Receiver/transmitter co-calibration of voltage levels in pulse amplitude modulation links

A multi-level pulse amplitude modulation (PAM) PAM-N transmitting device, comprising:

• a receiver interface circuit to receive distortion information from a PAM-N receiving device, the distortion information indicative of a level of non-linear distortion between N signal levels included in a first PAM-N signal where N is greater than 2 and is based on a combination of the PAM-N signal and a plurality of tap weights where each tap weight is an estimation of intersymbol interference (ISI) corresponding to the tap weight;
• and
• a driver control circuit to adjust one or more drive strength parameters of the driver circuit based on the distortion information;
• a driver circuit to transmit a second PAM-N signal via a communication channel to the PAM-N receiving device according to the adjusted one or more drive strength parameters.

A method, comprising:

• transmitting, by a driver circuit of a multi-level pulse amplitude modulation (PAM) PAM-N transmitting device, a PAM-N signal via a communication channel, wherein N is greater than 2, and the PAM-N signal has N signal levels;
• receiving, by a PAM-N receiving device, the PAM-N signal;
• generating, by the PAM-N receiving device, a plurality of tap weights where each tap weight is an estimation of intersymbol interference (ISI) corresponding to the tap weight;
• generating, by the PAM-N receiving device, distortion information indicative of a level of non-linear distortion between the N signal levels based on a combination of the PAM-N signal and the plurality of tap weights;
• transmitting, by the PAM-N receiving device to the PAM-N transmitting device, the distortion information indicative of the level of the non-linear distortion;
• receiving, by the PAM-N transmitting device, the distortion information;
• and
• adjusting, by the PAM-N transmitting device, one or more drive strength parameters of the driver circuit of the PAM-N transmitting device based on the distortion information.