Electronic devices including equalizers operating based on coefficients adjusted in training operations

An electronic device includes a reception equalizer that performs, a first equalization on a first signal based on a first coefficient, and one or more second equalizations on one or more second signals based on the first coefficient, the one or more second signals being based on a second coefficient associated with one or more characteristics of a transmission equalizer of the external device, and circuitry that iteratively sends control information generated based on the first coefficient to the external device until a termination condition is satisfied with regard to the first coefficient, the control information causing the second coefficient to be increased or decreased, the iteratively sent control information causing a first absolute value of the first coefficient corresponding to a final equalization of the one or more second equalizations to become smaller than a second absolute value of the first coefficient corresponding to the first equalization.