What brand/type of FPGA

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bprosman
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What brand/type of FPGA

Post by bprosman » Wed Nov 21, 2018 10:40 am

As I would like to become more familiar with FPGA’s (I see Dave "Hoglet" doing magic with these on multiple projects) and learn im looking into a small development board with FPGA, some Sdram, displays ( can be 7 segment) a bunch of buttons and leds, what FPGA ( family ) would be ok to choose ? This looking at , availability in the (near) future, availability of development software without expensive licenses. Is the Spartan 6 a wise choice ? Or another Xilinx device , or even Altera ?
Thanks for your thoughts.

Kind regards, Bram

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BigEd
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Re: What brand/type of FPGA

Post by BigEd » Wed Nov 21, 2018 11:41 am

Much depends on your budget! There's a several-page topic over here which might help.

Broadly, any manufacturer will do - they all offer free tools, which are sometimes a massive download and sometimes not excellent quality, but they work. I've found myself mostly using Xilinx, in the older flavours, and the older ISE software rather than the newer Vivado. If you choose Lattice, there's also an open source tool chain which works well and is in active development. It mightn't support all Lattice devices though, so check.

One thing about RAM: SRAM is by far the easiest to use, and pSRAM isn't too hard, but according to hoglet SDRAM is much harder, and presumably that goes more so for DDR, DDR2 and DDR3. You don't see too many boards with SRAM though. BlackIce from mystorm is one such - it has a Lattice FPGA and can be used with open source tools. But it was made only in smallish batches - maybe look out for their next project.

Digilent do a variety of boards, including some with 7 segment displays:
https://store.digilentinc.com/fpga-prog ... em-boards/
but you might be better off with say a DE0-Nano or something even smaller and cheaper, and hooking up a 7 segment display as a project.

Note that almost all FPGAs these days run at 3.3V and need some level-shifting circuit to interface safely with 5V systems, such as Acorn's machines and any other 8bitter.

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Re: What brand/type of FPGA

Post by bprosman » Wed Nov 21, 2018 11:56 am

Last edited by bprosman on Wed Nov 21, 2018 11:57 am, edited 1 time in total.

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BigEd
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Re: What brand/type of FPGA

Post by BigEd » Wed Nov 21, 2018 12:16 pm

Might well be fine! This one has a recognisable brand (ALINX) but you'll always be taking a bit of a punt - usual ebay rules apply! I see all three are from the same seller.

It's worth noting that for many dev boards you will need some kind of programming dongle/adaptor. So that adds to the price, for the first board you buy with that make of FPGAs.

As you are sure to be debugging your designs and scratching your head, the last thing you want is a dodgy board with problems of its own, so I would be inclined to go for something branded, from someone with a reputation to protect.

Bear in mind all the boards we just mentioned use SDRAM, so bear in mind hoglet's warning.

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hoglet
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Re: What brand/type of FPGA

Post by hoglet » Wed Nov 21, 2018 12:16 pm

I think this is largely a matter of personal preference.

In your case, I would probably suggest a board based on the Xilinx Spartan 6 for several reasons:
1. You already have some experience of the using the Xilinx design tools (ISE) for CPLD work
2. Devices newer than the Spartan-6 use a different design tool (Vivado) which appears more complex
3. Spartan-6 is pretty widely used (even though it's a bit dated now)
4. There are lots of examples, tutorials, and existing projects that use this device
5. It's big enough to do some nice projects

I would also advise you to look for a board with SRAM rather than SDRAM. Using SDRAM from a FPGA is an order of magnitude harder/more involved than using SRAM. You generally have to worry much more about timing constraints. I have yet to do an SDRAM based project!

My favourite board is the Papilio Duo:
pap_1.jpg
With the Classic Computing Shield
pap_2.jpg
And with the Logic Start Shield
pap_3.jpg
Seeed is one place to buy these:
https://www.seeedstudio.com/s/papilio.html?sort=4

They sometimes show up on eBay:
https://www.ebay.co.uk/itm/Papilio-Logi ... 3610970710

The company Gadget Factory is mostly one person (Jack Gassett) and I think he is in the process of winding things down now. But the hardware products are good and stable and still available.

There is also the Pepino board:
pep_1.jpg
http://www.saanlima.com/pepino/index.ph ... _to_Pepino
http://www.saanlima.com/store/
This is a bit more integrated.

If that's too all much, then this would be my final choice:
mimasv2_2.jpg
https://numato.com/product/mimas-v2-spa ... -ddr-sdram
But it uses SDRAM not SRAM.

This is a very good list of the currently available FPGA boards:
https://joelw.id.au/FPGA/CheapFPGADevelopmentBoards
You can search that page for SRAM to see how few boards there are with SRAM.

Dave

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Re: What brand/type of FPGA

Post by bprosman » Wed Nov 21, 2018 1:18 pm

@BigEd,

The programming tools for Xilinx and Altera I already have.
I am already using it for CPLD's where I have some experience with.

@All,
If I would go this route :
but you might be better off with say a DE0-Nano or something even smaller and cheaper, and hooking up a 7 segment display as a project.
Would I be also able to "solder" (maybe with level shifters) a regular SRAM (maybe a fast video cache one) to it and use it ?
As I already have 2 of these boards :
https://www.ebay.com/itm/Xilinx-FPGA-Sp ... 1640406811?

Thanks for thinking with me / helping me.
Last edited by bprosman on Wed Nov 21, 2018 1:23 pm, edited 1 time in total.

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BigEd
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Re: What brand/type of FPGA

Post by BigEd » Wed Nov 21, 2018 2:52 pm

For sure you could connect up an SRAM - and almost certainly could find one to work at 3.3V.

I/O is slightly more tricky: first port of call for me has usually been a serial port. VGA out isn't too difficult once you've got a suitable adapter board. Keyboards are a little more involved than serial, but not too much. Again, you probably need a PS/2 connector. (Dave's suggested Compute Shield board is useful for giving you these connectors for free, likewise an SD card.)

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Re: What brand/type of FPGA

Post by bprosman » Mon Sep 02, 2019 7:47 pm

Last week I picked up 3 Spartan 3 development boards.
I do realize they are outdated but 2 of them have an xc3s200 and one is an xc3s1000, the latter still is big enough I think for large experiments.
And I got them very cheap.

It's this board :
https://www.xilinx.com/support/document ... /ug130.pdf
S3BOARD_top_400__85177.1427229376.1280.1280.gif
S3BOARD_top_400__85177.1427229376.1280.1280.gif (91.16 KiB) Viewed 341 times
David "Hoglet" already pointed me to this tutorial :
http://hamsterworks.co.nz/mediawiki/ind ... PGA_course

Got the ISE 14.7 to work under Windows 10 as well as the programmer.
First thing is to try to embed an AVR core (and do a "Hello world" on the serial port) as well as adressing the SRAM.
Last edited by bprosman on Mon Sep 02, 2019 7:48 pm, edited 1 time in total.

dominicbeesley
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Re: What brand/type of FPGA

Post by dominicbeesley » Tue Sep 03, 2019 8:22 am

For reference it's worth considering the Waveshare products https://www.waveshare.com/product/fpga- ... boards.htm they're relatively inexpensive and well made - the documentation is a bit convoluted but once you've worked out what pin does what they stuff all works well.

For ease of debugging I find the Altera stuff the best - a proper version of ModelSim is included for simulation which makes debugging easier. The ISIM included in Xilinx for the older devices is full of bugs and quirks which means you have to bodge code to get it to run in ISIM defeating the object of simulation!

I've used the Lattice stuff quite a bit with their Mach XO boards and I'd place their tool chain in 2nd place behind Altera for ease of use. The simulator is not bad and their break out boards are very nice with lots and lots of pins and relatively inexpensive.

D

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Elminster
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Re: What brand/type of FPGA

Post by Elminster » Tue Sep 03, 2019 6:39 pm

Over in the thread viewtopic.php?f=41&t=17590&hilit=Fpga

I went for BlackIce, and waiting for ice breaker on the open source front. Which means Verilog.

And the Dave’s 1mhz board for XLinix.

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Re: What brand/type of FPGA

Post by cmorley » Tue Sep 03, 2019 6:50 pm

THe QMTech boards are great value. Xilinx and Altera/Intel ones in their lineup. The Aliexpress shop is cheaper than eBay but they are available from both. Took less than a week to arrive too. I bought a couple for prototyping.

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Re: What brand/type of FPGA

Post by Elminster » Mon Sep 09, 2019 10:08 pm

Got a few PMODs to play with, got bored with breadboards. Waiting on an SDCARD eBay jobbie to turn the FPGA Atom 1Mhz thing. Also have an ICEBreaker HDMI PMOD appearing at some point.

Please with my 4+8 LED chase verilog code. Possibly not hugely adding to the world of FPGA ......
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