Digital data transfer in a digital television receiver between an internal central processing unit, or an external computer, and the video/audio processing circuitry by way of an internal bus is accomplished efficiently and without producing noise interference by using a high-frequency clock signal and a relatively low-frequency clock signal at different times. The high-frequency signal would normally produce visually perceptable noise, however, it is employed only during vertical blanking intervals, and the low-frequency clock signal, which would not produce visually perceptable noise, is used at all times other than the vertical blanking intervals, whereby noise interference that would be otherwise seen on the visual display of the television receiver is suppressed.