rtd cpuModule CMX47786HX, User Manual

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CMX47786HX RTD Embedded Technologies, Inc.
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Serial Ports, CN7 and CN8
The two serial ports are implemented on connectors CN7 and CN8 respectively. Each port is nor-
mally configured as a PC compatible full-duplex RS232 port, but you may use the Setup program to
re-configure it is as full-duplex RS422 or half-duplex RS485. The I/O address and corresponding
interrupt must also be selected using Setup. The available I/O addresses and the corresponding in-
terrupts are shown in the following table
Serial Port UART
The serial port is implemented with a 16550-compatible UART (Universal Asynchronous Receiver/
Transmitter). This UART is capable of baud rates up to 115.2 kbaud in 16450 and 16550A compat-
ible mode, and includes a 16-byte FIFO. Please refer to any standard PC-AT hardware reference for
the register map of the UART.
RS232 Serial Port (Default)
The full-duplex RS232 mode is the default setting on the cpuModule. With this mode enabled, the
serial port connector must be connected to RS232 compatible devices. The following table gives the
connector pinout and shows how to connect to an external serial connector, either DB25 or DB9
compatible.
Table 6: Serial Port Base Address and IRQ Options
I/O Address IRQ
03F8H IRQ4
02F8H IRQ3
03E8H IRQ4
02E8H IRQ3
Table 7: Serial Port in RS-232 Mode
Pin Signal Function in/out DB25 DB9
1 DCD Data Carrier Detect in 8 1
2 DSR Data Set Ready in 6 6
3 RXD Receive Data in 3 2
4 RTS Request To Send out 4 7
5 TXD Transmit data out 2 3
6 CTS Clear To Send in 5 8
7 DTR Data Terminal Ready out 20 4
8 RI Ring Indicate in 22 9
9,10 GND Signal Ground -- 7 5