Patent ID: 7623600

Claim:
A communications system comprising: an automatic gain control stage comprising: a variable gain amplifier configured to receive an input data signal having a first data rate and a control signal from an automatic gain control circuit, the variable gain amplifier being configured to amplify the input data signal based on the control signal to provide a gain adjusted signal to a continuous time filter; the continuous time filter coupled to the variable gain amplifier, the continuous time filter being configured to filter the gain adjusted signal to provide a filtered signal; and the automatic gain control circuit configured to receive the filtered signal and to provide the control signal to the variable gain amplifier based on the filtered signal; a decision feedback equalizer configured to receive the filtered signal and to generate equalized data signals based on the filtered signal, and wherein the decision feedback equalizer includes a retimer configured to generate recovered equalized data signals from the equalized data signals in response to an extracted clock signal; a clock and data recovery circuit coupled to the decision feedback equalizer, wherein the clock and data recovery circuit is configured to generate the extracted clock signal from at least a portion of the equalized data signals based on a delay adjust signal; a demultiplexer configured to demultiplex the recovered equalized data into a plurality of signals each having a data rate lower than the first data rate of the received signal; and an adaptation circuit coupled to the continuous time filter, the clock and data recovery circuit, and the decision feedback equalizer, the adaptation circuit being configured to adapt equalization in the communications system according to at least one dithering algorithm by adjusting the delay adjust signal in a same direction as a previous adjustment to the equalization if a mean square error of the equalized data signals decreases and adjusting the delay adjust signal in an opposite direction from the previous adjustment to the equalization if the mean square error of the equalized data signals increases.