45.6.10.1 Mode of Operation
To configure the USART to act as a LON node, the value 0x9 must be written to US_MR.USART_MODE.
To avoid unpredictable behavior, any change of the LON node configuration must be preceded by a software reset of the transmitter and the receiver (except the initial node configuration after a hardware reset) and followed by a transmitter/receiver enable. See Section 7.10.2.