
It's the digital block from algofoogle's TT08 VGA FUN! project, with a simple sequencer loop to make it work standalone and some dithering to simulate 8 bit output on the 4 bit Digilent PmodVGA.
Plug it into a VGA monitor, reset the project, then sit back and enjoy.
You can also manually select the mode and bit depth if you override the sequencer by pulling bit 7 of the input high.
Digilent PmodVGA
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | (mode bit 0) | r0 | g0 |
| 1 | (mode bit 1) | r1 | g1 |
| 2 | (mode bit 2) | r2 | g2 |
| 3 | (depth bit 0) | r3 | g3 |
| 4 | (depth bit 1) | b0 | hsync |
| 5 | (depth bit 2) | b1 | vsync |
| 6 | (depth bit 3) | b2 | |
| 7 | override sequencer | b3 |