... I finally managed to publish the design files of this project. Sorry for the enormous delay!

Why did all this took so long? – I originally had the plan to build the board, verify most of the functionality and then hit publish. Going down the rabbit whole of FPGA design, it took me much longer to get the correctly SRAM running (first it didn't work at all, later it didn't pass a random read/write test). Silly me messed up with the pin definition in Migen (it is very beneficial to assign all address lines to an IO pin!!!), which caused some serious lack of motivation. Now, before trying to publish the next/my current project, I want to make some progress here.

What is (not) published?

• Complete KiCad project (schematic and pcb design) as CERN-OHL-W V2.0
  • SWO pin of the i.MXRT1021 is not fixed
  • No separate power supply for FPGA/µC
  • USB PHY is still completely untested; Its USB-DP routing and trace dimensioning is also not optimal
  • Tested and working: µC programming, FPGA programming, µC–FPGA communitation, SRAM interface, PMODs :)
  • The project is published without 3D models, as some are from the vendors and I don't want to check for possible licencing issues.
• Basic board definition and examples for nMigen need to be updated → not yet finished :(
• Basic firmware for USB and FPGA communication needs to be rewritten → not yet finished :(

What is (not) coming aka the future roadmap?

This board was intended to learn some FPGA basics, BGA soldering and enhance my layout skills. So far I accomplished all three. I'd like to play a bit more with the i.MXRT1021 running tinyusb as well as nMigen on the iCE40, so new "softwork" can be expected for this board.
The hardware will not get any further revision. Most things are running and we have more powerful alternatives like the Pergola.

Special thanks to all people working on the open FPGA toolchain and Migen/nMigen!
Also thanks to Greg Davill for writing down his journey designing the Boson Frame Grabber and his beautiful electronics pictures! Your project motivated me to try soldering BGAs by hand :)

Sources of inspiration:

• CAT Board
• BlackIce II
• TinyFPGA B
• Boson Frame Grabber