When configured as a DDS (TP_MIXER_MODE=0) the output of the DDS is intended to be the components of a unit vector. For TT_DATA = cfloat, this means that the outputs will be in the range -1.0 to +1.0. For TT_DATA = cint16 the output is scaled by 2 to the power 15 such that the binary point follows the most significant bit of the output. Therefore, if the DDS output is used to multiply/mix, you must account for this 15 bit shift.