Variable Precision DSP in Arria V Devices

hey Tricky,

Thanks for reply. But if I add outside the following problems will come.

1) it will take extra LUTs

2) it may reduce frequency as we are not sure where it will place this logic. it may take luts for routing also. Instead if I can infer directly I can use dedicated routing for dsps which may increase overall freq.

As u said second solution : ( a x b + c x 1) It takes 2 dsps for multiplication, which increase overall dsps.

I tried even inferring with my logic like

d <= a x b;

out <= d+c;

In this case also also it's taking extra logic for adder.

One-way If i code directly out <= (a x b) + c it's inferring as varible dsps but i want multiplier put to be registered.