC) SERDES circuit may be used to provide improved gain control for SERDES operation. This AGC SERDES circuit uses an initial gain convergence to determine and store an initial gain level. Once the initial gain convergence is complete, the AGC SERDES circuit uses a signal peak tracking to reduce or prevent saturation events. By setting the gain target based on tracked changes in the equalizer coefficients, the AGC SERDES circuit adapts the gain target to reduce or prevent saturation events and provide the improved communication throughput. A SERDES receiver circuit also provides improved performance using an improved convergence flow within its subcomponent blocks. The improved convergence flow also provides the ability to track environmental changes, voltage changes, and changes to input parameters, and can be performed while data is running on the link to provide continuously improved communication channel performance.

Some examples described herein provide for an integrated circuit including a continuous time linear equalizer (CTLE) circuit and a method of operating the integrated circuit. In an example, an integrated circuit includes a transconductance amplifier stage and a transimpedance amplifier stage. The transconductance amplifier stage has a first input node and a first output node. The transconductance amplifier stage includes a first complementary device inverter. The transimpedance amplifier stage has a second input node and a second output node. The first output node is electrically connected to the second input node. The transimpedance amplifier stage includes a second complementary device inverter.

An equalization training method and apparatus are described. The method includes obtaining a training rate of each of a master chip and a slave chip in a target phase of equalization training. The method also includes determining a target rate threshold interval within which the training rate in the target phase falls, determining, based on a correspondence between N+1 rate threshold intervals and N+1 equalization timeout periods, a target equalization timeout period corresponding to the target rate threshold interval, and configuring the target equalization timeout period as an equalization timeout period in the target phase. According to this method, an equalization timeout period used for equalization training can be flexibly configured for each equalization training process, so that the configured equalization timeout period better conforms to a training rate currently used for link negotiation, to better ensure that an equalization parameter is found within the configured equalization timeout period, thereby improving an equalization training success rate.

A receiver includes a continuous-time equalizer, a decision-feedback equalizer (DFE), data and error sampling logic, and an adaptation engine. The receiver corrects for inter-symbol interference (ISI) associated with the most recent data symbol (first post cursor ISI) by establishing appropriate equalization settings for the continuous-time equalizer based upon a measure of the first-post-cursor ISI.

Transmission of baseband and carrier-modulated vector codewords, using a plurality of encoders, each encoder configured to receive information bits and to generate a set of baseband-encoded symbols representing a vector codeword; one or more modulation circuits, each modulation circuit configured to operate on a corresponding set of baseband-encoded symbols, and using a respective unique carrier frequency, to generate a set of carrier-modulated encoded symbols; and, a summation circuit configured to generate a set of wire-specific outputs, each wire-specific output representing a sum of respective symbols of the carrier-modulated encoded symbols and at least one set of baseband-encoded symbols.