Absolute bare minimum FPGA thats breadboardable?

[asmi]

When I hear that kind of characterisation, that something is a toy because it only offers relatively modest capabilities versus something high end, I can't help but think the person making the characterisation either doesn't know how to design things to be efficient and needs all that real estate just to get something simple done (e.g. we all know people who take megabytes and lots of MIPs to do something that many of us can do with a few bytes and a few hundred CPU cycles AKA "python programmers"  )  Or they are compensating for other feelings of inadequacy - cf "big car syndrome".  Or it's like the boss who needs the biggest and fastest computer in the office just to read emails and surf the web, pure self aggrandisement. I'm not saying that is the case here, just that it's what that kind of posturing always makes me think.

Time to market is just as important as resources required, that's why Python is a de-facto standard in data science, ML/AI, capital markets and other areas where getting results fast is more important than optimizing resources required. I don't use that approach and do optimizations when warranted, but there are cases when you simply can't do certain things with those super low-end toy FPGAs. Since I do a lot of image and video processing, the dividing line for me is ability of FPGA to natively handle 1080p@60 video. None of those toy FPGA can do anything in this regard to any meaningful degree, as simply running all logic and hardIPs like BRAM and DSPs at 150 MHz is often a challenge for them.
They still have a niche as companion chips in larger designs (as I remember ice40 were/are used in iPhones to control notification LED), but as far as their usage as a main processing chip they simply lack the speed and resources for most modern tasks.

As far as FPGAs that have modestly sized and modestly priced breakout boards available (on the same scale as bluepill and blackpill boards for STM32 microprocessors) there are quite a range of boards for the Lattice iCE40 series of FPGAs. I won't recommend specifics, as the one I have personal experience of, the original upduino, is no longer available (it was all of $7 for a complete board with a 5k LUT FPGA!!!). There have been other boards produced under the 'upduino' name that are currently available. Typically they have 4k or 5k LUTs wihich is a useful middle ground, not so large as to be expensive or encourage wasteful inefficient implementation ( ), not so small that you'll be fighting to find enough LUTs to do more than implement relatively trivial logic.

You are behind the times when it comes to FPGAs. Artix-7 and Spartan-7 are low-end nowadays (Xilinx politely calls them "Cost-optimized" even though some of them still cost few hundred bucks ), with Kintex-7/Virtex-7 and Kintex Ultrascale being a mid-range and Ultrascale+ series is high-end. So tiny toy FPGA like Lattice UltraPlus are not "modestly sized", they are ultra low-end. It's just the fact that even midrange devices are out of price range for all but the richest hobbyists, makes those toy FPGA seem like anything more than what they are. Heck, Artix-7 was introduced 11 years ago! Do you remember what CPU was high-end at that time, and how it ranks now? It's no different with FPGA, just the pricing scale is VERY different. Just because I (and most others) can not afford high-end devices doesn't change the fact that low end is a low end.

An upside for those who care is that the iCE40 range has a completely open source toolchain available for it. I have no philosophical axe to grind on that front, but the availability of a toolchain that is all command line orientated rather than GUI oriented better suits my way of working, and may better suit other folks of a similar bent.

All vendor-provided toolchains I know of are command line based, and have integrating scripting language (Tcl) to aid in automation. I know this for sure of Vivado, but as far as I remember Quartus is very similar in this aspect.
--------------
As for what's good for beginners, I think something capable of displaying a fullHD video is a good place to start because it offers a very visual feedback, which aids in maintaining your interest in this topic. Blinking LEDs becomes old very quickly, so having something more visual is much better in my opinion. At least it's been the case personally for me.

[Cerebus]

Hmm, your insistence on continuing to characterise anything that isn't 'big' as 'toy' suggests that you've never heard the expression "Horses for courses". An M3 screw isn't 'toy' just because M20 bolts exist. Your instance at taking a joke about python programmers (the year before last I invoiced over 6 figures GBP for work in python) as if it was a serious point indicates an inability to see the wood for the trees. I am however beginning to suspect that you approach woodscrews with a  hammer.

[fourfathom]

As for what's good for beginners, I think something capable of displaying a fullHD video is a good place to start because it offers a very visual feedback, which aids in maintaining your interest in this topic. Blinking LEDs becomes old very quickly, so having something more visual is much better in my opinion. At least it's been the case personally for me.

If this is your criterion then go ahead and call anything less a "toy".  But don't expect many people to agree with you.  There is a huge universe of FPGA designs and functions out there, and there's a good reason why the vendors still sell those "toy" devices.

[dorkshoei]

Hmm, your insistence on ....

Can you and asmi please take the swinging-d****s competition elsewhere.

[Cerebus]

Hmm, your insistence on ....

Can you and asmi please take the swinging-d****s competition elsewhere.

Sorry, that was most definitely not intended to be or become a dick swinging contest, quite the opposite in fact. The whole point is that as one probably doesn't want to learn to drive in a Formula One car, or even a road going Porsche, but to tackle learning to drive to the shops in a Mini, so one probably wants the FPGA equivalent when starting out.

[dorkshoei]

Hmm, your insistence on ....

Can you and asmi please take the swinging-d****s competition elsewhere.

Sorry, that was most definitely not intended to be or become a dick swinging contest, quite the opposite in fact. The whole point is that as one probably doesn't want to learn to drive in a Formula One car, or even a road going Porsche, but to tackle learning to drive to the shops in a Mini, so one probably wants the FPGA equivalent when starting out.

All I can say is that it's probably not a great idea to use phrases like "feelings of inadequacy" in technical threads  

The topic of this thread was "Absolute bare minimum FPGA thats breadboardable?"  We're way off-topic.   

[Bassman59]

I want to get into FPGAs but I dont want a kit with all the bells and whistles. I want the absolute bare minimum so I can do it all myself and learn. I think id love to just have a FPGA presoldered to a breakout board that i could connect to a breadboard. Kind of like the CMOD FPGA boards. I cant find any bare kits like what i want. Any ideas?

To bring this thread back around and answer your question, there's the Lattice MachXO2 Breakout Board.

No bells and whistles. Just the FPGA -- and it's a decently big one, too -- soldered to a board with a whole lotta holes for wiring to whatever else you cook up. It includes the programmer. In stock. Uses the free Diamond software.

[NorthGuy]

Depending on what you do, the smallest FPGA may be suffcient for you, or may be not. If you get a bigger FPGA you can do everything that you could've done with a small one. But the opposite is not true.

I would suggest buying CMOD S7 (or A7) while you still can. You may not be able to do so few months from now

[rstofer]

I know the topic is "minimum FPGA" but I'm going to go off the rails anyway!

I like development boards with lots of gadgets.  Things like switches, pushbuttons, LEDs and 7-segment displays.  I suppose Ethernet is handy but I haven't used it.  The more gadgets, the better.  It keeps me from having to use breadboards and discrete components.

I like this Digilent board even if it is pricey.  I call it 'future proofing'.  Just about anything I want, I can build with this board.  The 100T variant, of course.

https://digilent.com/shop/nexys-a7-fpga-trainer-board-recommended-for-ece-curriculum/

I have been excited about digital systems for over 50 years and I just like to work with logic design.  That board will hold a dumpster full of discrete logic.

But I have the A7, the Basys 3 (very nice!) and a couple of Arty 7 boards.  And that's just current stuff, I go back far enough to have Spartan 2 and a couple of incantations of the Spartan 3 Starter Board.  But I use that Nexys board most often.

At a minimum, I might consider the GO Board from Nandland - plus the tutorials

https://nandland.com/

[cvriv]

So I ordered a CMOD S7 even though theyre backorderd. I saw some of you talking about the capabilities of different FPGAs... I like power. Lol. I am knew to FPGAs but i learn real quick and always require more than what something can offer so the more the better. While i wait for this S7 to arrive, im going to check out some of the other stuff yall suggested. Wouldnt mind having a few different flavors tobplay with.

[brucehoult]

there are cases when you simply can't do certain things with those super low-end toy FPGAs. Since I do a lot of image and video processing, the dividing line for me is ability of FPGA to natively handle 1080p@60 video. None of those toy FPGA can do anything in this regard to any meaningful degree, as simply running all logic and hardIPs like BRAM and DSPs at 150 MHz is often a challenge for them.

Well, good for you. Not everyone is using FPGAs to process 1080p@60 video, or implement quad core OoO CPU soft cores with MMU and FPU and all the trimmings.

I don't know if this is easy to believe for you, but there are people out there who want to do things such as re-implement an Apple ][ or C64 using a real 65C02 (still available new), but they'd like to use a small FPGA for the control circuitry instead of a square foot of TTL chips. And it only has to run at 1 or 2 MHz.

256 LUTs might well be enough for that (having enough I/O pins might be more limiting, I don't know).

Why pay for more if you don't need more?

[SiliconWizard]

Yep, and even implementing a C64 on FPGA is way, way beyond what a beginner would need to learn an HDL and using FPGAs. So...
And I personally do not agree with starting with the biggest FPGA you can afford. Starting with small and simple parts and tools is IMHO almost always better for learning purposes, and avoids the temptation of working on projects that are way too complex for your skills, which would usually lead to abandoning shortly after, once you have played a little with ready-made projects that you are unable to comprehend.

Now yeah, those small, "feather" form factor boards tend to be expensive for what they are, but that's marketing here. And they're not all created equal. If you want something simple, with few IOs (as those boards would offer), you can consider the UPduino 3.0, for instance. I think it's about $25, and the iCE40 UP5K is large enough (5K LUTs, 128 KB RAM) to learn, and even implement useful stuff with. Lattice Radiant is easy to use and reasonably "lightweight".

[dorkshoei]

Yep, and even implementing a C64 on FPGA is way, way beyond what a beginner would need to learn an HDL and using FPGAs. So...
And I personally do not agree with starting with the biggest FPGA you can afford. Starting with small and simple parts and tools is IMHO almost always better for learning purposes, and avoids the temptation of working on projects that are way too complex for your skills, which would usually lead to abandoning shortly after, once you have played a little with ready-made projects that you are unable to comprehend.

It also minimizes the financial cost of the "buy and never get around to using" syndrome I have piles of "that looks cool; it's only $50" eval boards I've bought with the best of intentions to do something with and there they sit gathering dust.    Shame on me of course.

[RoGeorge]

I want to get into FPGAs but I dont want a kit with all the bells and whistles. I want the absolute bare minimum so I can do it all myself and learn.

See if you like something like this:
https://www.knjn.com/ShopBoards_RS232_Parallel.html

knjn is the shop of the fpga4fun website, a website I found very useful when I first stepped into the FPGA world:  https://www.fpga4fun.com/FPGAinfo1.html

[nctnico]

there are cases when you simply can't do certain things with those super low-end toy FPGAs. Since I do a lot of image and video processing, the dividing line for me is ability of FPGA to natively handle 1080p@60 video. None of those toy FPGA can do anything in this regard to any meaningful degree, as simply running all logic and hardIPs like BRAM and DSPs at 150 MHz is often a challenge for them.

Well, good for you. Not everyone is using FPGAs to process 1080p@60 video, or implement quad core OoO CPU soft cores with MMU and FPU and all the trimmings.

I don't know if this is easy to believe for you, but there are people out there who want to do things such as re-implement an Apple ][ or C64 using a real 65C02 (still available new), but they'd like to use a small FPGA for the control circuitry instead of a square foot of TTL chips. And it only has to run at 1 or 2 MHz.

256 LUTs might well be enough for that (having enough I/O pins might be more limiting, I don't know).

Why pay for more if you don't need more?

Not just that but a typical larger FPGA has loads of documentation; it is not very easy to start with. With a small FPGA (say up to a couple to thousand LUTs) it is still possible to graps what is going on. A CPLD (like the Xilinx XC9500xl series) might even be a better place to get started with programmable logic. Besides being relatively simple the advantage of a CPLD is that the internal delays have much less variation because the building blocks and routing are more rigid. You don't have to worry about setting timing constraints.

[james_s]

One of my favorite FPGA boards is this: https://www.ebay.com/itm/183713814541?

Yes it's an old and small part by modern standards but it's still quite powerful, I have built entire 8 bit computers and arcade games on them. They aren't as cheap as they used to be but they're still pretty cheap. You also need a programming cable which costs about $6.

[RoGeorge]

Hmm, your insistence on ....

Can you and asmi please take the swinging-d****s competition elsewhere.

Sorry, that was most definitely not intended to be or become a dick swinging contest, quite the opposite in fact. The whole point is that as one probably doesn't want to learn to drive in a Formula One car, or even a road going Porsche, but to tackle learning to drive to the shops in a Mini, so one probably wants the FPGA equivalent when starting out.

All I can say is that it's probably not a great idea to use phrases like "feelings of inadequacy" in technical threads  

The topic of this thread was "Absolute bare minimum FPGA thats breadboardable?"  We're way off-topic.

That's a great advice to yourself, dorkshoei, because you were the one who started to talk about swinging dicks in an FPGA topic.

The fact that you spelled that with stars doesn't change a bit what you meant, certainly didn't mellow down that idiom.  Beating around the bush with improperly typed words often indicates weakness, or hypocrisy.  My advice:  either you say it properly, or you don't say it at all.  That advice is for outside of EEVblog.

Here, on EEVblog forum, let's just not start talking derogatory to each other, please.

[cvriv]

Digilent notified me that the CMOD S7s are back in stock so i ordered two more.

[bingo600]

You could start with a CPLD - $14 including programmer
https://www.ebay.com/itm/172477210445

The CPLD will give you a "taste" of vhdl , and will not cost a kazillion if you blow it up.

The same programmer works with the
https://www.ebay.com/itm/183713814541

Note: You will need Quartus 13.sp1 (Not higher)


Edit:
Is chipsgate also hitting here ?
I used to pay $6..8 for the CPLD board , and $10..12 for the CycloneII board.
...Well some of it might be the new eBay VAT ...

/Bingo

[Cerebus]

I used to pay $6..8 for the CPLD board , and $10..12 for the CycloneII board.
...Well some of it might be the new eBay VAT ...

/Bingo

Yes it is. Before LCMXO2-7000HE-B-EVN £23.15 on 18 Feb 2020, now £66.08 (both prices from Digikey, one from the invoice from 2020, one from their website today).

[SiliconWizard]

Yeah, I bought a few of those MachXO2 and MachXO3 boards when they were about $25, now price has skyrocketed for Lattice boards...

But as I said, if a small number of IOs is OK with you, the UPduino boards can definitely be considered here. Pretty cheap, and more than enough for learning purposes IMO.

[Bassman59]

Yeah, I bought a few of those MachXO2 and MachXO3 boards when they were about $25, now price has skyrocketed for Lattice boards...

I thought that the price quoted by Lattice for the MachXO2 board was quite high, so I just checked. I paid $26 in 2017 to Mouser for it. They're $90 now. Yikes.

I rarely bother with eval boards but I needed to verify that something would work before committing to a board, and for $26 it was a no-brainer.

[Canis Dirus Leidy]

Something like this:
https://www.seeedstudio.com/Sipeed-Tang-Nano-FPGA-board-powered-by-GW1N-1-FPGA-p-4304.html
I have used this FPGA in a project and it is quite straightforward to use.

And there is also a version with 4608 LUTs, and hardware Cortex-M3. Average price at Aliexpress is around $15 (without shipping).

P.S. And, if a perfoboard is fine too. QMTech sell bunch of "core boards" with (FPGA and RAM chip only) at a price of $40-$50 for variants with Cyclone IV (EP4CE15) or Zynq 7000 (XC7Z010).