RTD Embedded Technologies, Inc.
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23
GPS35190 User’s Manual
7
Software
7.1
Installing the Software
The GPS35190 use a PCIe UART which will require software and drivers for proper operation. Drivers are provided for Windows XP/7, DOS,
and Linux Kernel 2.6.37 and newer.
The drivers are provided on the companion CD and are also available on the RTD web site (
) for download.
7.2
Serial Port Configuration
A software utility is required to configure serial port mode and termination setting. This utility along with source code for the utility is provided on
the companion CD and is also available on the RTD web site (
) for download.
For additional support concerning the software utility please contact RTD tech support.
7.3
Software Programming
7.3.1
API
I
NTERFACE
Once the drivers for the GPS35190 have been properly loaded, all eight RS-232/422/485 ports should be available as standard serial ports. All
eight ports can then be controlled using the standard serial port interfaces built into the operating system.
A description of serial port programming for operating systems is beyond the scope of this manual. Consult the operating system
documentation for information on how to interface with serial ports via software.
7.3.2
COM
P
ORT
N
UMBERING
Serial ports (aka COM ports) are typically assigned numbers by the operating system (e.g. COM1). These numbers are typically dynamically
assigned by the operating system. However, different applications may enumerate the COM ports differently, assigning different port numbers
(e.g. COM3-10 vs COM5-12). When developing your o
wn serial port application, consult your operating system’s documentation for the proper
method of enumerating COM ports.
Note:
Some applications are written to assume that no more than four COM ports are present in a system. These
applications may have compatibility issues with the Exar PCIe UART.
7.3.3
B
ASE
A
DDRESS AND
R
EGISTER
M
APPING
The GPS35190 exposes all of the registers available on the Exar XR17V358. The register set of the XR17V358 mimics the standard 16C550
UART register map. However, the XR17V358 contains some additional registers not found in a typical ISA-based UART.
Additionally, the base address of the GPS35190
’s serial ports will be different than the standard PC serial port locations (0x3F8, 0x2F8, etc).
The GPS35190 is a memory mapped device. Since it is PCI-based, it may be mapped to any location within the 4GB address space of the
CPU. The base address of PCI devices is determined by the CPU’s BIOS and operating system at boot time.
The register-level differences between the GPS35190 and a standard 16C550 UART should be abstracted via the software drivers. Most users
will not need to concern themselves with the actual registers of the board. If one is interested in directly accessing the registers of the board,
consult the XR17V358 data sheet available from Exar.
