Using The 24-Bit Audio Codec - Altera DE2-70 User Manual

5.8 Using the 24-bit Audio CODEC

The DE2-70 board provides high-quality 24-bit audio via the Wolfson WM8731 audio CODEC
(enCOder/DECoder). This chip supports microphone-in, line-in, and line-out ports, with a sample
rate adjustable from 8 kHz to 96 kHz. The WM8731 is controlled by a serial I2C bus interface,
which is connected to pins on the Cyclone II FPGA. A schematic diagram of the audio circuitry is
shown in Figure 5.14, and the FPGA pin assignments are listed in Table 5.12. Detailed information
for using the WM8731 codec is available in its datasheet, which can be found on the manufacturer's
web site, or in the Datasheet/Audio CODEC folder on the DE2-70 System CD-ROM.
Signal Name
AUD_ADCLRCK
AUD_ADCDAT
AUD_DACLRCK
AUD_DACDAT
AUD_XCK
AUD_BCLK
I2C_SCLK
I2C_SDAT
Figure 5.14. Audio CODEC schematic.
FPGA Pin No.
PIN_F19
PIN_E19
PIN_G18
PIN_F18
PIN_D17
PIN_E17
PIN_J18
PIN_H18
Table 5.12. Audio CODEC pin assignments.
48
Description
Audio CODEC ADC LR Clock
Audio CODEC ADC Data
Audio CODEC DAC LR Clock
Audio CODEC DAC Data
Audio CODEC Chip Clock
Audio CODEC Bit-Stream Clock
I2C Data
I2C Clock
DE2-70 User Manual