The CS8405A is a monolithic CMOS device which encodes and transmits audio data according to the AES3, IEC60958, S/PDIF, or EIAJ CP1201. The CS8405A accepts audio and digital data, which is then multiplexed, encoded, and driven onto a cable. The audio data is input through a configurable, 3-wire input port. The channel status and user bit data are input through an SPI or IC microcontroller port, and may be assembled in block-sized buffers. For systems with no microcontroller, a standalone mode allows direct access to channel status and user bit data pins. Target applications include A/V Receivers, CD-R, DVD receivers, digital mixing consoles, effects processors, set-top boxes, and computer or automotive audio systems.