Subversion Repositories pipelined_fft_128

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////  FFT/IFFT 128 points transform                              ////

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

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

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////  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.////

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//// 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,               ////

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

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

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

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//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~           

// DESCRIPTION  :        Complex Multiplier by 0.5411

// FUNCTION:               Constant multiplier   to cos(PI/8)-cos(3*PI/8) =0.5411

// FILES:                        MPUŃ541.v

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

//                                                      2) for short input bit width 0.541 is approximated as 0_1000_1010_1                            

//                                                      3) for medium bit width 1.3066 is approximated as 0_1000_1010_1001             

//                                                      4) for long  bit width 1.30656 is approximated as 0_1000_1010_1000_11   

//                                                  5) hardware is 3,or4, or 5  adders   +1

//                                                  6) MPYJ switches multiply by j                               

//                                                      6) A complex data is multiplied for 2 cycles, latent delay=4

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

`include "FFT128_CONFIG.inc"

module MPUC541 ( CLK,DS ,ED, MPYJ,DR,DI ,DOR ,DOI,  );

        `FFT128paramnb

        input CLK ;

        wire CLK ;

        input DS ;

        wire DS ;

        input ED;                                       //data strobe

        input MPYJ ;                            //the result is multiplied by -j

        wire MPYJ ;

        input [nb-1:0] DR ;

        wire signed [nb-1:0] DR ;

        input [nb-1:0] DI ;

        wire signed [nb-1:0] DI ;

        output [nb-1:0] DOR ;

        reg [nb-1:0] DOR ;

        output [nb-1:0] DOI ;

        reg [nb-1:0] DOI ;

        reg signed [nb :0] dx5;

        reg signed [nb :0] dx3;

        reg signed [nb-1 :0] dii;

        reg signed      [nb-1 : 0] dt;

        wire signed [nb+1 : 0]  dx5p;

        wire  signed  [nb+1 : 0] dot;

        reg edd,edd2, edd3;                     //delayed data enable impulse        

        reg mpyjd,mpyjd2,mpyjd3;

        reg [nb-1:0] doo ;

        reg [nb-1:0] droo ;

        always @(posedge CLK)

                begin

                        if (ED) begin

                                        edd<=DS;

                                        edd2<=edd;

                                        edd3<=edd2;

                                        mpyjd<=MPYJ;

                                        mpyjd2<=mpyjd;

                                        mpyjd3<=mpyjd2;

                                        if (DS)  begin                                          //       0_1000_1010_1000_11    

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

                                                        dx3<=DR+(DR >>>1);       //multiply by 3, 

                                                        dt<=DR;

                                                        dii<=DI;

                                                end

                                        else     begin

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

                                                        dx3<=dii +(dii >>>1);    //multiply by  3 

                                                        dt<=dii;

                                                end

                                        doo<=dot >>>2;

                                        droo<=doo;

                                        if (edd3)

                                                if (mpyjd3) begin

                                                                DOR<=doo;

                                                        DOI<= - droo; end

                                                else begin

                                                                DOR<=droo;

                                                        DOI<=  doo; end

                                end

                end

        assign  dx5p=(dt<<1)+(dx5>>>3);         // multiply by  0_1000_101 

        `ifdef FFT128bitwidth_coef_high

        assign   dot=   (dx5p+(dt>>>7) +(dx3>>>11));// multiply by //    0_1000_1010_1000_11 

        `else

        assign    dot=  dx5p+(dt>>>7);

        `endif

endmodule