The WM8944 is a highly integrated low power hi-fi codec designed for portable devices such as digital still cameras. Up to 2 analog inputs may be connected, and a stereo digital microphone interface is also provided. Flexible output mixing options support single-ended and differential configurations, with outputs derived from the digital audio paths or from analog bypass paths. Mono line output and mono BTL headphone/speaker drive is supported. Flexible digital mixing and powerful DSP functions are available. Programmable filters and other processes may be applied to the ADC and DAC signal paths simultaneously. The DSP functions include 5 notch filters, 5-band EQ, dynamic range control and the Cirrus Logic ReTune™ feature. The ReTune™ feature is a sophisticated digital filter that can compensate for imperfect characteristics of the housing, loudspeaker or microphone components in an application. The ReTune™ algorithm can provide acoustic equalisation and selective phase (delay) control of specific frequency bands. The WM8944 is controlled via a I²C or SPI interface. Additional functions include digital beep generator, video buffer, programmable GPIO functions, Frequency Locked Loop (FLL) for flexible clocking support and integrated LDO for low noise supply regulation. The WM8944 is supplied in 25-ball W-CSP package, ideal for portable systems.