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Audio Codec

Altera_Forum
Honored Contributor II
836 Views

Hi , 

 

I have developed a embedded controller in VHDL to send I2C commands to the audio codec on DE2-115 board i.e WM8731.  

 

When i send the programming data over I2C for it to send ADC data and i send it back into DAC . It works but everytime i program the FPGA , i hear clicking noise along with the sample audio from left or sometimes from right . And then i reset it again and i can still hear audio as if the device is shorted from inside and it is always transmitting ADC data ??:(, 

 

I have taken a screen shot of audio data coming in from ADC and whats going into DAC , and this is when there is no audio input to ADC , and i can see some pulses there ??:confused: 

 

Although on the DE2-115 schematic the mic line is grounded , there should not be any noise on this line . 

 

Following are the data values i am sending over I2C : 

 

constant R_Llinin_dat : std_logic_vector(8 downto 0):= "000011010";  

constant R_Lheadfon_out_dat: std_logic_vector(8 downto 0):= "001111001"; 

constant Analgaudio_dat : std_logic_vector(8 downto 0):= "000010010"; -- Muting Mic  

constant Digtlaudio_dat : std_logic_vector(8 downto 0):= "000000110"; 

constant PWR_dat : std_logic_vector(8 downto 0):= "000000000"; 

constant Digtlintf_dat : std_logic_vector(8 downto 0):= "000000001"; 

constant Samplng_dat : std_logic_vector(8 downto 0):= "000000010"; 

constant ActiveCtrl_dat : std_logic_vector(8 downto 0):= "000000001"; 

constant Rst_dat : std_logic_vector(8 downto 0):= "000000000"; 

 

 

 

 

Any clues ??
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1 Reply
Altera_Forum
Honored Contributor II
157 Views

Has any one come across this problem , or you are all using Nios to control audio codec ???

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