The DDS can be programmed to a desired frequency f by loading a suitable frequency word. As described above a feed back circuits checks whether the frequencies are in the ratio 128 / 129. In appilications where the ratio is not 128 / 129, the feed back circuit can be disabled by sending the control word 0xCC and pulling the comp_reset signal low. The frequency words can then be loaded as given in the sampler program. The other control words and their fuctions are :
a.0xAA + comp_reset low - for resetting and loading the default frequencies to the DDSs;
b.0xAE + comp_reset low - to reset the DDSs alone.