1. A method of supplying tap weights to taps of a decision feedback equalizer comprising: determining a channel impulse response of a channel through which the decision feedback equalizer receives a signal; determining constrained tap weights based on the channel impulse response and a differentiable tap weight constraint function, wherein the differentiable tap weight constraint function is an approximation of a non-differentiable tap weight constraint function; and, supplying the constrained tap weights to the decision feedback equalizer.