text: /*
   * Library: libcrc
   * File:    include/checksum.h
   * Author:  Lammert Bies
   *
   * This file is licensed under the MIT License as stated below
   *
   * Copyright (c) 1999-2016 Lammert Bies
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   * 
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   *
   * Description
   * -----------
   * The headerfile include/checksum.h contains the definitions and prototypes
   * for routines that can be used to calculate several kinds of checksums.
   */
  
  #ifndef DEF_LIBCRC_CHECKSUM_H
  #define DEF_LIBCRC_CHECKSUM_H
  
  #include <stdint.h>
  
  /*
   * #define CRC_POLY_xxxx
   *
   * The constants of the form CRC_POLY_xxxx define the polynomials for some well
   * known CRC calculations.
   */
  
  #define		CRC_POLY_CCITT		0x1021
  
  /*
   * #define CRC_START_xxxx
   *
   * The constants of the form CRC_START_xxxx define the values that are used for
   * initialization of a CRC value for common used calculation methods.
   */
  
  #define		CRC_START_XMODEM	0x0000
  
  /*
   * Prototype list of global functions
   */
  
  uint16_t		crc_xmodem(         const unsigned char *input_str, size_t num_bytes       );
  uint16_t		update_crc_ccitt(   uint16_t crc, unsigned char c                          );
  
  #endif  // DEF_LIBCRC_CHECKSUM_H
  