Subversion Repositories pipelined_fft_64

/////////////////////////////////////////////////////////////////////

////                                                             ////

////  Multiplier by 0.7071                                       ////

////                                                             ////

////  Authors: Anatoliy Sergienko, Volodya Lepeha                ////

////  Company: Unicore Systems http://unicore.co.ua              ////

////                                                             ////

////  Downloaded from: http://www.opencores.org                  ////

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/////////////////////////////////////////////////////////////////////

////                                                             ////

//// Copyright (C) 2006-2010 Unicore Systems LTD                 ////

//// www.unicore.co.ua                                           ////

//// o.uzenkov@unicore.co.ua                                     ////

////                                                             ////

//// This source file may be used and distributed without        ////

//// restriction provided that this copyright statement is not   ////

//// removed from the file and that any derivative work contains ////

//// the original copyright notice and the associated disclaimer.////

////                                                             ////

//// THIS SOFTWARE IS PROVIDED "AS IS"                           ////

//// AND ANY EXPRESSED OR IMPLIED WARRANTIES,                    ////

//// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED                  ////

//// WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT              ////

//// AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.        ////

//// IN NO EVENT SHALL THE UNICORE SYSTEMS OR ITS                ////

//// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,            ////

//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL            ////

//// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT         ////

//// OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,               ////

//// DATA, OR PROFITS; OR BUSINESS INTERRUPTION)                 ////

//// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,              ////

//// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT              ////

//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING                 ////

//// IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,                 ////

//// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.          ////

////                                                             ////

/////////////////////////////////////////////////////////////////////

// Design_Version       : 1.0

// File name            : MPU707.v

// File Revision        : 

// Last modification    : Sun Sep 30 20:11:56 2007

/////////////////////////////////////////////////////////////////////

// FUNCTION: Constant multiplier

// PROPERTIES:1)Is based on shifts right and add

//                2)for short input bit width 0.7071 is approximated as

//              10110101 then rounding is not used

//                3)for long input bit width 0.7071 is approximated as 

//              10110101000000101              

//                4)hardware is 3 or 4 adders 

/////////////////////////////////////////////////////////////////////

`include "FFT64_CONFIG.inc"

module MPU707 ( CLK ,DO ,DI ,EI );

`USFFT64paramnb

        input CLK ;

        wire CLK ;

        input [nb+1:0] DI ;

        wire signed [nb+1:0] DI ;

        input EI ;

        wire EI ;

        output [nb+1:0] DO ;

        reg [nb+1:0] DO ;

        reg signed [nb+5 :0] dx5;

        reg signed      [nb+2 : 0] dt;

        wire signed [nb+6 : 0]  dx5p;

        wire  signed  [nb+6 : 0] dot;

        always @(posedge CLK)

                begin

                        if (EI) begin

                                        dx5<=DI+(DI <<2);        //multiply by 5

                                        dt<=DI;

                                        DO<=dot >>>4;

                                end

                end

        `ifdef USFFT64bitwidth_0707_high

        assign   dot=   (dx5p+(dt>>>4)+(dx5>>>12));        // multiply by 10110101000000101           

        `else

        assign    dot=          (dx5p+(dt>>>4) )        ;  // multiply by 10110101         

        `endif

                assign  dx5p=(dx5<<1)+(dx5>>>2);                // multiply by 101101                   

endmodule