DA7212: Connecting two codecs from different I2S clocks

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zaz
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DA7212: Connecting two codecs from different I2S clocks

Hello,

I have two dev DA7212 arduino boards connected as DAI slaves (receiving same clocks, but from different CPU's).
I am trying to set one kit as input (microphone) and the other as output (headphones) over I2S by connecting DAI output (first kit) to DAI input (second kit).
If I share same clock (WCLK and BCLK) from one CPU for both codecs everything working well.
But if I set WCLK and BCLK from different CPU's, only noise came from headphones.

Is it possible to connect two audio codecs from different I2S clocks.
Thanks.

Device: 
ED_Dialog
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Hello Zaz,

Hello Zaz,

 

I will look into this for you.

 

Could you share you’re script and clock frequencies?

 

Kind regards,
Elliott Dexter 

ED_Dialog
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Hello Zaz,

Hello Zaz,

 

This could be an issue with your clocks not be in sync. Could you share your Clk Frequencies and script? I have also attached a diagram for your use case setup, could you confirm which one you plan on using?

 

Kind regards,
Elliott Dexter 

zaz
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Hello,

Hello,

Thanks for fast response.

My setup exactly as described in "scenario 2".
1. I don't have internal PLL on codec dev boards, so both devices DAI set as slaves and receive MCLK from CPU's.
2. Both devices A and B receive same MCLK from they CPU's (CPU A and B respectively).
3. When I make loopback from Dout to Din: I receive noise from speaker.

Setup config:
Sample Rate - 8kHz
MCLK - 12MHz
PLL Registers:
0x24 0x18
0x25 0x93
0x26 0x20
0x27 0xC4
0x94 0x02

ED_Dialog
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H

H

Hello Zaz,

Thanks for the information. We have put together two scripts that are in relation to your settings and scenario 2. Could you also check that the PLL is locked, this can be achieved by reading back the 0x03 register.

In relation to connecting Dout to Din, if they are across two boards you will need to keep the wires short and accompanied by a ground.

 

Kind regards,

Elliott Dexter 

Attachment: 
zaz
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Hello,

Hello,

Thank you for help,
I made connection between Dout to Din like in scenario 2 schematic, but unfortunately issue is still exist.
Used short wire and common ground.
0x03 register value in both devices is: 0x0d (PLL locked).

Regards,
Zaz.

ED_Dialog
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Hello Zaz,

Hello Zaz,

 

Could you share your schematic, a picture of your set-up and a plot of the clocks on each device?

 

Kind regards,

Elliott Dexter 

ED_Dialog
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Hello Zaz,

Hello Zaz,

 

Could you also provide a register dump of the devices?

 

Kind regards,
Elliott Dexter 

ED_Dialog
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Hello Zaz,

Hello Zaz,

Do you need any further support/Help?

Kind regards,
Elliott Dexter 

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