Sigma DE2-70 manual Using the 24-bit Audio Codec, I2C Address Read is 0x34 I2C Address Write is

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.

	C38	1u			R99	4.7K
		C39	1u		R100	4.7K
VCC33 VCC33
				R101	R102
R108	R109			4.7K	4.7K
2K	2K			AGND AGND
I2C_SDAT
I2C_SCLK			R103	330

J11			LINE IN
LCN R RCN L DNG
5	2	4	1	3	PHONE JACK B
				AGND
J10			MIC IN
LC		RC		DN

I2C ADDRESS READ IS 0x34 I2C ADDRESS WRITE IS 0x35

A_VCC33

AGND

AUD_XCK

AUD_BCLK

AUD_DACDAT

AUD_DACLRCK

AUD_ADCDAT

AUD_ADCLRCK

	U13		28 27		26 25 24 23 22
			LKC IND BS ED INE INE INIC S S C O LLIN LIN M M R
1	XTI/MCLK
2
	XTO
3
	DCVDD				WM8731
4
	DGND
5
	DBVDD
6
	CLKOUT
7
	BCLK
		DES TA KCLR TA KCLR D TU TU OPX DCA CA DCD CD DVP OPLH OPH E D D A A H R
			8	9
	29				10	11	12	13	14
AGND
						A_VCC33

MBIAS VMID AGND AVDD ROUT LOUT HPGND

					C40
					1u
21	C41	10u	R104	680
20				C42	R105
19			AGND
18	A_VCC33
				1n	47K
17
16
15	AGND			AGND AGND
	C43	100u
		C44	100u
				R106	R107
				47K	47K

N R N L G
5	2	4	1	3	PHONE JACK P
				AGND
J12 LINE OUT
LCN R RCN L DNG
					PHONE JACK G
5	2	4	1	3
				AGND

		AGND AGND
	Figure 5.14. Audio CODEC schematic.
Signal Name	FPGA Pin No.	Description
AUD_ADCLRCK	PIN_F19	Audio CODEC ADC LR Clock
AUD_ADCDAT	PIN_E19	Audio CODEC ADC Data
AUD_DACLRCK	PIN_G18	Audio CODEC DAC LR Clock
AUD_DACDAT	PIN_F18	Audio CODEC DAC Data
AUD_XCK	PIN_D17	Audio CODEC Chip Clock
AUD_BCLK	PIN_E17	Audio CODEC Bit-Stream Clock
I2C_SCLK	PIN_J18	I2C Data
I2C_SDAT	PIN_H18	I2C Clock

Table 5.12. Audio CODEC pin assignments.

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