The Benefits of FPGA-Enabled Instruments

in RF and Communications Test

1

Johan Olsson

National Instruments Sweden AB

Agenda

• Introduction to FPGAs in test

• New FPGA-enabled test applications

• FPGA for test hardware

• Using FPGA instruments in test applications

2

• Using FPGA instruments in test applications

Software-Defined Test System Architecture

Software Hardware

DriverNI LabVIEW

Measurement

Analog or

Digital

Front End

Bus Interface

and I/O Control

Standard Virtual

Instrumentation

Model

3

10011011

FPGA-Based Test System Architecture

DriverLabVIEW

Open FPGA

System

Model

Measurement

Analog or

Digital

Front End

Bus Interface/

Programmable

FPGA

4

• System intelligence and decision making

can be moved from software to hardware

Software NI Hardware

Benefits of FPGAs in Test Systems

• High Reliability – Designs implemented in hardware

• Low Latency – Run algorithms at deterministic rates down to 5

ns

• Reconfigurable – Create DUT / application-specific

personalities

5

personalities

• High Performance – Computational abilities open new

possibilities for measurement and data processing speed

• True Parallelism – Enables parallel tasks and pipelining,

reducing test times

New FPGA-enabled test applications

6

Stimulus

RFID Testing – Response-Stimulus RFID

Reader (Emulated)RFID

Tag (DUT)

7

Response

RFID Testing – Response-Stimulus

• Testing an RFID tag requires emulating the tag reader

� Interrogates and responds to tag within microseconds

• Coding/decoding, modulation/demodulation, and decision

making must be completed in hardware to meet timing

Closed-Loop Test

8

Test

Real-time spectral measurements

Processing

9

RF

Processing

A Simple Digital Protocol: I2C

Integrated

Circuit

SDA

SCL

Pattern Generator010ZZ01

10

SCL

Logic Analyzer

Traditional Approach

• Static stimulus and expected responses

• Difficult to accommodate multiple clock domains

0101101

A Simple Digital Protocol: I2C

Integrated

Circuit

SDA

SCL

Protocol-Aware

Tester

Address, Data, Address, Receive

Protocols

11

Protocol-Aware Approach

Response Data

• Intelligence built into the

tester• Accommodates wait cycles

• Easy to cross clock domains

• Test with high-level

commands • Real-world scenario

• Inherently easier to program

Protocols

Test System Control

PXI Data or Trigger Bus

• Transfer of system timing and decision making from software to

hardware

System

Controller

(FPGA)

DUT

Instrument

Controller

(SMC)

Instrument

Controller

(SMC)

AD

C

DA

C

Digital Communication

FPGA for Test Hardware

13

National Instruments FlexRIO

PXI

14

• Synchronization

• Clocking/triggers

• Power/cooling

• Data streaming

PXI PlatformNI FlexRIO FPGA Module

• Virtex-5 FPGA

• 132 digital I/O lines

• 128 MB of DDR2 DRAM

NI FlexRIO Adapter Module

• Interchangeable I/O

• Customizable by users

• Adapter Module

Development Kit (MDK)

NI FlexRIO FPGA Modules for PXI

• Virtex-5 FPGA� LX30, LX50, LX85, LX110

• Direct access to FPGA I/O� 132 single-ended lines or 66

differential pairs

� 400 Mbps single-ended

15

� 1 Gbps differential

• 128 MB onboard DRAM� 2x 64 MB banks

� 800 MB/s per bank

• Adapter module required for IO

NI 6581

High-Speed Digital Adapter Module

� 100 MHz digital I/O

� 54 single-ended channels

� Selectable voltage levels

16

� 1.8, 2.5, 3.3 V (5 V compatible)

� External DIO voltage reference

� 1.8 to 5.5 V

� Configurable by connector

NI 6581

NI 6585

200 MHz LVDS Digital Instrument

� 200 MHz digital I/O

� 32 / 42 LVDS channels

� 200 Mbps SDR, 300 Mbps DDR

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� 200 Mbps SDR, 300 Mbps DDR

PXI-6585R

• Gigabit Ethernet

interfaces

• MAC and Ethernet

frames

• Fault-injection software

• Camera Link Interface

• High-speed image processing

• Low-latency control

NI FlexRIO Partner Modules

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• IEEE-1394b interface

• 3 ports at 800 Mbps

• 100 MHz vector digital

I/O

• 8 ch. per-pin PMU

NI PXIe-5641R RIO IF Transceiver

• 2 IF Inputs and 2 IF Outputs

• 14-bit ADCs and DACs

• 20 MHz Instantaneous

Bandwidth (25 MS/s I/Q)

• IFs from 250 kHz to 80 MHz

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• IFs from 250 kHz to 80 MHz

• Xilinx Virtex-5 SX95T

LabVIEW-programmable

FPGA

How these instruments fit into test

applications

20

applications

RFID Testing – Response-Stimulus

• FPGA on PXIe-5641R IF Transceiver can perform

necessary processing

• Upconverter and downconverter condition the

signal for the correct RF frequency of the tag

PXI-5610

21

PXI-5610

UpconverterRFID

TagPXI-5600

Downconverter

A Real-Time Spectrum Analyzer

22

A Simple Digital Example: I2C

Integrated

Circuit

SDA

SCL

Protocol-Aware

Tester

Address, Data, Address, Receive

23

Protocol-Aware Approach

Response Data

• Intelligence built into the

tester• Accommodates wait cycles

• Easy to cross clock domains

• Test with high-level

commands • Real-world scenario

• Inherently easier to program

Digital Filter LabVIEW FPGA Implementation

I/O Node

IP

Integratio

n Node

FIFO

24

I/O Node

FIFOFIFO

FIFO

NIWeek 2009 Case StudyLTE Base Station Emulator Prototype

NI PXIe-8108 Real-Time Dual-Core Controller

NI PXIe-5641R IF Transceiver

NI PXI-5610 2.7 GHz RF Upconverter

LTE PHY Base Station Transmitter

fc

25

NI PXI-5600 2.7 GHz RF Downconverter

Device Under Test

Higher-Layer SW and Link Control

LTE PHY Base Station Receiver

fc

Conclusions and additional resources

• FPGAs enable some types of test

applications not previously possible, and

make others faster

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www.ni.com/automatedtest

www.ni.com/flexrio

www.ni.com/iftransceivers

http://www.ni.com/rf