AC97

AC 97 (Audio Codec '97)  is a standardized set of features and system controller interconnect for sound chips. Version 2.3 specifies the ability for audio chips to detect how the analog ports are being used and reconfigure accordingly. Version 2.2 added the most important feature for HTPC Home Theatre PC use:[ S/PDIF|http://en.wikipedia.org/wiki/Spdif] output.

This has also become a colloquial way to identify soft-audio chips from fully accelerated audio processors. Traditionally the on-board audio of motherboards has been basic (cheap) soft-audio which harnesses the AC97 link in the system's southbridge to provide a CPU assisted sound interface. The chip merely provides the front-end interfaces: It provides a basic Digital to Analogue Converter (DAC) for the outputs, an Analogue to Digital Converter (ADC) for the inputs, as well as a S/PDIF compatible interface for direct digital output.