Digital input on ADAU1772

RMSacoustics Question

Dec 7, 2015 00:00

Hi all,

I am working quite successfully with the ADAU 1772 as controller in a fast loudspeaker feedback system.

Up till now I only used the analog inputs but I want to use a digital input to be able to combine it with ADAU 1442 DSP for more sophisticated signal treatment without repeated AD/DA conversion.

The problem is that I do not get the digital input working in the Evaluation board EVAL ADAU1772. All MP pin jumpers are not used

I tried all kind of hardware settings (see attached the Sigma Studio file for the test system with only the digital input directly connected to the output). The source is set as master and the ADAU1772 as slave and I only connect the DAC_SDATA, LRCLK, BCLK and GND to the appropriate pins on the board. The I2S signal is 3.3V and the ADAU is also set at 3.3V.

The input signal is generated by an APx analyser and converted to I2S by a WM8804 receiver. I used different sample rates but no result.

Thanks for the help.

Rob

sigma studio

adau1772

Integrated/Special Purpose A/D Converters

digital_input_

adau 1772

Audio CODECs

eval-adau1772

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DaveThib Reply

Dec 8, 2015 00:00

Hello Robert,

I just opened up your project to check a few things. I have not studied all of your documents.

I see that you need to enable the Output ASRCs so that would explain why the serial output will not work. I see you are sending the core outputs to the two serial ports. I am not sure which ports you want to route to the 1442, but it looks like it is core output 0 and I see the return is on core input 3. So this was all on the Signal Routing tab.

Next is the Chip Control Tab. You need to turn on power to the decimators and interpolators for the ASRCs. They were all off.

Now, looking at the pin/pad control I see an issue. If you are planning on using the DSP Core output 0 routed to serial port 0 then you have a multi-purpose pin issue. Serial port ADC_SDATA0 is located on the pin that I think you are using for the push button volume up switch. You have MP6 setup for serial port output 1 so just use that pin/port. You will have to route the core output 0 over to that serial port. I will not do that in the project I will attach. I think should now know what to do.

So I will make a few changes in your project and attach it.

Let me know if there still are issues.

Dave T

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RMSacoustics Reply

Mar 24, 2016 00:00

Hi Dave,

Sorry for not responding earlier but indeed I used the settings that you advised and it works.

I thought I replied it at the time but apparently I forgot

thanks,

Rob

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