Thu Aug 16 17:11:54 EDT 2018
Why do FPGAs use LUTs?
I don't know, but a guess is that a LUT doesn't introduce any bias
against certain functions. Each n-ary function is implemented with
the same cost. As such, LUTs are universal.
They are probably also easy to implement as compared to other
The question is more: why 3 to 1, and not any other n to m
There does seem to be some variability here. 3-1, 4-1, even mult-out?
This says 4-1 is best for size, 5-1 is best for performance.