SOFA/BENCHMARK/dct_mac/rtl/zigzag.v

202 lines
7.4 KiB
Coq
Raw Normal View History

2020-12-16 09:05:53 -06:00
/////////////////////////////////////////////////////////////////////
//// ////
//// Zig-Zag Unit ////
//// Performs zigzag-ing, as used by many DCT based encoders ////
//// ////
//// 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: zigzag.v,v 1.2 2002-10-23 09:06:59 rherveille Exp $
//
// $Date: 2002-10-23 09:06:59 $
// $Revision: 1.2 $
// $Author: rherveille $
// $Locker: $
// $State: Exp $
//
// Change History:
// $Log: not supported by cvs2svn $
// synopsys translate_off
`include "timescale.v"
// synopsys translate_on
module zigzag(
clk,
ena,
dstrb,
din_00, din_01, din_02, din_03, din_04, din_05, din_06, din_07,
din_10, din_11, din_12, din_13, din_14, din_15, din_16, din_17,
din_20, din_21, din_22, din_23, din_24, din_25, din_26, din_27,
din_30, din_31, din_32, din_33, din_34, din_35, din_36, din_37,
din_40, din_41, din_42, din_43, din_44, din_45, din_46, din_47,
din_50, din_51, din_52, din_53, din_54, din_55, din_56, din_57,
din_60, din_61, din_62, din_63, din_64, din_65, din_66, din_67,
din_70, din_71, din_72, din_73, din_74, din_75, din_76, din_77,
dout,
douten
);
//
// inputs & outputs
//
input clk; // system clock
input ena; // clock enable
input dstrb; // data-strobe. Present dstrb 1clk-cycle before data block
input [11:0]
din_00, din_01, din_02, din_03, din_04, din_05, din_06, din_07,
din_10, din_11, din_12, din_13, din_14, din_15, din_16, din_17,
din_20, din_21, din_22, din_23, din_24, din_25, din_26, din_27,
din_30, din_31, din_32, din_33, din_34, din_35, din_36, din_37,
din_40, din_41, din_42, din_43, din_44, din_45, din_46, din_47,
din_50, din_51, din_52, din_53, din_54, din_55, din_56, din_57,
din_60, din_61, din_62, din_63, din_64, din_65, din_66, din_67,
din_70, din_71, din_72, din_73, din_74, din_75, din_76, din_77;
output [11:0] dout;
output douten; // data-out enable
//
// variables
//
reg ld_zigzag;
reg [11:0] sresult [63:0]; // store results for zig-zagging
//
// module body
//
always @(posedge clk)
if(ena)
ld_zigzag <= #1 dstrb;
assign douten = ld_zigzag;
//
// Generate zig-zag structure
//
// This implicates that the quantization step be performed after
// the zig-zagging.
//
// 0: 1: 2: 3: 4: 5: 6: 7: 0: 1: 2: 3: 4: 5: 6: 7:
// 0: 63 62 58 57 49 48 36 35 3f 3e 3a 39 31 30 24 23
// 1: 61 59 56 50 47 37 34 21 3d 3b 38 32 2f 25 22 15
// 2: 60 55 51 46 38 33 22 20 3c 37 33 2e 26 21 16 14
// 3: 54 52 45 39 32 23 19 10 36 34 2d 27 20 17 13 0a
// 4: 53 44 40 31 24 18 11 09 35 2c 28 1f 18 12 0b 09
// 5: 43 41 30 25 17 12 08 03 2b 29 1e 19 11 0c 08 03
// 6: 42 29 26 16 13 07 04 02 2a 1d 1a 10 0d 07 04 02
// 7: 28 27 15 14 06 05 01 00 1c 1b 0f 0e 06 05 01 00
//
// zig-zag the DCT results
integer n;
always @(posedge clk)
if(ena)
if(ld_zigzag) // reload results-register file
begin
sresult[63] <= #1 din_00;
sresult[62] <= #1 din_01;
sresult[61] <= #1 din_10;
sresult[60] <= #1 din_20;
sresult[59] <= #1 din_11;
sresult[58] <= #1 din_02;
sresult[57] <= #1 din_03;
sresult[56] <= #1 din_12;
sresult[55] <= #1 din_21;
sresult[54] <= #1 din_30;
sresult[53] <= #1 din_40;
sresult[52] <= #1 din_31;
sresult[51] <= #1 din_22;
sresult[50] <= #1 din_13;
sresult[49] <= #1 din_04;
sresult[48] <= #1 din_05;
sresult[47] <= #1 din_14;
sresult[46] <= #1 din_23;
sresult[45] <= #1 din_32;
sresult[44] <= #1 din_41;
sresult[43] <= #1 din_50;
sresult[42] <= #1 din_60;
sresult[41] <= #1 din_51;
sresult[40] <= #1 din_42;
sresult[39] <= #1 din_33;
sresult[38] <= #1 din_24;
sresult[37] <= #1 din_15;
sresult[36] <= #1 din_06;
sresult[35] <= #1 din_07;
sresult[34] <= #1 din_16;
sresult[33] <= #1 din_25;
sresult[32] <= #1 din_34;
sresult[31] <= #1 din_43;
sresult[30] <= #1 din_52;
sresult[29] <= #1 din_61;
sresult[28] <= #1 din_70;
sresult[27] <= #1 din_71;
sresult[26] <= #1 din_62;
sresult[25] <= #1 din_53;
sresult[24] <= #1 din_44;
sresult[23] <= #1 din_35;
sresult[22] <= #1 din_26;
sresult[21] <= #1 din_17;
sresult[20] <= #1 din_27;
sresult[19] <= #1 din_36;
sresult[18] <= #1 din_45;
sresult[17] <= #1 din_54;
sresult[16] <= #1 din_63;
sresult[15] <= #1 din_72;
sresult[14] <= #1 din_73;
sresult[13] <= #1 din_64;
sresult[12] <= #1 din_55;
sresult[11] <= #1 din_46;
sresult[10] <= #1 din_37;
sresult[09] <= #1 din_47;
sresult[08] <= #1 din_56;
sresult[07] <= #1 din_65;
sresult[06] <= #1 din_74;
sresult[05] <= #1 din_75;
sresult[04] <= #1 din_66;
sresult[03] <= #1 din_57;
sresult[02] <= #1 din_67;
sresult[01] <= #1 din_76;
sresult[00] <= #1 din_77;
end
else // shift results out
for (n=1; n<=63; n=n+1) // do not change sresult[0]
sresult[n] <= #1 sresult[n -1];
assign dout = sresult[63];
endmodule