I have a DAC37J84 running with Fs at 984MHz. I need to generate a 400Mhz carrier. I can do this just fine using the coarse mixer of the DAC with FS/2 (and inputting a carrier at -92MHz), but when I try to use the NCO it does not really work.
I'm setting DAC config reg 13 to 0d0000 (no coarse mix), reg 2 to 022052 (use mixer and nco enable). Also am setting reg 20,21, and 22 to 14ba68, 15a681, and 166810. Is there something else I need to set too?
SPI readbacks indicate these registers are correctly setup.