Cheap FPGA Development Boards • Hacker News Board

Re: Cheap FPGA Development Boards

#11

Post by bXVsbGVy » Sat, Aug 08, 2020, 6:39 PM UTC

b1ackb0x wrote: post #9

amelius wrote: post #6

So which company is the most open-source friendly provider of FPGA chips these days?

FPGA tools allow a lot of customization if you need it, what difference will it make if they are fully opensource? FPGA chip design isn't opensource anyway

The vendors tools are notoriously buggy, don't conform to the HDL standard and lacks support to inference of some functional block (cascade DSPs and FIFOs for example).

Some FPGAs features are only available on yearly paid subscription. Also, the license is very restrictive, publishing benchmarking is not allowed, therefore, there is no public information on how to chose a computer to have faster synthesis.

Other than solving those issues, an open source framework enable the researches to search for newer place and route algorithms; enables new HDL languages to target the actual hardware instead of using verilog as intermediate language.

Re: Cheap FPGA Development Boards

#12

Post by rudedogg » Sat, Aug 08, 2020, 6:50 PM UTC

Whenever I look for an FPGA board I keep ending up on https://www.crowdsupply.com/tinyfpga/tinyfpga-ex. The campaign hasn't been updated in over a year though.

Is the project dead, or is there something better out there I should look at?

Re: Cheap FPGA Development Boards

#13

Post by bXVsbGVy » Sat, Aug 08, 2020, 7:05 PM UTC

amelius wrote: post #6

So which company is the most open-source friendly provider of FPGA chips these days?

AFAIK, none.

Recently Lattice updated their licensing forbidding reverse engineering, but changed their mind once the community complained.

Also, a while back, lattice added support to something that was already implemented on the open source tools, but with a different name -- thus, code that worked on open source don't work on the official tool. (I'm not sure if this was "fixed").

The open source tools have been create by hard work of many hackers. If you want to know more, watch this 35C3 talk [1] where MathiasL describes how they reverse engineered the Artix-7 bitstream.

Last time I checked, Symbflow [2] only supported Lattices FPGAs and Artix-7 (smallest fpga from Xilinx 7-series). Both are quite small FPGAs.

[1] https://www.youtube.com/watch?v=Y1Wwa8csFjk [2] https://symbiflow.github.io/

Re: Cheap FPGA Development Boards

#14

Post by metaphor » Sat, Aug 08, 2020, 7:07 PM UTC

tyingq wrote: post #8

If you need 5V compatibility, or large sizes for cheap, search eBay for [altera university]. Since these boards were mandatory for many classes there are pretty easy to find for under $50, and include lots of peripherals, buttons, LEDs, connectors, etc. The cheap ones are old, of course, but still useful.

> If you need 5V compatibility...

The devil in the details is that when 5V-tolerant I/O are naively configured as such, device reliability drops like a rock. You'll likely find this disclosed in the manual fine print. Something to consider when prototyping a design destined for production.

Re: Cheap FPGA Development Boards

#15

Post by neuro_mnem » Sat, Aug 08, 2020, 7:16 PM UTC

rudedogg wrote: post #12

Whenever I look for an FPGA board I keep ending up on https://www.crowdsupply.com/tinyfpga/tinyfpga-ex . The campaign hasn't been updated in over a year though. Is the project dead, or is there something better out there I should look at?

Check out ulx3s [1], it's a quite an impressive open source dev board with lots of features, based on the same ECP5-series FPGA chip.

[1] https://www.crowdsupply.com/radiona/ulx3s#details-top

Re: Cheap FPGA Development Boards

#16

Post by rudedogg » Sat, Aug 08, 2020, 7:19 PM UTC

neuro_mnem wrote: post #15

rudedogg wrote: post #12

Whenever I look for an FPGA board I keep ending up on https://www.crowdsupply.com/tinyfpga/tinyfpga-ex . The campaign hasn't been updated in over a year though. Is the project dead, or is there something better out there I should look at?

Check out ulx3s [1], it's a quite an impressive open source dev board with lots of features, based on the same ECP5-series FPGA chip. [1] https://www.crowdsupply.com/radiona/ulx3s#details-top

Thanks, that one looks great.

Re: Cheap FPGA Development Boards

#17

Post by tyingq » Sat, Aug 08, 2020, 7:21 PM UTC

metaphor wrote: post #14

tyingq wrote: post #8

If you need 5V compatibility, or large sizes for cheap, search eBay for [altera university]. Since these boards were mandatory for many classes there are pretty easy to find for under $50, and include lots of peripherals, buttons, LEDs, connectors, etc. The cheap ones are old, of course, but still useful.

> If you need 5V compatibility... The devil in the details is that when 5V-tolerant I/O are naively configured as such, device reliability drops like a rock. You'll likely find this disclosed in the manual fine print. Something to consider when prototyping a design destined for production.

In these boards it's not "5V tolerant". It's actual 5V I/O. EPF10K70. They are obsolete, and so the production part doesn't apply. Solely for hobby stuff.

Re: Cheap FPGA Development Boards

#18

Post by baybal2 » Sat, Aug 08, 2020, 7:25 PM UTC

metaphor wrote: post #14

tyingq wrote: post #8

If you need 5V compatibility, or large sizes for cheap, search eBay for [altera university]. Since these boards were mandatory for many classes there are pretty easy to find for under $50, and include lots of peripherals, buttons, LEDs, connectors, etc. The cheap ones are old, of course, but still useful.

> If you need 5V compatibility... The devil in the details is that when 5V-tolerant I/O are naively configured as such, device reliability drops like a rock. You'll likely find this disclosed in the manual fine print. Something to consider when prototyping a design destined for production.

What do people need 5V for these days?

Re: Cheap FPGA Development Boards

#19

Post by snvzz » Sat, Aug 08, 2020, 7:25 PM UTC

amelius wrote: post #6

So which company is the most open-source friendly provider of FPGA chips these days?

QuickLogic (EOS S3) do actively contribute to the open stack (to support their own FPGA series) themselves.

https://www.crowdsupply.com/quicklogic/quickfeather

OTOH, while not actively contributing, Lattice (iCE40, ECP5) are aware and do tolerate the open stack.

They reversed some new terms of use recently (stating it was a mistake), when the community realized they had added some clauses against reverse engineering and made a lot of noise about it. It means they are aware of the positive effect the open stack has provided from a marketing standpoint.

Re: Cheap FPGA Development Boards

#20

Post by tyingq » Sat, Aug 08, 2020, 7:28 PM UTC

baybal2 wrote: post #18

metaphor wrote: post #14

Earlier quoted context omitted.

> If you need 5V compatibility... The devil in the details is that when 5V-tolerant I/O are naively configured as such, device reliability drops like a rock. You'll likely find this disclosed in the manual fine print. Something to consider when prototyping a design destined for production.

What do people need 5V for these days?

I have a lot of old 8 bit computers, and there's many interesting things you can do with a native 5v FPGA or CPLD there.

I assume interfacing simply with cheap ATMEL and PIC MCUs is another use case.

The university boards can also support 3.3v.