Dac Configuration; Audiohwinit(); Audiohwconfig(); Mic Processing Example - XMOS xCORE-200 Multi-channel Audio board Design Manual

USB Audio Design Guide
6.7.2 DAC Configuration
The board is equipped with a single stereo audio DAC with integrated headphone
amplifier (Cirrus Logic CS43L21)
Configuration of both the DAC takes place using I2C. The design uses the I2C
component sc_i2c
The reset lines of the DAC is connected to bits 0 PORT 4F.

6.7.3 AudioHwInit()

The
the following:
Puts the DAC into reset
Initialise the I2C master software module
Initialises the CS2100 part over I2C
Configures the CS2100 part to output a ratio for a suitable initial master clock
frequency (DEFAULT_MCLK_FREQ)
6.7.4 AudioHwConfig()
The
The
into reset by writing to PORT 4F.
It then sets the required ratio in the CS2100 via I2C based on the mClk parameter.
After a delay, in order to allow the master clock from the CS2100 to settle the DAC
is take out of reset. The DAC is then configured via I2C, this primarily involves
switching the DAC into I2S slave mode

6.7.5 Mic Processing Example

The provided application includes a basic example of processing the data
from the PDM microphones.
user_pdm_process() . It takes a block of PCM microphone samples as an input and
writes processed samples into the output array parameter.
The processing involves applying a simple gain globally to all of the microphones.
Normal operation sees this gain applied to the data from the 7 microphones and
then written to output[0-6] . The gain is increased and decreased by pressing
buttons B and C respectively.
31
http://www.github.com/xcore/sc_i2c
XM0088546.1
31
.
AudioHwInit() function is called on power up and is implemented to perform
AudioHwConfig() function is called on every sample frequency change.
AudioHwConfig() function first puts the both the DAC/headphone-amp and
This basic processing example is located in
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