I have a low-skill question. I want a register/signal that has this pattern over time:
```
0000
0001
0000
0011
0000
0001
0000
0111
0000
0001
0000
0011
0000
0001
0000
1111
```
I think the way I'm going to do this is have a sync signal of length N which counts up, and a comb signal of length N that for each bit is wired "high if current frame is 1 and last frame is 0"