$n$ -bit adder

Design a circuit that performs the addition of two $n$ -bit numbers. The result must be represented in $n$ bits also. The number of bits $n$ must be a parameter of the module.

Specification

module adder (a, b, cin, sum, cout);
    parameter N=16;
    input [N-1:0] a, b;
    input cin;
    output [N-1:0] sum;
    output cout;

Hint

You may want to use several instances of a 1-bit full adder.

Input

a and b are the two $n$ -bit numbers.
cin is the input carry.

Output

sum is the $n$ -bit output representing $(a+b) \textrm{~mod~} 2^n$ .
cout is the output carry.

Problem information

Author: Jordi Cortadella