rt-thread-official/bsp/lpc408x/Libraries/Drivers/source/lpc_crc.c

/**********************************************************************
* $Id$      lpc_crc.c           2011-06-02
*//**
* @file     lpc_crc.c
* @brief    Contains all functions support for CRC firmware library on
*           LPC
* @version  1.0
* @date     02. June. 2011
* @author   NXP MCU SW Application Team
* 
* Copyright(C) 2011, NXP Semiconductor
* All rights reserved.
*
***********************************************************************
* Software that is described herein is for illustrative purposes only
* which provides customers with programming information regarding the
* products. This software is supplied "AS IS" without any warranties.
* NXP Semiconductors assumes no responsibility or liability for the
* use of the software, conveys no license or title under any patent,
* copyright, or mask work right to the product. NXP Semiconductors
* reserves the right to make changes in the software without
* notification. NXP Semiconductors also make no representation or
* warranty that such application will be suitable for the specified
* use without further testing or modification.
* Permission to use, copy, modify, and distribute this software and its
* documentation is hereby granted, under NXP Semiconductors'
* relevant copyright 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.
**********************************************************************/
#ifdef __BUILD_WITH_EXAMPLE__
#include "lpc_libcfg.h"
#else
#include "lpc_libcfg_default.h"
#endif /* __BUILD_WITH_EXAMPLE__ */
#ifdef _CRC

/* Includes ------------------------------------------------------------------- */
#include "lpc_crc.h"
#include "lpc_clkpwr.h"

/* Private Variables ----------------------------------------------------------- */
volatile CRC_Type crc_cur_type;

/* Public Functions ----------------------------------------------------------- */
/** @addtogroup CRC_Public_Functions
 * @{
 */
/*********************************************************************//**
 * @brief       Initialize CRC operation
 * @param[in]   CRCType CRC standard type, should be:
 *              - CRC_POLY_CRCCCITT: CRC-CCITT polynomial
 *              - CRC_POLY_CRC16: CRC-16 polynomial
 *              - CRC_POLY_CRC32: CRC-32 polynomial
 * @return      None
 **********************************************************************/
void CRC_Init(CRC_Type CRCType)
{
    if(CRCType == CRC_POLY_CRCCCITT)
    {
        LPC_CRC->MODE = 0x00;
        LPC_CRC->SEED = 0xFFFF;
        crc_cur_type = CRC_POLY_CRCCCITT;
    }
    else if(CRCType == CRC_POLY_CRC16)
    {
        LPC_CRC->MODE = 0x15;
        LPC_CRC->SEED = 0x0000;
        crc_cur_type = CRC_POLY_CRC16;

    }
    else if(CRCType == CRC_POLY_CRC32)
    {
        LPC_CRC->MODE = 0x36;
        LPC_CRC->SEED = 0xFFFFFFFF;
        crc_cur_type = CRC_POLY_CRC32;
    }
    else
    {
        //Invalid input parameter
        while(1);//error loop
    }
}
/*********************************************************************//**
 * @brief       CRC reset
 * @param[in]   None
 * @return      None
 **********************************************************************/
void CRC_Reset(void)
{
    if(crc_cur_type == CRC_POLY_CRCCCITT)
        LPC_CRC->SEED = 0xFFFF;
    else if (crc_cur_type == CRC_POLY_CRC16)
        LPC_CRC->SEED = 0x0000;
    else if (crc_cur_type == CRC_POLY_CRC32)
        LPC_CRC->SEED = 0xFFFFFFFF;
}

/*********************************************************************//**
 * @brief       CRC data checksum calculation
 * @param[in]   data    input data
 * @return      data checksum result
 **********************************************************************/
uint32_t CRC_CalcDataChecksum(uint32_t data, CRC_WR_SIZE SizeType)
{
    if(SizeType == CRC_WR_8BIT)
        LPC_CRC->WR_DATA_BYTE.DATA = (uint8_t)data;
    else if(SizeType == CRC_WR_16BIT)
        LPC_CRC->WR_DATA_WORD.DATA = (uint16_t)data;
    else
        LPC_CRC->WR_DATA_DWORD.DATA = data;
    return(LPC_CRC->SUM);
}

/*********************************************************************//**
 * @brief       CRC block data checksum calculation
 * @param[in]   blockdata   pointer to block input data
 * @param[in]   blocksize   size of block data
 * @param[in]   SizeType    size of data width per write, should be:
                - CRC_WR_8BIT : 8-bit write
                - CRC_WR_16BIT: 16-bit write
                - CRC_WR_32BIT: 32-bit write
 * @return      block data checksum result
 **********************************************************************/
uint32_t CRC_CalcBlockChecksum(void *block_data, uint32_t block_size, CRC_WR_SIZE data_size)
{
    uint8_t  *data = (uint8_t*) block_data;
    
    while(block_size !=0) {
        
      switch(data_size) {
        
        case CRC_WR_8BIT:
        {
           uint8_t *tmp = data;
               LPC_CRC->WR_DATA_BYTE.DATA = *tmp;
                   data++;
        }
        break;
        case CRC_WR_16BIT:
        {
           uint16_t *tmp = (uint16_t*)data;
                   LPC_CRC->WR_DATA_WORD.DATA = *tmp;
                   data +=2;
        }
         break;
        default:
        {
           uint32_t *tmp = (uint32_t*)data;
                   LPC_CRC->WR_DATA_DWORD.DATA = *tmp;
                   data += 4;
        }
        break;
      }
      block_size--;
    }
    return(LPC_CRC->SUM);
}

/**
 * @}
 */
#endif /*_CRC*/

/**
 * @}
 */

/* --------------------------------- End Of File ------------------------------ */