Subversion Repositories dblclockfft

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

//

// Filename:    ifft_tb.v

//

// Project:     A Doubletime Pipelined FFT

//

// Purpose:     This file is used to test whether an FFT followed by an

//              immediate IFFT produces the input again.  It is a test

//              bench for the composition of the two programs, and specifically

//              for the IFFT.  As designed and built, this test bench would

//              be difficult to implement in an FPGA (although I wouldn't

//              put it past a smart individual), it was designed to be

//              used within Verilator as part of a C++ simulation.  The

//              simulation source may be found in this project inside

//              ifft_tb.cpp.

//

// Creator:     Dan Gisselquist, Ph.D.

//              Gisselquist Tecnology, LLC

//

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

//

// Copyright (C) 2015, Gisselquist Technology, LLC

//

// This program is free software (firmware): you can redistribute it and/or

// modify it under the terms of  the GNU General Public License as published

// by the Free Software Foundation, either version 3 of the License, or (at

// your option) any later version.

//

// This program is distributed in the hope that it will be useful, but WITHOUT

// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

//

// You should have received a copy of the GNU General Public License along

// with this program.  (It's in the $(ROOT)/doc directory, run make with no

// target there if the PDF file isn't present.)  If not, see

// <http://www.gnu.org/licenses/> for a copy.

//

// License:     GPL, v3, as defined and found on www.gnu.org,

//              http://www.gnu.org/licenses/gpl.html

//

//

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

module  ifft_tb(i_clk, i_rst, i_ce, i_left, i_right, o_left, o_right, o_sync);

        parameter       IWIDTH=16, MIDWIDTH=22, OWIDTH=28;

        input                                   i_clk, i_rst, i_ce;

        input           [(2*IWIDTH-1):0] i_left, i_right;

        output  wire    [(2*OWIDTH-1):0] o_left, o_right;

        output  wire                            o_sync;

        wire                            m_sync;

        wire    [(2*MIDWIDTH-1):0]       m_left, m_right;

        fftmain fft(i_clk, i_rst, i_ce, i_left, i_right,

                                m_left, m_right, m_sync);

        wire    w_syncd;

        reg     r_syncd;

        always @(posedge i_clk)

                if (i_rst)

                        r_syncd <= 1'b0;

                else

                        r_syncd <= r_syncd || m_sync;

        assign  w_syncd = r_syncd || m_sync;

        ifftmain        ifft(i_clk, i_rst, (i_ce)&&(w_syncd), m_left, m_right,

                                o_left, o_right, o_sync);

endmodule