I am trying to set up a proper communication between the Core2 of the ADSP-21593 and an on-board LAN-Chip. The SPI1 is used for this communication. This works fine for the simple approach of communicating in terms of sending 3 bytes and receiving 4 bytes from the LAN-Chip (1 register value) in both single and quad SPI mode. The problem occurs when it is tried to send 3 bytes and receiving more than 4 bytes (register polling). Then the SPI1 receives wrong data. This problem can be avoided if there is a print-statement inserted which only prints '\n' AFTER the actual SPI-transmission. Then the data is valid. Also running on a breakpoint which is set after the SPI-transmission validates the data in some way. But this solution is not satisfying at all. I cannot figure out what the problem is at the moment. Also waiting for a certain amount of time after the SPI-transmission does not solve it. Is there any reasonable explanation for that?