A feedback module is defined to receive as input a set of data sample signals and a set of reference sample signals. Each of the data and reference sample signals is generated by sampling a differential signal having been transmitted through a FIR filter. The feedback module is defined to operate a respective post cursor counter for each post cursor of the FIR filter and update the post cursor counters based on the received sets of data and reference sample signals. Also, the feedback module is defined to generate a tap weight adjustment signal for a given tap weight of the FIR filter when a magnitude of a post cursor counter corresponding to the given tap weight is greater than or equal to a threshold value. An adaptation module is defined to adapt a reference voltage used to generate the reference sample signals to a condition of the differential signal.