Zeros as the output values from miniDSP aic3254

Do you use PPS with the EVM or are you loading the configuration into your own hardware design? If you insert a biquad or alaw encoder between the splitter and the I2S out and you have a valid input signal to the splitter, you will not get all zeroes on the I2S.

I loading the configuration into my own hardware design. I get all zeroes in one channel and const value in the other channel when I add alaw encoder in the first channel:

I check the dsp coefficients after writing. They are OK. The device starts to get zeros when I add any unit other than the splitter, but it is obvious that the encoder does some work in the first channel.

Thank you for the answer, it has began to work properly. Could you explain how the data are presented inside and outside minidsp. In the explanatory notes to alaw encoder indication about the format 3.29. As far as I understand the output i2s 3 sign bits must become one bit, isn't it?

I get the next result:

16 bit 16 Khz data

As it connected with a-law compression? For example, 0x78F6 -> 0x1080, but I calculate this manually and get result equal to 0x00AB. As connected it with this format 3.29 in miniDSP? Do I need to shift the data after receiving them?

The 3.29 format is a floating point value presented as a signed 32-bit integer.

To convert, take the 32-bit integer and divide it by 2^29.

For example: 0x1234ABCD, 3.29 format equals

n = 0x1234ABCD / (0x20000000) = 0x0.91A55E68 = 0.5689295772463083..

Thanks for your help!

But I get the data in 16-bit format, and not in 32-bit. What happens when the data format 3.29 are converted to 16 bit format in I2S block in codec?