Subversion Repositories programming

/**
 * Copyright 2006, Ira W. Snyder (devel@irasnyder.com)
 * License: GNU General Public License v2 (or, at your option, any later
 * version)
 */

/**
 * Name: Ira Snyder
 * Class: CS365 - Computer Architecture
 * Project #1 - Part 1
 * Due: 2006-02-06
 */

/**
 * File: ALU4.v
 * Purpose: Implementation of a 4-bit ALU.
 */

module ALU4 (a, b, cin, op, cout, result);
    input[0:3] a, b;
    input[0:1] op;
    input cin;

    output[0:3] result;
    output cout;

    wire bit3_cout, bit2_cout, bit1_cout;

    /* Link 4 1-bit ALU's together to make a 4-bit ALU.
     * Connect from LSB to MSB so the ripple-carry works correctly. */
    ALU1 bit3 (a[3], b[3], cin, op, bit3_cout, result[3]);
    ALU1 bit2 (a[2], b[2], bit3_cout, op, bit2_cout, result[2]);
    ALU1 bit1 (a[1], b[1], bit2_cout, op, bit1_cout, result[1]);
    ALU1 bit0 (a[0], b[0], bit1_cout, op, cout, result[0]);
endmodule