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NxpNfcRdLib/.svn/pristine/0d/0d707689f306a674f4c6e6439d0eea0077db3a66.svn-base
2024-07-08 21:03:06 +08:00

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/*
* @brief LPC17xx/40xx Cyclic Redundancy Check (CRC) Engine driver
*
* @note
* Copyright(C) NXP Semiconductors, 2014
* 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.
*/
#include "chip.h"
#if defined(CHIP_LPC177X_8X) || defined(CHIP_LPC40XX)
/*****************************************************************************
* Private types/enumerations/variables
****************************************************************************/
/*****************************************************************************
* Public types/enumerations/variables
****************************************************************************/
/*****************************************************************************
* Private functions
****************************************************************************/
/*****************************************************************************
* Public functions
****************************************************************************/
/* Sets up the CRC engine with defaults based on the polynomial to be used */
void Chip_CRC_UseDefaultConfig(CRC_POLY_T poly)
{
switch (poly) {
case CRC_POLY_CRC16:
LPC_CRC->MODE = MODE_CFG_CRC16;
LPC_CRC->SEED = CRC_SEED_CRC16;
break;
case CRC_POLY_CRC32:
LPC_CRC->MODE = MODE_CFG_CRC32;
LPC_CRC->SEED = CRC_SEED_CRC32;
break;
case CRC_POLY_CCITT:
default:
LPC_CRC->MODE = MODE_CFG_CCITT;
LPC_CRC->SEED = CRC_SEED_CCITT;
break;
}
}
/* configure CRC engine and compute CCITT checksum from 8-bit data */
uint32_t Chip_CRC_CRC8(const uint8_t *data, uint32_t bytes)
{
Chip_CRC_UseDefaultConfig(CRC_POLY_CCITT);
while (bytes > 0) {
Chip_CRC_Write8(*data);
data++;
bytes--;
}
return Chip_CRC_Sum();
}
/* Convenience function for computing a standard CRC16 checksum from 16-bit data block */
uint32_t Chip_CRC_CRC16(const uint16_t *data, uint32_t hwords)
{
Chip_CRC_UseDefaultConfig(CRC_POLY_CRC16);
while (hwords > 0) {
Chip_CRC_Write16(*data);
data++;
hwords--;
}
return Chip_CRC_Sum();
}
/* Convenience function for computing a standard CRC32 checksum from 32-bit data block */
uint32_t Chip_CRC_CRC32(const uint32_t *data, uint32_t words)
{
Chip_CRC_UseDefaultConfig(CRC_POLY_CRC32);
while (words > 0) {
Chip_CRC_Write32(*data);
data++;
words--;
}
return Chip_CRC_Sum();
}
#endif /* defined(CHIP_LPC177X_8X) || defined(CHIP_LPC40XX) */