view Common/Drivers/STM32F4xx/Include/system_stm32f4xx.h @ 238:a9d798e8c11f div-fixes-5

cleanup, bugfix: do not mask I2C_SystemStatus with local variable This commit is partly cleanup, and partly possible bugfix. Masking the global I2C_SystemStatus with a local variable is (very) bad practice, but more importantly, dangerous, as other code uses this I2C_SystemStatus to base decisions on. So, this is definitely non-trivial, as it can possibly change the flow of control. This said, its tested and seems to have no negative effects (but also no positive, as I sort of hoped for), so that is why I mark it cleanup as well. Constructs like this shall be heavily documented in the code, when there is a reason to do things like this. Further, remove a 2nd rather useless construct. There is no reason to & 0x03 the output of I2C_SystemStatus. This is the only location in the entire code base where this is done, so, its not only useless but also inconsistent and confusing the true intentions here. Finally, littered to code with todo's that I will take care of in next commits. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
author Jan Mulder <jlmulder@xs4all.nl>
date Mon, 08 Apr 2019 10:16:17 +0200
parents c78bcbd5deda
children 4e10a3e087a1
line wrap: on
line source

/**
  ******************************************************************************
  * @file    system_stm32f4xx.h
  * @author  MCD Application Team
  * @brief   CMSIS Cortex-M4 Device System Source File for STM32F4xx devices.       
  ******************************************************************************  
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2017 STMicroelectronics</center></h2>
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************  
  */ 

/** @addtogroup CMSIS
  * @{
  */

/** @addtogroup stm32f4xx_system
  * @{
  */  
  
/**
  * @brief Define to prevent recursive inclusion
  */
#ifndef __SYSTEM_STM32F4XX_H
#define __SYSTEM_STM32F4XX_H

#ifdef __cplusplus
 extern "C" {
#endif 

/** @addtogroup STM32F4xx_System_Includes
  * @{
  */

/**
  * @}
  */


/** @addtogroup STM32F4xx_System_Exported_types
  * @{
  */
  /* This variable is updated in three ways:
      1) by calling CMSIS function SystemCoreClockUpdate()
      2) by calling HAL API function HAL_RCC_GetSysClockFreq()
      3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency 
         Note: If you use this function to configure the system clock; then there
               is no need to call the 2 first functions listed above, since SystemCoreClock
               variable is updated automatically.
  */
extern uint32_t SystemCoreClock;          /*!< System Clock Frequency (Core Clock) */

extern const uint8_t  AHBPrescTable[16];    /*!< AHB prescalers table values */
extern const uint8_t  APBPrescTable[8];     /*!< APB prescalers table values */

/**
  * @}
  */

/** @addtogroup STM32F4xx_System_Exported_Constants
  * @{
  */

/**
  * @}
  */

/** @addtogroup STM32F4xx_System_Exported_Macros
  * @{
  */

/**
  * @}
  */

/** @addtogroup STM32F4xx_System_Exported_Functions
  * @{
  */
  
extern void SystemInit(void);
extern void SystemCoreClockUpdate(void);
/**
  * @}
  */

#ifdef __cplusplus
}
#endif

#endif /*__SYSTEM_STM32F4XX_H */

/**
  * @}
  */
  
/**
  * @}
  */  
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/