baudrate,int,baud rate,Baud rate in bits per second
bits,int,data bits,Number of data bits
parity,enum sp_parity,parity setting,Parity setting
stopbits,int,stop bits,Number of stop bits
rts,enum sp_rts,RTS pin behaviour,RTS pin mode
cts,enum sp_cts,CTS pin behaviour,CTS pin mode
dtr,enum sp_dtr,DTR pin behaviour,DTR pin mode
dsr,enum sp_dsr,DSR pin behaviour,DSR pin mode
xon_xoff,enum sp_xonxoff,XON/XOFF configuration,XON/XOFF mode
