Anyone knows how to fit 2 bit 2-to-1 mux into one LUT in virtex-5?

[rex_nyu]

Hi,

I am trying to fit a 2bit 2-to-1 mux into one LUT. It seems that LUT5_D has 5 inputs and 2 outputs. Can I program the LUT as what I want?

I have used LUT3, LUT4 before. From the virtex-5 library guide, it seems that to instantiate LUT5_D I need to program proper init value, but there is only one init value to program, so only one of the output will be actually use? or both of the output will give the same value any time?

LUT5_D #(
.INIT(32'h55550f0f),
) LUT5_D_inst
(.O(O), // General LUT output (1-bit)
.LO(LO), // Local LUT output (1-bit)
.I0(I0), // LUT input (1-bit)
.I1(I1), // LUT input (1-bit)
.I2(I2), // LUT input (1-bit)
.I3(I3), // LUT input (1-bit)
.I4(SEL));


Thank you!

 

[FvM]

Read the library guide thoroughly (I hope it has no typos). Some LUT types have independent operation of both outputs according to the tables, e.g. LUT6_2.

 

[rex_nyu]

I figure it out. Thank you for the suggestion!