Sun doesn't supply all the serial ports modes you're likely to want as stock entries in /etc/ttydefs. (Sun seems to think that the whole world wants to run as 7 bits, even parity.) I'll show you how to set up the entries in /etc/ttydefs to match your own needs.
Serial port modes (the terminal I/O options found in stty(1)) are set in the file /etc/ttydefs. The name of the serial port mode (like contty5H) is used as the argument to the -l option in the ttyadm portion of the pmadm -a command. (This is the speed setting you use when you add a new port monitor.) See the stty manual page for all the available terminal I/O options.
The format of the entries in ttydefs is shown below and described in Table 133.