/////////////////////////////////////////////////////////////////////////                                                             ////////  Discrete Cosine Transform Testbench                        ////////                                                             ////////  Author: Richard Herveille                                  ////////          richard@asics.ws                                   ////////          www.asics.ws                                       ////////                                                             /////////////////////////////////////////////////////////////////////////////                                                             //////// Copyright (C) 2002 Richard Herveille                        ////////                    richard@asics.ws                         ////////                                                             //////// 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 WITHOUT ANY     //////// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   //////// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   //////// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      //////// OR 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.                                 ////////                                                             ///////////////////////////////////////////////////////////////////////////  CVS Log////  $Id: bench_top.v,v 1.2 2002/10/23 09:06:58 rherveille Exp $////  $Date: 2002/10/23 09:06:58 $//  $Revision: 1.2 $//  $Author: rherveille $//  $Locker:  $//  $State: Exp $//// Change History://               $Log: bench_top.v,v $//               Revision 1.2  2002/10/23 09:06:58  rherveille//               Improved many files.//               Fixed some bugs in Run-Length-Encoder.//               Removed dependency on ud_cnt and ro_cnt.//               Started (Motion)JPEG hardware encoder project.////`include "timescale.v"module bench_top();	//	// internal wires	//	reg clk;	reg rst;	reg dstrb;	reg [7:0] din;	wire den;	wire [11:0] dout;	reg [ 7:0] input_list  [63:0];	reg [11:0] output_list [63:0];	integer x,y;	integer err_cnt;	//	// DCT unit	//	////////////////////////////////////////////////////////////////////	//                                                                //	// ITU-T.81, ITU-T.83 & Coefficient resolution notes              //	//                                                                //	////////////////////////////////////////////////////////////////////	//                                                                //	// Worst case error (all input values -128) is                    //	// zero (i.e. no errors) when using 15bit coefficients            //	//                                                                //	// Using less bits for the coefficients produces a biterror       //	// approx. equal to (15 - used_coefficient-bits).                 //	// e.g. 14bit coefficients, errors in dout-bit[0] only            //	//      13bit coefficients, errors in dout-bits[1:0]              //	//      12bit coefficients, errors in dout-bits[2:0] etc.         //	// Tests with real non-continous tone image data have shown that  //	// even when using 13bit coefficients errors remain in the lsb    //	// only (i.e. dout-bit[0]                                         //	//                                                                //	// The amount of coefficient-bits needed is dependent on the      //	// desired quality.                                               //	// The JPEG-standard compliance specs.(ITU-T.83) prescribe        //	// that the output of the combined DCT AND Quantization unit      //	// shall not exceed 1 for the desired quality.                    //	//                                                                //	// This means for high quantization levels, lesser bits           //	// for the DCT unit can be used.                                  //	//                                                                //	// Looking at the recommended "quantization tables for generic    //	// compliance testing of DCT-based processes" (ITU-T.83 annex B)  //	// it can be noticed that relatively large quantization values    //	// are being used. Errors in the lower-order bits should          //	// therefore not be visible.                                      //	// For certain applications some of the lower-order bits could    //	// actually be discarded. When looking at the luminance and       //	// chrominance example quantization tables (ITU-T.81 annex K)     //	// it can be seen that the smallest quantization value is ten     //	// (qnt_val_min = 10). This means that the lowest 2bits can be    //	// discarded (set to zero '0') without having any effect on the   //	// final result. In this example 11 bit or 12 bit coefficients    //	// would be sufficient.                                           //	//                                                                //	////////////////////////////////////////////////////////////////////	fdct #(13)	dut (		.clk(clk),		.ena(1'b1),		.rst(rst),		.dstrb(dstrb),		.din(din),		.dout(dout),		.douten(den)	);	//	// testbench body	//	// generate clock	always #2.5 clk <= ~clk;	// initial statements	initial	begin		// waves statement		`ifdef WAVES		    $shm_open("waves");		    $shm_probe("AS",bench_top,"AS");		    $display("INFO: Signal dump enabled ...\n\n");		`endif		// fill input-table		input_list[00] <= 8'd139;		input_list[01] <= 8'd144;		input_list[02] <= 8'd149;		input_list[03] <= 8'd153;		input_list[04] <= 8'd155;		input_list[05] <= 8'd155;		input_list[06] <= 8'd155;		input_list[07] <= 8'd155;		input_list[08] <= 8'd144;		input_list[09] <= 8'd151;		input_list[10] <= 8'd153;		input_list[11] <= 8'd156;		input_list[12] <= 8'd159;		input_list[13] <= 8'd156;		input_list[14] <= 8'd156;		input_list[15] <= 8'd156;		input_list[16] <= 8'd150;		input_list[17] <= 8'd155;		input_list[18] <= 8'd160;		input_list[19] <= 8'd163;		input_list[20] <= 8'd158;		input_list[21] <= 8'd156;		input_list[22] <= 8'd156;		input_list[23] <= 8'd156;		input_list[24] <= 8'd159;		input_list[25] <= 8'd161;		input_list[26] <= 8'd162;		input_list[27] <= 8'd160;		input_list[28] <= 8'd160;		input_list[29] <= 8'd159;		input_list[30] <= 8'd159;		input_list[31] <= 8'd159;		input_list[32] <= 8'd159;		input_list[33] <= 8'd160;		input_list[34] <= 8'd161;		input_list[35] <= 8'd162;		input_list[36] <= 8'd162;		input_list[37] <= 8'd155;		input_list[38] <= 8'd155;		input_list[39] <= 8'd155;		input_list[40] <= 8'd161;		input_list[41] <= 8'd161;		input_list[42] <= 8'd161;		input_list[43] <= 8'd161;		input_list[44] <= 8'd160;		input_list[45] <= 8'd157;		input_list[46] <= 8'd157;		input_list[47] <= 8'd157;		input_list[48] <= 8'd162;		input_list[49] <= 8'd162;		input_list[50] <= 8'd161;		input_list[51] <= 8'd163;		input_list[52] <= 8'd162;		input_list[53] <= 8'd157;		input_list[54] <= 8'd157;		input_list[55] <= 8'd157;		input_list[56] <= 8'd162;		input_list[57] <= 8'd162;		input_list[58] <= 8'd161;		input_list[59] <= 8'd161;		input_list[60] <= 8'd163;		input_list[61] <= 8'd158;		input_list[62] <= 8'd158;		input_list[63] <= 8'd158;/*		input_list[00] <= 8'd0;		input_list[01] <= 8'd0;		input_list[02] <= 8'd0;		input_list[03] <= 8'd0;		input_list[04] <= 8'd0;		input_list[05] <= 8'd0;		input_list[06] <= 8'd0;		input_list[07] <= 8'd0;		input_list[08] <= 8'd0;		input_list[09] <= 8'd0;		input_list[10] <= 8'd0;		input_list[11] <= 8'd0;		input_list[12] <= 8'd0;		input_list[13] <= 8'd0;		input_list[14] <= 8'd0;		input_list[15] <= 8'd0;		input_list[16] <= 8'd0;		input_list[17] <= 8'd0;		input_list[18] <= 8'd0;		input_list[19] <= 8'd0;		input_list[20] <= 8'd0;		input_list[21] <= 8'd0;		input_list[22] <= 8'd0;		input_list[23] <= 8'd0;		input_list[24] <= 8'd0;		input_list[25] <= 8'd0;		input_list[26] <= 8'd0;		input_list[27] <= 8'd0;		input_list[28] <= 8'd0;		input_list[29] <= 8'd0;		input_list[30] <= 8'd0;		input_list[31] <= 8'd0;		input_list[32] <= 8'd0;		input_list[33] <= 8'd0;		input_list[34] <= 8'd0;		input_list[35] <= 8'd0;		input_list[36] <= 8'd0;		input_list[37] <= 8'd0;		input_list[38] <= 8'd0;		input_list[39] <= 8'd0;		input_list[40] <= 8'd0;		input_list[41] <= 8'd0;		input_list[42] <= 8'd0;		input_list[43] <= 8'd0;		input_list[44] <= 8'd0;		input_list[45] <= 8'd0;		input_list[46] <= 8'd0;		input_list[47] <= 8'd0;		input_list[48] <= 8'd0;		input_list[49] <= 8'd0;		input_list[50] <= 8'd0;		input_list[51] <= 8'd0;		input_list[52] <= 8'd0;		input_list[53] <= 8'd0;		input_list[54] <= 8'd0;		input_list[55] <= 8'd0;		input_list[56] <= 8'd0;		input_list[57] <= 8'd0;		input_list[58] <= 8'd0;		input_list[59] <= 8'd0;		input_list[60] <= 8'd0;		input_list[61] <= 8'd0;		input_list[62] <= 8'd0;		input_list[63] <= 8'd0;*/		// fill output-table		output_list[00] <= 12'h1d7;		output_list[01] <= 12'hffe;		output_list[02] <= 12'hfd3;		output_list[03] <= 12'hfea;		output_list[04] <= 12'hfdd; //16bit resolution returns 13'h1fdc		output_list[05] <= 12'hfe8;		output_list[06] <= 12'hff6;		output_list[07] <= 12'hff4;		output_list[08] <= 12'hfed;		output_list[09] <= 12'hff2;		output_list[10] <= 12'hfff;		output_list[11] <= 12'hffc;		output_list[12] <= 12'hffd;		output_list[13] <= 12'hffa;		output_list[14] <= 12'h004;		output_list[15] <= 12'hffd;		output_list[16] <= 12'hffa;		output_list[17] <= 12'h003;		output_list[18] <= 12'h000;		output_list[19] <= 12'hffe;		output_list[20] <= 12'h004;		output_list[21] <= 12'hffd;		output_list[22] <= 12'h000;		output_list[23] <= 12'h003;		output_list[24] <= 12'h003;		output_list[25] <= 12'h000;		output_list[26] <= 12'h000;		output_list[27] <= 12'hffb;		output_list[28] <= 12'h003;		output_list[29] <= 12'h001;		output_list[30] <= 12'hffe;		output_list[31] <= 12'h002;		output_list[32] <= 12'h003;		output_list[33] <= 12'h003;		output_list[34] <= 12'hfff;		output_list[35] <= 12'hffb;		output_list[36] <= 12'h003;		output_list[37] <= 12'hfff;		output_list[38] <= 12'hfff;		output_list[39] <= 12'h000;		output_list[40] <= 12'h000;		output_list[41] <= 12'hfff;		output_list[42] <= 12'hffe;		output_list[43] <= 12'h000;		output_list[44] <= 12'h000;		output_list[45] <= 12'hfff;		output_list[46] <= 12'hffe;		output_list[47] <= 12'hffd;		output_list[48] <= 12'hff8;		output_list[49] <= 12'hffc;		output_list[50] <= 12'hfff;		output_list[51] <= 12'h003;		output_list[52] <= 12'h001;		output_list[53] <= 12'h001;		output_list[54] <= 12'h003;		output_list[55] <= 12'h002;		output_list[56] <= 12'h003;		output_list[57] <= 12'h004;		output_list[58] <= 12'h002;		output_list[59] <= 12'h002;		output_list[60] <= 12'hffe;		output_list[61] <= 12'hffe;		output_list[62] <= 12'hfff;		output_list[63] <= 12'hfff;		clk = 0; // start with low-level clock		rst = 0; // reset system		dstrb = 1'b0;		rst = #17 1'b1;		// wait a while		repeat(20) @(posedge clk);		// present dstrb		dstrb = #1 1'b1;		@(posedge clk)		dstrb = #1 1'b0;		for(y=0; y<=7; y=y+1)		for(x=0; x<=7; x=x+1)		begin		  din = #1 input_list[y*8 +x] -8'd128;		  @(posedge clk);		end		// wait for 'den' signal		while (!den) @(posedge clk);		// den is presented 1clk cycle before data		@(posedge clk);		err_cnt = 0;		for(y=0; y<=7; y=y+1)		for(x=0; x<=7; x=x+1)		begin			if (dout !== output_list[y*8 +x])			begin			  $display("Data compare error, received %h, expected %h. %d",			           dout, output_list[y*8 +x], y*8 +x);			  err_cnt = err_cnt +1;			end			@(posedge clk);		end		$display("\nTotal errors: %d", err_cnt);		$stop;	endendmodule