fpga control througg vpx backplane

[higgi02]

Hi, being fairly new to FPGA's I need some advice regarding the hardware testing. I am using a Spartan 6 and have a design created using ISE design suite and everything in my simulation looks good. The pcb board I will be interfacing with has a back plane vita 46.0 interface. I need to produce the following inputs into the backplane interface.

1) Differential input clock signal @ 100MHz

 2) differential input data signal @ 200MHz 

3)  differential input  signal at 6.25 MHz 

4) receive a differential output signal at at 6.25MHz

5) input a 6 bit address

6) reset

Now the way I am thinking of approaching this is using something like National Instruments USB-6002 Low-Cost Multifunction DAQ for Basic, Quality Measurements and use the digital I/O ports wired to the Back plane interface of the vita 46.0 card. From here I would then use LabVIEW to generate the various input signals and receive the output signals. Is an appropriate way to test the functionality of the FPGA and pcb board? Also are there certain limitations in terms of the speed of my signals and what the DAQ can receive even though it is a digital signal and not analog? Again this is the first time doing hardware testing and do not know what the best way to interface with the board would be.      

Thanks

[iCan'tBerrPuns]

Hello higgi02,

When you ask if using digital inputs and outputs from the USB-6002 would be a good way to test the functionality of the FPGA and the PCB board, what do you mean?

What “functionality” are you trying to test?

What kinds of measurements or tests are you trying to perform?

As far as the “speed of [your] signals” is concerned, the only sort of timing that one can use on the USB-6002 with the digital I/O is software timing. Therefore, you will be unable to use external (hardware) timing and therefore will not have high rates of determinism within your system.

What rate are you wanting to input/output signals at?

For any additional concerns about the specifications of the USB-6002, I definitely recommend referring to the manuals for this device. I have provided a link to the specifications for this device below:

NI USB-6002 Specifications

http://www.ni.com/pdf/manuals/374371a.pdf

Please let me know if you have any additional questions/concerns.

[higgi02]

In terms of functionality I mean that I have a differential clock at 100MHZ and differential input data signal at 200MHz that goes straight into my FPGA can I use a DAQ to produce those signals, those signals are then read in by the fpga and go through my program and cause various pins to switch high and low but the main thing I want to know is, can I use the Digital I/Os of the DAQ to send signals to my FPGA. The DAQ's digial I/Os say that the timing is based on software so if I was using labView and set it up to produce the necessary signals I need and those frequencies It should be capable. From there I was thinking those outputs would then be connected to my fpga. My fpga would set certain things and I would be able to see if it is reading the input data correctly. However, I don't know if this is right. I am new to fpga's and want to test my hardware at a top level. I guess I mainly want to know what kind of hardware should I look at purchasing if I want to send my FPGA a

1) Differential input clock signal @ 100MHz

 2) differential input data signal @ 200MHz 

3)  differential input  signal at 6.25 MHz 

4) lastly receive a differential output signal at at 6.25MHz

[iCan'tBerrPuns · Accepted solution]

Hello higgi02,

Based on your specifications, it appears that the USB-6002 will not work for your purposes. For this device, the minimum high/low pulse width for a counter task (which one would most likely use as the clock signal) is 100 ns, which only translates to a maximum clock signal of 10 MHz. Any DI/O tasks on the USB-6002 would get their timebase from the counter of the device, and would therefore not be able exceed 10 MHz of frequency either. I have provided the document where I got this information below; please refer to the “Digital I/O” and “Counter” sections of the document for this information.

Specifications NI USB-6002

http://www.ni.com/pdf/manuals/374371a.pdf

Regarding what hardware you should use for your application, I very strongly recommend that you contact National Instruments’ team of Sales Engineers. They are much better equipped to collect all of the information needed in order ensure that you get the best hardware for your application within your budget, with all of the specifications you need, etc. To contact our Sales engineers, please call: (888) 280-7645. When you call in, the Sales Engineers will most likely be unaware of the specifications you have described on this forum post, so you will need to repeat the information that you have already posted here.

Thank you,