Hello NiVa_4337911 ,
The RX FIFO has a depth of 4, thus you can use it for receiving upto 32 bits. Thus, the I2S_ReadByte() needs to be called twice in order to read both the bytes. You need to take care in the firmware that the RX_FIFO is not empty before reading the data and also that the RX_FIFO overflow does not occur. You can use the I2S_ReadRxStatus() function for this purpose.