Methods and circuits for adaptive equalization
AssigneeRambus Inc.
InventorRamin Farjad-Rad
Life of this patent
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Abstract
An integrated circuit equalizes a data signal expressed as a series of symbols. The symbols form data patterns with different frequency components. By considering these patterns, the integrated circuit can experiment with equalization settings specific to a subset of the frequency components, thereby finding an equalization control setting that optimizes equalization. Optimization can be accomplished by setting the equalizer to maximize symbol amplitude.
Claims20
A receiver that receives an input signal having a higher-frequency component and a lower-frequency component, the receiver comprising:
- an equalizer that amplifies the higher-frequency component by a higher-frequency amplification factor and the lower-frequency component by a lower-frequency amplification factor to produce an equalized symbol pattern;
- an amplitude detector that detects an amplitude of the equalized symbol pattern;
- a data filter to detect a first specified pattern in the equalized symbol pattern;
- and
- control logic coupled to the amplitude detector and the data filter, the control logic to update at least one of the higher-frequency amplification factor and the lower-frequency amplification factor in response to the amplitude of the equalized symbol pattern and the first specified pattern detected by the data filter.
A receiver that receives an input signal having a higher-frequency component and a lower-frequency component, the receiver comprising:
- an equalizer that amplifies the higher-frequency component by a higher-frequency amplification factor and the lower-frequency component by a lower-frequency amplification factor to produce an equalized symbol pattern;
- an amplitude detector that detects an amplitude of the equalized symbol pattern;
- a data filter to detect a first specified pattern in the equalized symbol pattern;
- and
- means for controlling the higher-frequency amplification factor relative to the lower-frequency amplification factor in response to the amplitude of the equalized symbol pattern and the first specified pattern detected by the data filter.
A method for sampling an input signal having a higher-frequency component and a lower-frequency component, the method comprising:
- amplifying the higher-frequency component by a higher-frequency amplification factor and the lower-frequency component by a lower-frequency amplification factor to produce an equalized symbol pattern;
- detecting an amplitude of the equalized symbol pattern;
- detecting a first specified pattern in the equalized symbol pattern;
- and
- controlling the higher-frequency amplification factor relative to the lower-frequency amplification factor in response to the amplitude of the equalized symbol pattern and the first specified pattern.
Dependencies are inferred from the claim text.