Master baud rate and desired delimiter value should be configured by SW.
SW needs to set TXBRKSYNC bit in LCRH for break/synch transmission (TXBRKSYNC is
redundant in UART mode).
This should start break transmission if UART is idle else it completes ongoing
transmission and starts break/ synch transmission right after.
Counter is preloaded with value 12 and decremented to achieve break duration of
13-bit time.
Delimit duration should be based on delimit value configured.
Synch field 0x55 transmission should begin automatically (start, 8-bit data and
stop bit).
When synch transmission is completed, TXBRKSYNC bit should be reset
automatically by HW.
SW can write PID value into TXFIFO immediately after setting the TXBRKSYNC.
HW after synch transmission will check TXFE and if TXFE = 1 it does not transmit
anything and if TXFE = 0 it transmits data from TXFIFO (In LIN mode it is only
one-bytePID that will be written).