Subversion Repositories rtftextcontroller

/* ===============================================================

        (C) 2006 Robert Finch

        All rights reserved.

        rob@birdcomputer.ca

        change_det.v

        - detects a change in a value

        This source code is free for use and modification for

        non-commercial or evaluation purposes, provided this

        copyright statement and disclaimer remains present in

        the file.

        If you do modify the code, please state the origin and

        note that you have modified the code.

        NO WARRANTY.

        THIS Work, IS PROVIDEDED "AS IS" WITH NO WARRANTIES OF

        ANY KIND, WHETHER EXPRESS OR IMPLIED. The user must assume

        the entire risk of using the Work.

        IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR

        ANY INCIDENTAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES

        WHATSOEVER RELATING TO THE USE OF THIS WORK, OR YOUR

        RELATIONSHIP WITH THE AUTHOR.

        IN ADDITION, IN NO EVENT DOES THE AUTHOR AUTHORIZE YOU

        TO USE THE WORK IN APPLICATIONS OR SYSTEMS WHERE THE

        WORK'S FAILURE TO PERFORM CAN REASONABLY BE EXPECTED

        TO RESULT IN A SIGNIFICANT PHYSICAL INJURY, OR IN LOSS

        OF LIFE. ANY SUCH USE BY YOU IS ENTIRELY AT YOUR OWN RISK,

        AND YOU AGREE TO HOLD THE AUTHOR AND CONTRIBUTORS HARMLESS

        FROM ANY CLAIMS OR LOSSES RELATING TO SUCH UNAUTHORIZED

        USE.

=============================================================== */

module change_det(rst, clk, ce, i, cd);

        parameter WID=32;

        input rst;                      // reset

        input clk;                      // clock

        input ce;                       // clock enable

        input [WID:1] i;        // input signal

        output cd;                      // change detected

        reg [WID:1] hold;

        always @(posedge clk)

                if (rst)

                        hold <= i;

                else if (ce)

                        hold <= i;

        assign cd = i != hold;

endmodule