My application, running on the mcf52254, includes motor speed control. To do so a rectified sine wave from the 60Hz line is fed into one of the ATDs for line synch. I also have a 32768Hz crystal connected to the RTC. I'm asking if anyone has connected the rectified sine wave to RTC_EXTAL and configured the RTC in the clock module for external oscillator rather than crystal. I don't know if the waveform is suitable for the RTC. If it worked it would reduce the component count, no issues with getting the RTC crystal going and be at least as accurate as most wall clocks.