Abstract: In described embodiments, a transceiver includes a clock and data recovery module (CDR) with an eye monitor and a cycle slip monitor. The cycle slip detector monitors a CDR lock condition, which might be through detection of slips in sampling and/or transition timing detection. The cycle slip detector provides a check point to sense system divergence, allowing for a mechanism to recover CDR lock. In addition, when the CDR is out-of-lock, the various parameters that are adaptively set (e.g., equalizer parameters) might be invalid during system divergence. Consequently, these parameters might be declared invalid by the system and not used.

Abstract: In described embodiments, a transceiver includes an eye monitor and margin detector having one or more samplers with corresponding logic. One or more programmable provisioning parameters are defined based on a pre-defined minimum target operating margin for acceptable noise and jitter margins. For example, two programmable provisioning parameters, phase and voltage, correspond with thresholds for margin samplers placed within the eye. Initially, the transceiver applies equalization, after which an inner eye of the transceiver, as detected by the eye monitor, is relatively open with some margin for supporting channels. If the receiver margin goes below this target margin, the eye closes, which is registered by the samplers. In the presence of spectrally rich input data, if the receiver margin goes below this target margin, an updated adaptation of equalizer or other circuit parameters might be initiated; else, adaptation is not generally required.

Abstract: Methods and apparatus are provided for decision-feedback equalization with an oversampled phase detector. A method is provided for detecting data in a receiver employing decision-feedback equalization. A received signal is sampled using a data clock and a transition clock to generate a data sample signal and a transition sample signal. A DFE correction is obtained for each of the data sample and transition sample signals to generate DFE detected data and DFE transition data. One or more coefficients used for the DFE correction for the transition sample signals are adapted using the DFE transition data.

Abstract: Disclosed is a method and system that adapts coefficients of taps of a Finite Impulse Response (FIR) filter to increase elimination of Inter-Symbol Interference (ISI) introduced into a digital communications signal due to distortion characteristics caused by a real-world communications channel. In the communications system there is a Finite Impulse Response (FIR) filter. The FIR filter has at least one pre and/or post cursor tap that removes pre and/or post cursor ISI from the signal, respectively. The pre/post cursor taps each have pre/post cursor coefficients, respectively, that adjusts the effect of the pre/post cursor portion of the FIR filter. The FIR filtered signal is transmitted over the channel which distorts the signal due to the changing and/or static distortion characteristics of the channel. The channel distorted signal is received at a receiver that may pass the channel distorted signal through a quantifier/decision system (e.g.