Spartan 3E board - Page 1
Forum section: electronics / general

author: avogadro
author_rank: Contributor
timestamp: November 21, 2018, 07:32:03 pm
content: Is 60 euro a good price for used Spartan 3E board? Are there any better newer boards for better price? Any recommendations?

author: ataradov
author_rank: Super Contributor
timestamp: November 21, 2018, 07:59:31 pm
content: That entirely depends on what kind of a board it is and what you want to do with it.

author: NorthGuy
author_rank: Super Contributor
timestamp: November 21, 2018, 08:57:58 pm
content: Quote from: avogadro on November 21, 2018, 07:32:03 pmYou can get Spartan-7 board for less, so I wouldn't go with Spartan-3E. Of course, what is on the board is also important and will dramatically affect the price.

author: rstofer
author_rank: Super Contributor
timestamp: November 21, 2018, 09:58:37 pm
content: A link to the board would help. Some 3E Starter Boards (Digilent) have 7 segment displays, switches, LEDs and buttons. In my view, these add a LOT of value. At least one large IO header is a nice feature.The second important item is WHICH Spartan 3E chip is being used. Of course the less capable chips are going to cost less.This board has a lot of 'gadgets' and ABSOLUTELY I would buy it for 60 Euros considering what it cost some years back:https://store.digilentinc.com/nexys-2-spartan-3e-fpga-trainer-board-retired-see-nexys-4-ddr/Today, the Artix 7 is the flavor of the month and the Arty-7 is fairly popular and more capable than the Nexys 2https://store.digilentinc.com/arty-a7-artix-7-fpga-development-board-for-makers-and-hobbyists/But it doesn't have any gadgets and while I have a couple, they aren't my favorite boards. Instead I prefer the Nexys 4 DDR because it has a ton of gadgets:https://store.digilentinc.com/nexys-a7-fpga-trainer-board-recommended-for-ece-curriculum/Boards are priced all over the place and, in general, I would buy most any board priced at around 60 Euros if it had a decent number of gadgets. But it's the gadgets I want.Think about what the board has and what you might need. I find it easier to debug projects if I have gadgets.

author: legacy
author_rank: Super Contributor
timestamp: November 21, 2018, 10:25:35 pm
content: Quote from: avogadro on November 21, 2018, 07:32:03 pmit depends ... which board?The Digilent Xilinx S3-500 and S3-1500 are GOOD boards, extremely GOOD, useful, well manufactured, with a lot of gadgets, and well documented.There is a dude in the UK that has several for sale. Second hand, of course.I bought my first board brand new several years ago, I have just got a second board from him. This time a 1500 board, since it offers more LE.

author: legacy
author_rank: Super Contributor
timestamp: November 21, 2018, 10:27:39 pm
content: Quote from: rstofer on November 21, 2018, 09:58:37 pmThere is also a mini-3E version, it comes with a S3-200, small factor, no gadgets (except a few LEDs), but the price is something like 10 euro/board.It seems nobody wants them

author: rstofer
author_rank: Super Contributor
timestamp: November 21, 2018, 10:44:22 pm
content: Quote from: legacy on November 21, 2018, 10:27:39 pmI went with S3-1000 boards back when I was playing with Digilent's Sparten 3 Starter Board (prior to 3E boards). It had 3 50-pin headers and was very friendly in terms of plugging in attachments. None of the PMod stuff!More LEs is always better. More BlockRAM is even better!It's also important to try to decode what a logic element is. Sometimes it is a 4 input MUX with flop, sometimes it is a 6 input MUX with flop, sometimes it includes a carry-chain and, in general, different vendor specifications aren't directly comparable. Marketing gets into the picture and new buzz words flow!

author: james_s
author_rank: Super Contributor
timestamp: November 21, 2018, 11:55:21 pm
content: Yes block RAM, for my purposes my projects are almost always bound by block RAM, I would love it if FPGAs had ~4x as much block RAM for a given amount of logic resources as they do.The Spartan 3E is an older but still capable part, whether the board is a good deal mostly depends on what else is on it.

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 22, 2018, 01:26:16 am
content: The Numato Mimas V2 at around $50 with a Spartan V6 is most likely a way better deal, but I don't know what's on your board except a Spartan 3E.Heck, if you don't need anything more than I/Os, the Numato Mimas is like $35.

author: KE5FX
author_rank: Super Contributor
timestamp: November 22, 2018, 04:22:34 am
content: Don't mess with Spartan3E, it's obsolete along with the software needed to develop for it. Go for an Artix board.

author: james_s
author_rank: Super Contributor
timestamp: November 22, 2018, 04:30:40 am
content: That depends on what you're trying to do with it. I looked into them a while back and they are more than twice the price of the parts I've been using and the additional features offered by the Artix are utterly useless to me, I'd be just as well off tossing a $20 bill in the fireplace for each board I buy. As an example, Galaxian the arcade game uses ~29% of a Spartan3 500, so what benefit would there be to using a much larger more expensive part? It seems some people cant get past the fact that not everyone is doing FPGA development for a living, designing high end products using the latest technology. I would go so far as to say the vast majority of people asking about FPGAs on here are doing nothing of the sort.It all comes down to what you want to do with an FPGA, and as I previously stated, the other parts on the dev board are generally more important than the FPGA itself. You can get a minimal dev board with little more than the FPGA and config ROM for under $20 shipped, but if you need a bunch of peripherals then the cost starts to add up.

author: KE5FX
author_rank: Super Contributor
timestamp: November 22, 2018, 05:05:10 am
content: Quote from: james_s on November 22, 2018, 04:30:40 amThis amounts to being stingy with a small amount of money and wasteful with a large amount of time. The hardware isn't what's important in this business, because the software is what you spend your time interacting with. ISE is an ancient pile of junk compared to current-generation Vivado. For a novice, there's just no sense in messing with the former.If you haven't used both parts, you really have no idea how much nicer the 7-series parts are to work with than Spartan3. I have, and all I can think of is how much I wish someone had given me the same advice (along with the time machine required to take advantage of it).

author: james_s
author_rank: Super Contributor
timestamp: November 22, 2018, 05:23:13 am
content: Nicer in what sense? If the older parts are overkill for what I'm doing, precisely what advantage is there in changing? How is using a part that is massively overkill better than using one that is only twice the size it needs to be? I'm at a loss as to how it will save me time to re-learn something I already know how to do, that requires parts that cost more than twice as much, when the parts I'm already using are already much more powerful than I need?I'd really like to see some data here, let's use the Galaxian example. I could easily port it to an Artix board, I could afford to pay twice as much for the boards if there was a reason to do so, but using this example, in what way will the Artix board improve Galaxian? Will it compile faster than the ~30 seconds it takes for the Spartan 3? Will it save the world? What's the advantage that you are so passionate about? Keeping in mind that retro projects like this are the *only* thing I have any interest in doing with FPGAs. It's not being stingy, it's being sensible by using a part appropriately matched to the project. If a $14 board has twice the resources I need, it is irrational to argue that a $50 board with 20 times the resources amounts to a savings. Personally it just sounds like elitism to me, the same sort of attitude of people who look down their nose at anyone who buys anything less than top of the line gear regardless of their needs.

author: KE5FX
author_rank: Super Contributor
timestamp: November 22, 2018, 07:29:34 am
content: Quote from: james_s on November 22, 2018, 05:23:13 amThe question was, "Is 60 Euros a good price for a used Spartan3E board?" The answer is, "No."Youmay have other questions, but I was only attempting to answer the one that was actually asked.The second one, "Are there better, newer boards for a better price?" can be answered with "Yes and no." About 90 Euros will buy an Arty or similar board. The extra 30 Euros is well worth spending simply because the software is better, and time spent learning it is more likely to pay dividends later.If the poster were looking to go into production, they wouldn't be asking about a single used Spartan3E board, would they? The assumption is that they are looking to get started with FPGA work and need a trainer/dev board of some kind. For that purpose, it's not wise to start with an obsolete/NRND part that uses software that is no longer officially supported.

author: legacy
author_rank: Super Contributor
timestamp: November 22, 2018, 01:17:59 pm
content: LOL, in a university laboratory, they are still using boards based onXC3000, which is very very limited if compared to modern chip.I LOVE when the not-being allowed to use Logic/Arithmetic-SHIFTers and Barrel-SHIFTers is a mandatory constraint, so they have to implement everything while with Sp3 and Sp6 it would be just one line of VHDLBut they also have XC4000 ... which I speculate are still in use because the XC4000XL I/O structures have been designed to tolerate a constant input voltage of 5.5V using only the single 3.3V power supply connected to the device. The XC4000XL is able to directly drive 5V Inputs with TTL Thresholds, while the XC4000XL outputs drive rail to rail and it completely meets all TTL Standard Specifications.

author: asmi
author_rank: Super Contributor
timestamp: November 22, 2018, 02:40:49 pm
content: Quote from: james_s on November 21, 2018, 11:55:21 pmThen youdefinitelyneed to get 7 series FPGA as they have A LOT of BRAM compared to previous generations. And the ratio of BRAM-to-CLB is increasing as you go from S7->A7->K7->V7. And it's FAST (7 series BRAM's Fmax is more than double of that of S6).

author: asmi
author_rank: Super Contributor
timestamp: November 22, 2018, 02:50:10 pm
content: Quote from: james_s on November 22, 2018, 05:23:13 amI think he's talking about novice's perspective, and I'm 100% agree with him - usability-wise Vivado is eons ahead of ISE. For example, in Vivado I can design a system soft-core CPU, DDR3 memory controller and any amount of any standard peripherals I desire without even writing a single line of HDL code - this is a godsend when you're bringing up your board for the first time as it allows you to quickly verify that it works - and if it doesn't you can be 99% sure it's board issue, not that of a bitstream nor firmware for the CPU. Also few versions back they've added ability to directly instantiate your own RTL modules in the system diagram without creating and packaging it as IP (which was pain in the behind!), which makes integrating your own components a breeze - and self-documenting way, as diagram itself is a very good documentation/Bottom line - for today's beginners - unless theyneedto be able to work with pre-7 series devices I would strongly recommend to learn Vivado and forget ISE ever existed.

author: legacy
author_rank: Super Contributor
timestamp: November 22, 2018, 03:13:07 pm
content: Quote from: asmi on November 22, 2018, 02:50:10 pmI do find this comment very irritating.

author: asmi
author_rank: Super Contributor
timestamp: November 22, 2018, 03:23:06 pm
content: Quote from: legacy on November 22, 2018, 03:13:07 pmWhy is that?

author: rstofer
author_rank: Super Contributor
timestamp: November 22, 2018, 03:54:58 pm
content: I have a couple of Spartan 2 boards and a few Spartan 3(E) boards. My CPU project runs on a Spartan 3E board and, while I have thought about porting it to an Artix 7 board, I just can't build up any interest in such a project. What I have works and doing something twice is 'production' and I don't do production. So, I will likely always have to use ISE to alter that projects. I haven't done much with the project for the last 11 years except port from S3 to S3E and alter the IO ports and even that was a long time back.I also have a couple of Arty boards and a couple of the Nexys 4 DDR boards and these require Vivado. I didn't like the startup curve for Vivado and I still don't truly understand the constraints file but after I built a real project (LC3 RISC processor), I got a little way up the path. Some day I will admit to actually preferring Vivado. It's a nice tool. There's a thing about putting aside a well understood tool and taking up a new tool that actually increases the difficulty.It's a toss-up whether I prefer ISE which I have used for the better part of 15 years or Vivado which I have used for just a couple of projects. I think the nod would go to ISE because I am more comfortable. But that's because of history. Looking forward, Vivado is the way to go. ISE is a dead issue, Xilinx is no longer upgrading it, what it is is all it will ever be. I certainly wouldn't point a newcomer at ISE UNLESS the board in question was sufficiently loaded with gadgets and attractively priced. Otherwise, it's Artix-7 and Vivado.The ARTY-7 board is modern, uses Vivado but doesn't come with a lot of gadgets. It makes up for that with Arduino compatible headers and a lot of DDR3L ram (I prefer the static ram on the Sparten 3E boards). I thought it used to cost $99 but now I see it's $119. Maybe there is something else in that price range. OTOH, it uses the 35T chip and I don't know what to make of that. I would always prefer the 100T chip but I haven't really tried to stuff a large project in the 35T. If it fits, that's all that matters.Like it or not, moving forward it is going to be Artix 7 and Vivado, especially for newcomers to the field. Unless, of course, their university is stuck back in time. That happens...

author: asmi
author_rank: Super Contributor
timestamp: November 22, 2018, 05:02:55 pm
content: Another issue with using old devboards is that peripheral chips tend to become obsolete, which will become an obstacle should you ever decide to take your project on a dedicated board - and that is certainly my goal as I always design projects so that they will eventually be implemented on dedicated boards. Well-designed devboards are a good tool to aid initial R&D and prototyping, but at some point development will have to move on a dedicated board so that system-wide integration testing can happen as there is more into the design process than just FPGA bitstream and MCU/CPU software.

author: legacy
author_rank: Super Contributor
timestamp: November 22, 2018, 05:59:54 pm
content: TheNintendo Gameboy ADV's dev board is still based on a Spartan2, and it's a neat and funny idea if someone wants to learn how to develop a video game on a real portable console

author: KE5FX
author_rank: Super Contributor
timestamp: November 22, 2018, 11:13:23 pm
content: Quote from: legacy on November 22, 2018, 05:59:54 pmYeah, there's no question but that you can still do great things with Spartan3 and older parts, just as you can build a working computer by sticking a Z80 and a bunch of wires into a solderless breadboard. That doesn't mean it's a good use of limited educational and/or R&D time.It is true that flexibility in I/O standards has gotten somewhat worse since Spartan6, and it is also true that XDC constraints are a tire fire. I don't mean to sound like a Xilinx evangelist. But the original poster didn't leave us much to go on, in terms of what they are trying to accomplish. Advising them to start two full generations behind the curve doesn't seem like a good idea.

author: legacy
author_rank: Super Contributor
timestamp: November 23, 2018, 12:01:56 am
content: Quote from: KE5FX on November 22, 2018, 11:13:23 pmAnd advising to stay with the last technology, just because it's super-fast, super-amazing, super-wonderfull ... is just like being too obsessed with what the market needs to promote.Besides, THE point was the cost of these boards! Since Spartan3 is obsolete, boards come very cheap!

author: asmi
author_rank: Super Contributor
timestamp: November 23, 2018, 01:11:18 am
content: Quote from: KE5FX on November 22, 2018, 11:13:23 pmCan you please elaborate on that? The only standard that is missing on 7 series is 2.5 V (sans (B)LVDS), but I can't think of any chip that would require it except DDR1, which itself is long obsolete.Quote from: KE5FX on November 22, 2018, 11:13:23 pmWell there is GUI for creating/editing timing constraints, although typing them directly is probably easier for experienced designers.

author: asmi
author_rank: Super Contributor
timestamp: November 23, 2018, 01:14:12 am
content: Quote from: legacy on November 23, 2018, 12:01:56 am7 series is not the last technology as there are Ultrascale and Ultrascale+, which really is super amazing, but unfortunately it's also amazingly expensiveBut compared to equivalent chips from 6 series, 7 series is both better andcheaper!Quote from: legacy on November 23, 2018, 12:01:56 amThey are cheap because they are crap - the same reason they are obsolete.

author: KE5FX
author_rank: Super Contributor
timestamp: November 23, 2018, 03:13:10 am
content: Quote from: asmi on November 23, 2018, 01:11:18 amIt's not so much a question of missing I/O standards as how many supplies you need to support common standards. Compare table 1-55 in UG471 (7-series) with table 1-5 in UG381 (S6), for instance. On 7-series if you want LVCMOS18 input support in a given bank, you need Vcco=1.8V, and likewise for other standards (LVCMOS25, LVCMOS33, etc.) On Spartan6 you could use lots of different input voltage standards regardless of Vcco.

author: hamster_nz
author_rank: Super Contributor
timestamp: November 23, 2018, 03:29:03 am
content: Quote from: asmi on November 23, 2018, 01:11:18 amI too have a gut feeling that the earlier Spartan 3E chips had far more flexible I/O pins.Maybe it is because the more advanced dev boards run I/O banks at just the voltage you don't want to use...QuoteIMO Hand-editing the XDC file is really the only way to go to ensure you you get what you really want, in a nice clear concise set of statements. I has also to be said that the syntax is awful compared with the 'primitive' UCF files used in ISE.However, doesn't everybody just take the vendor's standard XDC with the devboard and uncomment a few lines and change the signal names

author: KE5FX
author_rank: Super Contributor
timestamp: November 23, 2018, 03:38:34 am
content: Quote from: hamster_nz on November 23, 2018, 03:29:03 am

author: asmi
author_rank: Super Contributor
timestamp: November 23, 2018, 03:53:33 am
content: Quote from: KE5FX on November 23, 2018, 03:13:10 amWell it's a trade-off between performance, on-chip power consumption and flexibility. And honestly that requirement makes a lot of sense to me as odds are whatever peripheral you're talking to is going to require that voltage for its' IO buffers.

author: asmi
author_rank: Super Contributor
timestamp: November 23, 2018, 04:04:45 am
content: Quote from: hamster_nz on November 23, 2018, 03:29:03 amWell designed devboards allow you to set I/O voltage to what you need. And this is how I design my own devboards too. For example here is my most recent board:Note zero ohm resistor and an empty footprint for another one at the lower right side of the board (as it is on a photo). By moving this resistor I can set IO voltage of one of connectors to 1.8 or 3.3 V. Second one is fixed at 1.8V as I'm using 1.8V QSPI flash chip for bitstream here.Quote from: hamster_nz on November 23, 2018, 03:29:03 amI actually found GUI for timing constraints pretty solid once you get used to it. Same goes for pin assignments - though I rarely use it as in most cases layout and routing drives pin assignments. I only use it after I completed board layout so that I can run P&R to make sure I didn't do anything stupid like using incorrect pin for clocks, or some other special functions (like aligning buses to IO byte groups in case I will need to use IO FIFOs in design).Quote from: hamster_nz on November 23, 2018, 03:29:03 amWell since I design boards myself I've become quite adept at writing pin constraintsThough I mostly write such file only once for a given board, and then just copy-paste it across designs. Same goes for MIG project file and DDR3 pin assignment files - but this gets a little more complicated in case I have several identical boards but fitted with different pin-compatible FPGAs. I also extensively use exporting diagram to tcl script function to save time for subsequent designs.

author: avogadro
author_rank: Contributor
timestamp: November 28, 2018, 07:59:43 pm
content: QuoteWhich board do you recommend that is 100ish euros?

author: KE5FX
author_rank: Super Contributor
timestamp: November 29, 2018, 12:42:28 am
content: Quote from: avogadro on November 28, 2018, 07:59:43 pmWhat are your goals and your current level of FPGA experience? I like theZTexboards a great deal because they are fully documented, but I'm not sure if any are available at that price point. For learning, something like the Arty board from Digilent might be better. I'm not sure Digilent has EU distribution, though, or if it's prohibitively expensive over there.

author: avogadro
author_rank: Contributor
timestamp: November 29, 2018, 03:21:32 pm
content: Well have started learning vhdl couple of months ago and I was planning on doing the LC3B project but before I get into that I would like to get more comfortable with vhdl and play around with leds, switches, 7-segment displays etc...I looked on the webs and yeah artys are almost double the price here in europe... I could get that ztex for 150?