File syn_crc.h¶

FileList > src > syntropic > util > syn_crc.h

CRC calculation for communication protocols. More...

#include <stddef.h>
#include <stdint.h>

Public Functions¶

Type	Name
uint16_t	syn_crc16_ccitt_update (uint16_t crc, const void * data, size_t len) Update CRC-16 CCITT with a block of data.
uint16_t	syn_crc16_modbus_update (uint16_t crc, const void * data, size_t len) Update CRC-16 Modbus with a block of data.
uint32_t	syn_crc32_update (uint32_t crc, const void * data, size_t len) Update CRC-32 with a block of data.
uint8_t	syn_crc8_update (uint8_t crc, const void * data, size_t len) Update CRC-8 with a block of data.

Public Static Functions¶

Type	Name
uint16_t	syn_crc16_ccitt (const void * data, size_t len) Compute CRC-16 CCITT of a complete buffer.
uint16_t	syn_crc16_modbus (const void * data, size_t len) Compute CRC-16 Modbus of a complete buffer.
uint32_t	syn_crc32 (const void * data, size_t len) Compute CRC-32 of a complete buffer.
uint32_t	syn_crc32_final (uint32_t crc) Finalize CRC-32 (XOR with 0xFFFFFFFF).
uint8_t	syn_crc8 (const void * data, size_t len) Compute CRC-8 of a complete buffer.

Macros¶

Type	Name
define	SYN_CRC16_CCITT_INIT `0xFFFFu` CRC-16 CCITT initial value.
define	SYN_CRC16_MODBUS_INIT `0xFFFFu` CRC-16 Modbus initial value.
define	SYN_CRC32_INIT `0xFFFFFFFFu` CRC-32 initial value.
define	SYN_CRC8_INIT `0x00u` CRC-8 initial value.
define	SYN_CRC_USE_TABLE `1`

Detailed Description¶

Provides CRC-8, CRC-16 (CCITT, Modbus), and CRC-32 (Ethernet). Configure SYN_CRC_USE_TABLE to trade ROM for speed: 1 = 256-entry lookup table (fast, ~256–1024 bytes ROM per variant) 0 = bit-by-bit computation (small, slower)

All variants support incremental (streaming) computation.

** **

uint16_t crc = syn_crc16_ccitt(data, len);

// Incremental:
uint16_t crc = SYN_CRC16_CCITT_INIT;
crc = syn_crc16_ccitt_update(crc, chunk1, len1);
crc = syn_crc16_ccitt_update(crc, chunk2, len2);

Public Functions Documentation¶

function syn_crc16_ccitt_update¶

Update CRC-16 CCITT with a block of data.

uint16_t syn_crc16_ccitt_update (
    uint16_t crc,
    const void * data,
    size_t len
)

Parameters:

crc Running CRC value (start with SYN_CRC16_CCITT_INIT).
data Data buffer.
len Length in bytes.

Returns:

Updated CRC-16.

function syn_crc16_modbus_update¶

Update CRC-16 Modbus with a block of data.

uint16_t syn_crc16_modbus_update (
    uint16_t crc,
    const void * data,
    size_t len
)

Parameters:

crc Running CRC value (start with SYN_CRC16_MODBUS_INIT).
data Data buffer.
len Length in bytes.

Returns:

Updated CRC-16.

function syn_crc32_update¶

Update CRC-32 with a block of data.

uint32_t syn_crc32_update (
    uint32_t crc,
    const void * data,
    size_t len
)

Parameters:

crc Running CRC value (start with SYN_CRC32_INIT).
data Data buffer.
len Length in bytes.

Returns:

Updated CRC-32 (call syn_crc32_final to finalize).

function syn_crc8_update¶

Update CRC-8 with a block of data.

uint8_t syn_crc8_update (
    uint8_t crc,
    const void * data,
    size_t len
)

Parameters:

crc Running CRC value (start with SYN_CRC8_INIT).
data Data buffer.
len Length in bytes.

Returns:

Updated CRC-8.

Public Static Functions Documentation¶

function syn_crc16_ccitt¶

Compute CRC-16 CCITT of a complete buffer.

static inline uint16_t syn_crc16_ccitt (
    const void * data,
    size_t len
)

Parameters:

data Data buffer.
len Length in bytes.

Returns:

CRC-16 CCITT value.

function syn_crc16_modbus¶

Compute CRC-16 Modbus of a complete buffer.

static inline uint16_t syn_crc16_modbus (
    const void * data,
    size_t len
)

Parameters:

data Data buffer.
len Length in bytes.

Returns:

CRC-16 Modbus value.

function syn_crc32¶

Compute CRC-32 of a complete buffer.

static inline uint32_t syn_crc32 (
    const void * data,
    size_t len
)

Parameters:

data Data buffer.
len Length in bytes.

Returns:

CRC-32 value.

function syn_crc32_final¶

Finalize CRC-32 (XOR with 0xFFFFFFFF).

static inline uint32_t syn_crc32_final (
    uint32_t crc
)

Parameters:

crc Running CRC-32 value.

Returns:

Final CRC-32.

function syn_crc8¶

Compute CRC-8 of a complete buffer.

static inline uint8_t syn_crc8 (
    const void * data,
    size_t len
)

Parameters:

data Data buffer.
len Length in bytes.

Returns:

CRC-8 value.

Macro Definition Documentation¶

define SYN_CRC16_CCITT_INIT¶

CRC-16 CCITT initial value.

#define SYN_CRC16_CCITT_INIT `0xFFFFu`

define SYN_CRC16_MODBUS_INIT¶

CRC-16 Modbus initial value.

#define SYN_CRC16_MODBUS_INIT `0xFFFFu`

define SYN_CRC32_INIT¶

CRC-32 initial value.

#define SYN_CRC32_INIT `0xFFFFFFFFu`

define SYN_CRC8_INIT¶

CRC-8 initial value.

#define SYN_CRC8_INIT `0x00u`

define SYN_CRC_USE_TABLE¶

#define SYN_CRC_USE_TABLE `1`

Set to 1 for lookup-table CRC (fast), 0 for bit-by-bit (small).

The documentation for this class was generated from the following file src/syntropic/util/syn_crc.h