The three key types of physical components in an Intel HD Audio solution are an Intel HD Audio Controller, an Intel HD Audio Link, and an Intel HD Audio Codec, as shown in Figure 4.2. The controller has responsibility for moving data to and from system memory via a memory controller. The link is the bi-directional interconnection across which audio data and commands flow. The codec interprets the commands and sends or receives data and to or from an attached acoustic device that is, a speaker or microphone.

Figure 4.2: Intel HD Audio Components

Multiple codecs can be attached to a single link. More rarely, a single system could have multiple controllers, each of which would have its own associated link and attached codecs. This situation might occur if a soundcard with an Intel HD Audio controller is inserted into a PCI or PCI Express slot.