Methods and apparatus are provided for determining the threshold position of one or more latches employed for decision-feedback equalization. A threshold position of a latch employed by a decision-feedback equalizer is determined by constraining input data such that the input data only contains transitions from a first binary value; obtaining a plurality of samples of a single-sided data eye associated with the constrained input data; and determining a threshold position of the latch based on the samples. The constrained input data can comprise (i) transitions from a binary value of 1 to a binary value of 0 or 1; or (ii) transitions from a binary value of 0 to a binary value of 0 or 1. The size of the single-sided data eye can be obtained by analyzing a histogram associated with the single-sided data eye to identify a region having a constant hit count.