These exist for LUTA, LUTB, and LUTC only
Can either be an external signal, another LUT‘s data input, or another LUT’s carry
Note: mux input pattern is irregular
The following bits are set for NI but not NMC31:
bit 00_00 ADI1MUX.AI bit 00_20 BDI1MUX.BI bit 01_43 BDI1MUX.CI
Additionally, test with unknown DI mux bits don't appear near NI bits
There is something strange going on