STM32F0xx Standard Peripherals Firmware Library: main.c Source File

00001 /**
00002   ******************************************************************************
00003   * @file    CRC/CRC_8BitsCRCMessage/main.c 
00004   * @author  MCD Application Team
00005   * @version V1.4.0
00006   * @date    24-July-2014
00007   * @brief   Main program body
00008   ******************************************************************************
00009   * @attention
00010   *
00011   * <h2><center>&copy; COPYRIGHT 2014 STMicroelectronics</center></h2>
00012   *
00013   * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
00014   * You may not use this file except in compliance with the License.
00015   * You may obtain a copy of the License at:
00016   *
00017   *        http://www.st.com/software_license_agreement_liberty_v2
00018   *
00019   * Unless required by applicable law or agreed to in writing, software 
00020   * distributed under the License is distributed on an "AS IS" BASIS, 
00021   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00022   * See the License for the specific language governing permissions and
00023   * limitations under the License.
00024   *
00025   ******************************************************************************
00026   */
00027 
00028 
00029 /* Includes ------------------------------------------------------------------*/
00030 #include "main.h"
00031 
00032 /** @addtogroup STM32F0xx_StdPeriph_Examples
00033   * @{
00034   */
00035 
00036 /** @addtogroup CRC_8BitsCRCMessage
00037   * @{
00038   */
00039 
00040 /* Private typedef -----------------------------------------------------------*/
00041 /* Private define ------------------------------------------------------------*/
00042 #define countof(a)             (uint8_t)(sizeof(a) / sizeof(*(a)))
00043 #define BUFFER_SIZE            (countof(CRCBuffer) - 1)
00044 
00045 /* Private macro -------------------------------------------------------------*/
00046 /* Private variables ---------------------------------------------------------*/
00047 uint8_t CRCBuffer[] = "STM32F0xx CortexM0 Device running on STM32072B-EVAL";
00048 uint8_t ComputedCRC = 0;
00049 uint8_t ExpectedCRC = 0xAF; /* The expected CRC value of CRCBuffer using the
00050                                polynomial x8 + x7 + x6 + x4 + x2 + 1.
00051                                This value is already computed using on-line CRC tool */
00052 
00053 /* Private function prototypes -----------------------------------------------*/
00054 static void CRC_Config(uint8_t poly);
00055 static uint8_t CRC_8BitsCompute(uint8_t* data, uint32_t size);
00056 
00057 /* Private functions ---------------------------------------------------------*/
00058 
00059 /**
00060   * @brief  Main program.
00061   * @param  None
00062   * @retval None
00063   */
00064 int main(void)
00065 {
00066   /*!< At this stage the microcontroller clock setting is already configured, 
00067        this is done through SystemInit() function which is called from startup
00068        file (startup_stm32f0xx.s) before to branch to application main.
00069        To reconfigure the default setting of SystemInit() function, refer to
00070        system_stm32f0xx.c file
00071      */
00072 
00073   /* Initialize LEDs available on STM32072B-EVAL board */
00074   STM_EVAL_LEDInit(LED1);
00075   STM_EVAL_LEDInit(LED3);
00076 
00077   /* Configure the CRC peripheral to use the polynomial x8 + x7 + x6 + x4 + x2 + 1 */
00078   CRC_Config(0xD5);
00079 
00080   /* Compute the CRC value of the 8-bit buffer: CRCBuffer */
00081   ComputedCRC = CRC_8BitsCompute(CRCBuffer, BUFFER_SIZE);
00082 
00083   /* Check if the computed CRC matches the expected one */
00084   if (ComputedCRC != ExpectedCRC)
00085   {
00086     /* Turn on LD3 */
00087     STM_EVAL_LEDOn(LED3);
00088   }
00089   else
00090   {
00091     /* Turn on LD1 */
00092     STM_EVAL_LEDOn(LED1);
00093   }
00094   
00095   /* Infinite loop */
00096   while(1)
00097   {
00098   }
00099 }
00100 
00101 /**
00102   * @brief  Configure CRC peripheral to use 8-bit polynomials
00103   * @param  poly: the CRC polynomial
00104   * @retval None
00105   */
00106 static void CRC_Config(uint8_t poly)
00107 {
00108   /* Enable CRC AHB clock interface */
00109   RCC_AHBPeriphClockCmd(RCC_AHBPeriph_CRC, ENABLE);
00110 
00111   /* DeInit CRC peripheral */
00112   CRC_DeInit();
00113   
00114   /* Init the INIT register */
00115   CRC_SetInitRegister(0);
00116   
00117   /* Select 8-bit polynomial size */
00118   CRC_PolynomialSizeSelect(CRC_PolSize_8);
00119   
00120   /* Set the polynomial coefficients */
00121   CRC_SetPolynomial(poly);
00122 }
00123 
00124 /**
00125   * @brief  Compute CRC value for input message
00126   * @param  data: pointer at uint8_t
00127   * @param  size: the size of the input message
00128   * @retval The computed CRC value
00129   */
00130 static uint8_t CRC_8BitsCompute(uint8_t* data, uint32_t size)
00131 {
00132   uint8_t* dataEnd = data+size;
00133 
00134   /* Reset CRC data register to avoid overlap when computing new data stream */
00135   CRC_ResetDR();
00136 
00137   while(data < dataEnd)
00138   {
00139     /* Write the input data in the CRC data register */
00140     CRC_CalcCRC8bits(*data++);
00141   }
00142   /* Return the CRC value */
00143   return (uint8_t)CRC_GetCRC();
00144 }
00145 
00146 #ifdef  USE_FULL_ASSERT
00147 
00148 /**
00149   * @brief  Reports the name of the source file and the source line number
00150   *         where the assert_param error has occurred.
00151   * @param  file: pointer to the source file name
00152   * @param  line: assert_param error line source number
00153   * @retval None
00154   */
00155 void assert_failed(uint8_t* file, uint32_t line)
00156 { 
00157   /* User can add his own implementation to report the file name and line number,
00158      ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
00159 
00160   /* Infinite loop */
00161   while (1)
00162   {
00163   }
00164 }
00165 #endif
00166 
00167 /**
00168   * @}
00169   */
00170 
00171 /**
00172   * @}
00173   */
00174 
00175 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/