How to synchronize two I2S

[wiewiór]

Hi, 

I want to get synchronized samples from 4 microphones connected via I2S2 and I2S3. First I set one as master and other as slave and just connect Clock and Word Select, but I have only 0 values on slave interface. Is it possible to do it this way? Or there is another better one? 

I am using STM32H533

[wiewiór]

I connected oscilloscope to both master and slave interfaces and both seems to be working fine (there is data that changes when I make noise). Unfortunately the problem is in GPDMA configuration and I cannot find it.