JTEncode/src/crc14.h

122 wiersze
3.2 KiB
C

/**
* \file
* Functions and types for CRC checks.
*
* Generated on Thu Dec 6 17:52:01 2018
* by pycrc v0.9.1, https://pycrc.org
* using the configuration:
* - Width = 14
* - Poly = 0x2757
* - XorIn = Undefined
* - ReflectIn = Undefined
* - XorOut = Undefined
* - ReflectOut = Undefined
* - Algorithm = bit-by-bit
*
* This file defines the functions crc_init(), crc_update() and crc_finalize().
*
* The crc_init() function returns the inital \c crc value and must be called
* before the first call to crc_update().
* Similarly, the crc_finalize() function must be called after the last call
* to crc_update(), before the \c crc is being used.
* is being used.
*
* The crc_update() function can be called any number of times (including zero
* times) in between the crc_init() and crc_finalize() calls.
*
* This pseudo-code shows an example usage of the API:
* \code{.c}
* crc_cfg_t cfg = {
* 0, // reflect_in
* 0, // xor_in
* 0, // reflect_out
* 0, // xor_out
* };
* crc_t crc;
* unsigned char data[MAX_DATA_LEN];
* size_t data_len;
*
* crc = crc_init(&cfg);
* while ((data_len = read_data(data, MAX_DATA_LEN)) > 0) {
* crc = crc_update(&cfg, crc, data, data_len);
* }
* crc = crc_finalize(&cfg, crc);
* \endcode
*/
#ifndef CRC14_H
#define CRC14_H
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* The definition of the used algorithm.
*
* This is not used anywhere in the generated code, but it may be used by the
* application code to call algorithm-specific code, if desired.
*/
#define CRC_ALGO_BIT_BY_BIT 1
/**
* The type of the CRC values.
*
* This type must be big enough to contain at least 14 bits.
*/
typedef uint_fast16_t crc_t;
/**
* The configuration type of the CRC algorithm.
*/
typedef struct {
bool reflect_in; /*!< Whether the input shall be reflected or not */
crc_t xor_in; /*!< The initial value of the register */
bool reflect_out; /*!< Whether the output shall be reflected or not */
crc_t xor_out; /*!< The value which shall be XOR-ed to the final CRC value */
} crc_cfg_t;
/**
* Calculate the initial crc value.
*
* \param[in] cfg A pointer to an initialised crc_cfg_t structure.
* \return The initial crc value.
*/
crc_t crc_init(const crc_cfg_t *cfg);
/**
* Update the crc value with new data.
*
* \param[in] crc The current crc value.
* \param[in] cfg A pointer to an initialised crc_cfg_t structure.
* \param[in] data Pointer to a buffer of \a data_len bytes.
* \param[in] data_len Number of bytes in the \a data buffer.
* \return The updated crc value.
*/
crc_t crc_update(const crc_cfg_t *cfg, crc_t crc, const void *data, size_t data_len);
/**
* Calculate the final crc value.
*
* \param[in] cfg A pointer to an initialised crc_cfg_t structure.
* \param[in] crc The current crc value.
* \return The final crc value.
*/
crc_t crc_finalize(const crc_cfg_t *cfg, crc_t crc);
#ifdef __cplusplus
} /* closing brace for extern "C" */
#endif
#endif /* CRC14_H */