A data processing circuit includes a subtraction circuit operable to subtract an ideal version of a data pattern from a sampled version of a data pattern to yield a difference signal, an error calculation circuit operable to calculate an error between the ideal version of the data pattern and the sampled version of the data pattern based on the difference signal, and a comparator circuit operable to compare the error with a threshold value and operable to assert a track refresh signal if the error is greater than the threshold value. The track refresh signal is operable to trigger a magnetic storage device to refresh data on a data track.