The WM8778 is a stereo audio codec with a multi-bit Delta Sigma A/D converter featuring programmable gain with automatic level control. A stereo multi-bit Delta Sigma D/A converter is used with digital audio input word lengths from 16-32 bits and sampling rates from 32 kHz to 192 kHz. A multiplexor after the DAC allows the selection of either an external analog input or DAC playback into the line outputs. The IC supports fully independent sample rates for both the ADC and DAC, and the audio data interface supports I²S, left justified, right justified and DSP formats. The device is controlled in software via a two- or three-wire serial interface which provides access to all features including volume controls, mutes and de-emphasis facilities. It can also be controlled in hardware which gives access to the most commonly used features. Control interface selection is done via the MODE pin (tri-level).