I am using a Teensy with a default clock of 600MHz and am able to read and write to the registers of the AD7768 successfully. I am also able to read data from the ADC registers. However the readings are just noise. I have attached the probe output when reading data from the ADC output. The signals probed in order from top to bottom are Chip Select/Enable, Clock, MOSI, MISO, DRDY and SYNC_IN. I have scoured AD7768 discussion boards and similar issues with random data being read have been reported; but no solutions provided other than potential grounding problems. I did try working on grounding; but that didn't help.
FYI: When I use the DE-10 to stream data instead of the Teensy, I am getting meaningful data under the same conditions and default filter/register settings.