Resolving Tang Nano 20K warnings from Gowin_V1.9.10_x64

[hagen-git]

Disclaimer: I still have to test the changes with my hardware.

• Maybe you want to wait for my tests
• Maybe you decide to cherry-pick some or all of my work beforehand - it's your choice!

Please don't feel obliged, I just want 'to give back' a tiny bit.

It's quite impressive to see such a compact USB HID host core. Wow! Many thanks!

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While I wait for my ordered USB-port modules, I installed the GOWIN toolchain and ran a synthesis of this project.
GOWIN showed a bunch of warnings, and I tried to resolve them.

Most of them are certainly safe to ignore, but I think I might have found one or two genuine oversights.

(From earlier work I know that it's useful when learning to work with a new FPGA toolchain to synthesize a nice sample project, check any warnings and try to understand and resolve them. So far I have used Altera Quartus, Xilinx ISE and Tang Dynasty for synthesis.)

[nand2mario]

Right, the code was hastily put together and could use some clean-ups. I'll merge after you test it on actual hardware.

[hagen-git]

Thank you for the fast and positive reply!

• Meanwhile I tested with real hardware (latest push also has a photo).
  • At first I thought something was broken, but it just turned out the two first devices I tested (a wireless keyboard adapter and a gamepad) don't support USB1.1
  • Checking my devices I learnt that not all mouse protocols are the same. In the latest push I add a file with the USB+HID descriptors that I have seen with my devices (and some comments).
• Keyboard works great, however, so my main use case is nicely covered. :-)
  • I also extended the processing a bit to support CTRL-A..Z, and to have enter output a carriage-return '\x0d' and shift-enter output a linefeed '\x0a'.)