Furaxa SYNTH300D User manual

SYNTH300D
Dual 300kHz - 300MHz Direct Digital Synthesizer
(Also covers SYNTH300S version)
PRELIMINARY Product Specification and Manual – v1.0
April 15, 2004
Covers Boards With Firmware rev 0.95 (12/1/03)
For Windows XP TM, Windows 2000 TM, Linux TM 7.2 and Solaris 8TM
Furaxa, Inc.
34 Canyon View, Orinda, CA 94563
[phone]
Fax [phone]
e-mail : [email protected]
URL : www.furaxa.com
copyright c 2004 Furaxa, Inc.

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TABLE OF CONTENTS
1. WARRANTY .........................................................................................................................................4
2. MODEL DESCRIPTIONS ...................................................................................................................5
2.1 MODEL SYNTH300D....................................................................................................................5
2.2 MODEL SYNTH300S ....................................................................................................................5
3. SPECIFICATIONS ...............................................................................................................................5
3.1 SYNTHESIZER OUTPUTS ....................................................................................................................5
3.2 FREQUENCY STABILITY ....................................................................................................................6
3.3 PHASE RESOLUTION .........................................................................................................................6
3.4 TTL TRIGGER/MODULATION INPUTS................................................................................................6
3.5 TTL OUTPUTS ..................................................................................................................................6
3.6 GENERAL..........................................................................................................................................6
3.7 PHYSICAL .........................................................................................................................................6
4. HARDWARE ARCHITECTURE .......................................................................................................7
4.1 SYNTHESIZER A&BOUTPUTS (DDS AOUT, DDS BOUT)..........................................................7
4.2 CONTROL TTL OUTPUT CONNECTOR ...............................................................................................7
4.2.1 AUX/MODA and TRIG/MODB Input Lines ............................................................................9
4.2.2 TTL_Out[7..0] .........................................................................................................................9
4.3 LED INDICATOR...............................................................................................................................9
5. HARDWARE INSTALLATION AND SETUP................................................................................10
6. SOFTWARE INSTALLATION AND SETUP .................................................................................11
6.1 SOFTWARE INSTALLATION FOR WINDOWS 2000 OR WINDOWS XP TM............................................11
6.1.1 Disabling the “Found New Hardware” prompt....................................................................11
6.1.2 Continuing with the software installation in 2000 and XP....................................................12
6.2 SOFTWARE INSTALLATION FOR SOLARIS 9, 8OR 7(SPARC PLATFORM EDITION ONLY)TM .............12
6.3 SOFTWARE INSTALLATION UNDER REDHATTM LINUX ....................................................................13
7. RUNNING SYNTH300 PROGRAMS ...............................................................................................15
7.1 USING THE SYNTH300 SERIES UNDER WINDOWS 2000/XP ............................................................15
7.2 USING THE SYNTH300 SERIES UNDER LINUX OR SOLARISTM..........................................................15
7.2.1 Example: Synthesizing two sinusoids with independent frequencies....................................15
7.2.2 Example: Sythesizing a 4-FSK signal...................................................................................16
7.2.3 Example: Synthesizing a QPSK signal .................................................................................16
7.2.4 Example: Frequency sweeping.............................................................................................16
7.2.5 Example: External modulation control ................................................................................16
8. USING THE SYNTH300 GUI UNDER WINDOWS XP.................................................................18
8.1 EXAMPLE #1 –TWO INDEPENDENT SINUSOIDS ...............................................................................19
8.2 EXAMPLE #2 –PHASE-LOCKED SINUSOIDS .....................................................................................20
8.3 EXAMPLE #3 –TWO FULLY INDEPENDENT SWEPT SINUSOIDS .........................................................21
8.4 EXAMPLE #4 –EXTERNAL MODULATION EXAMPLE .......................................................................22
9. LOW LEVEL SOFTWARE INTERFACE.......................................................................................23
9.1 PCI CONFIGURATION HEADER .......................................................................................................23
9.2 SYNTH300 CONTROL REGISTER ...................................................................................................23
9.2.1 Unreset (write only)...............................................................................................................24

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9.2.2 Update Frequency/Phase (write only)...................................................................................24
9.2.3 Synthesizer A Profile Select (write only) ...............................................................................24
9.2.4 Synthesizer B Profile Select (write only) ...............................................................................24
9.2.5 External Modulation Mode (write only)................................................................................25
9.2.6 Enable External Modulation (write only)..............................................................................25
9.2.7 Write is to Synth B, Write is to Synth A (write only)..............................................................25
9.2.8 Synthesizer IC Register Address (write only) ........................................................................26
9.2.9 Sample IC Data Word (write only)........................................................................................26
9.3 AUXILIARY REGISTER.....................................................................................................................28

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1. Warranty
Furaxa, Inc. hardware, software and firmware products are warranted against defects in materials
and workmanship for a period of two (2) years from the date of shipment of the product. During
the warranty period, Furaxa, Inc. shall, at its option, either repair or replace hardware, software or
firmware products which prove to be defective. This limited warranty does not cover damage
caused by misuse or abuse by customer, and specifically excludes damage caused by the
application of excessive voltages to the inputs and/or outputs of data acquisition boards. The
limited warranty additionally excludes damage caused by overheating due to installation of the
product in systems that do not have direct forced air flow over the PCI bus slots.
While Furaxa, Inc. hardware, software and firmware products are designed to function in a
reliable manner, Furaxa, Inc. does not warrant that the operation of the hardware, software or
firmware will be uninterrupted or error free. Furaxa products are not intended to be used as
critical components in life support systems, aircraft, military systems or other systems whose
failure to perform can reasonably be expected to cause significant injury to humans. Furaxa
expressly disclaims liability for loss of profits and other consequential damages caused by the
failure of any product, and recommends that customer purchase spare units for applications in
which the failure of any product would cause interruption of work or loss of profits, such as
industrial, shipboard or military equipment.
THIS LIMITED WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES EXPRESSED OR
IMPLIED. THE WARRANTIES PROVIDED HEREIN ARE BUYER’S SOLE REMEDIES. IN NO
EVENT SHALL FURAXA, INC. BE LIABLE FOR DIRECT, SPECIAL, INDIRECT, INCIDENTAL
OR CONSEQUENTIAL DAMAGES SUFFERED OR INCURRED AS A RESULT OF THE USE
OF, OR INABILITY TO USE THESE PRODUCTS. THIS LIMITATION OF LIABILITY REMAINS
IN FORCE EVEN IF FURAXA, INC IS INFORMED OF THE POSSIBILITY OF SUCH DAMAGES.
Some states do not allow the exclusion or limitation of incidental or consequential damages, so
the above limitation and exclusion may not apply to you. This warranty gives you specific legal
rights, and you may also have other rights which vary from state to state.

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2. Model Descriptions
The SYNTH300 series of Direct Digital Synthesizer (DDS) boards are complete low noise
precision synthesizers on a single PCI bus card. Designed for low jitter operation in
communications, industrial and scientific applications these boards function in PCI bus systems
using supplied drivers for Windows 2000TM or XPTM ,Solaris 8 (Sparc Platform EditionTM 10/00 or
later, Linux (Red HatTM 7.2, or Solaris 8TM or 9 (Sparc Platform Edition). In addition to their single
or dual synthesizers, all SYNTH300 boards have two TTL inputs which can be used to
dynamically switch between up to four frequency profiles, for generating modulated waveforms.
2.1 MODEL SYNTH300D
Model Synth300D is a Dual-channel DDS board having two independent Direct Digital
Synthesizers,each separately programmable for any frequency between 300kHz and 300MHz in
increments of approximately 0.223 Hz.
2.2 MODEL SYNTH300S
Model Synth300S is a Single-channel DDS board having a single Direct Digital
Synthesizers,each separately programmable for any frequency between 300kHz and 300MHz in
increments of approximately 0.223 Hz.
3. Specifications
3.1 Synthesizer outputs
Number of DDS Output Channels: 2, independently programmable, or single
channel ( Model SYNTH300S)
Analog output voltage (into 50 ohms): 250mV RMS +/-10% from 2-200MHz
250mV RMS +/-20% from 300kHz-300MHz
Output impedance: 50 ohms || 10pF
Output connectors: Two SMA connectors.
Wideband SFDR (DC to Nyquist):
40MHz Fout 60 dBc
100MHz Fout 54 dBc
180MHz Fout 53 dBc
Narrowband SFDR:
40MHz Fout (+- 1 MHz) 87 dBc
40MHz Fout (+- 50 kHz) 88 dBc
100MHz Fout (+- 1 MHz) 82 dBc
100MHz Fout (+- 50 kHz) 86 dBc
180MHz Fout (+- 1 MHz) 84 dBc
180MHz Fout (+- 50 kHz) 85 dBc

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Output Phase Noise (103MHz Iout):
@ 1kHz Offset -147 dBc/Hz
@ 10kHz Offset -150 dBc/Hz
@ 100kHz Offset -152 dBc/Hz
3.2 Frequency stability
Initial frequency accuracy +/-0.01% of specified frequency +/-0.223Hz
3.3 Phase Resolution
The intra-synthesizer (Synth A to Synth A) phase relationship is limited only by the DDS phase
resolution (14 bits). The inter-synthesizer (Synth A to Synth B) phase relationship is not
guaranteed to this accuracy, and varies proportional to the frequency of synthesis.
3.4 TTL Trigger/Modulation inputs
Number of TTL Input lines: 2, Standard TTL (V0l < 0.8V, Vih > 2.4V)
3.5 TTL Outputs
Number of TTL Ouput lines: 8, software programmable
Standard TTL (V0l < 0.8V, Vih > 2.4V)
8mA max output drive
3.6 General
Operating Temperature Range: 0 to +55 Degrees Celsius
Storage Temperature Range: -25 to +85 Degrees Celsius
Power Requirements:
SYNTH300D: +5V +/-5% at 0.3A Maximum
+3.3V +/-5% at 1.5A Maximum
SYNTH300S: +5V +/-5% at 0.3A Maximum
+3.3V+/-5%at1AMaximum
3.7 Physical
SYNTH300 boards are half size 32-bit PCI bus boards, which will operate in either 64-bit or 32-bit
33MHz or 66MHz PCI slots with either 5V or 3.3V signalling environment. The figure below
shows the locations of the SMA signal output and digital I/O connectors, and LED indicator.
To avoid overheating, all SYNTH300 boards must be installed a in well-cooled workstation,
PC or server chassis.

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Figure 3.1 SYNTH300D PCI Board (SYNTH 300S Similar)
4. Hardware Architecture
SYNTH300 series boards are comprised of a digital section and an analog section. The digital
section includes a high speed programmable logic devices which implement the bus interface
and the PCI interface.
The analog section contains a 1GHz low-jitter clock, and one or two single-chip Direct Digital
Synthesizer (DDS) ICs. The current outputs of each DDS are fed to a broadband RF
transformer and 300MHz low-pass filter.
4.1 Synthesizer A & B Outputs (DDS A OUT, DDS B OUT)
The two analog synthesizer outputs have SMA connectors and provide analog sine wave signals
with amplitude 0dBm 220mV RMS into 50 ohms). The frequency, frequency sweep (if any) rate,
and other parameters are software programmable. The output amplitude is fixed. If a lower
amplitude is desired, a wide range of 50 ohm coaxial attenuators, such as those from Mini-
Circuits (Brooklyn, NY) may be used.
4.2 Control TTL Output connector
Reserved for future use.
.
Note: EXTREME CARE MUST BE TAKEN TO ENSURE THAT NO VOLTAGES GREATER
THAN +/-3V ARE EVER CONNECTED TO ANY ANALOG OUTPUT, AND NO VOLTAGE
OUTSIDE THE 0 TO +5V RANGE IS EVER APPLIED TO ANY OTHER LINE.

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Pin Signal Name Pin Signal Name
1 TTL OUT 0 2 Digital GND
3 TTL OUT 1 4 Digital GND
5 TTL OUT 2 6 Digital GND
7 TTL OUT 3 8 Digital GND
9 TTL OUT 4 10 Digital GND
11 TTL OUT 5 12 Digital GND
13 TTL OUT 6 14 Digital GND
15 TTL OUT 7 16 Digital GND
17 Not used 18 Digital GND
19 Not used 20 Digital GND
21 Not used 22 Digital GND
23 Not used 24 Digital GND
25 Not used 26 Digital GND
Figure 4.1. Pinout for I/O cable for SYNTH300 models. .
PIN 25 Not used
PIN 23 Not used
PIN 21 Not used
PIN 19 Not used
PIN 17 Not used
PIN 15 TTL OUT 7
PIN 13 TTL OUT 6
PIN 11 TTL OUT 5
PIN 9 TTL OUT 4
PIN 7 TTL OUT 3
PIN 5 TTL OUT 2
PIN 1 TTL OUT 0
PIN 3 TTL OUT 1
PIN 26 Digital Ground
PIN 24 Digital Ground
PIN 22 Digital Ground
PIN 20 Digital Ground
PIN 18 Digital Ground
PIN 16 Digital Ground
PIN 14 Digital Ground
PIN 12 Digital Ground
PIN 10 Digital Ground
PIN 8 Digital Ground
PIN 6 Digital Ground
PIN 4 Digital Ground
PIN 2 Digital Ground
Figure 4.2 Bottom view of mating I/O connector for 26-conductor I/O cable.

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4.2.1 AUX/MODA and TRIG/MODB Input Lines
Two (2) TTL-compatible Trigger/Modulation signals permit low-latency switching between four
frequency/phase profiles for each synthesizer. This external modulation functionality enables
frequency/phase profile switching for applications in which the overhead or uncertainty of
software-controlled frequency/phase profile selection is not acceptable. The MOD_A and
MOD_B inputs are synchronized with the on-board 125MHz clock
The synthesizer profile selection is controlled by the 2 external TTL bits as described in section
9.2.5.
UNDER NO CIRCUMSTANCES MAY VOLTAGES BELOW 0V OR ABOVE +5V BE
CONNECTED TO THE TRIGGER/MODULATION INPUT JACKS.
4.2.2 TTL_Out[7..0]
Reserved for future use.
4.3 LED Indicator
The Red/Green LEDs on the top edge of the SYNTH300 board are useful during system
integration for monitoring the board status. The functions of the LEDs are outlined below.
CASE 1: NO EXTERNAL MODULATION: If the LED illuminates with a green color, and external
modulation has not been enabled, this means that the synthesizers have not yet been unreset
(via the software unreset command). If the LED illuminates with a red color, and external
modulation has not been enabled, this means that the synthesizers have been unreset and are
therefore running.
CASE 2: EXTERNAL MODULATION ENABLED: If the LED illuminates with a red color, this
means that the MOD A and MODB inputs are both 0, If the LED does not illuminate, and the
board has been told to run, this means that either the MOD A or MOD B input is 1.

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5. Hardware Installation and Setup
Before you begin, be sure your system has at least 256MB installed RAM. To avoid
overheating, the SYNTH300 must be installed in a well-cooled workstation or server
chassis, or alternatively in an industrial chassis PC. Installation in a standard desktop PC
without fans at the front end of the card cage may cause the SYNTH300 to overheat, and
resulting damage is not covered by warranty.
1. Use the shutdown command on your system and then turn OFF the power to the system.
BEFORE REMOVING THE COMPUTER SYSTEM COVER OR REMOVING ANY BOARD, BE
SURE THAT THE POWER TO THE COMPUTER, AS WELL AS TO ALL PERIPHERAL
DEVICES IS OFF. WEAR A STATIC-DISSIPATING WRISTBAND WHICH IS GROUNDED TO
THE SYSTEM CHASSIS WHILE OPENING OR WORKING ON YOUR SYSTEM.
2. Remove any screws that attach the computer system cover and remove the cover.
3. Remove the filler bracket from the PCI bus slot into which you wish to install your
SYNTH300 board. If a mixture of 5V and 3.3V slots are available in the system, choose a 32-bit
5V slot as your first preference. If that is not available, install it in a 32 or 64-bit 3.3V slot. For
details, refer to the hardware manual for your computer system.
4. Hold the SYNTH300 board by the top of the metal PCI bracket. Then hook the tab on the
bottom edge of the SYNTH300's metal bracket into the corresponding slot in the computer's rear
panel. Carefully push the SYNTH300 down so its PCI bus connector mates with the PCI bus
connector on the motherboard. Be sure that the SYNTH300 is seated firmly into the motherboard
PCI bus connector. Check that no other PCI boards have become unseated when the
SYNTH300 was installed, as motherboards may flex slightly when installing PCI boards.
5. Plug coaxial I/O cables for the analog outputs into the appropriate SMA connectors on
the SYNTH300's rear bracket at the rear of the system. Please refer to the diagram on page 8 of
this manual.
6. We recommend that synthesizer output channels Aand B (the 1st and 2nd SMA
connectors from the bracket top) initially be connected to an oscilloscope set for 200mV/div., so
you can observe the two synthesized waveforms operation when running the example software.
7. Replace the computer system cover, installing all screws you had removed. Reconnect
the power cables to the system and peripherals.
8. Power up and reboot the system. The system will then be ready for software installation.

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6. Software Installation and Setup
6.1 Software Installation for Windows 2000 or Windows XP TM
When you reboot your system for the first time with the Synth300 board, you may see a “Found
New Hardware Wizard” prompt. In order to disable this prompt upon powerup, complete the
following sequence:
6.1.1 Disabling the “Found New Hardware” prompt
6.1.1.1 Windows XP TM
The first step of the “Found New Hardware Wizard” prompts the user to select from one of two
methods for installing the drivers for the newly found “PCI Data Acquistion and Signal Processing
Controller”. The two options are as follows:
•Install the Software Automatically (recommended)
•Install from List or Specific Location (advanced)
The default option is to “Install the Software Automatically”, leave this as the selected option and
press “NEXT”. The wizard will search for an appropriate driver (this may take several minutes).
The wizard will prompt the user that it “Cannot Install this Hardware”. This is desired as
management of the driver is facilitated by the Synth300 executable. At the bottom of the current
window is a check box with the caption “Don’t prompt me again to install this software”. On
default the box is checked, insure that it is checked and press “FINISH”.
Note that if the user selects cancel at any step the “Found New Hardware Wizard” will run each
time after the system is rebooted. The above sequence must be completed to disable the wizard.
6.1.1.2 Windows 2000 TM
The first step prompts the user to install a device driver for a hardware device. Hit “next” to
continue. The next screen prompts the user to select from one of two methods for searching for
the driver. Choose the default option, “search for a suitable driver” and hit “next”. At the next
screen (options for search) hit “next”. Allow the search to complete. The wizard will then prompt
the user that “Windows was unable to locate a driver for this device”. This is desired as
management of the driver is facilitated by the Synth300 executable. The default option is to
disable the device. Insure that this option is selected, and press “Finish” to close.
Note that if the user selects cancel at any step the “Found New Hardware Wizard” will run each
time after the system is rebooted. The above sequence must be completed to disable the wizard.

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6.1.2 Continuing with the software installation in 2000 and XP
Before installing the software, be sure the board is installed in the system. Then, insert the
diskette titled SYNTH300 DRIVER PKG WITH USER DEMO SOFTWARE - FOR
Win2000/WinXPTM Create a directory for installing the SYNTH300 software, as follows:
C:> mkdir furaxa
Then, copy the entire contents of the diskette to the new directory as follows:
C:> xcopy a: C:\furaxa /s /e /v
To run the software, please refer to the chapter entitled Running the Example Programs Under
Windows 2000 or XPTM.
Windows, Windows 2000 and Windows XP are trademarks of Microsoft Corp TM.
6.2 Software Installation for Solaris 9, 8 or 7 (Sparc Platform Edition
only)TM
Before installing the software, be sure the board is installed in the system. Solaris 8 or 9 are the
preferred OS versions.
To begin the software installation insert the diskette titled SYNTH300 DRIVER PKG WITH
USER-DEMO SOFTWARE-FOR SOLARIS 8 or 9 SPARC.
Log in as root, and type in the following two lines at the prompt (shown here as #):
# volcheck
# pkgadd -a none -d /floppy/floppy0/uvpci
You will be shown a list of packages on the diskette and asked which you wish to install. You
can just take the default (press Return) to install the package.
Next, the installation script will ask you which directory should be the base directory for the
package. You can choose /opt/furaxa, or choose some other place on your system. You should
choose an empty directory for installation; extra files or directories might cause problems.
The pkgadd program may issue a warning about /etc/devlink.tab; ignore the warning, as it is just
going to modify the file, not overwrite it.
You may also see a question about running programs with superuser permissions – you should
just answer yes to this.
Once all the files have been copied to the base directory, some installation scripts are
automatically run, giving a usable binary distribution of the package.
One of the questions you are asked by the post-installation script is whether you wish to
recompile the package. If you have the Gnu C compiler (this compiler is free from Gnu and is the
recommended compiler for developing software for the Ultrad boards) or the SunPro C compiler,

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you can recompile. You will be asked where the compiler resides (eg. /opt/gnu/bin/).
Just before returning to the prompt, pkgadd will warn you that you need to reboot your system,
since a new driver has been added. Now it is necessary to reboot the system as shown below :
# /usr/bin/shutdown -y -i6 -g0
When the system reboots, the driver will be installed and operational.
After the driver has been installed as described above, it is now possible to immediately run the
demonstration programs. Go to the installation directory, to run a dual channel synthesizer
demo. Connect an the two DDS outputs (The top two SMA connectors) to two channels of an
oscilloscope set for 200mV/Div and 10 µs per division.
Now, run the example program “synth”; This example, which can be invoked with command line
arguments that specify the output frequencies for each synthesizer, the frequency sweep rate
and step size (if specified), and other parameters, are described in the next chapter.
Synth.c is commented, and is a good starting point for users who are developing their own code.
It can easily be modified and recompiled by suitably modifying the makefile and then typing
“make”.
6.3 Software Installation under RedHatTM Linux
Before installing the software, be sure the board is installed in the system. RedHat Linux 7.2 is
the preferred OS. While other versions of Linux may be usable, Furaxa can only support
installations in which the RedHat Linux 7.2 is used.
To avoid interruptions in synthesis, and hanging of user programs, permanently turn off all
power management options, screen savers, etc. The system must always remain in full-
power mode when running the synthesizer, and must not be allowed to go into sleep
mode, or even screen saving mode when the board is running.
To begin the software installation insert the diskette titled SYNTH300 DRIVER PKG WITH
USER-DEMO SOFTWARE-FOR RedHatTM LINUX 7.2.
Log in as root, and type in the following two lines at the prompt (shown here as #):
# mkdir /Furaxa (or other directory you wish to install the software in)
# cd Furaxa
# tar xvf /dev/fd0
Follow the directions in the README file, as well as the section “Running the Example Programs
under Linux”, below, for running the example programs.
If you wish to recompile the programs, you will need access to the kernel headers and
configuration used to build the kernel you are going to compile the driver against. If this kernel
source is not yet installed on your system, it must be installed. For example, on the second
binary CD of the RedHat Linux 7.2 CD set, there is a package:
/mnt/cdrom/RedHat/RPMS/kernel-source-2.4.7-10.i386.rpm
This should be installed. Once this package has been installed, do the following (the actual

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directories and file names may vary if you are using a different version of Linux):
# cd /usr/src/linux-2.4
# cp configs/kernel-2.4.7-i686.config .config
There should now be a file .config in your /usr/src/linux-2.4 directory. You may now go back to
/Furaxa and type “make clean” (which will remove the precompiled objects and executables),
followed by “make”. This should cause a rebuild of the entire release.

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7. Running Synth300 programs
The Synth300 series is supported under Windows 2000/XP, Solaris, and Linux. A GUI program
is provided (Synth300.exe) for Windows 2000/XP users. No such GUI is currently provided for
Solaris and Unix users, though a command line program (synth.exe) provides functionality that
users will find sufficient for a large number of applications.
Object Oriented (C++) as well as ANSI C source code is provided with simple function calls to
support custom application programming. This code is outlined further in the Synth300
Programmer’s Guide to be released in May of 2004.
7.1 Using the Synth300 series Under Windows 2000/XP
Running the Synth300 board under the Windows 2000/XP environment allows the use of a highly
functional user interface program, Synth300.exe. This program, outlined further in section 8 of
this document allows the user to specify each of the frequency and phase profiles for each
synthesizer, and select the active profile easily. Additionally, frequency sweeping capabilities can
be enabled and specified, and the board can be set for the two modes of external modulation.
This program will allow the user to access most of the features of the Synth300 board.
After the selecting and entering the fields, the user simply clicks on the “Configure Board” button
to program the Synth300. It is important to remember that no changes take effect until the
user selects “Configure Board”.
If an even higher level of control is desired, the user may modify the C code provided to create
custom user programs. The user library is provided in simple to use function calls, and the
compiled driver is supplied. Please refer to section 8 of this document and the Synth300
Programmer’s Guide for further detail.
7.2 Using the Synth300 series Under Linux or SolarisTM
There is a single directory (/Furaxa under Linux, or /opt/Furaxa under Solaris) with both source
and executables for the example program (synth.exe), which can immediately be run to
demonstrate the use of the board, and which forms an excellent basis for developing your own
custom software for the board. Full source and makefiles are provided, allowing for easy
modification and recompilation.
7.2.1 Example: Synthesizing two sinusoids with independent frequencies
The program synth.exe causes the SYNTH300X2 to generate waveforms of two different
frequencies, on its two DDS outputs.
The program may be invoked as in the following example:
# synth -f8000000 –g8000001
where..

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-f in this example instructs synthesizer A to generate an 8MHz signal.
-g in this example instructs synthesizer B to generate an 8.000001 MHz signal.
By attaching an oscilloscope to the two DDS outputs, two sine waves will be observed, with one
sine wave static (the signal on which the oscilloscope channel is triggered) and the second sine
wave slowly moving with respect to the first, with a 1Hz difference frequency.
If frequencies greater than 300 MHz are specified the output may not be usable.
7.2.2 Example: Sythesizing a 4-FSK signal
Invoking Synth.exe with the command line option –x1, as below,
# synth -x1
causes the SYNTH300D or SYNTH300S to generate a waveform emulating a 4-state Frequency
Shift Keyed waveform on the Synth_A channel. The four frequencies are determined by the 4
profiles in Synthesizer.h. Simple modification of the source code allows external modulation and
alternate FSK implementations.
7.2.3 Example: Synthesizing a QPSK signal
Invoking Synth.exe with the command line option –x2, as below,
# synth -x2
causes the SYNTH300D to generate a waveform emulating a 4-state Phase Shift Keyed (QPSK)
waveform at an IF frequency on the Synth_B channel. The four phases are determined by the 4
profiles. Simple modification of the source code allows external modulation and alternate PSK
implementations.
7.2.4 Example: Frequency sweeping
Invoking Synth.exe with the command line option –x3, as below,
# synth -x3
causes the SYNTH300 to generate a waveform with an increasing frequency, often called a
frequency sweep on both channels. The initial frequency and sweep rate are determined by
variables in Synthesizer.h. Simple modification of the source code allows external modulation
and alternate PSK implementations.
7.2.5 Example: External modulation control
Invoking Synth.exe with the command line option –x4, or –x5 as below,
# synth -x4

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or
# synth -x5
causes the SYNTH300 to enable external modulation. Invoking synth.exe with the “–x4” option
will allow external modulation as described in section 8.2.5 (MODMODE = 0). Invoking synth.exe
with the “–x5” option will allow external modulation as described in section 8.2.5 (MODMODE =
1). often called a frequency sweep on both channels. The frequency and phase profiles are
determined by variables in Synthesizer.h. Simple modification of the source code allows
alternate implementations.

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8. Using the Synth300 GUI under Windows XP
Synth300.exe is a simple-to-use User Interface program for use under Windows XP. Double-
clicking on the Synth300.exe icon will bring up the Furaxa Synth300 window below:
The window has four sections. The upper right section controls the settings for Synthesizer A.
The lower right section controls the settings for Synthesizer B. The upper left hand window shows
the configuration that has most recently been written to the synthesizer board initiating the
current settings and resulting outputs. Finally, the two check boxes at the bottom left control
modulation choices.
For a given use, the user simply enters the desired frequencies and phases for each synthesizer,
(and frequency sweeping and/or external modulation if desired) and then clicks on “Configure
Board”. It is important to note that no change will occur until the user clicks on the
“Configure Board” button (or hits “return”).
A few examples of common applications follow:

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8.1 Example #1 – Two independent sinusoids
123.000000 MHz is generated on Synth A, and 220.000001MHz on Synth B. Notice that “Profile
0” is selected on each synthesizer by use of the bullets to the right of the frequence and phase
settings. Press “Configure Board” to accept these settings.

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8.2 Example #2 – Phase-locked sinusoids
5.000000 MHz is generated on Synth A, and 5.000000MHz on Synth B with a 90 degree phase
offset. Profile 1 was used for both synthesizers, while retaining the Profile 0 settings. Each
synthesizer has four independent frequency and phase profiles.