High_Definition_Audio_1_0a.pdf

The High Definition Audio architecture was not developed with the intent of being backward compatible with AC‟97. Unlike AC‟ 97, the primary goal of the High Definition Audio Architecture is to develop a uniform programming interface and to provide fundamental flexibility and capabilities beyond those supported by AC‟97. Therefore, the High Definition Audio architecture and specification must be considered entirely a separate specification from AC‟97, implying no backward compatibility. Specifically, link protocol and operation between these two specifications is not compatible. AC‟97 and High Definition Audio codecs cannot be mixed on the same link or behind the same controller.