I'm learning migen and implemented my first core, VgaOutputGenerator:
https://pastebin.com/XC4kwgZq
But I think I didn't really understand how to use multiple clocks in a submodule. I tried to pass the clock domain object cd_vga, but this doesn't work. So I extracted the pin, and then created a new ClockDomain object in the submodule. Is this right?
Another question: How can I set a different default clock for a submodule? Later I need 2 clocks for the module, but if I just wanted to use cd_vga as the default clock for sync, how would I do this?