Read Guidance

This document consists of sections titled with Driver Overview, Data Structures, Enumerations, Functions, etc., each with an overview list and detailed documentation. It is recommended to read the Driver Overview first for it includes a comprehensive description of the peripheral, driver and driver changes. Other sections give detailed information for APIs, enums, macros, etc., for your further reference.

Driver Overview
	CRC Peripheral and Driver Overview
	Content including 1) peripheral features, work logic and work method; 2) driver design logic and use method; 3) typical use case.

	The Driver Change Log
	The current CRC driver version is 2.0.0.

Data Structures
struct	crc_config_t
	CRC protocol configuration. More...

Enumerations
enum	crc_protocol_type_t { kCRC_Crc16 = 0U, kCRC_Crc16CCITT = 1U, kCRC_Crc16Kermit = 2U, kCRC_Crc32 = 3U, kCRC_Crc32Posix = 4U }
	CRC protocol type. More...

enum	crc_bits_t { kCRC_Bits16 = 0U, kCRC_Bits32 = 1U }
	CRC protocol bit width. More...

enum	crc_transpose_type_t { kCRC_TransposeNone = 0U, kCRC_TransposeBits = 1U, kCRC_TransposeBitsAndBytes = 2U, kCRC_TransposeBytes = 3U }
	CRC type of transpose of read/write data. More...

Driver version
#define	FSL_CRC_DRIVER_VERSION (MAKE_VERSION(2, 0, 0))
	CRC driver version. More...

Initialization and De-initialization Interfaces
void	CRC_Init (CRC_Type base, const crc_config_t psConfig)
	Enables and configures the CRC peripheral module. More...

void	CRC_Deinit (CRC_Type *base)
	Disables the CRC peripheral module. More...

static void	CRC_GetDefaultConfig (crc_config_t *psConfig, crc_protocol_type_t eCrcProtocol)
	Provide default CRC protocol configuration. More...

CRC Configuration Interfaces
static void	CRC_SetSeedValue (CRC_Type *base, uint32_t u32CrcSeedValue)
	Set the CRC seed value. More...

static void	CRC_SetPolynomial (CRC_Type *base, uint32_t u32CrcPolynomial)
	Set the value of the polynomial for the CRC calculation. More...

static void	CRC_SetWriteTransposeType (CRC_Type *base, crc_transpose_type_t eTransposeIn)
	Set CRC type of transpose of write data. More...

static void	CRC_SetReadTransposeType (CRC_Type *base, crc_transpose_type_t eTransposeOut)
	Set CRC type of transpose of read data. More...

static void	CRC_EnableComplementChecksum (CRC_Type *base, bool bEnable)
	Enable/Disable complement of read CRC checksum. More...

static void	CRC_SetProtocolWidth (CRC_Type *base, crc_bits_t eCrcBits)
	Set bit width of CRC protocol. More...

CRC Write/Read Data Interfaces
void	CRC_WriteData (CRC_Type base, const uint8_t pu8Data, uint32_t u32DataSize)
	Writes data to the CRC module. More...

static uint32_t	CRC_Get32bitResult (CRC_Type *base)
	Reads the 32-bit checksum from the CRC module. More...

uint16_t	CRC_Get16bitResult (CRC_Type *base)
	Reads a 16-bit checksum from the CRC module. More...

Data Structure Documentation

struct crc_config_t

This structure holds the configuration for the CRC protocol.

Data Fields
uint32_t	u32CrcPolynomial
	CRC Polynomial, MSBit first. More...

uint32_t	u32CrcSeedValue
	Starting checksum value.

bool	bEnableComplementChecksum: 1
	Enable/Disable complement of read CRC checksum. More...

crc_transpose_type_t	eTransposeIn: 2
	Select type of transpose of input data. More...

crc_transpose_type_t	eTransposeOut: 2
	Select type of transpose of output data. More...

crc_bits_t	eCrcBits: 1
	Select 16-bit or 32-bit CRC protocol. More...

Field Documentation

uint32_t crc_config_t::u32CrcPolynomial

Example polynomial: 0x1021 = 1_0000_0010_0001 = x^12+x^5+1

bool crc_config_t::bEnableComplementChecksum

crc_transpose_type_t crc_config_t::eTransposeIn

crc_transpose_type_t crc_config_t::eTransposeOut

crc_bits_t crc_config_t::eCrcBits

Macro Definition Documentation

#define FSL_CRC_DRIVER_VERSION (MAKE_VERSION(2, 0, 0))

Version 2.0.0.

Enumeration Type Documentation

enum crc_protocol_type_t

Enumerator
kCRC_Crc16	CRC-16/MAXIM protocol.
kCRC_Crc16CCITT	CRC-16-CCITT protocol.
kCRC_Crc16Kermit	CRC-16/KERMIT protocol.
kCRC_Crc32	CRC-32 protocol.
kCRC_Crc32Posix	CRC-32/POSIX protocol.

enum crc_bits_t

Enumerator
kCRC_Bits16	Generate 16-bit CRC code.
kCRC_Bits32	Generate 32-bit CRC code.

enum crc_transpose_type_t

Enumerator
kCRC_TransposeNone	No transpose.
kCRC_TransposeBits	Transpose bits in bytes.
kCRC_TransposeBitsAndBytes	Transpose bytes and bits in bytes.
kCRC_TransposeBytes	Transpose bytes.

Function Documentation

void CRC_Init	(	CRC_Type *	base,
		const crc_config_t *	psConfig
	)

This function enables the clock gate in the SIM module for the CRC peripheral. It also configures the CRC module and starts a checksum computation by writing the seed.

Parameters

base	CRC peripheral address.
psConfig	CRC module configuration structure.

void CRC_Deinit ( CRC_Type * base )

This function disables the clock gate in the SIM module for the CRC peripheral.

Parameters

base	CRC peripheral address.

static void CRC_GetDefaultConfig	(	crc_config_t *	psConfig,
		crc_protocol_type_t	eCrcProtocol
	)

inlinestatic

The purpose of this API is to initialize the configuration structure to default value for CRC_Init to use. Provides the configuration of commonly used CRC protocols. refer to _crc_protocol_type.

This is an example:

       crc_config_t sConfig;
       //LoadCRC-16/MAXIM protocol configuration.
       CRC_GetDefaultConfig(&sConfig, kCRC_Crc16);
       CRC_Init(CRC, &sConfig);
* 

Parameters

psConfig	CRC protocol configuration structure.
eCrcProtocol	CRC protocol type. refer to _crc_protocol_type

static void CRC_SetSeedValue	(	CRC_Type *	base,
		uint32_t	u32CrcSeedValue
	)

inlinestatic

This function is help to write a 16/32 bit CRC seed value.

Parameters

base	CRC peripheral address.
u32CrcSeedValue	The value of seed.

static void CRC_SetPolynomial	(	CRC_Type *	base,
		uint32_t	u32CrcPolynomial
	)

inlinestatic

Write a 16-bit or 32-bit polynomial to CRC Polynomial register for the CRC calculation.

Parameters

base	CRC peripheral address.
u32CrcPolynomial	The CRC polynomial.

static void CRC_SetWriteTransposeType	(	CRC_Type *	base,
		crc_transpose_type_t	eTransposeIn
	)

inlinestatic

This function help to configure CRC type of transpose of write data.

Parameters

base	CRC peripheral address.
eTransposeIn	Type Of transpose for input. See _crc_transpose_type

static void CRC_SetReadTransposeType	(	CRC_Type *	base,
		crc_transpose_type_t	eTransposeOut
	)

inlinestatic

This function help to configure CRC type of transpose of read data.

Parameters

base	CRC peripheral address.
eTransposeOut	Type Of transpose for output. See _crc_transpose_type

static void CRC_EnableComplementChecksum	(	CRC_Type *	base,
		bool	bEnable
	)

inlinestatic

Set complement of read CRC checksum. Some CRC protocols require the final checksum to be XORed with 0xFFFFFFFF or 0xFFFF.

Parameters

base	CRC peripheral address.
bEnable	True or false. True if the result shall be complement of the actual checksum.

static void CRC_SetProtocolWidth	(	CRC_Type *	base,
		crc_bits_t	eCrcBits
	)

inlinestatic

Selects 16-bit or 32-bit CRC protocol.

Parameters

base	CRC peripheral address.
eCrcBits	16 or 32 bit CRC protocol. See _crc_bits

void CRC_WriteData	(	CRC_Type *	base,
		const uint8_t *	pu8Data,
		uint32_t	u32DataSize
	)

Writes input data buffer bytes to the CRC data register. The configured type of transpose is applied.

Parameters

base	CRC peripheral address.
pu8Data	Input data stream, MSByte in data[0].
u32DataSize	Size in bytes of the input data buffer.

static uint32_t CRC_Get32bitResult ( CRC_Type * base )

inlinestatic

Reads the CRC data register (either an intermediate or the final checksum). The configured type of transpose and complement is applied.

Parameters

base	CRC peripheral address.

Returns: An intermediate or the final 32-bit checksum, after transpose and complement operations configured.

uint16_t CRC_Get16bitResult ( CRC_Type * base )

Reads the CRC data register (either an intermediate or the final checksum). The configured type of transpose and complement is applied.

Parameters

base	CRC peripheral address.

Returns: An intermediate or the final 16-bit checksum, after transpose and complement operations configured.

Read Guidance

Driver Overview

Data Structures

Enumerations

Driver version

Initialization and De-initialization Interfaces

CRC Configuration Interfaces

CRC Write/Read Data Interfaces

Data Structure Documentation

Data Fields

Field Documentation

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation