/** * \file * <!-- * This file is part of BeRTOS. * * Bertos is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * As a special exception, you may use this file as part of a free software * library without restriction. Specifically, if other files instantiate * templates or use macros or inline functions from this file, or you compile * this file and link it with other files to produce an executable, this * file does not by itself cause the resulting executable to be covered by * the GNU General Public License. This exception does not however * invalidate any other reasons why the executable file might be covered by * the GNU General Public License. * * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/) * Copyright 1999 Bernie Innocenti <bernie@codewiz.org> * * --> * * \brief Cyclic Redundancy Check 16 (CRC). This algorithm is the one used by the XMODEM protocol. * * \note This algorithm is incompatible with the CCITT-CRC16. * * This code is based on the article Copyright 1986 Stephen Satchell. * * Programmers may incorporate any or all code into their programs, * giving proper credit within the source. Publication of the * source routines is permitted so long as proper credit is given * to Stephen Satchell, Satchell Evaluations and Chuck Forsberg, * Omen Technology. * * \author Bernie Innocenti <bernie@codewiz.org> * * $WIZ$ module_name = "crc16" */ #ifndef ALGO_CRC_H #define ALGO_CRC_H #include "cfg/cfg_arch.h" #include <cfg/compiler.h> #include <cpu/pgm.h> EXTERN_C_BEGIN /* CRC table */ extern const uint16_t crc16tab[256]; /** * \brief Compute the updated CRC16 value for one octet (macro version) * * \note This version is only intended for old/broken compilers. * Use the inline function in new code. * * \param c New octet (range 0-255) * \param oldcrc Previous CRC16 value (referenced twice, beware of side effects) */ #if CPU_HARVARD && !(defined(ARCH_BOOT) && (ARCH & ARCH_BOOT)) #define UPDCRC16(c, oldcrc) (pgm_read_uint16_t(&crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))]) ^ ((oldcrc) << 8)) #else #define UPDCRC16(c, oldcrc) ((crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))]) ^ ((oldcrc) << 8)) #endif /** CRC-16 init value */ #define CRC16_INIT_VAL ((uint16_t)0) #ifdef INLINE /** * \brief Compute the updated CRC16 value for one octet (inline version) */ INLINE uint16_t updcrc16(uint8_t c, uint16_t oldcrc) { #if CPU_HARVARD && !(defined(ARCH_BOOT) && (ARCH & ARCH_BOOT)) return pgm_read_uint16_t(&crc16tab[(oldcrc >> 8) ^ c]) ^ (oldcrc << 8); #else return crc16tab[(oldcrc >> 8) ^ c] ^ (oldcrc << 8); #endif } #endif // INLINE /** * This function implements the CRC 16 calculation on a buffer. * * \param crc Current CRC16 value. * \param buf The buffer to perform CRC calculation on. * \param len The length of the Buffer. * * \return The updated CRC16 value. */ extern uint16_t crc16(uint16_t crc, const void *buf, size_t len); int crc_testSetup(void); int crc_testRun(void); int crc_testTearDown(void); EXTERN_C_END #endif /* ALGO_CRC_H */