In described embodiments, filter parameters for a filter applied to a signal in, for example, a Serializer/De-serializer (SerDes) receiver and/or transmitter are generated based on real-time monitoring of a data eye. The real-time eye monitor monitors data eye characteristics of the signal present in a data path, the data path applying the filter to the signal. The eye monitor generates eye statistics from the monitored data eye characteristics and an adaptive controller generates a set of parameters for the filter of the data path for statistical calibration of the data eye, wherein the eye monitor continuously monitors the data eye and the adaptive controller continuously generates the set of parameters based on the eye statistics.

Real-time eye monitor for statistical filter parameter calibration

System, methods, and devices for determining an eye diagram of a serial input signal to an integrated circuit without an oscilloscope are provided. For example, one embodiment of an integrated circuit device may be capable of determining an eye diagram associated with a serial input signal either during or after equalization. The device may include an equalizer and eye viewer circuitry configured to select a node of the equalizer for eye monitoring of the input signal, which may be during or after equalization. In one embodiment, the eye viewer circuitry may provide a separate sampler for each respective node, while sharing a control logic and phase interpolator among the samplers. The eye viewer circuitry may determine horizontal and vertical boundaries of the eye diagram associated with the serial input signal, as seen from the selected node of the equalizer.

On-chip eye viewer architecture for highspeed transceivers

A method and a system for accurately calculating the timing margin in a clock and data recovery system (CDR) is provided that utilizes a singular path environment of hardware. The method entails adding an amount of jitter within the CDR to change the receiver phase. The amount of jitter is incrementally increased until a threshold level of bit errors occur. Based on the amount of jitter needed to cause the threshold level of bit errors, timing margin can be calculated.

Apparatus and Method to Measure Timing Margin in Clock and Data Recovery System Utilizing a Jitter Stressor

A method of analyzing a phase of a clock signal for receiving data is described. The method comprises identifying an end of an eye pattern associated with received data; testing points along a contour of the eye pattern to establish a margin for an opening of the eye pattern; and determining whether a phase of the clock signal is acceptable for receiving the received data. A circuit for analyzing a phase of a clock signal for receiving data is also described.

Methods of and circuits for analyzing a phase of a clock signal for receiving data

An adaptive equalizer for high-speed serial data comprises a programmable equalizer for equalizing an input serial data signal to generate an equalized serial data signal, wherein the equalization is based on an optimal equalization mode; a signal quality meter for computing an eye width indication based on the equalized serial data signal, wherein the eye width indication is an indicative of the quality of the equalized serial data signal; and a decision unit for determining the optimal equalization mode based on the eye width indication.

Adaptive equalizer for high-speed serial data

A system including a filter circuit, an error module, and a measurement module. The filter circuit receives, from a network device, an analog signal having jitter, generates an equalized signal based on digital feedback signals and the analog signal, and generates a recovered data signal based on the equalized signal. The recovered data signal includes data transmitted by the network device to the system. The error module generates an error signal based on the equalized signal and a threshold signal. The measurement module generates a multiple signals based on the recovered data signal, and the error signal. The multiple signals include the digital feedback signals and eye characteristic signals. The eye characteristic signals indicate characteristics of an eye diagram of the recovered data signal. The measurement module generates the digital feedback signals such that the eye diagram of the recovered data signal does not include the jitter.

Non-intrusive eye monitor system

A receiver including recovery, error, and control modules. The recovery module: receives a data signal and an offset value; based on a coefficient, equalizes the data signal to generate an equalized signal; and generates a recovered signal based on the equalized signal. The recovered signal includes data recovered by the recovery module. The error module generates an error value based on a difference between the equalized signal and a threshold. The control module, based on the offset value, the recovered signal, and the error value: generates the coefficient; determines the threshold; and determines a characteristic of an eye diagram of the recovered signal. The recovered signal has a non-repeating pattern such that overlaid traces of the recovered signal are in a shape of an eye and provide the eye diagram. The overlaid traces include jitter. The control module generates the coefficient to reduce an amount of the jitter.

William Lo

Papers

Non-intrusive eye monitor system

Method and apparatus for reducing jitter in overlaid traces of an eye diagram of a recovered signal generated based on a received data signal