AD9910 antibacklash pulse width control

Hi Engineerzone,

I've used the AD9910 for a while now, in its evaluation board and also successfully incorporated into my system.

My question is about the PFD antibacklash pulse width control. In the evaluation board software, we have a dropdown choice of integers which modify the second lowest byte value of control function register 3 at address 0x02. However, the datasheet makes no mention of the details of these bits, merely listing them as Open (in Table 20). Can Analog Device elucidate the details as to what the choices of 0,1,2,3 actually correspond to please ?

Thanks