AD5934 - perform a basic measurement?


I'm having trouble trying to verify that the device is measuring correctly when I tell it to do so.

I tried to replicate the information from page 15 of 32 of the datasheet but I don't get the expected results whatever I try to do. I connected a 200k resistor from Vout to Vin in place of Zunknown and a 200k resistor from Vin to RFB. PGA I set to a gain of 1, Vout range is the 2Vp-p one, Vdd=3.3V, and signal frequency 30kHz. System clock is set to external, roughly 8MHz (not that it matters, setting to internal does not work, if I don't plug anything to MCLK I don't get any output signal on Vout). I kinda followed the flowchart of fig. 24, but what I managed to read is a value arround 19700 for the magnitude, and I've changed to higher value resistors but no significant change in readings.