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Hey there I'm thinking about purchasing a Zybo or Zedboard to Implement a SDR application. I'm in electronics engineering student with microcontroller history but brand new to FPGAs. I have a few questions about the vivado license, ISE vs Vivado for DSP applications.

What exactly is it that the licence that Digilent sells offer that the webPack dosent? I have read here on the forums about some discrepancy between the Vado licenses and forgot it updates in this regard. Is the CihipScope offered in the wet pack now?

I may later decide to purchase the SDR software package offered by AVNET, or at least individually accumulate those licenses as my budget allows. So how dose the webpack version limit my ability to integrate with the software elements(currently unable to find the said software package) used for SDR & DSP development?

What are the limitations of the Pmod interface if I were to go with the Zybo and later try to coonect to a FMC interposer/Analog Devices ACD boards?

Im reading the zybo book but any links to more learning resources would be greatly appreciated. 

I'm ready to pull the trigger on a purchase today as soon as I get these questions answered. :) Looked high and low for a phone number :( 

 

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Hello,

The SDSoC voucher that you can bundle with the Zybo or Zedboard is a 1 year voucher that grants you access to Xilinx's SDSoC environment to install on a single machine. The one year starts from the time you redeem it. During that one year, you may download new editions of the SDSoC environment as they are released by Xilinx; after the one year is up, you will be able to continue to use the SDSoC environment that is installed on your machine permanently without any functionality loss, but won't be able to download new editions as they are released.

That being said, SDSoC is not like the Design Edition or System Edition of Vivado, it doesn't "unlock" other features that are built into Vivado, it just gives you access to that other environment. You can view how the various editions of Vivado compare with each other in terms of features in this table by Xilinx here. ChipScope isn't part of Vivado; Xilinx instead uses the Vivado Logic Analyzer (which from my understanding has the same functionality as ChipScope), and it does come with the free WebPack edition. 

I personally can't speak towards the WebPack version limitations to integrate with other software packages. All I know for sure is that just the System Edition of Vivado (as per the table I linked to earlier) enables the System Generator for DSP, although I don't know for certain what all that entails (I just have the WebPack version of Vivado). 

As for the Pmod interface, (as per this other thread) Pmods aren't a standard so they haven't been tested to determine the maximum data rate, but were observed working at 10 MHz. The Zybo has some high-speed Pmods with impedance matched differential pairs, so perhaps you can get up to 456 Mb/s (as this other Forum user did with a different board). 

In terms of additional resources; the ZedBoard materials are maintained by the community on ZedBoard.org and Digilent has a number of materials available for the Zybo on it's Resource Center.

Let me know if you have any more questions (or if I missed one of them).

Thanks,
JColvin

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@B Sully,

Welcome to the forum!

I'll add my two cents: if you are familiar with DSP from other environments (PC's, microcontrollers, etc), be prepared to do it all in fixed point on an FPGA.  You may just end up surprised at what you can accomplish.  (You can even find my own FFT implementation for FPGA's here, although Xilinx's implementation consumes far fewer resources.)

Also ... for SDR work ... don't underestimate what you can do with a CIC filter.  They're *really* useful, *really* easy to implement, and *really* easy on resources.

One of my own projects some time back was a downconverter that converted from anything up to your system clock rate, down to anything between 1/2 and 1/2^32 times that rate with 32-bit precision.  That project made heavy use of the CIC filter, fit on a Basys-3, and managed to keep the stop band 68 dB below the passband if I recall correctly.

At the same time, my wager is that you'll be spending most of your time figuring out how to get data in and out of that Zynq processor.  Please feel free to prove me wrong.  ;)

Dan

P.S.  Did you know you could turn an FPGA into a commercial band FM transmitter?  Those GPIO pins just ... leak.  Here's some code to exploit that--should you be interested in just having some fun.

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Dan,

When you talk about "spending most of your time figuring out how to get data in and out of that Zynq processor" do you mead the ARM core, the 'PS' part of the SOC or the APU within the PS?

I figured that most of the functions of a FM transmitter could be implemented of a FPGA but figured that the DAC implemented on a FPGA would be inferior to a dedicated DAC. I'm looking forward to sinking my teeth in to that code.

Brian

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@B Sully,

Yes, I mean the ARM core.  Getting a real-time stream of samples into a microcontroller, ARM or otherwise, can be a challenge.  You need an interrupt driven FIFO, a half-full watermark, a means of filling it, a means of reading the PL from the PS, etc., and you are often working across multiple clocks to get it done.  If you wish to transmit, you'll need the same thing in reverse.  Watch your clocks, though, one clock needs to drive the whole thing--and it's often a PL clock and not the PS clock.  I mean, it's not impossible, it's just a challenge.
Perhaps I say it'll be your hardest problem 'cause it's the only one I haven't done yet with an ARM, and therefore it's the one that I'm not yet certain of how to do ...

As for the FM transmitter, of course a DAC, antialiasing filter, a local oscillator, mixer, band-pass filter, and a antenna would be superior to what I just described.  That's just part of the fun of the transmitter I cited, and part of the reason why I personally call it a "hack."  No, it didn't broadcast very far.  I tested it using a XuLA2-LX25 board which is physically kind of small--I'd bet that using all the PMod ports on my Arty in a synchronous fashion would act closer to a real antenna and perhaps even get more than 12" of distance ... ;)

Dan

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