how to simulate

[thecrazyboy]

Hello ludde
have you simuluated it in modelsim or other simulator?
I have tried it by modelsim and failed ,because many signals are unkown (x state) during simuation cause cpu stop at some instruction.
and I do some modification by initialize signals in initial statement or during reset , but I can‘t fix it all because i am a newbie.

and also port it to cyclone4 device, after downloading, vga only show boarder, other area is black.

can you give me some suggestion on porting and simulation?