(一)组合逻辑基础语法

`timescale 1ns/1ps     /* 时延单位为1ns，时延精度为1ps */

module adderN #(
parameter N=4
)(
     input [N-1:0] a,
     input [N-1:0] b,
     input    cin,
    output  cout,
    output  [N-1:0]sum 
);

    assign {cout, sum} = a + b + cin;

endmodule