Apparatus and Methods for Digital Adaptive Equalizer in Serial Receiver

摘要

Circuits and methods for performing adaptive frequency compensation in a serial receiver coupled to a differential signal channel link are disclosed. In an exemplary embodiment, a receiver for signals over a serial channel link is provided including a linear equalization function. A data recovery circuit is coupled to the output of the receiver and receives frequency compensated analog signals. A digital feedback control circuit observes the digital output. A data accumulator circuit receives the output of a comparator and a signal indicating the data pattern observed in the digital data output. A digital filter receives the accumulator data and outputs control signals for modifying the linear equalization in a feedback loop. The receiver and linear equalization function are automatically and adaptively modified to provide frequency compensation. Methods for adaptively modifying the frequency response of a receiver and linear equalizer using digital feedback are disclosed.