No output from eval board

Set muxout control in bottom right of software to Dvdd, see if you can observe high logic on board muxout test point with multimeter. Repeat but with muxout set to gnd and check for low. This confirms device is powered up and your serial interface is working.

If not then there could be some driver issue or a faulty board.

If this test works, then set muxout to N divider and R divider and connect a scope to muxout test point. You should observe pulses at the PFD frequency. N counter will have much smaller duty cycle. If these are present then device is likely okay, could be a problem with your loop filter. If nothing here then check your VCO and reference signals

The high and low logic is achieved. However, there is no reading from my scope when I change to N divider and R divider.  

Is the eval board stock, or did you make modifications e.g. to the loop filter? If it is a stock board then sounds like it could be faulty

I didn't make any modifications, the board is just new come out of its box

I didn't make any modifications, the board is just new come out of its box

Serial interface, and thus drivers must be working since you can communicate with the part. It is strange that device won't give any output from N counter or R counter so I think this is likely main device has been damaged at some point. Can you arrange a return/replacement through the supplier you purchased it from?

Thanks for your advice. I think I will return the product to check it.