In my design I will adopt the AD9956 DDS to produce a set of fixed frequencies. I will use the DDS in Single-Tone Mode, and I am trying to keep as fast as possible the operating frequency switching time.
In the beginning my idea was to write the new FTW in the register PCR0 every time I need to change frequency; considering a 25Mb/sec write-speed and a 64bit long register, it would take me about 2.56usec. Am I correct?
Since the DDS has 8 different frequency profiles, is it possible to configure each profile with a different FTW (FTW0, ...., FTW7) and only switching the profile select pins (pin 21 to 23) in order to change the DDS operating frequency instead of writing the register? Will this procedure save time?
How fast is this frequency profiles switching?
Thank you for your support.