@Matt Venn I took a look at the verilog/rtl/user_defines.v in your RGB repo and it seems to me as if the bit-size of 10 of the constants is too short for the contents, 13 would be better.

I think it’s 13 for sky130, 10 for gf180mcu.

Ah, now I got it. Ok, then I was wrong. Sorry. And thanks for the explanation!