An audio system bus has a bus data line and a bus clock line. Audio producers are coupled to the bus to form a time-division multiplexed multi drop bus interface arrangement having protocol slots 0, 1, . . . N where N is an integer greater than two. A bus device is coupled to the bus that produces a) a frame marker on the bus data line in slot 0, and b) a data bit on the bus data line in slot 1. The audio producers are to produce their respective audio data bits in their assigned slots other than slots 0 and 1. Other embodiments are also described and claimed.