The device is compliant with the Intel AC'97 Rev 2.2 specification. It performs full-duplex 18-bit codec functions and supports variable sample rates from 8kHz to 48kHz with high signal to noise ratio. Analogue mixers are included to mix external analogue signals into the playback or record path. The WM9710 allows designers to easily integrate phone functions with other audio functions such as MP3 playback and voice recording. Mono inputs and outputs are provided to connect to an external voice codec. The on-chip headphone driver can distinguish between a stereo headphone and mono headset, and route the signals accordingly.