A system (10) for converting streaming digital data to frequency modulated data includes a digital decoder (12) providing content and associated data, a system controller (14) for formatting the associated data into frequency modulated sub-carrier data, and a frequency modulator (20) for modulating (24) the content and combining (25) the modulated content with a buffered version of the frequency modulated sub-carrier data. The streaming digital data can come from a satellite digital audio radio system receiver and the associated data can include at least one among a channel name, a channel number, an artist name, a song title, and traffic information. The system controller can format the associated data into an RDS Message format. The frequency modulator can include an RDS physical layer (32) and an RDS data link layer (30) that can generate a checksum. The frequency modulator can also include a register or buffer (28).