We are successfully working with an AD9176 in JESD mode 11, with main datapath interpolation set to 4, channelizer datapath interpolation set to 1, using the NCOs to mix an input frequency and output the upper sideband. This means that register 0x111 (interpolation setting) is set to value 0x41.
I would like to switch this on-the-fly to use raw data in real-only mode (dual-dac for now, so we do not have to switch JESD modes). After reading the datasheet for some time, it seems that this can be accomplished by setting register 0x111 to value 0x11 (which in table 13 seems to be permitted in JESD mode 11). So I do this, and my output waveform disappears. I am using a spectrum analyzer to view this waveform. It's like the DAC output has been completely disabled. Now, I set the register back to its previous value, 0x41. My output still appears to be completely disabled. So clearly more steps are needed to switch the interpolation and restart the data flow to the output of the DAC when changing interpolation values.
My question is: is there a simple way to do this (switch interpolation from (4,1) to (1,1) to bypass NCOs in JESD mode 11), or will it require something more complicated, like going through the entire register sequence as detailed in the "Start-Up Sequence" section of the datasheet?