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Diffstat (limited to 'source/fcs.v')
| -rw-r--r-- | source/fcs.v | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/source/fcs.v b/source/fcs.v deleted file mode 100644 index 6abf536..0000000 --- a/source/fcs.v +++ /dev/null @@ -1,142 +0,0 @@ -/* - * fcs.v - * - * Copyright (C) 2018, 2019 Mind Chasers Inc. - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - * - * function: FCS checksum - * - * - */ -`timescale 1ns /10ps - -//////////////////////////////////////////////////////////////////////////////// -// Copyright (C) 1999-2008 Easics NV. -// 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 SOURCE FILE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS -// OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED -// WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. -// -// Purpose : synthesizable CRC function -// * polynomial: x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + 1 -// * data width: 8 -// -// Info : tools@easics.be -// http://www.easics.com -//////////////////////////////////////////////////////////////////////////////// - -/* -* a) The first 32 bits of the frame are complemented. -* b) The n bits of the MAC frame considered to be the coefficients of a polynomial M(x) of degree n � 1. -* The first bit of the Destination Address field corresponds to the x(n�1) term -* and the last bit of the MAC Client Data field (or Pad field if present) corresponds to the x0 term. -* c) M(x) is multiplied by x**32 and divided by G(x), producing a remainder R(x) of degree = 31. -* d) The coefficients of R(x) are considered to be a 32-bit sequence. -* e) The bit sequence is complemented and the result is the CRC. -* f) FCS should be trnansmitted msbit first ( opposite of the rest of MAC frame ) -*/ -module fcs( - input rstn, - input clk, - - // control interface - input init, - input enable, - - // addr & data - input [1:0] addr, - input [0:7] din, - output [7:0] dout -); - - -reg [31:0] crc; -reg [7:0] d; - -assign dout = ~{ d[0],d[1],d[2],d[3],d[4],d[5],d[6],d[7] }; - -always @(*) - begin - case(addr) - 2'b00: d <= crc[31:24]; - 2'b01: d <= crc[23:16]; - 2'b10: d <= crc[15:8]; - 2'b11: d <= crc[7:0]; - endcase - end - -always @(posedge clk or negedge rstn) - if(!rstn) - crc <= 32'hffffffff; - else if (init) - crc <= 32'hffffffff; - else if (enable) - crc <= nextCRC32_D8(din,crc); - -// {d[0],d[1],d[2],d[3],d[4],d[5],d[6],d[7]} - - // polynomial: x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + 1 - // data width: 8 - // convention: the first serial bit is D[7] - function [31:0] nextCRC32_D8; - - input [0:7] Data; - input [31:0] crc; - reg [0:7] d; - reg [31:0] c; - reg [31:0] newcrc; - begin - d = Data; - c = crc; - - newcrc[0] = d[6] ^ d[0] ^ c[24] ^ c[30]; - newcrc[1] = d[7] ^ d[6] ^ d[1] ^ d[0] ^ c[24] ^ c[25] ^ c[30] ^ c[31]; - newcrc[2] = d[7] ^ d[6] ^ d[2] ^ d[1] ^ d[0] ^ c[24] ^ c[25] ^ c[26] ^ c[30] ^ c[31]; - newcrc[3] = d[7] ^ d[3] ^ d[2] ^ d[1] ^ c[25] ^ c[26] ^ c[27] ^ c[31]; - newcrc[4] = d[6] ^ d[4] ^ d[3] ^ d[2] ^ d[0] ^ c[24] ^ c[26] ^ c[27] ^ c[28] ^ c[30]; - newcrc[5] = d[7] ^ d[6] ^ d[5] ^ d[4] ^ d[3] ^ d[1] ^ d[0] ^ c[24] ^ c[25] ^ c[27] ^ c[28] ^ c[29] ^ c[30] ^ c[31]; - newcrc[6] = d[7] ^ d[6] ^ d[5] ^ d[4] ^ d[2] ^ d[1] ^ c[25] ^ c[26] ^ c[28] ^ c[29] ^ c[30] ^ c[31]; - newcrc[7] = d[7] ^ d[5] ^ d[3] ^ d[2] ^ d[0] ^ c[24] ^ c[26] ^ c[27] ^ c[29] ^ c[31]; - newcrc[8] = d[4] ^ d[3] ^ d[1] ^ d[0] ^ c[0] ^ c[24] ^ c[25] ^ c[27] ^ c[28]; - newcrc[9] = d[5] ^ d[4] ^ d[2] ^ d[1] ^ c[1] ^ c[25] ^ c[26] ^ c[28] ^ c[29]; - newcrc[10] = d[5] ^ d[3] ^ d[2] ^ d[0] ^ c[2] ^ c[24] ^ c[26] ^ c[27] ^ c[29]; - newcrc[11] = d[4] ^ d[3] ^ d[1] ^ d[0] ^ c[3] ^ c[24] ^ c[25] ^ c[27] ^ c[28]; - newcrc[12] = d[6] ^ d[5] ^ d[4] ^ d[2] ^ d[1] ^ d[0] ^ c[4] ^ c[24] ^ c[25] ^ c[26] ^ c[28] ^ c[29] ^ c[30]; - newcrc[13] = d[7] ^ d[6] ^ d[5] ^ d[3] ^ d[2] ^ d[1] ^ c[5] ^ c[25] ^ c[26] ^ c[27] ^ c[29] ^ c[30] ^ c[31]; - newcrc[14] = d[7] ^ d[6] ^ d[4] ^ d[3] ^ d[2] ^ c[6] ^ c[26] ^ c[27] ^ c[28] ^ c[30] ^ c[31]; - newcrc[15] = d[7] ^ d[5] ^ d[4] ^ d[3] ^ c[7] ^ c[27] ^ c[28] ^ c[29] ^ c[31]; - newcrc[16] = d[5] ^ d[4] ^ d[0] ^ c[8] ^ c[24] ^ c[28] ^ c[29]; - newcrc[17] = d[6] ^ d[5] ^ d[1] ^ c[9] ^ c[25] ^ c[29] ^ c[30]; - newcrc[18] = d[7] ^ d[6] ^ d[2] ^ c[10] ^ c[26] ^ c[30] ^ c[31]; - newcrc[19] = d[7] ^ d[3] ^ c[11] ^ c[27] ^ c[31]; - newcrc[20] = d[4] ^ c[12] ^ c[28]; - newcrc[21] = d[5] ^ c[13] ^ c[29]; - newcrc[22] = d[0] ^ c[14] ^ c[24]; - newcrc[23] = d[6] ^ d[1] ^ d[0] ^ c[15] ^ c[24] ^ c[25] ^ c[30]; - newcrc[24] = d[7] ^ d[2] ^ d[1] ^ c[16] ^ c[25] ^ c[26] ^ c[31]; - newcrc[25] = d[3] ^ d[2] ^ c[17] ^ c[26] ^ c[27]; - newcrc[26] = d[6] ^ d[4] ^ d[3] ^ d[0] ^ c[18] ^ c[24] ^ c[27] ^ c[28] ^ c[30]; - newcrc[27] = d[7] ^ d[5] ^ d[4] ^ d[1] ^ c[19] ^ c[25] ^ c[28] ^ c[29] ^ c[31]; - newcrc[28] = d[6] ^ d[5] ^ d[2] ^ c[20] ^ c[26] ^ c[29] ^ c[30]; - newcrc[29] = d[7] ^ d[6] ^ d[3] ^ c[21] ^ c[27] ^ c[30] ^ c[31]; - newcrc[30] = d[7] ^ d[4] ^ c[22] ^ c[28] ^ c[31]; - newcrc[31] = d[5] ^ c[23] ^ c[29]; - nextCRC32_D8 = newcrc; - end - endfunction -endmodule |
