AUDIO CODEC WITH AGC CONTROLLED BY A VOCODER

摘要

An audio band processor and a method and circuit for controlling its gain. T he audio band processor comprises a first variable gain amplifier (202) for receiving an analog audio signal; an analog to digital converter (204) for converting said analog audio signal to a digital audio signal; and an interface circuit (206) for encoding said digital audio signal. The interface circuit (206) also arranges said digital audio signal into a sequence of encoded transmit frames, and receives a sequence o f encoded receive frames, each receive frame comprising a predetermined number of encoded digital audio signal data bits and a predetermined number of digital gain control bits. The interface circuit (206) also adjusts a gain level of said first variable gain amplifier in response to said digital gain control bits. In another embodiment, the audio band processor further comprises a second variable gain amplifier (202 ), and the interface circuit adjusts a gain level of said second variable gain amplifier in response to said digital gain control bits.