The Codec includes a stereo pair of analog-to-digital converters and a stereo pair of digital-to-analog converters. Analog signals can be input at line levels or microphone levels. A software controlled programmable gain stage allows independent gain for each channel going into the ADC. The ADCs' output can be digitally mixed with the DACs' input. The left and right channel 16-bit outputs from the ADCs are available over a single bidirectional serial interface that also supports 16-bit digital input to the DACs and control information. The AD1849K can accept and generate 8-bit -law or A-law companded digital data.