------------------------------------------------------------------------- File:  PCK_CRC8_D8.vhd                              -- Date:  Sun Dec 31 07:41:19 2000                                                      --                                                                     -- Copyright (C) 1999 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: VHDL package containing a synthesizable CRC function--   * polynomial: (0 1 2 5 7 8)--   * data width: 8--                                                                     -- Info: jand@easics.be (Jan Decaluwe)                           --       http://www.easics.com                                  -----------------------------------------------------------------------library IEEE;use IEEE.std_logic_1164.all;package PCK_CRC8_D8 is  -- polynomial: (0 1 2 5 7 8)  -- data width: 8  -- convention: the first serial data bit is D(7)  function nextCRC8_D8    ( Data:  std_logic_vector(7 downto 0);      CRC:   std_logic_vector(7 downto 0) )    return std_logic_vector;end PCK_CRC8_D8;library IEEE;use IEEE.std_logic_1164.all;package body PCK_CRC8_D8 is  -- polynomial: (0 1 2 5 7 8)  -- data width: 8  -- convention: the first serial data bit is D(7)  function nextCRC8_D8      ( Data:  std_logic_vector(7 downto 0);      CRC:   std_logic_vector(7 downto 0) )    return std_logic_vector is    variable D: std_logic_vector(7 downto 0);    variable C: std_logic_vector(7 downto 0);    variable NewCRC: std_logic_vector(7 downto 0);  begin    D := Data;    C := CRC;    NewCRC(0) := D(6) xor D(4) xor D(2) xor D(1) xor D(0) xor C(0) xor                  C(1) xor C(2) xor C(4) xor C(6);    NewCRC(1) := D(7) xor D(6) xor D(5) xor D(4) xor D(3) xor D(0) xor                  C(0) xor C(3) xor C(4) xor C(5) xor C(6) xor C(7);    NewCRC(2) := D(7) xor D(5) xor D(2) xor D(0) xor C(0) xor C(2) xor                  C(5) xor C(7);    NewCRC(3) := D(6) xor D(3) xor D(1) xor C(1) xor C(3) xor C(6);    NewCRC(4) := D(7) xor D(4) xor D(2) xor C(2) xor C(4) xor C(7);    NewCRC(5) := D(6) xor D(5) xor D(4) xor D(3) xor D(2) xor D(1) xor                  D(0) xor C(0) xor C(1) xor C(2) xor C(3) xor C(4) xor                  C(5) xor C(6);    NewCRC(6) := D(7) xor D(6) xor D(5) xor D(4) xor D(3) xor D(2) xor                  D(1) xor C(1) xor C(2) xor C(3) xor C(4) xor C(5) xor                  C(6) xor C(7);    NewCRC(7) := D(7) xor D(5) xor D(3) xor D(1) xor D(0) xor C(0) xor                  C(1) xor C(3) xor C(5) xor C(7);    return NewCRC;  end nextCRC8_D8;end PCK_CRC8_D8;