Add Int Control Signals
Add eret, but not working...
Checkout to branch withVGA to implement the VGA with VRAM, along with a working 800*600 vga driver
Connection among arbiter, ram, vcache(pseudo module at present) and cpu done. Not verified yet.
Arbiter proven to be working.
CPU Int OK. Add Enable
VGA working in progress, capable of display images, but with minor errors at the edge of the screen.
VRAM reading logic rewritten. VGA and CPU are happily working together now, but the screen is flickering which calls for a fix.
VGA with VRAM development done.
Clean up before merge
Merge branch 'withVGA'
Merge branch 'withInt'
Clean up after merging two branches