A system for determining a data converter operating mode including measurement circuitry operable to measure a master clock frequency by comparing a frequency of a master clock signal and a frequency of a fixed frequency clock signal and operable to measure a frequency ratio between a frequency of a...http://www.google.de/patents/US7049988?utm_source=gb-gplus-sharePatent US7049988 - Systems and methods for clock mode determination utilizing a fixed-frequency reference signal
