Digital equalizer adaptation using on-die instrument

Adaptation circuitry in an integrated circuit, said circuitry comprising:

• circuitry that identifies, based on a matrix representation of a receiver's output generated from horizontal and vertical sweeps of the receiver's output, an eye opening of the receiver's output;
• circuitry that determines whether a vertical height of the eye opening needs to be changed;
• and
• circuitry that, when it is determined that the vertical height of the eye opening needs to be changed, generates a digital signal to change an AC gain setting and a DC gain setting of the receiver.

A communications system comprising:

• a receiver having at least one amplifier;
• an on-die instrument (ODI) configured to sample an output of the receiver;
• a first digital adaptation unit configured to:
• analyze outputs of the ODI;
• control horizontal and vertical sweeps of the receiver's output that are used to generate a matrix representation of the receiver's output;
• and
• generate a first set of digital signals for adjusting a gain setting of at least one amplifier in the receiver;
• a decision feedback equalizer (DFE) configured to amplify the output of the receiver;
• and
• a clock-data recovery (CDR) unit coupled to an output of the DFE and configured to send data to the ODI.