text: /*
   * @brief LPC8xx Cyclic Redundancy Check (CRC) Engine driver
   *
   * @note
   * Copyright(C) NXP Semiconductors, 2012
   * All rights reserved.
   *
   * @par
   * Software that is described herein is for illustrative purposes only
   * which provides customers with programming information regarding the
   * LPC products.  This software is supplied "AS IS" without any warranties of
   * any kind, and NXP Semiconductors and its licenser disclaim any and
   * all warranties, express or implied, including all implied warranties of
   * merchantability, fitness for a particular purpose and non-infringement of
   * intellectual property rights.  NXP Semiconductors assumes no responsibility
   * or liability for the use of the software, conveys no license or rights under any
   * patent, copyright, mask work right, or any other intellectual property rights in
   * or to any products. NXP Semiconductors reserves the right to make changes
   * in the software without notification. NXP Semiconductors also makes no
   * representation or warranty that such application will be suitable for the
   * specified use without further testing or modification.
   *
   * @par
   * Permission to use, copy, modify, and distribute this software and its
   * documentation is hereby granted, under NXP Semiconductors' and its
   * licensor's relevant copyrights in the software, without fee, provided that it
   * is used in conjunction with NXP Semiconductors microcontrollers.  This
   * copyright, permission, and disclaimer notice must appear in all copies of
   * this code.
   */
  
  #ifndef __CRC_8XX_H_
  #define __CRC_8XX_H_
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /** @defgroup CRC_8XX CHIP: LPC8xx Cyclic Redundancy Check Engine driver
   * @ingroup CHIP_8XX_Drivers
   * @{
   */
  
  /**
   * @brief CRC register block structure
   */
  typedef struct {					/*!< CRC Structure */
  	__IO    uint32_t    MODE;		/*!< CRC Mode Register */
  	__IO    uint32_t    SEED;		/*!< CRC SEED Register */
  	union {
  		__I     uint32_t    SUM;	/*!< CRC Checksum Register. */
  		__O     uint32_t    WRDATA32;	/*!< CRC Data Register: write size 32-bit*/
  		__O     uint16_t    WRDATA16;	/*!< CRC Data Register: write size 16-bit*/
  		__O     uint8_t     WRDATA8;	/*!< CRC Data Register: write size 8-bit*/
  	};
  
  } LPC_CRC_T;
  
  /*
   * @brief CRC MODE register description
   */
  #define CRC_MODE_POLY_BITMASK   ((0x03))	/** CRC polynomial Bit mask */
  #define CRC_MODE_POLY_CCITT     (0x00)		/** Select CRC-CCITT polynomial */
  #define CRC_MODE_POLY_CRC16     (0x01)		/** Select CRC-16 polynomial */
  #define CRC_MODE_POLY_CRC32     (0x02)		/** Select CRC-32 polynomial */
  #define CRC_MODE_WRDATA_BITMASK (0x03 << 2)	/** CRC WR_Data Config Bit mask */
  #define CRC_MODE_WRDATA_BIT_RVS (1 << 2)	/** Select Bit order reverse for WR_DATA (per byte) */
  #define CRC_MODE_WRDATA_CMPL    (1 << 3)	/** Select One's complement for WR_DATA */
  #define CRC_MODE_SUM_BITMASK    (0x03 << 4)	/** CRC Sum Config Bit mask */
  #define CRC_MODE_SUM_BIT_RVS    (1 << 4)	/** Select Bit order reverse for CRC_SUM */
  #define CRC_MODE_SUM_CMPL       (1 << 5)	/** Select One's complement for CRC_SUM */
  
  #define MODE_CFG_CCITT          (0x00)	/** Pre-defined mode word for default CCITT setup */
  #define MODE_CFG_CRC16          (0x15)	/** Pre-defined mode word for default CRC16 setup */
  #define MODE_CFG_CRC32          (0x36)	/** Pre-defined mode word for default CRC32 setup */
  
  #define CRC_SEED_CCITT          (0x0000FFFF)/** Initial seed value for CCITT mode */
  #define CRC_SEED_CRC16          (0x00000000)/** Initial seed value for CRC16 mode */
  #define CRC_SEED_CRC32          (0xFFFFFFFF)/** Initial seed value for CRC32 mode */
  
  /**
   * @brief CRC polynomial
   */
  typedef enum IP_CRC_001_POLY {
  	CRC_POLY_CCITT = CRC_MODE_POLY_CCITT,	/**< CRC-CCIT polynomial */
  	CRC_POLY_CRC16 = CRC_MODE_POLY_CRC16,	/**< CRC-16 polynomial */
  	CRC_POLY_CRC32 = CRC_MODE_POLY_CRC32,	/**< CRC-32 polynomial */
  	CRC_POLY_LAST,
  } CRC_POLY_T;
  
  /**
   * @brief	Initializes the CRC Engine
   * @return	Nothing
   */
  void Chip_CRC_Init(void);
  
  /**
   * @brief	Deinitializes the CRC Engine
   * @return	Nothing
   */
  void Chip_CRC_Deinit(void);
  
  /**
   * @brief	Set the polynomial used for the CRC calculation
   * @param	poly	: The enumerated polynomial to be used
   * @param	flags	: An Or'ed value of flags that setup the mode
   * @return	Nothing
   * @note	Flags for setting up the mode word include CRC_MODE_WRDATA_BIT_RVS,
   * CRC_MODE_WRDATA_CMPL, CRC_MODE_SUM_BIT_RVS, and CRC_MODE_SUM_CMPL.
   */
  STATIC INLINE void Chip_CRC_SetPoly(CRC_POLY_T poly, uint32_t flags)
  {
  	LPC_CRC->MODE = (uint32_t) poly | flags;
  }
  
  /**
   * @brief	Sets up the CRC engine for CRC16 mode
   * @return	Nothing
   */
  STATIC INLINE void Chip_CRC_UseCRC16(void)
  {
  	LPC_CRC->MODE = MODE_CFG_CRC16;
  	LPC_CRC->SEED = CRC_SEED_CRC16;
  }
  
  /**
   * @brief	Sets up the CRC engine for CRC32 mode
   * @return	Nothing
   */
  STATIC INLINE void Chip_CRC_UseCRC32(void)
  {
  	LPC_CRC->MODE = MODE_CFG_CRC32;
  	LPC_CRC->SEED = CRC_SEED_CRC32;
  }
  
  /**
   * @brief	Sets up the CRC engine for CCITT mode
   * @return	Nothing
   */
  STATIC INLINE void Chip_CRC_UseCCITT(void)
  {
  	LPC_CRC->MODE = MODE_CFG_CCITT;
  	LPC_CRC->SEED = CRC_SEED_CCITT;
  }
  
  /**
   * @brief	Engage the CRC engine with defaults based on the polynomial to be used
   * @param	poly	: The enumerated polynomial to be used
   * @return	Nothing
   */
  void Chip_CRC_UseDefaultConfig(CRC_POLY_T poly);
  
  /**
   * @brief	Set the CRC Mode bits
   * @param	mode	: Mode value
   * @return	Nothing
   */
  STATIC INLINE void Chip_CRC_SetMode(uint32_t mode)
  {
  	LPC_CRC->MODE = mode;
  }
  
  /**
   * @brief	Get the CRC Mode bits
   * @return	The current value of the CRC Mode bits
   */
  STATIC INLINE uint32_t Chip_CRC_GetMode(void)
  {
  	return LPC_CRC->MODE;
  }
  
  /**
   * @brief	Set the seed bits used by the CRC_SUM register
   * @param	seed	: Seed value
   * @return	Nothing
   */
  STATIC INLINE void Chip_CRC_SetSeed(uint32_t seed)
  {
  	LPC_CRC->SEED = seed;
  }
  
  /**
   * @brief	Get the CRC seed value
   * @return	Seed value
   */
  STATIC INLINE uint32_t Chip_CRC_GetSeed(void)
  {
  	return LPC_CRC->SEED;
  }
  
  /**
   * @brief	Convenience function for writing 8-bit data to the CRC engine
   * @param	data	: 8-bit data to write
   * @return	Nothing
   */
  STATIC INLINE void Chip_CRC_Write8(uint8_t data)
  {
  	LPC_CRC->WRDATA8 = data;
  }
  
  /**
   * @brief	Convenience function for writing 16-bit data to the CRC engine
   * @param	data	: 16-bit data to write
   * @return	Nothing
   */
  STATIC INLINE void Chip_CRC_Write16(uint16_t data)
  {
  	LPC_CRC->WRDATA16 = data;
  }
  
  /**
   * @brief	Convenience function for writing 32-bit data to the CRC engine
   * @param	data	: 32-bit data to write
   * @return	Nothing
   */
  STATIC INLINE void Chip_CRC_Write32(uint32_t data)
  {
  	LPC_CRC->WRDATA32 = data;
  }
  
  /**
   * @brief	Gets the CRC Sum based on the Mode and Seed as previously configured
   * @return	CRC Checksum value
   */
  STATIC INLINE uint32_t Chip_CRC_Sum(void)
  {
  	return LPC_CRC->SUM;
  }
  
  /**
   * @brief	Convenience function for computing a standard CCITT checksum from an 8-bit data block
   * @param	data	: Pointer to the block of 8-bit data
   * @param   bytes	: The number of bytes pointed to by data
   * @return	Check sum value
   */
  uint32_t Chip_CRC_CRC8(const uint8_t *data, uint32_t bytes);
  
  /**
   * @brief	Convenience function for computing a standard CRC16 checksum from 16-bit data block
   * @param	data	: Pointer to the block of 16-bit data
   * @param   hwords	: The number of 16 byte entries pointed to by data
   * @return	Check sum value
   */
  uint32_t Chip_CRC_CRC16(const uint16_t *data, uint32_t hwords);
  
  /**
   * @brief	Convenience function for computing a standard CRC32 checksum from 32-bit data block
   * @param	data	: Pointer to the block of 32-bit data
   * @param   words	: The number of 32-bit entries pointed to by data
   * @return	Check sum value
   */
  uint32_t Chip_CRC_CRC32(const uint32_t *data, uint32_t words);
  
  /**
   * @}
   */
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* __CRC_8XX_H_ */
  