RTD Embedded Technologies, Inc.
|
www.rtd.com
20
GPS25162HR/GPS35162HR User’s Manual
BDM-610020158 Rev A
6
Software
6.1
Installing the Software
The GPS35162 uses a PCIe UART which will require software and drivers for proper operation. Drivers are provided for Windows XP/7, DOS,
and Linux with pre-3.8 kernels. The UART is supported in 3.8+ kernels.
The drivers are provided on the companion CD and are also available on the RTD web site (
) for download.
6.2
Software Programming
6.2.1
API
I
NTERFACE
Once the drivers for the GPS35162 have been properly loaded, all ports should be available as standard serial ports. All 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.
6.2.2
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 own serial port application, c
onsult 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.
6.2.3
B
ASE
A
DDRESS AND
R
EGISTER
M
APPING
The GPS35162 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 GPS35162
’s serial ports will be different than the standard PC serial port locations (0x3F8, 0x2F8,
etc.).
The GPS35162 is a memory mapped device. Since it is PCI-based, it may be mapped to any location within the 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 GPS35162 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.
6.3
Windows
When using the GPS35162, a terminal emulator can be used to communicate with the GPS. Since HyperTerminal is no longer provided with
Windows, we recommend using Real Term or Tera Term. Default GPS serial settings can be found in the
section (page
). Default sensor interface serial settings can be found in the
Error! Reference source not found.
section (page
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defined.
).
NOTE: When using under Windows, the GPS may be incorrectly detected as
a Serial Mouse, causing erratic mouse cursor behavior. This issue
has been documented by Microsoft. For more information, refer to
Microsoft Knowledge Base Article 283063.
