4w ago

Good dev board to build a cpu?

Hey everyone i am a EE student and last semester i had a fpga design course wich was a lot of fun. We used some xylinx dev board that cost about 300€ and i dont really want to spend that much money right now. I would love to design a little cpu, not shure yet if i want to implement the risc instruction set or just wing it but i dont have a fixed set of requirements yet. Would you design your own board with a mcu for programming, the fpga and maybe dram or would you get a dev board? Does someone know a good dev board that does not break the bank? With the xylinx board i obviusly worked with vivado, how are the tools of alterra or others in comparison in your opinion? Thanks for your input!

4 comments

FPGA development boards from Lattice Semiconductor and the QuickLogic Corp should offer enough LUTs to implement a CPU without the added cost of Xilinx features like Zynq MPSoC, etc.
- Quicklogic was not on my radar, thanks i will have to look at their lineup.
Ive been playing around with these Alchitry boards. The IDE they've made for them is a little funky looking but you can make bit files with standard tools like Vivado and just use their tools to flash them. https://shop.alchitry.com/collections/products
The Digilent Arty boards aren't very expensive and are well supported, including board files and programming support in Vivado I believe. https://digilent.com/shop/arty-s7-spartan-7-fpga-development-board/
Cheaper than those you'll probably need to change FPGA vendors, like this Lattice board https://www.tindie.com/products/tinyvision_ai/upduino-v31-low-cost-lattice-ice40-fpga-board/
I'm a big advocate for open source hardware and software, which The FPGA industry really struggles with. I've heard the ICE40 FPGA is supported with an open source software tool chain. It looks capable enough to make a CPU and low speed peripherals, but I haven't used them.
Hi Im also a student but with a very a small budget. I figured I'd share some of the very cheap chinese boards Ive found. Cheap means some disadvantages ofcourse. Purchased one of these recently.
The first are boards with Altera's Cyclone IV on them. Boards with the EP4CE6 (6K LEs) and EP4CE10 (10K LEs) can be found on AliExpress.
Cyclone IV is supported by Quartus Lite so dev tools will be free. For the fpga itself Intel has documentation but for the peripherals on the board (if its a more fully-featured board) you either rely on the seller sending you pin numbers or finding it online documented by others.
I got one with EP4CE6 (no VGA jack or other bells and whistles, just some LEDs and buttons) for what comes out as 10 euros or so. There are others that resemble proper dev boards (with connectors and stuff like 7-segment displays) costing something like 25 euros.
There are also Sipeed Tang FPGA boards. They use Gowin FPGAs and Gowin's IDE is free. The Tang Nano 9k has been shown to run the PicoRV32 RISC-V core. It costs 15 euro on Aliexpress. The downside is that Gowin tools ofcourse wont be as good as Intel's Quartus.
Also interesting to note that the Tang Nano 4K has a Cortex M3 on it so I think it counts as an Fpga-Soc? I think its fun and might get one some time.