I have a couple of questions. I still haven't started working on the board yet. How exactly do you obtain the desired frequency using the NCO modes? and what is the ideal step-size that should be taken in the binary phase accumulators for obtaining desired frequency? also, what impact does the SPI frequency have on the desired output frequency and what's the relationship?

Additionally, which interpolation mode do you recommend i run to obtain highest possible frequency?

I am new to this field, please do help answer my questions. Thanks in advance.