How to fiix LUT inputs?

[d0nathan]

I implemented ring oscillators on an Altera Cyclone IV with Quartus II.

The compilation choses arbitrarily which inputs of the LUTs are used.
I could edit each LUT seperatly but this is very time-consuming.

Is there a way to determine which LUT inputs are used without changing each one severally?

 

[TrickyDicky]

Unfortunately, the only way to do this is but hand editing each lut. The tools are not really meant for this kind of logic.

 

[ads-ee]

Instantiate the LUTs using library primitives. I don't recall either Xilinx or Altera swapping pins when you instantiate a LUT.

 

[FvM]

When using cyclonexx_lcell_comb, the inputs may be reassigned by the fitter. As far as I understand, this done due to routing constraints, the routing options aren't orthogonal.