Read eye training

An integrated circuit, comprising:

• a receiver circuit having a slicer and decision feedback equalization (DFE) circuitry, the DFE circuitry having a DFE coefficient, the slicer having a reference voltage;
• and
• control circuitry configured to calibrate the DFE coefficient by:
• measuring, at a first sample timing and by varying the DFE coefficient, a first eye height while receiving a first data pattern;
• measuring, at the first sample timing by varying the DFE coefficient, a second eye height while receiving a second data pattern;
• and
• based on the first eye height and the second eye height, adjusting the DFE coefficient to a first setting.

A method of calibrating a decision feedback equalization (DFE) coefficient of a receiver, comprising:

• (a) finding a first sample timing of a slicer that corresponds to a first eye center;
• (b) providing a first data pattern and a second data pattern to an input of the receiver;
• (c) iteratively varying a reference voltage of the slicer and sweeping a value of the DFE coefficient to measure a plurality of first eye boundaries and a plurality of second eye boundaries corresponding to a plurality of reference voltage values;
• (d) based on the plurality of first eye boundaries and the plurality of second eye boundaries, determining a reference voltage value that maximizes a difference between a corresponding first eye boundary and second eye boundary;
• (e) while the receiver is using the reference voltage value that maximizes the difference between the corresponding first eye boundary and second eye boundary, finding a second sample timing of the slicer that corresponds to a second eye center;
• and
• (f) repeating steps (b) through (e) for a number of iterations.