Connect a TTL to RS-232 converter(circuit), to be able to use the plugs on the board, then to access the device on Linux, simply folllow the simple guidelines, below:
For creating the device for the COM1, do:
mknod /dev/ttySAC0 c 204 64
For the COM2:
mknod /dev/ttySAC1 c 204 65
For the COM3:
mknod /dev/ttySAC2 c 204 66
