Added files into modelsim folder

ModelSim/lu.sv

@@ -1,13 +1,13 @@
 `ifndef LU_H_SV
 `define LU_H_SV
 module lu #(parameter width = 2) (
-    input logic [1:0] op,
-    input logic [2**width-1:0] A,
+    input logic [1:0] op,           // 2 bit operand
+    input logic [2**width-1:0] A,  // width defined as 2^n 
 	 input logic [2**width-1:0] B,
     output logic [2**width-1:0] Y);
 	 
     always_comb begin
-		case (op)
+		case (op) // different operations of A and B based on operand
 			2'b00:	Y =   A & B;
 			2'b01:	Y =   A | B;
 			2'b10:	Y =   A ^ B;
@@ -16,4 +16,4 @@ module lu #(parameter width = 2) (
 		endcase
     end
 endmodule
-`endif
+`endif