rtt-f030/bsp/stm32f0x/Libraries/STM32F0xx_StdPeriph_Driver/src/stm32f0xx_crc.c

289 lines
8.2 KiB
C

/**
******************************************************************************
* @file stm32f0xx_crc.c
* @author MCD Application Team
* @version V1.0.0
* @date 23-March-2012
* @brief This file provides firmware functions to manage the following
* functionalities of CRC computation unit peripheral:
* + Configuration of the CRC computation unit
* + CRC computation of one/many 32-bit data
* + CRC Independent register (IDR) access
*
* @verbatim
===============================================================================
##### How to use this driver #####
===============================================================================
[..]
(+) Enable CRC AHB clock using RCC_AHBPeriphClockCmd(RCC_AHBPeriph_CRC, ENABLE)
function
(+) If required, select the reverse operation on input data
using CRC_ReverseInputDataSelect()
(+) If required, enable the reverse operation on output data
using CRC_ReverseOutputDataCmd(Enable)
(+) use CRC_CalcCRC() function to compute the CRC of a 32-bit data
or use CRC_CalcBlockCRC() function to compute the CRC if a 32-bit
data buffer
(@) To compute the CRC of a new data use CRC_ResetDR() to reset
the CRC computation unit before starting the computation
otherwise you can get wrong CRC values.
@endverbatim
*
******************************************************************************
* @attention
*
* <h2><center>&copy; COPYRIGHT 2012 STMicroelectronics</center></h2>
*
* Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.st.com/software_license_agreement_liberty_v2
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "stm32f0xx_crc.h"
/** @addtogroup STM32F0xx_StdPeriph_Driver
* @{
*/
/** @defgroup CRC
* @brief CRC driver modules
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/** @defgroup CRC_Private_Functions
* @{
*/
/** @defgroup CRC_Group1 Configuration of the CRC computation unit functions
* @brief Configuration of the CRC computation unit functions
*
@verbatim
===============================================================================
##### CRC configuration functions #####
===============================================================================
@endverbatim
* @{
*/
/**
* @brief Deinitializes CRC peripheral registers to their default reset values.
* @param None
* @retval None
*/
void CRC_DeInit(void)
{
/* Set DR register to reset value */
CRC->DR = 0xFFFFFFFF;
/* Reset IDR register */
CRC->IDR = 0x00;
/* Set INIT register to reset value */
CRC->INIT = 0xFFFFFFFF;
/* Reset the CRC calculation unit */
CRC->CR = CRC_CR_RESET;
}
/**
* @brief Resets the CRC calculation unit and sets INIT register content in DR register.
* @param None
* @retval None
*/
void CRC_ResetDR(void)
{
/* Reset CRC generator */
CRC->CR = CRC_CR_RESET;
}
/**
* @brief Selects the reverse operation to be performed on input data.
* @param CRC_ReverseInputData: Specifies the reverse operation on input data.
* This parameter can be:
* @arg CRC_ReverseInputData_No: No reverse operation is performed
* @arg CRC_ReverseInputData_8bits: reverse operation performed on 8 bits
* @arg CRC_ReverseInputData_16bits: reverse operation performed on 16 bits
* @arg CRC_ReverseInputData_32bits: reverse operation performed on 32 bits
* @retval None
*/
void CRC_ReverseInputDataSelect(uint32_t CRC_ReverseInputData)
{
uint32_t tmpcr = 0;
/* Check the parameter */
assert_param(IS_CRC_REVERSE_INPUT_DATA(CRC_ReverseInputData));
/* Get CR register value */
tmpcr = CRC->CR;
/* Reset REV_IN bits */
tmpcr &= (uint32_t)~((uint32_t)CRC_CR_REV_IN);
/* Set the reverse operation */
tmpcr |= (uint32_t)CRC_ReverseInputData;
/* Write to CR register */
CRC->CR = (uint32_t)tmpcr;
}
/**
* @brief Enables or disable the reverse operation on output data.
* The reverse operation on output data is performed on 32-bit.
* @param NewState: new state of the reverse operation on output data.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void CRC_ReverseOutputDataCmd(FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable reverse operation on output data */
CRC->CR |= CRC_CR_REV_OUT;
}
else
{
/* Disable reverse operation on output data */
CRC->CR &= (uint32_t)~((uint32_t)CRC_CR_REV_OUT);
}
}
/**
* @brief Initializes the INIT register.
* @note After resetting CRC calculation unit, CRC_InitValue is stored in DR register
* @param CRC_InitValue: Programmable initial CRC value
* @retval None
*/
void CRC_SetInitRegister(uint32_t CRC_InitValue)
{
CRC->INIT = CRC_InitValue;
}
/**
* @}
*/
/** @defgroup CRC_Group2 CRC computation of one/many 32-bit data functions
* @brief CRC computation of one/many 32-bit data functions
*
@verbatim
===============================================================================
##### CRC computation functions #####
===============================================================================
@endverbatim
* @{
*/
/**
* @brief Computes the 32-bit CRC of a given data word(32-bit).
* @param CRC_Data: data word(32-bit) to compute its CRC
* @retval 32-bit CRC
*/
uint32_t CRC_CalcCRC(uint32_t CRC_Data)
{
CRC->DR = CRC_Data;
return (CRC->DR);
}
/**
* @brief Computes the 32-bit CRC of a given buffer of data word(32-bit).
* @param pBuffer: pointer to the buffer containing the data to be computed
* @param BufferLength: length of the buffer to be computed
* @retval 32-bit CRC
*/
uint32_t CRC_CalcBlockCRC(uint32_t pBuffer[], uint32_t BufferLength)
{
uint32_t index = 0;
for(index = 0; index < BufferLength; index++)
{
CRC->DR = pBuffer[index];
}
return (CRC->DR);
}
/**
* @brief Returns the current CRC value.
* @param None
* @retval 32-bit CRC
*/
uint32_t CRC_GetCRC(void)
{
return (CRC->DR);
}
/**
* @}
*/
/** @defgroup CRC_Group3 CRC Independent Register (IDR) access functions
* @brief CRC Independent Register (IDR) access (write/read) functions
*
@verbatim
===============================================================================
##### CRC Independent Register (IDR) access functions #####
===============================================================================
@endverbatim
* @{
*/
/**
* @brief Stores an 8-bit data in the Independent Data(ID) register.
* @param CRC_IDValue: 8-bit value to be stored in the ID register
* @retval None
*/
void CRC_SetIDRegister(uint8_t CRC_IDValue)
{
CRC->IDR = CRC_IDValue;
}
/**
* @brief Returns the 8-bit data stored in the Independent Data(ID) register
* @param None
* @retval 8-bit value of the ID register
*/
uint8_t CRC_GetIDRegister(void)
{
return (CRC->IDR);
}
/**
* @}
*/
/**
* @}
*/
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/