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

//

// Filename:    butterfly_tb.cpp

//

// Project:     A Doubletime Pipelined FFT

//

// Purpose:     A test-bench for the butterfly.v subfile of the double

//              clocked FFT.  This file may be run autonomously.  If so,

//              the last line output will either read "SUCCESS" on success,

//              or some other failure message otherwise.

//

//              This file depends upon verilator to both compile, run, and

//              therefore test butterfly.v

//

// Creator:     Dan Gisselquist, Ph.D.

//              Gisselquist Technology, 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

//

//

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

#include <stdio.h>

#include <stdint.h>

#include "fftsize.h"

#include "Vbutterfly.h"

#include "verilated.h"

#include "twoc.h"

#define IWIDTH  TST_BUTTERFLY_IWIDTH

#define CWIDTH  TST_BUTTERFLY_CWIDTH

#define OWIDTH  TST_BUTTERFLY_OWIDTH

#define BFLYDELAY       TST_BUTTERFLY_MPYDELAY

class   BFLY_TB {

public:

        Vbutterfly      *m_bfly;

        unsigned long   m_left[64], m_right[64];

        bool            m_aux[64];

        int             m_addr, m_lastaux, m_offset;

        bool            m_syncd, m_waiting_for_sync_input;

        BFLY_TB(void) {

                m_bfly = new Vbutterfly;

                m_addr = 0;

                m_syncd = 0;

                m_waiting_for_sync_input = true;

        }

        void    tick(void) {

                m_lastaux = m_bfly->o_aux;

                m_bfly->i_clk = 0;

                m_bfly->eval();

                m_bfly->i_clk = 1;

                m_bfly->eval();

                if ((!m_syncd)&&(m_bfly->o_aux))

                        m_offset = m_addr;

                m_syncd = (m_syncd) || (m_bfly->o_aux);

        }

        void    reset(void) {

                m_bfly->i_ce    = 0;

                m_bfly->i_rst   = 1;

                m_bfly->i_coef  = 0l;

                m_bfly->i_left  = 0;

                m_bfly->i_right = 0;

                tick();

                m_bfly->i_rst = 0;

                m_bfly->i_ce  = 1;

                //

                // Let's run a RESET test here, forcing the whole butterfly

                // to be filled with aux=1.  If the reset works right,

                // we'll never get an aux=1 output.

                //

                m_bfly->i_rst = 1;

                m_bfly->i_aux = 1;

                for(int i=0; i<200; i++) {

                        m_bfly->i_ce = 1;

                        tick();

                }

                // Now here's the RESET line, so let's see what the test does

                m_bfly->i_rst = 1;

                m_bfly->i_ce  = 1;

                m_bfly->i_aux = 1;

                tick();

                m_bfly->i_rst = 0;

                m_syncd = 0;

                m_waiting_for_sync_input = true;

        }

        void    test(const int n, const int k, const unsigned long cof,

                        const unsigned lft, const unsigned rht, const int aux) {

                m_bfly->i_coef  = ubits(cof, 2*TST_BUTTERFLY_CWIDTH);

                m_bfly->i_left  = ubits(lft, 2*TST_BUTTERFLY_IWIDTH);

                m_bfly->i_right = ubits(rht, 2*TST_BUTTERFLY_IWIDTH);

                m_bfly->i_aux   = aux & 1;

                if ((m_waiting_for_sync_input)&&(aux&1)) {

                        m_waiting_for_sync_input = false;

                        m_addr = 0;

                }

                m_bfly->i_ce = 1;

                tick();

                if ((m_bfly->o_aux)&&(!m_lastaux))

                        printf("\n");

                printf("n,k=%d,%3d: COEF=%010lx, LFT=%08x, RHT=%08x, A=%d, OLFT =%09lx, ORHT=%09lx, AUX=%d\n",

                        n,k,

                        m_bfly->i_coef & (~(-1l<<40)),

                        m_bfly->i_left,

                        m_bfly->i_right,

                        m_bfly->i_aux,

                        m_bfly->o_left,

                        m_bfly->o_right,

                        m_bfly->o_aux);

                if ((m_syncd)&&(m_left[(m_addr-m_offset)&(64-1)] != m_bfly->o_left)) {

                        printf("WRONG O_LEFT! (%lx(exp) != %lx(sut))\n",

                                m_left[(m_addr-m_offset)&(64-1)],

                                m_bfly->o_left);

                        exit(-1);

                }

                if ((m_syncd)&&(m_right[(m_addr-m_offset)&(64-1)] != m_bfly->o_right)) {

                        printf("WRONG O_RIGHT (%10lx(exp) != (%10lx(sut))!\n",

                                m_right[(m_addr-m_offset)&(64-1)], m_bfly->o_right);

                        exit(-1);

                }

                if ((m_syncd)&&(m_aux[(m_addr-m_offset)&(64-1)] != m_bfly->o_aux)) {

                        printf("FAILED AUX CHANNEL TEST (i.e. the SYNC)\n");

                        exit(-1);

                }

                if ((m_addr > TST_BUTTERFLY_MPYDELAY+6)&&(!m_syncd)) {

                        printf("NO SYNC PULSE!\n");

                        // exit(-1);

                }

                // Now, let's calculate an "expected" result ...

                long    rlft, ilft;

                // Extract left and right values ...

                rlft = sbits(m_bfly->i_left >> IWIDTH, IWIDTH);

                ilft = sbits(m_bfly->i_left          , IWIDTH);

                // Now repeat for the right hand value ...

                long    rrht, irht;

                // Extract left and right values ...

                rrht = sbits(m_bfly->i_right >> IWIDTH, IWIDTH);

                irht = sbits(m_bfly->i_right          , IWIDTH);

                // and again for the coefficients

                long    rcof, icof;

                // Extract left and right values ...

                rcof = sbits(m_bfly->i_coef >> CWIDTH, CWIDTH);

                icof = sbits(m_bfly->i_coef          , CWIDTH);

                // Now, let's do the butterfly ourselves ...

                long sumi, sumr, difi, difr;

                sumr = rlft + rrht;

                sumi = ilft + irht;

                difr = rlft - rrht;

                difi = ilft - irht;

        /*

                printf("L=%5lx+%5lx,R=%5lx+%5lx,S=%5lx+%5lx,D=%5lx+%5lx, ",

                        rlft & 0x02ffffl,

                        ilft & 0x02ffffl,

                        rrht & 0x02ffffl,

                        irht & 0x02ffffl,

                        sumr & 0x02ffffl,

                        sumi & 0x02ffffl,

                        difr & 0x02ffffl,

                        difi & 0x02ffffl);

        */

                long p1, p2, p3, mpyr, mpyi;

                p1 = difr * rcof;

                p2 = difi * icof;

                p3 = (difr + difi) * (rcof + icof);

                mpyr = p1-p2;

                mpyi = p3-p1-p2;

                mpyr = rndbits(mpyr, (IWIDTH+2)+(CWIDTH+1), OWIDTH+4);

                mpyi = rndbits(mpyi, (IWIDTH+2)+(CWIDTH+1), OWIDTH+4);

        /*

                printf("RC=%lx, IC=%lx, ", rcof, icof);

                printf("P1=%lx,P2=%lx,P3=%lx, ", p1,p2,p3);

                printf("MPYr = %lx, ", mpyr);

                printf("MPYi = %lx, ", mpyi);

        */

                long    o_left_r, o_left_i, o_right_r, o_right_i;

                unsigned long   o_left, o_right;

                o_left_r = rndbits(sumr<<(CWIDTH-2), CWIDTH+IWIDTH+3, OWIDTH+4);

                        o_left_r = ubits(o_left_r, OWIDTH);

                o_left_i = rndbits(sumi<<(CWIDTH-2), CWIDTH+IWIDTH+3, OWIDTH+4);

                        o_left_i = ubits(o_left_i, OWIDTH);

                o_left = (o_left_r << OWIDTH) | (o_left_i);

                o_right_r = ubits(mpyr, OWIDTH);

                o_right_i = ubits(mpyi, OWIDTH);

                o_right = (o_right_r << OWIDTH) | (o_right_i);

        /*

                printf("oR_r = %lx, ", o_right_r);

                printf("oR_i = %lx\n", o_right_i);

        */

                m_left[ m_addr&(64-1)] = o_left;

                m_right[m_addr&(64-1)] = o_right;

                m_aux[  m_addr&(64-1)] = aux;

                m_addr++;

        }

};

int     main(int argc, char **argv, char **envp) {

        Verilated::commandArgs(argc, argv);

        BFLY_TB *bfly = new BFLY_TB;

        int16_t         ir0, ii0, lstr, lsti;

        int32_t         sumr, sumi, difr, difi;

        int32_t         smr, smi, dfr, dfi;

        int             rnd = 0;

        const int       TESTSZ = 256;

        bfly->reset();

        // Test whether or not the aux channel starts clear, like its supposed to

        bfly->test(9,0,0x4000000000l,0x000f0000,0x000f0000, 0);

        bfly->test(9,1,0x4000000000l,0x000f0000,0xfff10000, 0);

        bfly->test(9,2,0x4000000000l,0x0000000f,0x0000fff1, 0);

        bfly->test(9,3,0x4000000000l,0x0000000f,0x0000000f, 0);

        bfly->test(9,0,0x4000000000l,0x7fff0000,0x7fff0000, 1);

        bfly->test(9,1,0x4000000000l,0x7fff0000,0x80010000, 0);

        bfly->test(9,2,0x4000000000l,0x00007fff,0x00008001, 0);

        bfly->test(9,3,0x4000000000l,0x00007fff,0x00007fff, 0);

        bfly->test(8,0,0x4000000000l,0x80010000,0x80010000, 1);

        bfly->test(8,1,0x4000000000l,0x00008001,0x00008001, 0);

        bfly->test(9,0,0x4000000000l,0x40000000,0xc0000000, 1);

        bfly->test(9,1,0x4000000000l,0x40000000,0x40000000, 0);

        bfly->test(9,2,0x4000000000l,0x00004000,0x0000c000, 0);

        bfly->test(9,3,0x4000000000l,0x00004000,0x00004000, 0);

        bfly->test(9,0,0x4000000000l,0x20000000,0xe0000000, 1);

        bfly->test(9,1,0x4000000000l,0x20000000,0x20000000, 0);

        bfly->test(9,2,0x4000000000l,0x00002000,0x0000e000, 0);

        bfly->test(9,3,0x4000000000l,0x00002000,0x00002000, 0);

        bfly->test(9,0,0x4000000000l,0x00080000,0xfff80000, 1);

        bfly->test(9,1,0x4000000000l,0x00080000,0x00080000, 0);

        bfly->test(9,2,0x4000000000l,0x00000008,0x0000fff8, 0);

        bfly->test(9,3,0x4000000000l,0x00000008,0x00000008, 0);

        bfly->test(7,0,0x3fffbff9b9l,0xfffe0000,0x00000000, 1);

        bfly->test(7,1,0x3ffd4fed28l,0xfffc0000,0x00020000, 0);

        bfly->test(7,2,0x3ff85fe098l,0xfff80000,0x00060000, 0);

        bfly->test(7,3,0x3ff0efd409l,0xfff00000,0x000e0000, 0);

        bfly->test(7,4,0x3fe70fc77cl,0xffe60000,0x00180000, 0);

        bfly->test(7,5,0x3fdabfbaf1l,0xffda0000,0x00240000, 0);

        bfly->test(7,6,0x3fcbefae69l,0xffca0000,0x00340000, 0);

        bfly->test(7,7,0x3fbaafa1e4l,0xffba0000,0x00440000, 0);

        /*

        // Special tests

        bfly->test(9,0,0x4000000000l,0x00010000,0xffff0000, 1);

        bfly->test(9,1,0x4000000000l,0x00010000,0x00010000, 0);

        bfly->test(9,2,0x4000000000l,0x00000001,0x0000ffff, 0);

        bfly->test(9,3,0x4000000000l,0x00000001,0x00000001, 0);

        */

        for(int n=0; n<4; n++) for(int k=0; k<TESTSZ; k++) {

                long    iv, rv;

                unsigned long   lft, rht, cof;

                double  c, s, W;

                bool    inv = 1;

                int     aux;

                W = ((inv)?-1:1) * 2.0 * M_PI * (2*k) / TESTSZ * 64;

                c = cos(W); s = sin(W);

                rv = (long)((double)(1l<<(16-2-n))*c+0.5);

                iv = (long)((double)(1l<<(16-2-n))*s+0.5);

                rv = (rv << 16) | (iv & (~(-1<<16)));

                lft = rv;

                W = ((inv)?-1:1) * 2.0 * M_PI * (2*k+1) / TESTSZ * 64;

                c = cos(W); s = sin(W);

                rv = (long)((double)(1l<<(16-2-n))*c+0.5);

                iv = (long)((double)(1l<<(16-2-n))*s+0.5);

                rv = (rv << 16) | (iv & (~(-1<<16)));

                rht = rv;

                // Switch the sign of W

                W = ((inv)?1:-1) * 2.0 * M_PI * (2*k) / TESTSZ;

                c = cos(W); s = sin(W);

                rv = (long)((double)(1l<<(20-2))*c+0.5); // Keep 20-2 bits for

                iv = (long)((double)(1l<<(20-2))*s+0.5); // coefficients

                rv = (rv << 20) | (iv & (~(-1<<20)));

                cof = rv;

                aux = ((k&(TESTSZ-1))==0);

                bfly->test(n,k, cof, lft, rht, aux);

        }

        delete  bfly;

        printf("SUCCESS!\n");

        exit(0);

}