As shown in FIG. 7, a data receiver receives video data and audio data together with a frequency division parameter N that depends on the pixel clock of the video data and the sampling frequency of the audio data, and a count value CTS that is obtained by counting the period of the audio clock that has been subjected to frequency division by the frequency division parameter N, with the pixel clock, which are transmitted from a data transmitter, and subjects the pixel clock to frequency division by the count value CTS, phase-control the divided clock (s501) in accordance with a phase comparison clock (s505) that is obtained by dividing an audio clock (s403) oscillated from a VCO (504) by the frequency division parameter N, thereby generating an audio clock (s403).Accordingly, the data transmitter and the data receiver can satisfactorily implement multiplexing of audio data and video data, and transmission of the multiplexed data using an existing DVI cable, with a simple structure.