User guide

Using the System
17
3-5 24-bit Audio CODEC
WM8731 is used to implement the 24-bit Audio CODEC on DE2. This chip provides
Microphone in, Line In, and Line Out connectors. The sample rate is adjustable from
8Khz to 96Khz by using the I2C bus on DE2 board. For detailed information on how to
use the audio CODEC, users can refer to the spec under C:\DE2\Datasheet\Audio
CODEC.
Figure 3.7 shows the circuit diagram of the audio part of DE2. The pin assignment of
the associated interface is shown in Table 3.2.
Figure 3.7 24-bit Audio DAC
Signal Name FPGA Pin No. Description
AUD_ADCLRCK PIN_C5 Audio CODEC ADC LR Clock
AUD_ADCDAT PIN_B5 Audio CODEC ADC Data
AUD_DACLRCK PIN_C6 Audio CODEC DAC LR Clock
AUD_DACDAT PIN_A4 Audio CODEC DAC Data
AUD_XCK PIN_A5 Audio CODEC Chip Clock
AUD_BCLK PIN_B4 Audio CODEC Bit-Stream Clock
I2C_SCLK PIN_A6 I2C Data
I2C_SDAT PIN_B6 I2C Clock