Home » » GX3500   (PXI 3U)

FPGA PXI Digital I/O Card

  • User configurable, on-board Altera Cyclone III FPGA device
  • Module software is fully compatible with Altera object files
  • No proprietary FPGA design tools required
  • Compatible with Altera’s free web-based Quartus II design tools
  • 160 digital I/O signals available for application support
  • Accommodates standard and custom expansion boards
  • Compatible I/O with NI PXI 7811R / 7813R FPGA's
  • PXI hybrid slot compatible


The GX3500 is a user configurable 3U FPGA PXI card which offers 160 digital I/O signals for specific application needs, as well as providing pin for pin compatibility with NI PXI 7811R and 7813R FPGA cards. The card employs the Altera Cyclone III FPGA which can support clock rates up to 150 MHz and features over 55,000 logic elements and 2.34 Mb of memory. The 3U PXI FPGA card GX3500 can also accept an expansion card assembly which can be used to customize the interface to the UUT – eliminating the need for additional external boards which are cumbersome and physically difficult to integrate into a test system.  The design of the FPGA is done by using Altera’s free Quartus II Web Edition tool set. Once the user has compiled the FPGA design, the image can be loaded into the FPGA via the PXI bus interface or via an on-board EEPROM.


The GX3500’s four banks of 40 digital I/O signals can be selectively isolated from the I/O connectors under software control. The signals are 5 V tolerant. Logic families supported by the I/O interface include LVTTL and LVCMOS. The FPGA device supports up to four phase lock loops for clock synthesis, clock generation and for support of the I/O interface. An on-board 80 MHz oscillator is available for use with the FGPA device or alternatively, the PXI 10 MHz clock can be used as a clock reference by the FPGA.

The FPGA has access to all of the PXI bus resources including the PXI 10 MHz clock, the local bus, and the PXI triggers, allowing the user to create a custom instrument which incorporates all of the PXIbus’ resources. Control and access to the FPGA is provided via the GX3500’s driver (GxFPGA) which includes tools for downloading the compiled FPGA code as well as providing register read and write functionality.

The GX3500 can be configured with several different standard expansion boards - providing buffered I/O interfaces for TTL, LVDS, differential TTL and ECL logic families. Additionally, the GX3500 can be configured with a video generator board which supports VGA, PAL ,and NTSC interfaces.

Programming and Software

The board is supplied with the GXFPGA library, a software package that includes a virtual instrument panel, and a Windows 32/64-bit DLL driver library and documentation. The virtual panel can be used to interactively program and control the instrument from a window that displays the instrument’s current settings and status. In addition, interface files are provided to support access to programming tools and languages such as ATEasy, LabView, LabView/Real-Time, C/C++, Microsoft Visual Basic®, Delphi, and Pascal. An On-Line help file and PDF User's Guide provides documentation that includes instructions for installing, using and programming the board.
A separate software package - GtLinux - provides support for Linux 32/64 operating systems.


  • Automatic Test Equipment (ATE)
  • Semiconductor test
  • Custom interface emulation
  • Custom instrumentation