CRC: Cyclic Redundancy Check Driver

Overview

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.

Modules
	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 parameters configuration . More...

Enumerations
enum	crc_seed_value_t {   kCRC_Crc16Kermit = 0x0000U,   kCRC_CrcA = 0xC6C6U,   kCRC_Crc16Riello = 0xB2AAU,   kCRC_Crc16Tms37157 = 0x89ECU,   kCRC_Crc16Mcrf4xx = 0xFFFFU,   kCRC_Crc16CCITT = 0xFFFFU,   kCRC_Crc16Augccitt = 0x1D0FU,   kCRC_Crc16Xmodem = 0x0000U }
	CRC seed value. 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...
void	CRC_GetDefaultConfig (crc_config_t *psConfig)
	Provide default CRC seed value configuration. More...

CRC Write/Read Data Interfaces
void	CRC_SetSeedValue (CRC_Type *base, uint16_t u16CrcSeedValue)
	Set the CRC seed value. More...
void	CRC_WriteData (CRC_Type *base, const uint8_t *pu8Data, uint16_t u16DataSize, bool bRefin)
	Writes data to the CRC module. More...
uint16_t	CRC_Get16bitResult (CRC_Type *base, bool bRefOut)
	Reads a 16-bit checksum from the CRC module. More...
static uint8_t	CRC_TransposeByte (CRC_Type *base, uint8_t u8Input)
	CRC transpose module. More...

---

Data Structure Documentation

struct crc_config_t

This structure holds the configuration for the CRC required parameters.

Data Fields
uint16_t	u16CrcSeedValue
	Starting checksum value.
bool	bSetSeed
	Set the seed value to registers only when this value is true.

Macro Definition Documentation

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

Enumeration Type Documentation

enum crc_seed_value_t

Enumerator
kCRC_Crc16Kermit	CRC-16/KERMIT protocol.
kCRC_CrcA	CRC/CRCA protocol.
kCRC_Crc16Riello	CRC-16/RIELLO protocol.
kCRC_Crc16Tms37157	CRC-16/TMS37157 protocol.
kCRC_Crc16Mcrf4xx	CRC-16-MCRF4XX protocol.
kCRC_Crc16CCITT	CRC-16-CCITT protocol.
kCRC_Crc16Augccitt	CRC-16/AUG-CCITT protocol.
kCRC_Crc16Xmodem	CRC-16/XMODEM protocol.

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.

void CRC_GetDefaultConfig

(

crc_config_t *

psConfig

)

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 seed values. refer to crc_seed_value_t.

Parameters

psConfig

CRC parameters configuration structure.

void CRC_SetSeedValue	(	CRC_Type *	base,
		uint16_t	u16CrcSeedValue
	)

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

Parameters

base	CRC peripheral address.
u16CrcSeedValue	The value of seed.

void CRC_WriteData	(	CRC_Type *	base,
		const uint8_t *	pu8Data,
		uint16_t	u16DataSize,
		bool	bRefin
	)

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].
u16DataSize	Size in bytes of the input data buffer.
bRefin	Invert when input calculations.

uint16_t CRC_Get16bitResult	(	CRC_Type *	base,
		bool	bRefOut
	)

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.
bRefOut	Invert the calculated CRC value as a whole.

Returns

A 16-bit checksum with or without transposed configuration.

static uint8_t CRC_TransposeByte ( CRC_Type *  base, uint8_t  u8Input  )

inlinestatic

The CRC module provides an additional feature to transpose data (invert bit order)

Parameters

base	CRC peripheral address.
u8Input	An 8-bit input data.