I manually made one MACRO (.nmc file), in V2P30, ISE 8.2.03,
for 16-bit AND function
using 8 slices.
Every LUT was manually programmed by "A1 * A2"
Strangely, after place and route (PAR),
I observe that some of LUTs in the MACRO are modified by
"A1 * A3" or "A2 * A4"
Though it is still "16-bit AND" function,
I do not understand who, why, how change these PIN information.
Is it because of routing congestion?
Does anyone have this experience?