57.7.9.5.7 CRC
The two last bytes of LON frames are dedicated to CRC.
When transmitting, the CRC of the frame is automatically generated and sent when expected.
When receiving frames, the CRC is automatically checked and the FLEX_US_CSR.LCRCE flag is set if the calculated CRC does not match the received one. Note that the two received CRC bytes are seen as two additional data from the user point of view.