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Konstantin Pavlov (pt) 40533743d7 Added altera cookbook
2015-12-15 22:44:58 +03:00

193 lines
6.4 KiB
Verilog

// Copyright 2009 Altera Corporation. All rights reserved.
// Altera products are protected under numerous U.S. and foreign patents,
// maskwork rights, copyrights and other intellectual property laws.
//
// This reference design file, and your use thereof, is subject to and governed
// by the terms and conditions of the applicable Altera Reference Design
// License Agreement (either as signed by you or found at www.altera.com). By
// using this reference design file, you indicate your acceptance of such terms
// and conditions between you and Altera Corporation. In the event that you do
// not agree with such terms and conditions, you may not use the reference
// design file and please promptly destroy any copies you have made.
//
// This reference design file is being provided on an "as-is" basis and as an
// accommodation and therefore all warranties, representations or guarantees of
// any kind (whether express, implied or statutory) including, without
// limitation, warranties of merchantability, non-infringement, or fitness for
// a particular purpose, are specifically disclaimed. By making this reference
// design file available, Altera expressly does not recommend, suggest or
// require that this reference design file be used in combination with any
// other product not provided by Altera.
/////////////////////////////////////////////////////////////////////////////
//
// 32 bit CRC of 27 data bits (forward - LSB first)
// polynomial : 00a00805
// x^23 + x^21 + x^11 + x^2 + x^0
//
// CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC DDDDDDDDDDDDDDDDDDDDDDDDDDD
// 00000000001111111111222222222233 000000000011111111112222222
// 01234567890123456789012345678901 012345678901234567890123456
// C00 = .....#........#.#......#..##.... ...........................
// C01 = ......#........#.#......#..##... ...........................
// C02 = .....#.#......#...#....#.#####.. ...........................
// C03 = ......#.#......#...#....#.#####. ...........................
// C04 = .......#.#......#...#....#.##### ...........................
// C05 = ........#.#......#...#....#.#### ...........................
// C06 = .........#.#......#...#....#.### ...........................
// C07 = ..........#.#......#...#....#.## ...........................
// C08 = ...........#.#......#...#....#.# ...........................
// C09 = ............#.#......#...#....#. ...........................
// C10 = .............#.#......#...#....# ...........................
// C11 = .....#....................#..... ...........................
// C12 = ......#....................#.... ...........................
// C13 = .......#....................#... ...........................
// C14 = ........#....................#.. ...........................
// C15 = .........#....................#. ...........................
// C16 = ..........#....................# ...........................
// C17 = ...........#.................... ...........................
// C18 = ............#................... ...........................
// C19 = .............#.................. ...........................
// C20 = ..............#................. ...........................
// C21 = .....#........###......#..##.... ...........................
// C22 = ......#........###......#..##... ...........................
// C23 = .....#.#......#..##....#.#####.. ...........................
// C24 = ......#.#......#..##....#.#####. ...........................
// C25 = .......#.#......#..##....#.##### ...........................
// C26 = ........#.#......#..##....#.#### ...........................
// C27 = #........#.#......#..##....#.### ...........................
// C28 = .#........#.#......#..##....#.## ...........................
// C29 = ..#........#.#......#..##....#.# ...........................
// C30 = ...#........#.#......#..##....#. ...........................
// C31 = ....#........#.#......#..##....# ...........................
//
// Number of XORs used is 32
// Maximum XOR input count is 11
// Best possible depth in 4 LUTs = 2
// Best possible depth in 5 LUTs = 2
// Best possible depth in 6 LUTs = 2
// Total XOR inputs 196
//
module fec_rot_27 (
input [31:0] c,
output [31:0] co
);
assign co[0] =
c[5] ^ c[14] ^ c[16] ^ c[23] ^ c[26] ^ c[27];
assign co[1] =
c[6] ^ c[15] ^ c[17] ^ c[24] ^ c[27] ^ c[28];
assign co[2] =
c[5] ^ c[7] ^ c[14] ^ c[18] ^ c[23] ^ c[25] ^
c[26] ^ c[27] ^ c[28] ^ c[29];
assign co[3] =
c[6] ^ c[8] ^ c[15] ^ c[19] ^ c[24] ^ c[26] ^
c[27] ^ c[28] ^ c[29] ^ c[30];
assign co[4] =
c[7] ^ c[9] ^ c[16] ^ c[20] ^ c[25] ^ c[27] ^
c[28] ^ c[29] ^ c[30] ^ c[31];
assign co[5] =
c[8] ^ c[10] ^ c[17] ^ c[21] ^ c[26] ^ c[28] ^
c[29] ^ c[30] ^ c[31];
assign co[6] =
c[9] ^ c[11] ^ c[18] ^ c[22] ^ c[27] ^ c[29] ^
c[30] ^ c[31];
assign co[7] =
c[10] ^ c[12] ^ c[19] ^ c[23] ^ c[28] ^ c[30] ^
c[31];
assign co[8] =
c[11] ^ c[13] ^ c[20] ^ c[24] ^ c[29] ^ c[31];
assign co[9] =
c[12] ^ c[14] ^ c[21] ^ c[25] ^ c[30];
assign co[10] =
c[13] ^ c[15] ^ c[22] ^ c[26] ^ c[31];
assign co[11] =
c[5] ^ c[26];
assign co[12] =
c[6] ^ c[27];
assign co[13] =
c[7] ^ c[28];
assign co[14] =
c[8] ^ c[29];
assign co[15] =
c[9] ^ c[30];
assign co[16] =
c[10] ^ c[31];
assign co[17] =
c[11];
assign co[18] =
c[12];
assign co[19] =
c[13];
assign co[20] =
c[14];
assign co[21] =
c[5] ^ c[14] ^ c[15] ^ c[16] ^ c[23] ^ c[26] ^
c[27];
assign co[22] =
c[6] ^ c[15] ^ c[16] ^ c[17] ^ c[24] ^ c[27] ^
c[28];
assign co[23] =
c[5] ^ c[7] ^ c[14] ^ c[17] ^ c[18] ^ c[23] ^
c[25] ^ c[26] ^ c[27] ^ c[28] ^ c[29];
assign co[24] =
c[6] ^ c[8] ^ c[15] ^ c[18] ^ c[19] ^ c[24] ^
c[26] ^ c[27] ^ c[28] ^ c[29] ^ c[30];
assign co[25] =
c[7] ^ c[9] ^ c[16] ^ c[19] ^ c[20] ^ c[25] ^
c[27] ^ c[28] ^ c[29] ^ c[30] ^ c[31];
assign co[26] =
c[8] ^ c[10] ^ c[17] ^ c[20] ^ c[21] ^ c[26] ^
c[28] ^ c[29] ^ c[30] ^ c[31];
assign co[27] =
c[0] ^ c[9] ^ c[11] ^ c[18] ^ c[21] ^ c[22] ^
c[27] ^ c[29] ^ c[30] ^ c[31];
assign co[28] =
c[1] ^ c[10] ^ c[12] ^ c[19] ^ c[22] ^ c[23] ^
c[28] ^ c[30] ^ c[31];
assign co[29] =
c[2] ^ c[11] ^ c[13] ^ c[20] ^ c[23] ^ c[24] ^
c[29] ^ c[31];
assign co[30] =
c[3] ^ c[12] ^ c[14] ^ c[21] ^ c[24] ^ c[25] ^
c[30];
assign co[31] =
c[4] ^ c[13] ^ c[15] ^ c[22] ^ c[25] ^ c[26] ^
c[31];
endmodule