// 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 20 data bits (forward - LSB first) // polynomial : 00a00805 // x^23 + x^21 + x^11 + x^2 + x^0 // // CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC DDDDDDDDDDDDDDDDDDDD // 00000000001111111111222222222233 00000000001111111111 // 01234567890123456789012345678901 01234567890123456789 // 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 7 // Best possible depth in 4 LUTs = 2 // Best possible depth in 5 LUTs = 2 // Best possible depth in 6 LUTs = 2 // Total XOR inputs 120 // module fec_rot_20 ( input [31:0] c, output [31:0] co ); assign co[0] = c[12] ^ c[21] ^ c[23] ^ c[30]; assign co[1] = c[13] ^ c[22] ^ c[24] ^ c[31]; assign co[2] = c[12] ^ c[14] ^ c[21] ^ c[25] ^ c[30]; assign co[3] = c[13] ^ c[15] ^ c[22] ^ c[26] ^ c[31]; assign co[4] = c[14] ^ c[16] ^ c[23] ^ c[27]; assign co[5] = c[15] ^ c[17] ^ c[24] ^ c[28]; assign co[6] = c[16] ^ c[18] ^ c[25] ^ c[29]; assign co[7] = c[17] ^ c[19] ^ c[26] ^ c[30]; assign co[8] = c[18] ^ c[20] ^ c[27] ^ c[31]; assign co[9] = c[19] ^ c[21] ^ c[28]; assign co[10] = c[20] ^ c[22] ^ c[29]; assign co[11] = c[12]; assign co[12] = c[13]; assign co[13] = c[14]; assign co[14] = c[15]; assign co[15] = c[16]; assign co[16] = c[17]; assign co[17] = c[18]; assign co[18] = c[19]; assign co[19] = c[20]; assign co[20] = c[0] ^ c[21]; assign co[21] = c[1] ^ c[12] ^ c[21] ^ c[22] ^ c[23] ^ c[30]; assign co[22] = c[2] ^ c[13] ^ c[22] ^ c[23] ^ c[24] ^ c[31]; assign co[23] = c[3] ^ c[12] ^ c[14] ^ c[21] ^ c[24] ^ c[25] ^ c[30]; assign co[24] = c[4] ^ c[13] ^ c[15] ^ c[22] ^ c[25] ^ c[26] ^ c[31]; assign co[25] = c[5] ^ c[14] ^ c[16] ^ c[23] ^ c[26] ^ c[27]; assign co[26] = c[6] ^ c[15] ^ c[17] ^ c[24] ^ c[27] ^ c[28]; assign co[27] = c[7] ^ c[16] ^ c[18] ^ c[25] ^ c[28] ^ c[29]; assign co[28] = c[8] ^ c[17] ^ c[19] ^ c[26] ^ c[29] ^ c[30]; assign co[29] = c[9] ^ c[18] ^ c[20] ^ c[27] ^ c[30] ^ c[31]; assign co[30] = c[10] ^ c[19] ^ c[21] ^ c[28] ^ c[31]; assign co[31] = c[11] ^ c[20] ^ c[22] ^ c[29]; endmodule