Embodiments of the invention can be manifested as methods for converting analog waveforms into digital sampled signals. In at least one such embodiment, the method includes (i) sampling, based on a sampling-clock signal, an analog waveform received from a transmission channel to generate a digital sampled signal, (ii) generating a digital target signal by applying a specified reference data pattern to a model of the transmission channel, and (iii) adjusting the sampling-clock signal by comparing the digital sampled signal to the digital target signal. Embodiments of the invention can also be manifested as apparatuses that convert analog waveforms into digital sampled signals.