I want to be able to use the phase register setting in an ADF4350. To be to get consistent phase settings, I need to take the N-divider input from the Output Divider. This works okay so long as the Output Divider is 2 or 1. When the Output Divider is >2, then the synthesizer becomes unlocked.
Monitoring the N-divider output from the MUX shows there is no output from the N-divider (see note below) when the Output Divider >2 and the N-divider is from the Output Divider.
Is there something wrong with being able to use the feedback from the output divider in some conditions?
To get the N-divider output from the MUX output function correctly, the registers must first be written in descending order with R2 MUX set to tri-state. Then re-write register 2 with MUX = N-divider output.