The WM9714L is a highly integrated input/output device designed for mobile computing and communications. The chip is architected for dual CODEC operation, supporting Hi-Fi stereo Codec functions via the AC link interface, and additionally supporting voice Codec functions via a PCM type Synchronous Serial Port (SSP). A third Aux DAC is provided which may be used to support generation of supervisory tones, or ring-tones etc. at different sample rates to the main codec.