TME-104-CLR-86DX-R0V2.doc
Rev. 0.2
19(
44
)
3.8
Serial Ports
The maximum supported baud rates with COM1, COM2, COM3, Com4 and COM9 (for Redundancy mode): up to
750 Kbit/s in high speed mode, 115.2 Kbit/s in normal mode
The serial ports COM1 and COM2 are located on two IDC10 headers "COM1" and "COM2". Adapter cables with
standard DSUB-9 male connectors are available. The ports either work in RS232 or RS485 mode, selectable in
BIOS or by software. When entering Chipset
à
Southbridge Configuration
à
Multi-Function Port Configuration,
COM Port Modes can be selected by GPIO Port 0 bits 6 and 7:
COM1 mode: GPIO06=0
à
RS232, GPIO06=1
à
RS485
COM2 mode: GPIO07=0
à
RS232, GPIO07=1
à
RS485
Termination resistors for RS485 Mode can be set with Jumpers on pin headers as described in this chapter.
To enable transmitters of COM1 and COM2 in RS485 Mode set RTS signal to ‘1’.
The serial ports COM3, COM4 and COM9 are LVTTL (Low Voltage TTL) UARTs, which means the UARTs are not
connected to a transceiver. An additional difference to COM1 and COM2 is that these serial ports only have RX
and TX signals. All three of them have special tasks:
COM3: GPS connection
COM4: FPGA connection (physically: to use it, first a UART has to be implemented into FPGA)
COM9: Part of BoR (Bridge of Redundancy)
The serial ports are programmable in BIOS setup. When entering Chipset
à
Southbridge Configuration
à
Serial/Parallel Port Configuration, configuration of the serial ports is accessible.
The following settings are possible for COM1 … COM4:
•
IO-Address: Disabled / 0x3F8 / 0x2F8 / 0x3E8 / 0x2E8 / 0x10(normally for COM9 reserved)
•
IRQs: 3 / 4 / 5 / 6 / 7 / 9 / 10 / 11 / 12 / 14 / 15
•
Bits per Second: 2400 / 4800 / 9600 / 19200 / 38400 / 56700 / 115200
COM1
Connector type
IDC10 pin header 2.54 mm
Matching connector
IDC10 pin female connector 2.54 mm
Pin
RS232
RS485
Pin
RS232
RS485
1
DCD
Not used
2
DSR
RXD+
3
RXD
RXD-
4
RTS
TXD+
5
TXD
TXD-
6
CTS
Not used
7
DTR
Not used
8
RI
Not used
9
GND
GND
10
+5 Volt
4
+5 Volt
4
0.5 A is the maximum current for that pin
X10