rtd cpuModule CMC6686GX, User Manual

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Serial Port 1, P1
or CN7
The first serial port is implemented on connector P1 or CN7. It is normally configured as a PC com-
patible full-duplex RS232 port, but you may use the Setup program to re-configure is as half-duplex
or full-duplex RS422 or RS485. The I/O address and corresponding interrupt must also be selected
using Setup. The available I/O addresses and the corresponding interrupts are shown in the following
table
First Serial Port UART
The first serial port is implemented with a 16550-compatible UART (Universal Asynchronous Re-
ceiver/Transmitter). This UART is capable of baud rates up to 115.2 kbaud in 16450 and 16550A
compatible mode and 1.5 Mbaud in Enhanced UART 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, con-
nector
P1
or CN7 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.
First Serial Port Settings
I/O Address
IRQ
03F8H IRQ4
02F8H IRQ3
03E8H IRQ4
02E8H IRQ3
Connector
P1 or CN7
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