W681308DG Datasheet, PDF (43/64 Pages) Nuvotem Talema – W681308 USB Audio Controller from Nuvoton integrates fast 8051 Microcontroller Unit (MCU)

W681308
XXXX PRODUCT DESCRIPTION
13.
Audio Codec Interface
13.1 Overview
The audio CODEC interface allows the USB Audio Controller Device to be connected to one or more of the following:
ƒ 16 bit internal linear PCM CODEC and Echo Cancellation block.
ƒ 8/16/48 KHz CODEC sampling rate
ƒ An I2S interface to and from the on chip linear CODEC.
ƒ A PCM interface to connect to a external Nuvoton ProX SLIC/CODEC
The audio data is flowing between USB interface and CODEC through 2 segmented FIFOs that allow MCU processing of
audio data.
13.2 Audio CODEC Signal Path
Figure 8 W681308 CODEC Signal Path Control
Transmit Path Operation
The microphone is biased through pins MCP by an internal programmable voltage reference and programmable resistor. The
microphone ac signal is gained up by the input amplifier and filtered to prevent aliasing at the input of the sigma delta ADC.
The sigma delta ADC converts the signal in a 2 bit digital representation, which is decimated and low pass filtered to the
base band sampling rate of 8kHz to 48kHz. A high pass filter can be enabled in the transmit path.
43
Rev1.2