TLV320AIC3 clipping

ranchu

Guru 20755 points

Hello,

I am using HPROUT of codec tlv320aic3x (connected to output of DM8148 mcasp2) .

I checked it with aplay utility, and there is very much noise in it (more noise than sound)

Here are samples for the custom board, and for the evm board. With evm there is no such issue (but evm was tested with HPLOUT/HPROUT).

There is also some speed issue, but I'm not sure if this is the cuase for the noise or not.

When observing the recorded file (sinus test pattern) in PC it seems to be cut from below (some sort of clipping). See the following image:

With EVM board the signal is nicer:

I also observe that I can only function with 100% volume, below that I get no output.

This are the commands I am using:

amixer cset name='PCM Playback Volume' 100%,100%
amixer cset name='Right HP Mixer DACL1 Switch' on
amixer cset name='Right HP Mixer DACL1 Playback Volume' 100%
amixer cset name='Line DAC Playback Volume' 0

This is the HW schematic for codec :

Does anybody have any idea why there is clipping ?

Regards,

Ran

over 8 years ago

0 Luis Fernando Rodriguez S. over 8 years ago

TI__Guru* 84915 points

Hi, Ran,

Have you made the same test on the line outputs (LEFT_LOP/M )? Do you obtain the same results?

Best regards,
Luis Fernando Rodríguez S.

0 ranchu over 8 years ago in reply to Luis Fernando Rodriguez S.

Guru 20755 points

Hi,

No, becuase I don't have them available on board.
Does it looks more like a HW issue or a SW issue ?

Regards,
Ran

0 ranchu over 8 years ago in reply to ranchu

Guru 20755 points

Hi,

Is there any idea ?
Does it looks more like a HW issue or a SW issue ?

Thanks,
Ran

0 Luis Fernando Rodriguez S. over 8 years ago in reply to ranchu

TI__Guru* 84915 points

Hi, Ran,

It could be related with a SW issue. Is it possible to provide the codec register configuration? We don't support the linux sound architecture. If you provide the register configuration, we could have a better approach of this problem. Additionally, do you have a complete codec schematic? The last schematic doesn't show all the codec connections.

Thank you.

Best regards,
Luis Fernando Rodríguez S.

0 ranchu over 8 years ago in reply to Luis Fernando Rodriguez S.

Guru 20755 points

Hi Luis,

Thank you very much.

I've attached the full codec scematics.

Are there any specific registers that you want me to dump ?

Regards,

Ran

Koby_Audio.pdf

0 Luis Fernando Rodriguez S. over 8 years ago in reply to ranchu

TI__Guru* 84915 points

Hi, Ran,

Is it possible to provide the registers related with the DACs, headphone output, line output and volume control?

Thank you.

Best regards,
Luis Fernando Rodríguez S.

0 ranchu over 8 years ago in reply to Luis Fernando Rodriguez S.

Guru 20755 points

Hi,

I can't dump registers in Linux, becuase I get "Driver is busy" when trying to dump registers with i2c-tools (i2cget etc)
But Anyway, we solved the issue:
It was wrong connectivity in the analog board.

Regards,
Ran

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TLV320AIC3 clipping