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Published 20 hours ago • verified publisher icon projf

Preliminary support for the ULX3S.

Open tristanitschner opened this issue 2 years ago • 3 comments

This adds support for the

  • graphics/framebuffers
  • graphics/pong

examples for the ULX3S board.

Has been tested on my board.

tristanitschner avatar Sep 24 '22 18:09 tristanitschner

Thank you for your PR. I am currently on leave and will review your request in October.

WillGreen avatar Sep 27 '22 07:09 WillGreen

Thank you for your patience. 🙏 I have merged my outstanding branches, so your PR is the next thing I'll work on.

WillGreen avatar Oct 16 '22 12:10 WillGreen

Hi there, no problem, since I'm usually very busy anyway.

May I elaborate a little on my changes:

  • The main constraints file for the ULX3S was taken from: https://github.com/emard/ulx3s/blob/master/doc/constraints/ulx3s_v20.lpf It is the same for every project. It might be a good idea, to make it global.
  • The ULX3S' main chip, the ECP5, does not support SERDES. HDMI is implemented using a "hack" using the ECP5 ODDRX1F primitive, which allows for doubling the data rate and thus makes 720p@60Hz and 1080p@30Hz possible. Still the naming is somewhat awkward as I used CVR-RBv2. My feeling is to make these settings available as generics and thus reduce code deduplication.
  • Most of the code is Verilog and not System Verilog. You will probably like this to be adapted.
  • There are still some examples missing, I'll wait for your feedback first.
  • I have tried to get the animated-shapes examples running, but so far in vain. I suspect missing attributes on cdc paths / timing failure to be the problem.

tristanitschner avatar Oct 16 '22 15:10 tristanitschner

I've dusted off my ULX3S board and have successfully built the first few of your versions.

I think the best way to handle this is to take each FPGA Graphics part, work together on the ULX3S version, and then merge it to main.

I've created a branch called fpga-graphics-ulx3s. If you could checkout this branch, add your designs for projf-explore/graphics/fpga-graphics, and then create a fresh PR against this branch, we can work on that first.

Once we're happy with fpga-graphics, we can merge it to main, then create a fresh branch for fpga-pong etc.

I hope this sounds good to you, but do let me know if you have any concerns.

WillGreen avatar Oct 26 '22 08:10 WillGreen

Agreed with @tristanitschner to close this PR. There is a new PR #128 covering FPGA Graphics.

WillGreen avatar Oct 31 '22 15:10 WillGreen