5 ms·

FPGAs need their "Arduino moment". There have been so, so, so many projects where I've wanted just a little bit of moderately-complicated glue logic. Something

FPGAs need their "Arduino moment". There have been so, so, so many projects where I've wanted just a little bit of moderately-complicated glue logic. Something pretty easy to dash off in VHDL or whatever. But the damn things require so much support infrastructure: they're complicated to put down on boards, they're complicated to load bitstreams in to, they're complicated to build those bitstreams for, and they're complicated to manage the software projects for. As soon as they reach the point where it's as easy to put down an FPGA as it is an old STM32 or whatever, they'll get a lot more interesting.

timthorn 10mo ago
Sounds like a PLD might suit your usecase? Simpler than an FPGA, programmed like an EEPROM, perfect for glue logic.
- exmadscientist 10mo ago
  "Programmed like an EEPROM" is part of the problem, any system that needs more than one piece of firmware to be wrangled during the assembly/bringup process is asking for pain. But, really, no one cares what's inside the box. CPLD or FPGA, they're all about the same. The available PLDs are still not really acceptable. There's a bunch of 5V dinosaurs that the manufacturers would obviously love to axe, and a few tiny little micro-BGA things where you've got to be buying 100k to even submit a documentation bug report. Not much for stuff in the middle.
- javawizard 10mo ago
  I wish CPLDs were more well known in the common vernacular. The industry draws a distinction between CPLDs and FPGAs, and rightly so, but most "Arduino-level" hobbyists think "I want something I can program so that it acts like such-and-such a circuit, I know, I need an FPGA!" when what they probably want is what the professional world would call a CPLD - and the distinction in terminology between the two does more to confuse than to clarify. I don't know how to fix this; it'd be lovely if the two followed convergent paths, with FPGAs gaining on-board storage and the line between them blurring. Or maybe we need a common term that encompasses both. ("Programmable logic device" is technically that, but no-one knows that.) Anyway. CPLDs are neat.
  - bee_rider 10mo ago
    I don’t know anything about this (other than doing mediocre in some undergrad Verilog classes one million years ago). Wikipedia seems to call FPGAs a type of PLD. Of course, everybody has heard of FPGAs; is it right to think they’ve sort of branched off, become their own thing, and eclipsed their superset?
  - tverbeure 10mo ago
    I don’t see how CPLDs solve anything? You write RTL for them just like you do for FPGAs, you need to configure them as well. The only major benefit is that they don’t have a delay between power up and logic active? But that’s not something that would make a difference for most people. CPLDs are also a dying breed and being replaced with FPGAs that have parallel on-board flash to allow fast configuration after power up. (e.g. MAX10)
tverbeure 10mo ago
The strong point of FPGAs is their versatility. If you wanted an FPGA that would be easy to put on a board, you’d have to drop support for multiple voltage rails and thus multiple IO standards, which is exactly what you don’t want to lose. Building bitstreams is IMO not complicated. (I just copy a Makefile from a previous project and go from there.) Loading them is a matter of plugging in a JTAG cable and typing “make program”. I don’t know what you mean with the “manage SW projects for”?
- exmadscientist 10mo ago
  > you’d have to drop support for multiple voltage rails and thus multiple IO standards, which is exactly what you don’t want to lose. Yes? Yes it is? 9 times out of 10, my entire board is LVCMOS33. I would love to have the option to drop all of the power rail complexity in a simplified series of parts. Sometimes you need maximum I/O speed. Sometimes you need maximum I/O flexibility. Sometimes you need processing horsepower. And sometimes you need the certainty of hardware timing, which you get on a gate array and don't get any time there's a processor involved. Or, often, what I actually need is just a little bit of weird logic that's asynchronous, but too hard to do with the remnants of 74-series or 4000-series logic that are still available. > Building bitstreams is IMO not complicated. (I just copy a Makefile from a previous project and go from there.) It is not complicated for people who have spent a long time learning and who have past designs they can copy from. (I have a few of those myself.) It is nasty to explain to a new person and very nasty to explain well enough to reproduce in the future without me around. > Loading them is a matter of plugging in a JTAG cable and typing “make program”. Yes, for you on the bench. Now program them into a product on an assembly line. Of course it is possible. It is still a giant headache, and quite a bit worse than just dealing with an MCU. > I don’t know what you mean with the “manage SW projects for”? Two words: Xilinx ISE.
  - exmadscientist 10mo ago
    > often, what I actually need is just a little bit of weird logic that's asynchronous As a concrete example of this: two weeks ago I wanted a 21-input OR gate. It would have been wonderful if I could spend a little bit of money, buy a programmable thing in a 24-pin package, put it down, figure out some way to get the bitstream in (this is never pleasant in medium-volume manufacturing, so it's not like we're going to solve it now), and get my gate function that is literally one line of HDL. One. Line. As it was, a 21-input OR gate is so much work in 74-series logic that I abandoned that whole thing and we did the bigger-picture job in a different, worse, way.
15155 10mo ago
> they're complicated to put down on boards https://gowinsemi.com/en/product/detail/46/ https://gowinsemi.com/en/product/detail/46/ - Requires just 1V2 + 3V3 - Available in QFN - Bitstream is saved in internal flash or programmed to SRAM via a basic JTAG sequence https://www.efinixinc.com/products-trion.html https://www.efinixinc.com/products-trion.html
- pclmulqdq 10mo ago
  The Altera Max 10 devices are also relatively simple to support (flash on the chip, few power rails, etc.)
- exmadscientist 10mo ago
  > Contact Sales > Request Sample > Please login to download the document. I mean, yeah. My argument isn't that anything is impossible. My argument is that all of this is harder than it needs to be and this is not countering me!
  - 15155 10mo ago
    This is your job, and it really shouldn't feel difficult. This is really not tedious: the minimum board design for these chips literally consists of just power, JTAG pins, and a clock (if the internal oscillator isn't good enough.) The Gowin FPGAs are available (at a massive premium) from Mouser, just like whatever MCU you are already using. Many are available for <$1-2 in China. Efinix are available from DigiKey, with some SKUs under <$10. All of the Gowin documentation is available on their site with a free, approval-less email login and no NDA, or via Google directly (PDFs, just like Xilinx, even numbered similarly.)
    - mschuster91 10mo ago
      > All of the Gowin documentation is available on their site with a free, approval-less email login The problem is trust. I'm hesitant to hand out my e-mail anywhere because far too often I have been hounded by salespeople as a result, not to mention data breaches or bombardment of newsletters.
fennecbutt 10mo ago
It's basically because they're so locked down, hard to get docs, stupid toolchains and ides like others have mentioned. It's like fpga companies don't want people using them, much like others like the pixart sensor I wanted to use: NDA because some parasite dipshit executive or manager thinks that register layouts are extremely sensitive information. I've had dozens of uses for an fpga...but every single time I just can't be bothered. Why, when they make it a pain in the ass on purpose.
- 15155 10mo ago
  None of these things are true for the new, cheap Chinese contenders.
willis936 10mo ago
It's already happened, people just haven't realized. iCE40-UP5K costs a few bucks, needs minimal support circuitry, and is supported by FOSS toolchains (yosys). Fun packages like the pico-ice bring it all the way down to the entry-level arduino crowd. It just doesn't have the marketing mindshare.
- ithkuil 10mo ago
  A few times over the past decade I wanted to start with a side project where I design and develop a CPU. I bought a relatively cheap artic 7 board with 33kLUT and whatnot which I know people have used to implement risc-v implementations on. But then I always lost my patience on the tooling. For a side projects these days I need something comfortable. Something that that I can easily switch my context to without having to juggle VMs and installing unfriendly tools and use horrible IDEs
- nrhrjrjrjtntbt 10mo ago
  Funny enough it is available on an UPDuino board: https://tinyvision.ai/pages/the-upduino https://tinyvision.ai/pages/the-upduino
rramadass 10mo ago
> FPGAs need their "Arduino moment". This is exactly it. Why hasn't some expert group produced a very simple open design board with a simple Arduino-like IDE for FPGAs? Make it easy to access and use, get it into the hands of makers/hobbyists and watch the apps/ecosystem explode. As an example, one could provide soft-cores for 8051/RISC-V etc. right out of the box with a menu of peripherals to mix and match. Provide a simple language library wrapper say over SystemVerilog (or whatever the community settles on) just like Arduino did (with C++) that makes it "easy" to program the FPGA. For apps, one good example would be putting TinyML (or any other ML/LLM models) on a FPGA. This would take advantage of the current technology wave to make this project a success. PS: Folks might find the book FPGAs for Software Programmers by Dirk Koch et al. (https://link.springer.com/book/10.1007/978-3-319-26408-0 https://link.springer.com/book/10.1007/978-3-319-26408-0) useful.
- deleted 10mo ago
  [deleted]
PunchyHamster 10mo ago
They can't, by nature of the proprietary bitstream. Arduino was only built thanks to ability to do whatever they wanted with open source compilers

timthorn 10mo ago

Sounds like a PLD might suit your usecase? Simpler than an FPGA, programmed like an EEPROM, perfect for glue logic.

exmadscientist 10mo ago
"Programmed like an EEPROM" is part of the problem, any system that needs more than one piece of firmware to be wrangled during the assembly/bringup process is asking for pain. But, really, no one cares what's inside the box. CPLD or FPGA, they're all about the same. The available PLDs are still not really acceptable. There's a bunch of 5V dinosaurs that the manufacturers would obviously love to axe, and a few tiny little micro-BGA things where you've got to be buying 100k to even submit a documentation bug report. Not much for stuff in the middle.
javawizard 10mo ago
I wish CPLDs were more well known in the common vernacular. The industry draws a distinction between CPLDs and FPGAs, and rightly so, but most "Arduino-level" hobbyists think "I want something I can program so that it acts like such-and-such a circuit, I know, I need an FPGA!" when what they probably want is what the professional world would call a CPLD - and the distinction in terminology between the two does more to confuse than to clarify. I don't know how to fix this; it'd be lovely if the two followed convergent paths, with FPGAs gaining on-board storage and the line between them blurring. Or maybe we need a common term that encompasses both. ("Programmable logic device" is technically that, but no-one knows that.) Anyway. CPLDs are neat.
- bee_rider 10mo ago
  I don’t know anything about this (other than doing mediocre in some undergrad Verilog classes one million years ago). Wikipedia seems to call FPGAs a type of PLD. Of course, everybody has heard of FPGAs; is it right to think they’ve sort of branched off, become their own thing, and eclipsed their superset?
- tverbeure 10mo ago
  I don’t see how CPLDs solve anything? You write RTL for them just like you do for FPGAs, you need to configure them as well. The only major benefit is that they don’t have a delay between power up and logic active? But that’s not something that would make a difference for most people. CPLDs are also a dying breed and being replaced with FPGAs that have parallel on-board flash to allow fast configuration after power up. (e.g. MAX10)

tverbeure 10mo ago

The strong point of FPGAs is their versatility. If you wanted an FPGA that would be easy to put on a board, you’d have to drop support for multiple voltage rails and thus multiple IO standards, which is exactly what you don’t want to lose. Building bitstreams is IMO not complicated. (I just copy a Makefile from a previous project and go from there.) Loading them is a matter of plugging in a JTAG cable and typing “make program”. I don’t know what you mean with the “manage SW projects for”?

exmadscientist 10mo ago
> you’d have to drop support for multiple voltage rails and thus multiple IO standards, which is exactly what you don’t want to lose. Yes? Yes it is? 9 times out of 10, my entire board is LVCMOS33. I would love to have the option to drop all of the power rail complexity in a simplified series of parts. Sometimes you need maximum I/O speed. Sometimes you need maximum I/O flexibility. Sometimes you need processing horsepower. And sometimes you need the certainty of hardware timing, which you get on a gate array and don't get any time there's a processor involved. Or, often, what I actually need is just a little bit of weird logic that's asynchronous, but too hard to do with the remnants of 74-series or 4000-series logic that are still available. > Building bitstreams is IMO not complicated. (I just copy a Makefile from a previous project and go from there.) It is not complicated for people who have spent a long time learning and who have past designs they can copy from. (I have a few of those myself.) It is nasty to explain to a new person and very nasty to explain well enough to reproduce in the future without me around. > Loading them is a matter of plugging in a JTAG cable and typing “make program”. Yes, for you on the bench. Now program them into a product on an assembly line. Of course it is possible. It is still a giant headache, and quite a bit worse than just dealing with an MCU. > I don’t know what you mean with the “manage SW projects for”? Two words: Xilinx ISE.
- exmadscientist 10mo ago
  > often, what I actually need is just a little bit of weird logic that's asynchronous As a concrete example of this: two weeks ago I wanted a 21-input OR gate. It would have been wonderful if I could spend a little bit of money, buy a programmable thing in a 24-pin package, put it down, figure out some way to get the bitstream in (this is never pleasant in medium-volume manufacturing, so it's not like we're going to solve it now), and get my gate function that is literally one line of HDL. One. Line. As it was, a 21-input OR gate is so much work in 74-series logic that I abandoned that whole thing and we did the bigger-picture job in a different, worse, way.

15155 10mo ago

> they're complicated to put down on boards https://gowinsemi.com/en/product/detail/46/ https://gowinsemi.com/en/product/detail/46/ - Requires just 1V2 + 3V3 - Available in QFN - Bitstream is saved in internal flash or programmed to SRAM via a basic JTAG sequence https://www.efinixinc.com/products-trion.html https://www.efinixinc.com/products-trion.html

pclmulqdq 10mo ago
The Altera Max 10 devices are also relatively simple to support (flash on the chip, few power rails, etc.)
exmadscientist 10mo ago
> Contact Sales > Request Sample > Please login to download the document. I mean, yeah. My argument isn't that anything is impossible. My argument is that all of this is harder than it needs to be and this is not countering me!
- 15155 10mo ago
  This is your job, and it really shouldn't feel difficult. This is really not tedious: the minimum board design for these chips literally consists of just power, JTAG pins, and a clock (if the internal oscillator isn't good enough.) The Gowin FPGAs are available (at a massive premium) from Mouser, just like whatever MCU you are already using. Many are available for <$1-2 in China. Efinix are available from DigiKey, with some SKUs under <$10. All of the Gowin documentation is available on their site with a free, approval-less email login and no NDA, or via Google directly (PDFs, just like Xilinx, even numbered similarly.)
  - mschuster91 10mo ago
    > All of the Gowin documentation is available on their site with a free, approval-less email login The problem is trust. I'm hesitant to hand out my e-mail anywhere because far too often I have been hounded by salespeople as a result, not to mention data breaches or bombardment of newsletters.

fennecbutt 10mo ago

It's basically because they're so locked down, hard to get docs, stupid toolchains and ides like others have mentioned. It's like fpga companies don't want people using them, much like others like the pixart sensor I wanted to use: NDA because some parasite dipshit executive or manager thinks that register layouts are extremely sensitive information. I've had dozens of uses for an fpga...but every single time I just can't be bothered. Why, when they make it a pain in the ass on purpose.

15155 10mo ago
None of these things are true for the new, cheap Chinese contenders.

willis936 10mo ago

It's already happened, people just haven't realized. iCE40-UP5K costs a few bucks, needs minimal support circuitry, and is supported by FOSS toolchains (yosys). Fun packages like the pico-ice bring it all the way down to the entry-level arduino crowd. It just doesn't have the marketing mindshare.

ithkuil 10mo ago
A few times over the past decade I wanted to start with a side project where I design and develop a CPU. I bought a relatively cheap artic 7 board with 33kLUT and whatnot which I know people have used to implement risc-v implementations on. But then I always lost my patience on the tooling. For a side projects these days I need something comfortable. Something that that I can easily switch my context to without having to juggle VMs and installing unfriendly tools and use horrible IDEs
nrhrjrjrjtntbt 10mo ago
Funny enough it is available on an UPDuino board: https://tinyvision.ai/pages/the-upduino https://tinyvision.ai/pages/the-upduino

rramadass 10mo ago

> FPGAs need their "Arduino moment". This is exactly it. Why hasn't some expert group produced a very simple open design board with a simple Arduino-like IDE for FPGAs? Make it easy to access and use, get it into the hands of makers/hobbyists and watch the apps/ecosystem explode. As an example, one could provide soft-cores for 8051/RISC-V etc. right out of the box with a menu of peripherals to mix and match. Provide a simple language library wrapper say over SystemVerilog (or whatever the community settles on) just like Arduino did (with C++) that makes it "easy" to program the FPGA. For apps, one good example would be putting TinyML (or any other ML/LLM models) on a FPGA. This would take advantage of the current technology wave to make this project a success. PS: Folks might find the book FPGAs for Software Programmers by Dirk Koch et al. (https://link.springer.com/book/10.1007/978-3-319-26408-0 https://link.springer.com/book/10.1007/978-3-319-26408-0) useful.

deleted 10mo ago
[deleted]

PunchyHamster 10mo ago

They can't, by nature of the proprietary bitstream. Arduino was only built thanks to ability to do whatever they wanted with open source compilers