/***************************************************************************//** | |
* @file | |
* @brief General Purpose Cyclic Redundancy Check (GPCRC) API. | |
* @version 5.1.2 | |
******************************************************************************* | |
* @section License | |
* <b>Copyright 2016 Silicon Laboratories, Inc. http://www.silabs.com</b> | |
******************************************************************************* | |
* | |
* Permission is granted to anyone to use this software for any purpose, | |
* including commercial applications, and to alter it and redistribute it | |
* freely, subject to the following restrictions: | |
* | |
* 1. The origin of this software must not be misrepresented; you must not | |
* claim that you wrote the original software. | |
* 2. Altered source versions must be plainly marked as such, and must not be | |
* misrepresented as being the original software. | |
* 3. This notice may not be removed or altered from any source distribution. | |
* | |
* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no | |
* obligation to support this Software. Silicon Labs is providing the | |
* Software "AS IS", with no express or implied warranties of any kind, | |
* including, but not limited to, any implied warranties of merchantability | |
* or fitness for any particular purpose or warranties against infringement | |
* of any proprietary rights of a third party. | |
* | |
* Silicon Labs will not be liable for any consequential, incidental, or | |
* special damages, or any other relief, or for any claim by any third party, | |
* arising from your use of this Software. | |
* | |
******************************************************************************/ | |
#ifndef EM_GPCRC_H | |
#define EM_GPCRC_H | |
#include "em_bus.h" | |
#include "em_device.h" | |
#if defined(GPCRC_PRESENT) && (GPCRC_COUNT > 0) | |
#include <stdint.h> | |
#include <stdbool.h> | |
#ifdef __cplusplus | |
extern "C" { | |
#endif | |
/***************************************************************************//** | |
* @addtogroup emlib | |
* @{ | |
******************************************************************************/ | |
/***************************************************************************//** | |
* @addtogroup GPCRC | |
* @brief General Purpose Cyclic Redundancy Check (GPCRC) API. | |
* | |
* @details | |
* The GPCRC API functions provide full support for the GPCRC peripheral. | |
* | |
* The GPCRC module is a peripheral that implements a Cyclic Redundancy Check | |
* (CRC) function. It supports a fixed 32-bit polynomial and a user | |
* configurable 16-bit polynomial. The fixed 32-bit polynomial is the commonly | |
* used IEEE 802.3 polynomial 0x04C11DB7. | |
* | |
* When using a 16-bit polynomial it's up to the user to choose a polynomial | |
* that fits the application. Commonly used 16-bit polynomial are 0x1021 | |
* (CCITT-16), 0x3D65 (IEC16-MBus), and 0x8005 (ZigBee, 802.15.4, and USB). | |
* See this link for other polynomials: | |
* https://en.wikipedia.org/wiki/Cyclic_redundancy_check | |
* | |
* Before a CRC calculation can begin it is important to call the | |
* @ref GPCRC_Start function. This function will reset the CRC calculation | |
* by copying the configured initialization value over to the CRC data register. | |
* | |
* There are two ways of sending input data to the GPCRC. You can either write | |
* the input data into the input data register using the input functions | |
* @ref GPCRC_InputU32, @ref GPCRC_InputU16 and @ref GPCRC_InputU8, or the | |
* user can setup the @ref LDMA to transfer data directly to one of the GPCRC | |
* input data registers. | |
* | |
* <b> Examples of GPCRC usage: </b> | |
* | |
* A CRC-32 Calculation: | |
* | |
* @include em_gpcrc_crc32.c | |
* | |
* A CRC-16 Calculation: | |
* | |
* @include em_gpcrc_crc16.c | |
* | |
* A CRC-CCITT calculation: | |
* | |
* @include em_gpcrc_ccit.c | |
* | |
* @{ | |
******************************************************************************/ | |
/******************************************************************************* | |
******************************* STRUCTS *********************************** | |
******************************************************************************/ | |
/** CRC initialization structure. */ | |
typedef struct | |
{ | |
/** | |
* CRC polynomial value. The GPCRC support either a fixed 32-bit polynomial | |
* or a user configurable 16 bit polynomial. The fixed 32-bit polynomial | |
* is the one used in IEEE 802.3, which has the value 0x04C11DB7. To use the | |
* 32-bit fixed polynomial just assign 0x04C11DB7 to the crcPoly field. To use | |
* a 16-bit polynomial assign a value to crcPoly where the upper 16 bit's are | |
* zero. | |
* | |
* The polynomial should be written in normal bit order. So for instance | |
* if you want to use the CRC-16 polynomial X^16 + X^15 + X^2 + 1 then we | |
* can first convert it to hex representation and remove the highest order term | |
* of the polynomial. This would give us 0x8005 as the value to write into | |
* crcPoly. | |
*/ | |
uint32_t crcPoly; | |
/** | |
* CRC initialization value. This value is assigned to the GPCRC_INIT register. | |
* The initValue is loaded into the data register when calling the | |
* @ref GPCRC_Start function or when one of the data registers are read | |
* while @ref autoInit is enabled. | |
*/ | |
uint32_t initValue; | |
/** | |
* Reverse byte order. This has an effect when sending a 32-bit word or | |
* 16-bit half word input to the CRC calculation. When set to true the input | |
* bytes are reversed before entering the CRC calculation. When set to | |
* false the input bytes stay in the same order. | |
*/ | |
bool reverseByteOrder; | |
/** | |
* Reverse bits within each input byte. This setting enables or disable byte | |
* level bit reversal. When byte-level bit reversal is enabled then each byte | |
* of input data will be reversed before entering the CRC calculation. | |
*/ | |
bool reverseBits; | |
/** | |
* Enable/disable byte mode. When byte mode is enabled then all input | |
* is treated as single byte input, even though the input is a 32-bit word | |
* or a 16-bit half word. Only the least significant byte of the data-word | |
* will be used for CRC calculation for all writes. | |
*/ | |
bool enableByteMode; | |
/** | |
* Enable automatic initialization by re-seeding the CRC result based on | |
* the init value after reading one of the CRC data registers | |
*/ | |
bool autoInit; | |
/** Enable/disable GPCRC when initialization is completed. */ | |
bool enable; | |
} GPCRC_Init_TypeDef; | |
/** Default configuration for GPCRC_Init_TypeDef structure. */ | |
#define GPCRC_INIT_DEFAULT \ | |
{ \ | |
0x04C11DB7UL, /* CRC32 Polynomial value. */ \ | |
0x00000000UL, /* Initialization value. */ \ | |
false, /* Byte order is normal. */ \ | |
false, /* Bit order is not reversed on output. */ \ | |
false, /* Disable byte mode. */ \ | |
false, /* Disable automatic init on data read. */ \ | |
true, /* Enable GPCRC. */ \ | |
} | |
/******************************************************************************* | |
****************************** PROTOTYPES ********************************* | |
******************************************************************************/ | |
void GPCRC_Init(GPCRC_TypeDef * gpcrc, const GPCRC_Init_TypeDef * init); | |
void GPCRC_Reset(GPCRC_TypeDef * gpcrc); | |
/***************************************************************************//** | |
* @brief | |
* Enable/disable GPCRC. | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
* | |
* @param[in] enable | |
* True to enable GPCRC, false to disable. | |
******************************************************************************/ | |
__STATIC_INLINE void GPCRC_Enable(GPCRC_TypeDef * gpcrc, bool enable) | |
{ | |
BUS_RegBitWrite(&gpcrc->CTRL, _GPCRC_CTRL_EN_SHIFT, enable); | |
} | |
/***************************************************************************//** | |
* @brief | |
* Issues a command to initialize the CRC calculation. | |
* | |
* @details | |
* This function issues the command INIT in GPCRC_CMD that initializes the | |
* CRC calculation by writing the initial values to the DATA register. | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
******************************************************************************/ | |
__STATIC_INLINE void GPCRC_Start(GPCRC_TypeDef * gpcrc) | |
{ | |
gpcrc->CMD = GPCRC_CMD_INIT; | |
} | |
/***************************************************************************//** | |
* @brief | |
* Set the initialization value of the CRC. | |
* | |
* @param [in] initValue | |
* The value to use to initialize a CRC calculation. This value is moved into | |
* the data register when calling @ref GPCRC_Start | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
******************************************************************************/ | |
__STATIC_INLINE void GPCRC_InitValueSet(GPCRC_TypeDef * gpcrc, uint32_t initValue) | |
{ | |
gpcrc->INIT = initValue; | |
} | |
/***************************************************************************//** | |
* @brief | |
* Writes a 32 bit value to the input data register of the CRC. | |
* | |
* @details | |
* Use this function to write a 32 bit input data to the CRC. The CRC | |
* calculation is based on the provided input data using the configured | |
* CRC polynomial. | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
* | |
* @param[in] data | |
* Data to be written to the input data register. | |
******************************************************************************/ | |
__STATIC_INLINE void GPCRC_InputU32(GPCRC_TypeDef * gpcrc, uint32_t data) | |
{ | |
gpcrc->INPUTDATA = data; | |
} | |
/***************************************************************************//** | |
* @brief | |
* Writes a 16 bit value to the input data register of the CRC. | |
* | |
* @details | |
* Use this function to write a 16 bit input data to the CRC. The CRC | |
* calculation is based on the provided input data using the configured | |
* CRC polynomial. | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
* | |
* @param[in] data | |
* Data to be written to the input data register. | |
******************************************************************************/ | |
__STATIC_INLINE void GPCRC_InputU16(GPCRC_TypeDef * gpcrc, uint16_t data) | |
{ | |
gpcrc->INPUTDATAHWORD = data; | |
} | |
/***************************************************************************//** | |
* @brief | |
* Writes an 8 bit value to the input data register of the CRC. | |
* | |
* @details | |
* Use this function to write a 8 bit input data to the CRC. The CRC | |
* calculation is based on the provided input data using the configured | |
* CRC polynomial. | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
* | |
* @param[in] data | |
* Data to be written to the input data register. | |
******************************************************************************/ | |
__STATIC_INLINE void GPCRC_InputU8(GPCRC_TypeDef * gpcrc, uint8_t data) | |
{ | |
gpcrc->INPUTDATABYTE = data; | |
} | |
/***************************************************************************//** | |
* @brief | |
* Reads the data register of the CRC. | |
* | |
* @details | |
* Use this function to read the calculated CRC value. | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
* | |
* @return | |
* Content of the CRC data register. | |
******************************************************************************/ | |
__STATIC_INLINE uint32_t GPCRC_DataRead(GPCRC_TypeDef * gpcrc) | |
{ | |
return gpcrc->DATA; | |
} | |
/***************************************************************************//** | |
* @brief | |
* Reads the data register of the CRC bit reversed. | |
* | |
* @details | |
* Use this function to read the calculated CRC value bit reversed. When | |
* using a 32-bit polynomial then bits [31:0] are reversed, when using a | |
* 16-bit polynomial then bits [15:0] are reversed. | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
* | |
* @return | |
* Content of the CRC data register bit reversed. | |
******************************************************************************/ | |
__STATIC_INLINE uint32_t GPCRC_DataReadBitReversed(GPCRC_TypeDef * gpcrc) | |
{ | |
return gpcrc->DATAREV; | |
} | |
/***************************************************************************//** | |
* @brief | |
* Reads the data register of the CRC byte reversed. | |
* | |
* @details | |
* Use this function to read the calculated CRC value byte reversed. | |
* | |
* @param[in] gpcrc | |
* Pointer to GPCRC peripheral register block. | |
* | |
* @return | |
* Content of the CRC data register byte reversed. | |
******************************************************************************/ | |
__STATIC_INLINE uint32_t GPCRC_DataReadByteReversed(GPCRC_TypeDef * gpcrc) | |
{ | |
return gpcrc->DATABYTEREV; | |
} | |
/** @} (end addtogroup GPCRC) */ | |
/** @} (end addtogroup emlib) */ | |
#ifdef __cplusplus | |
} | |
#endif | |
#endif /* defined(GPCRC_COUNT) && (GPCRC_COUNT > 0) */ | |
#endif /* EM_GPCRC_H */ |