ADLINK Technology ReadyBoard 910, Reference Manual

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Chapter 3 Hardware
24 Reference Manual ReadyBoard 910
Serial Interfaces
The Super I/O (SCH3114I-NU) chip provides the circuitry for the two serial ports. The Super I/O chip
provides serial port 1 through a standard DB9 connector (CN17) and serial port 2 through a 10-pin header
(CN8). The two serial ports support the following features:
•
Four individual 16550-compatible UARTs
•
Programmable word length, stop bits and parity
•
16-bit programmable baud rate generator
•
Interrupt generator
•
Loop-back mode
•
Four individual 16-bit FIFOs
•
Serial Interface
♦
Serial Port 1 (COM0) supports RS-232/RS-485/RS-422 and full modem support
♦
Serial Port 2 (COM1) supports RS-232/RS-485/RS-422 and full modem support
To implement the two-wire RS-485 mode on serial ports 1 or 2, you must tie the equivalent pins together for
the selected port.
For example, on Serial Port 2, tie pin 3 to 5 and pin 4 to 6 on the Serial 2 (COM1) interface header as shown
in
Figure 3-1 . As an alternate, tie pin 2 to 3 and pin 7 to 8 on the DB9 connector for serial port 1 (COM0) as
shown in Figure 3-1 . Refer to Table 3-4 for the specific pin signals of serial port 2. The corresponding pins
on the DB9 serial 1 connector are also available in Table 3-4 .
The RS-422 mode uses a four-wire interface and does not need any pins tied together, but you must select
RS-485 mode in BIOS Setup.
Figure 3-1. RS-485 Serial Port Implementation
NOTE The RS-232/RS-485/RS-422 modes are selected in BIOS Setup under the
Advanced/Super I/O Configuration menu However, the RS-232 mode is the
default (Standard) for any serial port.
RS-485 mode termination is selected with jumper header JP2 (COM1), and JP3
(COM2), when the RS-485 mode is selected in BIOS Setup.
RB910RS485jump_a
Or
1
3 5
7
9
2 4
6 8 10
Serial Port 2
(CN8, COM1)
Standard DB9
Serial Port 1
(CN17, COM0)
Connector (Male)
Front View
5 4
3
2 1
9
8 7 6