Write TXEN and RXEN in US_CR to enable both the transmitter and
the receiver.
Write USART_MODE in US_MR to select the LON mode
configuration.
Write CD and FP in US_BRGR to configure the baud rate.
Write COMMT, COLDET, TCOL, CDTAIL, RDMNBM and DMAM in US_LONMR
to configure the LON operating mode.
Write BETA2, BETA1TX, BETA1RX, PCYCLE, PSNB, NPS, IDTTX and
ITDRX respectively in US_FIDI, US_LONB1TX, US_LONB1RX, US_TTGR, US_LONPRIO, US_LONIDTTX
and US_LONIDTRX to set the LON network configuration.
Write RXIDLEV and RX_PL in US_MAN to indicate the receiver line
value and select the preamble pattern to use.
Wait until RXRDY in US_CSR rises.
Read RCHR in US_RHR.
If all the data and the two CRC bytes have not been read, redo
the two previous steps.
