crc.h
Go to the documentation of this file.00001 //====================================================================== 00029 //====================================================================== 00030 00031 #ifndef CRC_h_ 00032 #define CRC_h_ 00033 00034 #include "sdhlibrary_settings.h" 00035 00036 //---------------------------------------------------------------------- 00037 // System Includes - include with <> 00038 //---------------------------------------------------------------------- 00039 00040 00041 //---------------------------------------------------------------------- 00042 // Project Includes - include with "" 00043 //---------------------------------------------------------------------- 00044 00045 #include "basisdef.h" 00046 00047 //---------------------------------------------------------------------- 00048 // Defines, enums, unions, structs 00049 //---------------------------------------------------------------------- 00050 00051 NAMESPACE_SDH_START 00052 00053 00054 typedef UInt16 tCRCValue; 00055 00056 //---------------------------------------------------------------------- 00057 // Global variables (declarations) 00058 //---------------------------------------------------------------------- 00059 00060 00061 //---------------------------------------------------------------------- 00062 // External functions (function declarations) 00063 //---------------------------------------------------------------------- 00064 00065 00066 //---------------------------------------------------------------------- 00067 // Function prototypes (function declarations) 00068 //---------------------------------------------------------------------- 00069 00070 00071 //---------------------------------------------------------------------- 00072 // Class declarations 00073 //---------------------------------------------------------------------- 00074 00082 class VCC_EXPORT cCRC 00083 { 00084 protected: 00086 tCRCValue current_crc; 00087 00089 tCRCValue initial_value; 00090 00092 tCRCValue const* crc_table; 00093 00094 public: 00096 cCRC( tCRCValue const* _crc_table, tCRCValue _initial_value ) 00097 { 00098 crc_table = _crc_table; 00099 initial_value = _initial_value; 00100 current_crc = initial_value; 00101 } 00102 00104 tCRCValue AddByte( unsigned char byte ) 00105 { 00106 current_crc = ( (current_crc & 0xFF00) >> 8 ) ^ crc_table[ ( current_crc & 0x00FF ) ^ (byte & 0x00FF)]; 00107 return current_crc; 00108 } 00109 00111 tCRCValue AddBytes( unsigned char* bytes, int nb_bytes ) 00112 { 00113 for ( int i=0; i<nb_bytes; i++ ) 00114 current_crc = ( (current_crc & 0xFF00) >> 8 ) ^ crc_table[ ( current_crc & 0x00FF ) ^ (bytes[i] & 0x00FF)]; 00115 return current_crc; 00116 } 00117 00119 inline tCRCValue GetCRC() 00120 { 00121 return current_crc; 00122 } 00123 00125 inline UInt8 GetCRC_LB() 00126 { 00127 return current_crc & 0x00ff; 00128 } 00129 00131 inline UInt8 GetCRC_HB() 00132 { 00133 return (current_crc >> 8) & 0x00ff; 00134 } 00135 00137 inline tCRCValue Reset() 00138 { 00139 current_crc = initial_value; 00140 return current_crc; 00141 } 00142 }; 00143 //---------------------------------------------------------------------- 00144 //---------------------------------------------------------------------- 00145 00147 class VCC_EXPORT cCRC_DSACON32m : public cCRC 00148 { 00149 protected: 00151 static tCRCValue const crc_table_dsacon32m[256]; 00152 00153 public: 00155 inline cCRC_DSACON32m( void ) 00156 : cCRC( crc_table_dsacon32m, 0xffff ) 00157 { 00158 // nothing more to do 00159 } 00160 }; 00161 //---------------------------------------------------------------------- 00162 //---------------------------------------------------------------------- 00163 00170 class VCC_EXPORT cCRC_SDH : public cCRC_DSACON32m 00171 { 00172 public: 00174 inline cCRC_SDH( void ) 00175 : cCRC_DSACON32m() 00176 { 00177 // nothing more to do 00178 } 00179 }; 00180 //---------------------------------------------------------------------- 00181 //---------------------------------------------------------------------- 00182 00183 NAMESPACE_SDH_END 00184 00185 #endif 00186 00187 00188 //====================================================================== 00189 /* 00190 Here are some settings for the emacs/xemacs editor (and can be safely ignored): 00191 (e.g. to explicitely set C++ mode for *.h header files) 00192 00193 Local Variables: 00194 mode:C 00195 mode:ELSE 00196 End: 00197 */ 00198 //======================================================================}