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Requirements and Compatibility  |  Detailed Specifications For user manuals and dimensional drawings, visit the product page resources tab on

Last Revised: 2014-10-09 08:02:16.0

NI FlexRIO FPGA Modules



The NI FlexRIO family consists of PXI and PXI Express field-programmable gate array (FPGA) modules coupled to I/O adapter modules. Programmed with the NI LabVIEW FPGA Module, these modules together provide high-performance I/O and user-defined hardware processing on the PXI platform. NI FlexRIO FPGA modules feature the latest in FPGA technology and high-performance bus interfaces. National Instruments and third parties offer NI FlexRIO adapter modules, and you can build your own adapter modules using the NI FlexRIO Adapter Module Development Kit (MDK). With custom adapter modules, you can implement the exact analog and digital I/O your application requires, along with graphical FPGA programming provided by LabVIEW. View a current list of NI and third-party adapter modules at

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Requirements and Compatibility

OS Information

  • FPGA
  • Real-Time OS
  • Windows 2000/XP
  • Windows 7
  • Windows Vista

Driver Information

  • NI FlexRIO Adapter Module Support
  • NI-RIO

Software Compatibility

  • LabVIEW
  • LabVIEW FPGA Module

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Application and Technology

Model Bus/Form Factor FPGA FPGA Slices FPGA DSP Slices FPGA Memory (Block RAM) Onboard Memory (DRAM)
NI PXIe-7965R/
PXI Express Virtex-5 SX95T 14,720 640 8,784 kbit 512 MB
NI PXIe-7962R PXI Express Virtex-5 SX50T 8,160 288 4,752 kbit 512 MB
NI PXIe-7961R PXI Express Virtex-5 SX50T 8,160 288 4,752 kbit 0 MB
NI PXI-7954R PXI Virtex-5 LX110 17,280 64 4,608 kbit 128 MB
NI PXI-7953R PXI Virtex-5 LX85 12,960 48 3,456 kbit 128 MB
NI PXI-7952R PXI Virtex-5 LX50 7,200 48 1,728 kbit 128 MB
NI PXI-7951R PXI Virtex-5 LX30 4,800 32 1,152 kbit 0 MB
1These two devices have different speed grade FPGAs: (–1) for the NI PXIe-7965R and (–2) for the NI PXIe-7966R. For more information on Xilinx Virtex-5 FPGA speed grades, refer to the Virtex-5 FPGA Data Sheet: DC and Switching Characteristics at

Table 1. NI FlexRIO FPGA Module Options


Figure 1. NI FlexRIO Architecture


Application Example Algorithm
Inline signal processing Continuous filtering, thresholding, peak detections, data reduction/compression, zero suppression, averaging
Custom triggering Multievent, protocol-specific, variable hysteresis, logical AND/OR, data mask, multichannel
Software defined radio Digital upconversion, downconversion, modulation, demodulation, packet assembly
"Protocol aware" semiconductor test systems DUT-specific master and slave protocols
Custom RF communication scheme development and test Custom modulation and demodulation, bit error rate test, fading profiles, additive noise
High-speed serial communication protocols Serialization, deserialization, parallel algorithms
Deterministic analog or digital closed-loop control and interfacing Frequency-based control loops, PID, emergency stop criteria evaluations, and assertion
High-performance and custom control or PXI-based test systems Deterministic, low-latency instrument sequencing; high-performance DUT control
FPGA-based coprocessing/hardware acceleration Algorithms exploiting FPGA throughput and parallelism, complementing host processing

Table 2. Example Applications and Algorithms That Benefit From User-Defined 
       FPGA Processing and High-Performance I/O on the PXI Platform

NI FlexRIO FPGA Modules for PXI Express

PXI Express NI FlexRIO FPGA modules feature Xilinx Virtex-5 SXT FPGAs with up to 512 MB of onboard DRAM, which you can access at bandwidths up to 3.2 GB/s. In addition to general-purpose reconfigurable logic, SXT FPGAs are optimized for high-speed digital signal processing (DSP), with up to 640 DSP slices for single-cycle multiplication and filtering functions. PXI Express NI FlexRIO FPGA modules also feature the NI STC-3 application-specific integrated circuit (ASIC) to provide an optimized, high-bandwidth PCI Express x4 communications link to the backplane of the PXI Express chassis. This ASIC reduces the FPGA resources needed to implement host communication and enables new data transfer technology in the unique peer-to-peer streaming feature.

For multiadapter module synchronization, PXI Express NI FlexRIO FPGA modules include the I/O Module Synchronization Clock, which you can use to synchronize multiple adapter modules, provided the adapter module supports this signal.

Figure 2. NI ASIC technology and Xilinx FPGAs provide a high-performance
platform for flexible, user-customizable instrumentation.

Peer-to-Peer Data Streaming

With NI peer-to-peer data streaming technology, you can continually transfer data to and from PXI Express NI FlexRIO FPGA modules at rates greater than 800 MB/s with minimal latency. High-performance data switches on NI PXI Express chassis offer high-bandwidth communication, and routing data from one module directly to another (without transferring data through the host controller) minimizes the latency of the transfer. Peer-to-peer transfers are supported between multiple PXI Express NI FlexRIO FPGA modules and between select NI PXI Express digitizers and PXI Express NI FlexRIO FPGA modules. Figure 3 depicts a peer-to-peer system with an NI PXIe-5122 digitizer and two NI PXIe-7965R NI FlexRIO FPGA modules for distributed serial data processing.

Figure 3. Peer-to-peer systems rely on high-performance PXI Express chassis and controllers as well as proprietary 
NI data streaming technology on NI FlexRIO FPGA modules and NI modular instruments.

In LabVIEW FPGA, you access these peer-to-peer streams through simple first-in-first-out (FIFO) nodes. An easy-to-use API on the host controller sets up a peer-to-peer stream between multiple FPGA modules after you configure peer-to-peer FIFOs on each.

Figure 4. The NI-P2P driver offers simple, high-level access to the high-performance capabilities of peer-to-peer streaming, and intuitive nodes on the FPGA block diagram simplify data transfer.

NI FlexRIO FPGA Modules for PXI

PXI NI FlexRIO FPGA modules feature Xilinx Virtex-5 LX FPGAs with up to 128 MB of onboard DRAM, which you can access at bandwidths up to 1.6 GB/s. They feature all of the benefits of the PXI platform including synchronization, triggering, and high-speed data transfer to and from their hosts.


Feature PXI NI FlexRIO
FPGA Modules
PXI Express NI FlexRIO
FPGA Modules
Xilinx Virtex-5 FPGAs
132-Line Adapter Module Interface
I/O Module Synchronization  
Peer-to-Peer Data Streaming  

Table 3. PXI and PXI Express FPGA Module Comparison

NI FlexRIO Adapter Modules

NI and National Instruments Alliance Partners offer NI FlexRIO adapter modules. You also can build your own with the NI FlexRIO Adapter MDK. View a list of NI FlexRIO adapter modules at

NI Adapter Modules

NI FlexRIO adapter modules provide high-performance I/O that you can customize with the NI FlexRIO FPGA module. With these adapter modules, National Instruments includes the module-specific Component-Level IP (CLIP) Node, which defines the interface between LabVIEW and the adapter module. This helps you begin programming your application immediately, without a low-level understanding of the adapter module design or functionality. Examples demonstrate how to effectively use the CLIP Node.

Third-Party Adapter Modules

In addition to NI FlexRIO adapter modules built by National Instruments, NI Alliance Partners can build adapter modules with the same degree of performance, functionality, and integration. These modules are available as either standard or custom products.

Custom Adapter Modules

If you cannot find an adapter module that meets your application needs from National Instruments or an NI Alliance Partner, you can build your own custom adapter module using the NI FlexRIO Adapter Module Development Kit (MDK).

Figure 5. The NI FlexRIO Adapter Module Development Kit (MDK) features the documentation, design files, and adapter module enclosures to build your own NI FlexRIO adapter module.

With the NI FlexRIO Adapter MDK, you receive the following:

  • A comprehensive module development user manual
  • Example adapter module support files
  • Three blank adapter module enclosures 
  • One windowed adapter module enclosure for debugging
  • Mechanical drawings for the adapter module PCB, card-edge connector, and front panel
  • Direct support from NI R&D engineers, including a one-hour design review to help ensure electrical compatibility with NI FlexRIO FPGA modules

Programming NI FlexRIO With the LabVIEW FPGA Module

Graphical FPGA Programming

NI LabVIEW and the LabVIEW FPGA Module deliver graphical development for FPGA devices on NI reconfigurable I/O (RIO) hardware targets. You can create embedded FPGA VIs that combine direct access to I/O with user-defined LabVIEW logic to define custom hardware.

Figure 6. This LabVIEW code depicts a user-configurable, hardware-based FFT operation. It features fixed-point data processing, a dedicated 100 MHz clock domain in a single-cycle Timed Loop (100 MHz FFT clock), FIFOs to enter and exit the clock domain (FIFO to FFT and FIFO from FFT), flow control to ensure sample-accurate execution and account for multicycle IP latency, and a user-configurable FFT function (FFT).

Integrating HDL

While LabVIEW is an effective tool for FPGA programming, you may have existing hardware description language (HDL) intellectual property (IP) that you must integrate into your NI FlexRIO hardware applications. You have three options for doing this. The first is the IP Integration Node. This node provides a simple, inline interface to HDL IP and Xilinx CORE Generator XCO files. It features automatic LabVIEW interface generation and the ability to generate cycle-accurate simulation models for host execution. Using the latter functionality, you can run your LabVIEW FPGA VI on the host to ensure proper functionality before compiling it for the FPGA.

Figure 7. With the IP Integration Node, you can import VHDL and Xilinx CORE Generator XCO files. It automatically generates the LabVIEW interface (for use in a single clock domain) and creates a cycle-accurate simulation model for host PC code emulation.

For more complex HDL that may use multiple clock domains and execute asynchronously, the CLIP Node offers an interface. Through an XML wrapper, you import the HDL into LabVIEW and access it through I/O nodes. You also use the CLIP Node to interface to the NI FlexRIO adapter module as well as the FPGA module onboard DRAM. The CLIP Node executes asynchronously to the LabVIEW block diagram, can support multiple clocks, and is required for customizing certain features of the hardware such as the adapter module interface. This is different from the IP Integration Node, which executes inline with the LabVIEW block diagram and can be accurately simulated with the LabVIEW host simulation.

Figure 8. With the CLIP Node, you can import HDL or netlists through an XML wrapper file for asynchronous execution.

The Xilinx CORE Generator IP functions are designed to streamline the process for importing Xilinx CORE Generator files. The Xilinx CORE Generator uses the IP Integration Node to conveniently incorporate Xilinx CORE Generator IP into an FPGA VI by allowing you to configure the Xilinx CORE from within the LabVIEW environment.

Figure 9. The Xilinx CORE Generator IP functions incorporate the IP Integration Node and 
Xilinx CORE Generator so you can configure the Xilinx CORE from within LabVIEW.

NI FlexRIO Development Tools

NI FlexRIO development tools consist of the NI FlexRIO Instrument Development Library and the NI-573xR Example Instrument Driver. Both are available for download from

NI FlexRIO Instrument Development Library

The NI FlexRIO Instrument Development Library is a collection of LabVIEW Host and FPGA code designed to provide FPGA capabilities commonly found in instruments such as acquisition engines, DRAM interfaces, and trigger logic, along with the associated host APIs. This code is open and modular, so you can choose only the components you need, and it delivers efficient implementation. You also can use it to modify the code provided in the library, if necessary, to meet your unique application needs. 

Figure 10. The NI FlexRIO Instrument Development Library provides LabVIEW Host and FPGA 
code building blocks for capabilities commonly found in instruments.

NI-573xR Example Instrument Driver

The NI-573xR Example Instrument Driver builds on the NI FlexRIO Instrument Development Library to deliver a familiar software API and default FPGA personality for NI 573xR digitizer adapter modules. It helps you quickly begin taking measurements, modify both the LabVIEW Host and FPGA code to suit your application, and provides access to the full capabilities of user-customizable instrumentation hardware.

Figure 11. The NI-573xR Example Instrument Driver builds on the NI FlexRIO Instrument Development Library 
to provide a high-level Host API with an underlying FPGA acquisition engine.

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Software Recommendations

LabVIEW Professional Development System for Windows

  • Advanced software tools for large project development
  • Automatic code generation using DAQ Assistant and Instrument I/O Assistant
  • Tight integration with a wide range of hardware
  • Advanced measurement analysis and digital signal processing
  • Open connectivity with DLLs, ActiveX, and .NET objects
  • Capability to build DLLs, executables, and MSI installers


  • Design FPGA applications for NI reconfigurable I/O (RIO) hardware targets
  • Program with the same graphical environment used for desktop and real-time applications
  • Execute control algorithms with loop rates up to 300 MHz
  • Implement custom timing and triggering logic, digital protocols, and DSP algorithms
  • Incorporate existing HDL code and third-party IP including Xilinx CORE Generator functions
  • Included in the LabVIEW Embedded Control and Monitoring Suite

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Support and Services

System Assurance Programs

NI system assurance programs are designed to make it even easier for you to own an NI system. These programs include configuration and deployment services for your NI PXI, CompactRIO, or Compact FieldPoint system. The NI Basic System Assurance Program provides a simple integration test and ensures that your system is delivered completely assembled in one box. When you configure your system with the NI Standard System Assurance Program, you can select from available NI system driver sets and application development environments to create customized, reorderable software configurations. Your system arrives fully assembled and tested in one box with your software preinstalled. When you order your system with the standard program, you also receive system-specific documentation including a bill of materials, an integration test report, a recommended maintenance plan, and frequently asked question documents. Finally, the standard program reduces the total cost of owning an NI system by providing three years of warranty coverage and calibration service. Use the online product advisors at to find a system assurance program to meet your needs.

Technical Support

Get answers to your technical questions using the following National Instruments resources.

  • Support - Visit to access the NI KnowledgeBase, example programs, and tutorials or to contact our applications engineers who are located in NI sales offices around the world and speak the local language.
  • Discussion Forums - Visit for a diverse set of discussion boards on topics you care about.
  • Online Community - Visit to find, contribute, or collaborate on customer-contributed technical content with users like you.


While you may never need your hardware repaired, NI understands that unexpected events may lead to necessary repairs. NI offers repair services performed by highly trained technicians who quickly return your device with the guarantee that it will perform to factory specifications. For more information, visit

Training and Certifications

The NI training and certification program delivers the fastest, most certain route to increased proficiency and productivity using NI software and hardware. Training builds the skills to more efficiently develop robust, maintainable applications, while certification validates your knowledge and ability.

  • Classroom training in cities worldwide - the most comprehensive hands-on training taught by engineers.
  • On-site training at your facility - an excellent option to train multiple employees at the same time.
  • Online instructor-led training - lower-cost, remote training if classroom or on-site courses are not possible.
  • Course kits - lowest-cost, self-paced training that you can use as reference guides.
  • Training memberships and training credits - to buy now and schedule training later.
Visit for more information.

Extended Warranty

NI offers options for extending the standard product warranty to meet the life-cycle requirements of your project. In addition, because NI understands that your requirements may change, the extended warranty is flexible in length and easily renewed. For more information, visit


NI offers design-in consulting and product integration assistance if you need NI products for OEM applications. For information about special pricing and services for OEM customers, visit


Our Professional Services Team is comprised of NI applications engineers, NI Consulting Services, and a worldwide National Instruments Alliance Partner program of more than 700 independent consultants and integrators. Services range from start-up assistance to turnkey system integration. Visit

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Detailed Specifications

Reconfigurable FPGA
Device FPGA LUTs/Flip-Flops DSP48 Slices
(25 x 18 Multiplier)
Embedded Block
RAM (kbits)
NI PXI-7951R Virtex-5 LX30 19,200 32 1,152
NI PXI-7952R Virtex-5 LX50 28,800 48 1,728
NI PXI-7953R Virtex-5 LX85 51,840 48 3,456
NI PXI-7954R Virtex-5 LX110 69,120 64 4,608
NI PXI-7961R Virtex-5 SX50T 32,640 288 4,752
NI PXI-7962R Virtex-5 SX50T 32,640 288 4,752
NI PXI-7965R Virtex-5 SX95T 58,880 640 8,784


Default timebase


Timebase reference sources

NI PXI-795xR

  PXI 10 MHz

NI PXI-796xR

  PXIe 100 MHz

Timebase accuracy

NI PXI-795xR

  ±100 ppm, 250 ps
peak-to-peak jitter

NI PXI-796xR

  ±50 ppm, 250 ps
peak-to-peak jitter

Data transfers

  DMA, interrupts, programmed I/O

Number of DMA channels

NI PXI-795xR


NI PXI-796xR

FPGA Digital Input/Output

Number of general-purpose channels

  132, configurable as 132 single-ended, 66 differential, or a combination of both1

Channels per bank

Bank 0/Bank 2

  32, single-ended per bank

Bank 1/Bank 3

  34, single-ended per bank


  Configured via FPGA, 1.2 V to 3.3 V I/O standards (refer to


  Refer to


  Refer to

Maximum I/O data rates


  400 Mb/s for LVDCI25


  1 Gb/s for LVDS

Global clock inputs


Connection resources

NI PXI-795xR

  PXI triggers, Clk10, and PXI star trigger

NI PXI-796xR

  PXI triggers, Clk10, PXI star trigger, DStarA, DStarB, DStarC, and Sync100
Device Signals

                          1 RSVD_B2 on the NI PXI-795xR                                                                  2 RSVD_B1 on the NI PXI-795xR

Figure 1. NI FlexRIO FPGA Module Front Connector Pin Assignments and Locations

Onboard DRAM

Memory size

NI PXI-795xR

  2 banks; 64 MB per bank

NI PXI-796xR

  2 banks; 256 MB per bank

Maximum theoretical data rate

NI PXI-795xR

  800 MB/s per bank

NI PXI-796xR

  1.6 GB/s per bank
Bus Interface



Master, slave

PXI Express

Form factor

  x4 PXI Express, specification v1.0 compliant

Slot compatibility

  x4, x8, and x16 PXI Express or PXI Express hybrid slots
Maximum Power Requirement



Master, slave

NI PXI-795xR

+5 VDC (±5%)

  2 A

+3.3 VDC (±5%)

  2 A

+12 V


0.5 A

-12 V


0 A

NI PXI-796xR

+5 VDC (±5%)

  3 A

+3.3 VDC (±5%)

  2 A

Dimensions (not including connectors)

NI PXI-795xR

  18.8 cm × 12.9 cm (7.4 in. × 5.1 in.)

NI PXI-796xR

  16.1 cm × 10.8 cm (6.3 in. × 4.3 in.)


NI PXI-795xR

  190 g (6.7 oz)

NI PXI-796xR

  213 g (7.5 oz)

I/O connector

  High-density card edge
Maximum Working Voltage

Maximum working voltage refers to the signal voltage plus the common-mode voltage.


  0 V to 3.3 V, Measurement Category I


  0 V to 3.3 V, Measurement Category I

Caution   Do not use this device for connection to signals in Measurement Categories II, III, or IV.


This device is intended for indoor use only.

Operating environment

  0°C to 55°C, tested in accordance with IEC-60068-2-1 and IEC-60068-2-2.

Relative humidity range

  10% to 90%, noncondensing, tested in accordance with IEC-60068-2-56.


  2,000 m at 25°C ambient temperature

Pollution Degree


Storage environment

Ambient temperature range

  –40°C to 70°C, tested in accordance with IEC-60068-2-1 and IEC-60068-2-2.

Relative humidity range

  5% to 95%, noncondensing, tested in accordance with IEC-60068-2-56.
Shock and Vibration

Operational shock

  30 g peak, half-sine, 11 ms pulse, tested in accordance with IEC-60068-2-27. Test profile developed in accordance with MIL-PRF-28800F.

Random vibration


  5 Hz to 500 Hz, 0.3 grms


  5 Hz to 500 Hz, 2.4 grms, tested in accordance with IEC-60068-2-64. Nonoperating test profile exceeds the requirements of MIL-PRF-28800F, Class 3.
This product is designed to meet the requirements of the following standards of safety for electrical equipment for measurement, control, and laboratory use:
  • IEC 61010-1, EN 61010-1
  • UL 61010-1, CSA 61010-1

Note For UL and other safety certifications, refer to the product label or the Online Product Certification section.

Electromagnetic Compatibility

This product meets the requirements of the following EMC standards for electrical equipment for measurement, control, and laboratory use:

  • EN 61326 (IEC 61326): Class A emissions; Basic immunity
  • EN 55011 (CISPR 11): Group 1, Class A emissions
  • AS/NZS CISPR 11: Group 1, Class A emissions
  • FCC 47 CFR Part 15B: Class A emissions
  • ICES-001: Class A emissions

Note For the standards applied to assess the EMC of this product, refer to the Online Product Certification section.

Note EMC compliance evaluated with a wrapback adapter module and general purpose I/O (GPIO) signals configured to LVTTL I/O standard, slew rate set to slow, and drive strength set to 6 mA. EMC compliance of other I/O standards, faster slew rates, and greater drive strength is not guaranteed.

CE Compliance
This product meets the essential requirements of applicable European Directives, as amended for CE marking, as follows:
  • 2006/95/EC; Low-Voltage Directive (safety)
  • 2004/108/EC; Electromagnetic Compatibility Directive (EMC)
Online Product Certification
Refer to the product Declaration of Conformity (DoC) for additional regulatory compliance information. To obtain product certifications and the DoC for this product, visit, search by module number or product line, and click the appropriate link in the Certification column.
Environmental Management

National Instruments is committed to designing and manufacturing products in an environmentally responsible manner. NI recognizes that eliminating certain hazardous substances from our products is beneficial not only to the environment but also to NI customers.

For additional environmental information, refer to the NI and the Environment Web page at This page contains the environmental regulations and directives with which NI complies, as well as other environmental information not included in this document.

Waste Electrical and Electronic Equipment (WEEE)

EU Customers At the end of the product life cycle, all products must be sent to a WEEE recycling center. For more information about WEEE recycling centers, National Instruments WEEE initiatives, and compliance with WEEE Directive 2002/96/EC on Waste Electrical and Electronic Equipment, visit


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