A system can be configured to control an equalizer circuit to equalize a data signal without requiring prior knowledge of the data signal's data rate. In an example, the system includes an equalizer circuit configured to equalize a data signal based on an equalizer control signal to produce an equalized signal, and a pattern detector configured to detect a specified data pattern in the equalized signal at each of multiple sampling rates. A control circuit can be configured to generate a preferred equalization control signal based on a sampling rate, selected from the multiple sampling rates, at which the pattern detector detects the specified data pattern in the equalized signal.