| # CLBn5FFMUX Fuzzer |
| |
| ## Purpose |
| Document A5FFMUX family of CLB muxes |
| |
| ## Algorithm |
| 5FFMUX |
| Inputs can come from either the LUT6_2 NO5 output or the CLB NX input |
| To perturb the CLB the smallest, want LUT6 always instantiated |
| However, some routing congestion that would require putting FFs in bypass |
| (which turns out is actually okay, but didn't realize that at the time) |
| Decided instead ot instantiate LUT8, but not use the output |
| Turns out this is okay and won't optimize things away |
| So then, the 5FF D input is switched between the O5 output and an external CLB input |
| |
| ## Outcome |
| Bits are one hot encoded per mux position |
| |
