stm32f0xx_flash.c

stm32f0固件库

/**
  ******************************************************************************
  * @file    stm32f0xx_flash.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 the FLASH peripheral:
  *            - FLASH Interface configuration
  *            - FLASH Memory Programming
  *            - Option Bytes Programming
  *            - Interrupts and flags management
  *
  *  @verbatim
 ===============================================================================
                    ##### How to use this driver #####
 ===============================================================================
    [..] This driver provides functions to configure and program the Flash 
         memory of all STM32F0xx devices. These functions are split in 4 groups
         (#) FLASH Interface configuration functions: this group includes the 
             management of following features:
             (++) Set the latency
             (++) Enable/Disable the prefetch buffer

         (#) FLASH Memory Programming functions: this group includes all needed 
             functions to erase and program the main memory:
             (++) Lock and Unlock the Flash interface.
             (++) Erase function: Erase Page, erase all pages.
             (++) Program functions: Half Word and Word write.

         (#) FLASH Option Bytes Programming functions: this group includes all 
             needed functions to:
             (++) Lock and Unlock the Flash Option bytes.
             (++) Launch the Option Bytes loader
             (++) Erase the Option Bytes
             (++)Set/Reset the write protection
             (++) Set the Read protection Level
             (++) Program the user option Bytes
             (++) Set/Reset the BOOT1 bit
             (++) Enable/Disable the VDDA Analog Monitoring
             (++) Get the user option bytes
             (++) Get the Write protection
             (++) Get the read protection status

         (#) FLASH Interrupts and flag management functions: this group includes 
             all needed functions to:
             (++) Enable/Disable the flash interrupt sources
             (++) Get flags status
             (++) Clear flags
             (++) Get Flash operation status
             (++) Wait for last flash operation

 @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_flash.h"

/** @addtogroup STM32F0xx_StdPeriph_Driver
  * @{
  */

/** @defgroup FLASH 
  * @brief FLASH driver modules
  * @{
  */ 

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
 
/** @defgroup FLASH_Private_Functions
  * @{
  */ 

/** @defgroup FLASH_Group1 FLASH Interface configuration functions
  *  @brief   FLASH Interface configuration functions 
 *
@verbatim   
 ===============================================================================
               ##### FLASH Interface configuration functions #####
 ===============================================================================

    [..] FLASH_Interface configuration_Functions, includes the following functions:
       (+) void FLASH_SetLatency(uint32_t FLASH_Latency):
    [..] To correctly read data from Flash memory, the number of wait states (LATENCY) 
     must be correctly programmed according to the frequency of the CPU clock (HCLK) 
    [..]
        +--------------------------------------------- +
        |  Wait states  |   HCLK clock frequency (MHz) |
        |---------------|------------------------------|
        |0WS(1CPU cycle)|       0 < HCLK <= 24         |
        |---------------|------------------------------|
        |1WS(2CPU cycle)|       24 < HCLK <= 48        |
        +----------------------------------------------+
    [..]
       (+) void FLASH_PrefetchBufferCmd(FunctionalState NewState);
    [..]
     All these functions don't need the unlock sequence.

@endverbatim
  * @{
  */

/**
  * @brief  Sets the code latency value.
  * @param  FLASH_Latency: specifies the FLASH Latency value.
  *   This parameter can be one of the following values:
  *     @arg FLASH_Latency_0: FLASH Zero Latency cycle
  *     @arg FLASH_Latency_1: FLASH One Latency cycle
  * @retval None
  */
void FLASH_SetLatency(uint32_t FLASH_Latency)
{
   uint32_t tmpreg = 0;

  /* Check the parameters */
  assert_param(IS_FLASH_LATENCY(FLASH_Latency));

  /* Read the ACR register */
  tmpreg = FLASH->ACR;  

  /* Sets the Latency value */
  tmpreg &= (uint32_t) (~((uint32_t)FLASH_ACR_LATENCY));
  tmpreg |= FLASH_Latency;

  /* Write the ACR register */
  FLASH->ACR = tmpreg;
}

/**
  * @brief  Enables or disables the Prefetch Buffer.
  * @param  NewState: new state of the FLASH prefetch buffer.
  *         This parameter can be: ENABLE or DISABLE. 
  * @retval None
  */
void FLASH_PrefetchBufferCmd(FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if(NewState != DISABLE)
  {
    FLASH->ACR |= FLASH_ACR_PRFTBE;
  }
  else
  {
    FLASH->ACR &= (uint32_t)(~((uint32_t)FLASH_ACR_PRFTBE));
  }
}

/**
  * @brief  Checks whether the FLASH Prefetch Buffer status is set or not.
  * @param  None
  * @retval FLASH Prefetch Buffer Status (SET or RESET).
  */
FlagStatus FLASH_GetPrefetchBufferStatus(void)
{
  FlagStatus bitstatus = RESET;

  if ((FLASH->ACR & FLASH_ACR_PRFTBS) != (uint32_t)RESET)
  {
    bitstatus = SET;
  }
  else
  {
    bitstatus = RESET;
  }
  /* Return the new state of FLASH Prefetch Buffer Status (SET or RESET) */
  return bitstatus; 
}

/**
  * @}
  */

/** @defgroup FLASH_Group2 FLASH Memory Programming functions
 *  @brief   FLASH Memory Programming functions
 *
@verbatim   
 ===============================================================================
                ##### FLASH Memory Programming functions #####
 ===============================================================================

    [..] The FLASH Memory Programming functions, includes the following functions:
       (+) void FLASH_Unlock(void);
       (+) void FLASH_Lock(void);
       (+) FLASH_Status FLASH_ErasePage(uint32_t Page_Address);
       (+) FLASH_Status FLASH_EraseAllPages(void);
       (+) FLASH_Status FLASH_ProgramWord(uint32_t Address, uint32_t Data);
       (+) FLASH_Status FLASH_ProgramHalfWord(uint32_t Address, uint16_t Data);

    [..] Any operation of erase or program should follow these steps:
       
       (#) Call the FLASH_Unlock() function to enable the flash control register and 
           program memory access
       (#) Call the desired function to erase page or program data
       (#) Call the FLASH_Lock() to disable the flash program memory access 
      (recommended to protect the FLASH memory against possible unwanted operation)

@endverbatim
  * @{
  */

/**
  * @brief  Unlocks the FLASH control register and program memory access.
  * @param  None
  * @retval None
  */
void FLASH_Unlock(void)
{
  if((FLASH->CR & FLASH_CR_LOCK) != RESET)
  {
    /* Unlocking the program memory access */
    FLASH->KEYR = FLASH_FKEY1;
    FLASH->KEYR = FLASH_FKEY2;
  }
}

/**
  * @brief  Locks the Program memory access.
  * @param  None
  * @retval None
  */
void FLASH_Lock(void)
{
  /* Set the LOCK Bit to lock the FLASH control register and program memory access */
  FLASH->CR |= FLASH_CR_LOCK;
}

/**
  * @brief  Erases a specified page in program memory.
  * @note    To correctly run this function, the FLASH_Unlock() function
  *           must be called before.
  *          Call the FLASH_Lock() to disable the flash memory access 
  *          (recommended to protect the FLASH memory against possible unwanted operation)
  * @param  Page_Address: The page address in program memory to be erased.
  * @note   A Page is erased in the Program memory only if the address to load 
  *         is the start address of a page (multiple of 1024 bytes).
  * @retval FLASH Status: The returned value can be: 
  *         FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_COMPLETE or FLASH_TIMEOUT.
  */
FLASH_Status FLASH_ErasePage(uint32_t Page_Address)
{
  FLASH_Status status = FLASH_COMPLETE;

  /* Check the parameters */
  assert_param(IS_FLASH_PROGRAM_ADDRESS(Page_Address));
 
  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(FLASH_ER_PRG_TIMEOUT);
  
  if(status == FLASH_COMPLETE)
  { 
    /* If the previous operation is completed, proceed to erase the page */
    FLASH->CR |= FLASH_CR_PER;
    FLASH->AR  = Page_Address;
    FLASH->CR |= FLASH_CR_STRT;
    
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(FLASH_ER_PRG_TIMEOUT);
    
    /* Disable the PER Bit */
    FLASH->CR &= ~FLASH_CR_PER;
  }
    
  /* Return the Erase Status */
  return status;
}

/**
  * @brief  Erases all FLASH pages.
  * @note    To correctly run this function, the FLASH_Unlock() function
  *           must be called before.
  *          Call the FLASH_Lock() to disable the flash memory access 
  *          (recommended to protect the FLASH memory against possible unwanted operation)
  * @param  None
  * @retval FLASH Status: The returned value can be: FLASH_ERROR_PG,
  *         FLASH_ERROR_WRP, FLASH_COMPLETE or FLASH_TIMEOUT.
  */
FLASH_Status FLASH_EraseAllPages(void)
{
  FLASH_Status status = FLASH_COMPLETE;

  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(FLASH_ER_PRG_TIMEOUT);
  
  if(status == FLASH_COMPLETE)
  {
    /* if the previous operation is completed, proceed to erase all pages */
     FLASH->CR |= FLASH_CR_MER;
     FLASH->CR |= FLASH_CR_STRT;
    
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(FLASH_ER_PRG_TIMEOUT);

    /* Disable the MER Bit */
    FLASH->CR &= ~FLASH_CR_MER;
  }

  /* Return the Erase Status */
  return status;
}

/**
  * @brief  Programs a word at a specified address.
  * @note    To correctly run this function, the FLASH_Unlock() function
  *           must be called before.
  *          Call the FLASH_Lock() to disable the flash memory access 
  *          (recommended to protect the FLASH memory against possible unwanted operation)
  * @param  Address: specifies the address to be programmed.
  * @param  Data: specifies the data to be programmed.
  * @retval FLASH Status: The returned value can be: FLASH_ERROR_PG,
  *         FLASH_ERROR_WRP, FLASH_COMPLETE or FLASH_TIMEOUT. 
  */
FLASH_Status FLASH_ProgramWord(uint32_t Address, uint32_t Data)
{
  FLASH_Status status = FLASH_COMPLETE;
  __IO uint32_t tmp = 0;

  /* Check the parameters */
  assert_param(IS_FLASH_PROGRAM_ADDRESS(Address));

  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(FLASH_ER_PRG_TIMEOUT);
  
  if(status == FLASH_COMPLETE)
  {
    /* If the previous operation is completed, proceed to program the new first 
    half word */
    FLASH->CR |= FLASH_CR_PG;
  
    *(__IO uint16_t*)Address = (uint16_t)Data;
    
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(FLASH_ER_PRG_TIMEOUT);
 
    if(status == FLASH_COMPLETE)
    {
      /* If the previous operation is completed, proceed to program the new second 
      half word */
      tmp = Address + 2;

      *(__IO uint16_t*) tmp = Data >> 16;
    
      /* Wait for last operation to be completed */
      status = FLASH_WaitForLastOperation(FLASH_ER_PRG_TIMEOUT);
        
      /* Disable the PG Bit */
      FLASH->CR &= ~FLASH_CR_PG;
    }
    else
    {
      /* Disable the PG Bit */
      FLASH->CR &= ~FLASH_CR_PG;
    }
  }
   
  /* Return the Program Status */
  return status;
}

/**
  * @brief  Programs a half word at a specified address.
  * @note    To correctly run this function, the FLASH_Unlock() function
  *           must be called before.
  *          Call the FLASH_Lock() to disable the flash memory access 
  *          (recommended to protect the FLASH memory against possible unwanted operation)
  * @param  Address: specifies the address to be programmed.