Q1. How do I use three method , Initialization Latch, CE pin method and Counter reset method, separately ?
Q2. How long should I take the interval of times to program between one latch and another latch ?
There are 3 separate methods to initialise the ADF4106. Only one needs to be used, the choice of which one to use is your decision based on what is best for your application. We use the CE method on our evaluation boards. If you do not have access to a GPIO pin to toggle CE then the counter reset method can be used, but it requires an extra write.
Page 18 of the datasheet describes each method of initialization pretty well. Is there a step you are not sure about?
No delay required, except for when the CE method is used, in which case a delay of 1us is required after CE pin goes high