Generate for-loop 100-bit binary adder2

Problem statement

Create a 100-bit binary ripple-carry adder by instantiating 100 full adders. The adder adds two 100-bit numbers and a carry-in to produce a 100-bit sum and carry out. To encourage you to actually instantiate full adders, also output the carry-out from each full adder in the ripple-carry adder. cout[99] is the final carry-out from the last full adder, and is the carry-out you usually see.

module top_module( 
    input [99:0] a, b,
    input cin,
    output [99:0] cout,
    output [99:0] sum );

endmodule

Solution

module top_module( 
    input [99:0] a, b,
    input cin,
    output [99:0] cout,
    output [99:0] sum );
    always @(*) begin
        {cout[0],sum[0]}=a[0]+b[0]+cin;
        for (int i=1;i<$bits(cout);i++)
            {cout[i],sum[i]}=a[i]+b[i]+cout[i-1];
    end
endmodule