115 lines
No EOL
2.8 KiB
C
115 lines
No EOL
2.8 KiB
C
/**
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* \file
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* Functions and types for CRC checks.
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*
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* Generated on Sat Jun 15 14:34:05 2019
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* by pycrc v0.9.2, https://pycrc.org
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* using the configuration:
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* - Width = 16
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* - Poly = 0xed2f
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* - XorIn = 0xbeef
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* - ReflectIn = False
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* - XorOut = 0x0000
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* - ReflectOut = False
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* - Algorithm = table-driven
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*
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* This file defines the functions NVM_CRC_init(), NVM_CRC_update() and NVM_CRC_finalize().
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*
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* The NVM_CRC_init() function returns the inital \c crc value and must be called
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* before the first call to NVM_CRC_update().
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* Similarly, the NVM_CRC_finalize() function must be called after the last call
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* to NVM_CRC_update(), before the \c crc is being used.
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* is being used.
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*
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* The NVM_CRC_update() function can be called any number of times (including zero
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* times) in between the NVM_CRC_init() and NVM_CRC_finalize() calls.
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*
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* This pseudo-code shows an example usage of the API:
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* \code{.c}
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* NVM_CRC_t crc;
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* unsigned char data[MAX_DATA_LEN];
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* size_t data_len;
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*
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* crc = NVM_CRC_init();
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* while ((data_len = read_data(data, MAX_DATA_LEN)) > 0) {
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* crc = NVM_CRC_update(crc, data, data_len);
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* }
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* crc = NVM_CRC_finalize(crc);
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* \endcode
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*
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* ## Additional Notes
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*
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* The CRC polynomial (0xED2F) was chosen based on the research published by Philip Koopman of Carnegie Mellon
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* University [here](http://users.ece.cmu.edu/~koopman/crc/). Dr. Koopman claims this polynomial has a
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* Hamming Distance of 10.
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*
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* The initial value, 0xBEEF, was chosen simply to avoid the most common EE values of 0xFFFF and 0x0000.
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*
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*/
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#ifndef NVM_CRC_H
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#define NVM_CRC_H
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#include <stdlib.h>
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#include <stdint.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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/**
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* The definition of the used algorithm.
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*
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* This is not used anywhere in the generated code, but it may be used by the
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* application code to call algorithm-specific code, if desired.
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*/
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#define CRC_ALGO_TABLE_DRIVEN 1
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/**
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* The type of the CRC values.
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*
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* CRCs are sixteen bits wide.
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*/
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typedef uint16_t NVM_CRC_t;
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/**
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* Calculate the initial crc value.
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*
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* \return The initial crc value.
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*/
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static inline NVM_CRC_t NVM_CRC_init(void)
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{
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return 0xbeef;
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}
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/**
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* Update the crc value with new data.
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*
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* \param[in] crc The current crc value.
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* \param[in] data Pointer to a buffer of \a data_len bytes.
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* \param[in] data_len Number of bytes in the \a data buffer.
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* \return The updated crc value.
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*/
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NVM_CRC_t NVM_CRC_update(NVM_CRC_t crc, const void *data, size_t data_len);
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/**
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* Calculate the final crc value.
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*
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* \param[in] crc The current crc value.
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* \return The final crc value.
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*/
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static inline NVM_CRC_t NVM_CRC_finalize(NVM_CRC_t crc)
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{
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return crc;
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}
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#ifdef __cplusplus
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} /* closing brace for extern "C" */
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#endif
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#endif /* NVM_CRC_H */ |