stm32f10x_flash.c

#include "stm32f10x_flash.h"

/* Flash Access Control Register bits */
#define ACR_LATENCY_Mask         ((uint32_t)0x00000038)
#define ACR_HLFCYA_Mask          ((uint32_t)0xFFFFFFF7)
#define ACR_PRFTBE_Mask          ((uint32_t)0xFFFFFFEF)

/* Flash Access Control Register bits */
#define ACR_PRFTBS_Mask          ((uint32_t)0x00000020) 

/* Flash Control Register bits */
#define CR_PG_Set                ((uint32_t)0x00000001)
#define CR_PG_Reset              ((uint32_t)0x00001FFE) 
#define CR_PER_Set               ((uint32_t)0x00000002)
#define CR_PER_Reset             ((uint32_t)0x00001FFD)
#define CR_MER_Set               ((uint32_t)0x00000004)
#define CR_MER_Reset             ((uint32_t)0x00001FFB)
#define CR_OPTPG_Set             ((uint32_t)0x00000010)
#define CR_OPTPG_Reset           ((uint32_t)0x00001FEF)
#define CR_OPTER_Set             ((uint32_t)0x00000020)
#define CR_OPTER_Reset           ((uint32_t)0x00001FDF)
#define CR_STRT_Set              ((uint32_t)0x00000040)
#define CR_LOCK_Set              ((uint32_t)0x00000080)

/* FLASH Mask */
#define RDPRT_Mask               ((uint32_t)0x00000002)
#define WRP0_Mask                ((uint32_t)0x000000FF)
#define WRP1_Mask                ((uint32_t)0x0000FF00)
#define WRP2_Mask                ((uint32_t)0x00FF0000)
#define WRP3_Mask                ((uint32_t)0xFF000000)

/* FLASH Keys */
#define RDP_Key                  ((uint16_t)0x00A5)
#define FLASH_KEY1               ((uint32_t)0x45670123)
#define FLASH_KEY2               ((uint32_t)0xCDEF89AB)

/* Delay definition */   
#define EraseTimeout             ((uint32_t)0x00000FFF)
#define ProgramTimeout           ((uint32_t)0x0000000F)

static void delay(void);

/*
 * 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
 * @arg FLASH_Latency_2: FLASH Two Latency cycles
 * @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 &= ACR_LATENCY_Mask;
  tmpreg |= FLASH_Latency;
  
  /* Write the ACR register */
  FLASH->ACR = tmpreg;
}

/*
 * Enables or disables the Half cycle flash access.
 * @param FLASH_HalfCycleAccess: specifies the FLASH Half cycle Access mode.
 *   This parameter can be one of the following values:
 * @arg FLASH_HalfCycleAccess_Enable: FLASH Half Cycle Enable
 * @arg FLASH_HalfCycleAccess_Disable: FLASH Half Cycle Disable
 * @retval : None
 */
void FLASH_HalfCycleAccessCmd(uint32_t FLASH_HalfCycleAccess)
{
  /* Check the parameters */
  assert_param(IS_FLASH_HALFCYCLEACCESS_STATE(FLASH_HalfCycleAccess));
  
  /* Enable or disable the Half cycle access */
  FLASH->ACR &= ACR_HLFCYA_Mask;
  FLASH->ACR |= FLASH_HalfCycleAccess;
}

/*
 * Enables or disables the Prefetch Buffer.
 * @param FLASH_PrefetchBuffer: specifies the Prefetch buffer status.
 *   This parameter can be one of the following values:
 * @arg FLASH_PrefetchBuffer_Enable: FLASH Prefetch Buffer Enable
 * @arg FLASH_PrefetchBuffer_Disable: FLASH Prefetch Buffer Disable
 * @retval : None
 */
void FLASH_PrefetchBufferCmd(uint32_t FLASH_PrefetchBuffer)
{
  /* Check the parameters */
  assert_param(IS_FLASH_PREFETCHBUFFER_STATE(FLASH_PrefetchBuffer));
  
  /* Enable or disable the Prefetch Buffer */
  FLASH->ACR &= ACR_PRFTBE_Mask;
  FLASH->ACR |= FLASH_PrefetchBuffer;
}

/*
 * Unlocks the FLASH Program Erase Controller.
 * @param  None
 * @retval : None
 */
void FLASH_Unlock(void)
{
  /* Authorize the FPEC Access */
  FLASH->KEYR = FLASH_KEY1;
  FLASH->KEYR = FLASH_KEY2;
}

/*
 * Locks the FLASH Program Erase Controller.
 * @param  None
 * @retval : None
 */
void FLASH_Lock(void)
{
  /* Set the Lock Bit to lock the FPEC and the FCR */
  FLASH->CR |= CR_LOCK_Set;
}

/*
 * Erases a specified FLASH page.
 * @param Page_Address: The page address to be erased.
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   FLASH_ERROR_PG, 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_ADDRESS(Page_Address));
  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(EraseTimeout);
  
  if (status == FLASH_COMPLETE) { 
    /* if the previous operation is completed, proceed to erase the page */
    FLASH->CR|= CR_PER_Set;
    FLASH->AR = Page_Address; 
    FLASH->CR|= CR_STRT_Set;
    
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(EraseTimeout);

    if (status != FLASH_BUSY) {
      /* if the erase operation is completed, disable the PER Bit */
      FLASH->CR &= CR_PER_Reset;
    } /* if (status != FLASH_BUSY) */

  } /* if (status == FLASH_COMPLETE) */

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

/*
 * Erases all FLASH pages.
 * @param  None
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   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(EraseTimeout);
  
  if (status == FLASH_COMPLETE) {
    /* if the previous operation is completed, proceed to erase all pages */
    FLASH->CR |= CR_MER_Set;
    FLASH->CR |= CR_STRT_Set;
    
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(EraseTimeout);

    if( status != FLASH_BUSY) {
      /* if the erase operation is completed, disable the MER Bit */
      FLASH->CR &= CR_MER_Reset;
    } /* if (status != FLASH_BUSY) */

  } /* if (status == FLASH_COMPLETE) */
   
  /* Return the Erase Status */
  return status;
}

/*
 * Erases the FLASH option bytes.
 * @param  None
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   FLASH_ERROR_PG, FLASH_ERROR_WRP, FLASH_COMPLETE or 
 *   FLASH_TIMEOUT.
 */
FLASH_Status FLASH_EraseOptionBytes(void)
{
  FLASH_Status status = FLASH_COMPLETE;
  
  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(EraseTimeout);

  if (status == FLASH_COMPLETE) {

    /* Authorize the small information block programming */
    FLASH->OPTKEYR = FLASH_KEY1;
    FLASH->OPTKEYR = FLASH_KEY2;
    
    /* 
     * if the previous operation is completed, 
     * proceed to erase the option bytes 
     */
    FLASH->CR |= CR_OPTER_Set;
    FLASH->CR |= CR_STRT_Set;

    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(EraseTimeout);
    
    if (status == FLASH_COMPLETE) {

      /* if the erase operation is completed, disable the OPTER Bit */
      FLASH->CR &= CR_OPTER_Reset;
       
      /* Enable the Option Bytes Programming operation */
      FLASH->CR |= CR_OPTPG_Set;
      /* Enable the readout access */
      OB->RDP= RDP_Key; 
      /* Wait for last operation to be completed */
      status = FLASH_WaitForLastOperation(ProgramTimeout);
 
      if (status != FLASH_BUSY) {
        /* if the program operation is completed, disable the OPTPG Bit */
        FLASH->CR &= CR_OPTPG_Reset;
      } /* if (status != FLASH_BUSY) */

    } else { /* if (status == FLASH_COMPLETE) */

      if (status != FLASH_BUSY) {
        /* Disable the OPTPG Bit */
        FLASH->CR &= CR_OPTPG_Reset;
      } /* if (status != FLASH_BUSY) */

    } /* if (status == FLASH_COMPLETE) */

  } /* if (status == FLASH_COMPLETE) */

  /* Return the erase status */
  return status;
}

/*
 * Programs a word at a specified address.
 * @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_BUSY, 
 *   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;
  /* Check the parameters */
  assert_param(IS_FLASH_ADDRESS(Address));
  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(ProgramTimeout);
  
  if (status == FLASH_COMPLETE) {

    /* 
     * if the previous operation is completed, proceed to program 
     * the new first half word 
     */
    FLASH->CR |= CR_PG_Set;
  
    *(__IO uint16_t*)Address = (uint16_t)Data;
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(ProgramTimeout);
 
    if (status == FLASH_COMPLETE) {
      /* 
       * if the previous operation is completed, proceed to program 
       * the new second half word 
       */
      *(__IO uint16_t*)(Address + 2) = Data >> 16;
      
      /* Wait for last operation to be completed */
      status = FLASH_WaitForLastOperation(ProgramTimeout);
        
      if (status != FLASH_BUSY) {
        /* Disable the PG Bit */
        FLASH->CR &= CR_PG_Reset;
      } /* if (status != FLASH_BUSY) */

    } else { /* if (status == FLASH_COMPLETE) */

      if (status != FLASH_BUSY) {
        /* Disable the PG Bit */
        FLASH->CR &= CR_PG_Reset;
      } /* if (status != FLASH_BUSY) */

    } /* if (status == FLASH_COMPLETE) */

  } /* if (status == FLASH_COMPLETE) */

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

/*
 * Programs a half word at a specified address.
 * @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_BUSY, 
 *   FLASH_ERROR_PG, FLASH_ERROR_WRP, FLASH_COMPLETE or 
 *   FLASH_TIMEOUT. 
 */
FLASH_Status FLASH_ProgramHalfWord(uint32_t Address, uint16_t Data)
{
  FLASH_Status status = FLASH_COMPLETE;

  /* Check the parameters */
  assert_param(IS_FLASH_ADDRESS(Address));
  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(ProgramTimeout);
  
  if (status == FLASH_COMPLETE) {
    /*
     * if the previous operation is completed, 
     * proceed to program the new data 
     */
    FLASH->CR |= CR_PG_Set;
  
    *(__IO uint16_t*)Address = Data;
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(ProgramTimeout);

    if (status != FLASH_BUSY) {
      /* if the program operation is completed, disable the PG Bit */
      FLASH->CR &= CR_PG_Reset;
    } /* if (status != FLASH_BUSY) */

  } /* if (status == FLASH_COMPLETE) */

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

/*
 * Programs a half word at a specified Option Byte Data address.
 * @param Address: specifies the address to be programmed.
 *   This parameter can be 0x1FFFF804 or 0x1FFFF806. 
 * @param Data: specifies the data to be programmed.
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   FLASH_ERROR_PG, FLASH_ERROR_WRP, FLASH_COMPLETE or 
 *   FLASH_TIMEOUT. 
 */
FLASH_Status FLASH_ProgramOptionByteData(uint32_t Address, uint8_t Data)
{
  FLASH_Status status = FLASH_COMPLETE;

  /* Check the parameters */
  assert_param(IS_OB_DATA_ADDRESS(Address));
  status = FLASH_WaitForLastOperation(ProgramTimeout);

  if (status == FLASH_COMPLETE) {

    /* Authorize the small information block programming */
    FLASH->OPTKEYR = FLASH_KEY1;
    FLASH->OPTKEYR = FLASH_KEY2;
    /* Enables the Option Bytes Programming operation */
    FLASH->CR |= CR_OPTPG_Set; 
    *(__IO uint16_t*)Address = Data;
    
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(ProgramTimeout);

    if (status != FLASH_BUSY) {
      /* if the program operation is completed, disable the OPTPG Bit */
      FLASH->CR &= CR_OPTPG_Reset;
    } /* if (status != FLASH_BUSY) */

  } /* if (status == FLASH_COMPLETE) */

  /* Return the Option Byte Data Program Status */
  return status;
}

/*
 * Write protects the desired pages
 * @param FLASH_Pages: specifies the address of the pages to be 
 *   write protected. This parameter can be:
 * @arg For STM32F10Xxx Medium-density devices (FLASH page size equal to 1 KB)
 * A value between FLASH_WRProt_Pages0to3 and FLASH_WRProt_Pages124to127
 * @arg For STM32F10Xxx High-density devices (FLASH page size equal to 2 KB) 
 * A value between FLASH_WRProt_Pages0to1 and  FLASH_WRProt_Pages60to61 
 * or FLASH_WRProt_Pages62to255 
 * @arg FLASH_WRProt_AllPages
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   FLASH_ERROR_PG, FLASH_ERROR_WRP, FLASH_COMPLETE or 
 *   FLASH_TIMEOUT.
 */
FLASH_Status FLASH_EnableWriteProtection(uint32_t FLASH_Pages)
{
  uint16_t WRP0_Data, WRP1_Data, WRP2_Data, WRP3_Data;
  FLASH_Status status;

  status = FLASH_COMPLETE;

  WRP0_Data = 0xFFFF;
  WRP1_Data = 0xFFFF;
  WRP2_Data = 0xFFFF;
  WRP3_Data = 0xFFFF;
  
  /* Check the parameters */
  assert_param(IS_FLASH_WRPROT_PAGE(FLASH_Pages));
  
  FLASH_Pages = (uint32_t)(~FLASH_Pages);
  WRP0_Data = (uint16_t)(FLASH_Pages & WRP0_Mask);
  WRP1_Data = (uint16_t)((FLASH_Pages & WRP1_Mask) >> 8);
  WRP2_Data = (uint16_t)((FLASH_Pages & WRP2_Mask) >> 16);
  WRP3_Data = (uint16_t)((FLASH_Pages & WRP3_Mask) >> 24);
  
  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(ProgramTimeout);
  
  if (status == FLASH_COMPLETE) {

    /* Authorizes the small information block programming */
    FLASH->OPTKEYR = FLASH_KEY1;
    FLASH->OPTKEYR = FLASH_KEY2;
    FLASH->CR |= CR_OPTPG_Set;

    if (WRP0_Data != 0xFF) {
      OB->WRP0 = WRP0_Data;
      
      /* Wait for last operation to be completed */
      status = FLASH_WaitForLastOperation(ProgramTimeout);
    } /* if (WRP0_Data != 0xFF) */

    if ((status == FLASH_COMPLETE) && (WRP1_Data != 0xFF)) {
      OB->WRP1 = WRP1_Data;
      
      /* Wait for last operation to be completed */
      status = FLASH_WaitForLastOperation(ProgramTimeout);
    } /* if ((status == FLASH_COMPLETE) && (WRP1_Data != 0xFF)) */

    if ((status == FLASH_COMPLETE) && (WRP2_Data != 0xFF)) {
      OB->WRP2 = WRP2_Data;
      
      /* Wait for last operation to be completed */
      status = FLASH_WaitForLastOperation(ProgramTimeout);
    } /* if ((status == FLASH_COMPLETE) && (WRP2_Data != 0xFF)) */
    
    if ((status == FLASH_COMPLETE)&& (WRP3_Data != 0xFF)) {
      OB->WRP3 = WRP3_Data;
     
      /* Wait for last operation to be completed */
      status = FLASH_WaitForLastOperation(ProgramTimeout);
    } /* if ((status == FLASH_COMPLETE)&& (WRP3_Data != 0xFF)) */
          
    if (status != FLASH_BUSY) {
      /* if the program operation is completed, disable the OPTPG Bit */
      FLASH->CR &= CR_OPTPG_Reset;
    } /* if (status != FLASH_BUSY) */

  }  /* if (status == FLASH_COMPLETE) */  

  /* Return the write protection operation Status */
  return status;       
}

/*
 * Enables or disables the read out protection.
 *   If the user has already programmed the other option bytes before 
 *   calling this function, he must re-program them since this 
 *   function erases all option bytes.
 * @param Newstate: new state of the ReadOut Protection.
 *   This parameter can be: ENABLE or DISABLE.
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   FLASH_ERROR_PG, FLASH_ERROR_WRP, FLASH_COMPLETE or 
 *   FLASH_TIMEOUT.
 */
FLASH_Status FLASH_ReadOutProtection(FunctionalState NewState)
{
  FLASH_Status status = FLASH_COMPLETE;

  /* Check the parameters */
  assert_param(IS_FUNCTIONAL_STATE(NewState));
  status = FLASH_WaitForLastOperation(EraseTimeout);

  if (status == FLASH_COMPLETE) {

    /* Authorizes the small information block programming */
    FLASH->OPTKEYR = FLASH_KEY1;
    FLASH->OPTKEYR = FLASH_KEY2;
    FLASH->CR |= CR_OPTER_Set;
    FLASH->CR |= CR_STRT_Set;

    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(EraseTimeout);

    if (status == FLASH_COMPLETE) {

      /* if the erase operation is completed, disable the OPTER Bit */
      FLASH->CR &= CR_OPTER_Reset;
      /* Enable the Option Bytes Programming operation */
      FLASH->CR |= CR_OPTPG_Set; 

      if (NewState != DISABLE) {
        OB->RDP = 0x00;
      } else { /* if (NewState != DISABLE) */
        OB->RDP = RDP_Key;  
      } /* if (NewState != DISABLE) */

      /* Wait for last operation to be completed */
      status = FLASH_WaitForLastOperation(EraseTimeout); 
    
      if (status != FLASH_BUSY) {
        /* if the program operation is completed, disable the OPTPG Bit */
        FLASH->CR &= CR_OPTPG_Reset;
      } /* if (status != FLASH_BUSY) */

    } else { /* if (status == FLASH_COMPLETE) */

      if (status != FLASH_BUSY) {
        /* Disable the OPTER Bit */
        FLASH->CR &= CR_OPTER_Reset;
      } /* if (status != FLASH_BUSY) */

    } /* if (status == FLASH_COMPLETE) */

  } /* if (status == FLASH_COMPLETE) */

  /* Return the protection operation Status */
  return status;      
}

/*
 * Programs the FLASH User Option Byte: IWDG_SW / RST_STOP /
 *   RST_STDBY.
 * @param OB_IWDG: Selects the IWDG mode
 *   This parameter can be one of the following values:
 * @arg OB_IWDG_SW: Software IWDG selected
 * @arg OB_IWDG_HW: Hardware IWDG selected
 * @param OB_STOP: Reset event when entering STOP mode.
 *   This parameter can be one of the following values:
 * @arg OB_STOP_NoRST: No reset generated when entering in STOP
 * @arg OB_STOP_RST: Reset generated when entering in STOP
 * @param OB_STDBY: Reset event when entering Standby mode.
 *   This parameter can be one of the following values:
 * @arg OB_STDBY_NoRST: No reset generated when entering in STANDBY
 * @arg OB_STDBY_RST: Reset generated when entering in STANDBY
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   FLASH_ERROR_PG, FLASH_ERROR_WRP, FLASH_COMPLETE or 
 *   FLASH_TIMEOUT.
 */
FLASH_Status FLASH_UserOptionByteConfig(uint16_t OB_IWDG, uint16_t OB_STOP, 
					uint16_t OB_STDBY)
{
  FLASH_Status status = FLASH_COMPLETE; 

  /* Check the parameters */
  assert_param(IS_OB_IWDG_SOURCE(OB_IWDG));
  assert_param(IS_OB_STOP_SOURCE(OB_STOP));
  assert_param(IS_OB_STDBY_SOURCE(OB_STDBY));

  /* Authorize the small information block programming */
  FLASH->OPTKEYR = FLASH_KEY1;
  FLASH->OPTKEYR = FLASH_KEY2;
  
  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(ProgramTimeout);
  
  if (status == FLASH_COMPLETE) {  

    /* Enable the Option Bytes Programming operation */
    FLASH->CR |= CR_OPTPG_Set; 
           
    OB->USER = ( OB_IWDG | OB_STOP |OB_STDBY) | (uint16_t)0xF8; 
  
    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(ProgramTimeout);

    if (status != FLASH_BUSY) {
      /* if the program operation is completed, disable the OPTPG Bit */
      FLASH->CR &= CR_OPTPG_Reset;
    } /* if (status != FLASH_BUSY) */

  } /* if (status == FLASH_COMPLETE) */

  /* Return the Option Byte program Status */
  return status;
}

/*
 * Returns the FLASH User Option Bytes values.
 * @param  None
 * @retval : The FLASH User Option Bytes values:IWDG_SW(Bit0), RST_STOP(Bit1)
 *   and RST_STDBY(Bit2).
 */
uint32_t FLASH_GetUserOptionByte(void)
{
  /* Return the User Option Byte */
  return (uint32_t)(FLASH->OBR >> 2);
}

/*
 * Returns the FLASH Write Protection Option Bytes Register value.
 * @param  None
 * @retval : The FLASH Write Protection  Option Bytes Register value
 */
uint32_t FLASH_GetWriteProtectionOptionByte(void)
{
  /* Return the Falsh write protection Register value */
  return (uint32_t)(FLASH->WRPR);
}

/*
 * Checks whether the FLASH Read Out Protection Status is set 
 *   or not.
 * @param  None
 * @retval : FLASH ReadOut Protection Status(SET or RESET)
 */
FlagStatus FLASH_GetReadOutProtectionStatus(void)
{
  FlagStatus readoutstatus = RESET;

  if ((FLASH->OBR & RDPRT_Mask) != (uint32_t)RESET) {
    readoutstatus = SET;
  } else { /* if ((FLASH->OBR & RDPRT_Mask) != (uint32_t)RESET) */
    readoutstatus = RESET;
  } /* if ((FLASH->OBR & RDPRT_Mask) != (uint32_t)RESET) */

  return readoutstatus;
}

/*
 * 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 & ACR_PRFTBS_Mask) != (uint32_t)RESET) {
    bitstatus = SET;
  } else { /* if ((FLASH->ACR & ACR_PRFTBS_Mask) != (uint32_t)RESET) */
    bitstatus = RESET;
  } /* if ((FLASH->ACR & ACR_PRFTBS_Mask) != (uint32_t)RESET) */

  /* Return the new state of FLASH Prefetch Buffer Status (SET or RESET) */
  return bitstatus; 
}

/*
 * Enables or disables the specified FLASH interrupts.
 * @param FLASH_IT: specifies the FLASH interrupt sources to be 
 *   enabled or disabled.
 *   This parameter can be any combination of the following values:
 * @arg FLASH_IT_ERROR: FLASH Error Interrupt
 * @arg FLASH_IT_EOP: FLASH end of operation Interrupt
 * @param NewState: new state of the specified Flash interrupts.
 *   This parameter can be: ENABLE or DISABLE.      
 * @retval : None 
 */
void FLASH_ITConfig(uint16_t FLASH_IT, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_FLASH_IT(FLASH_IT)); 
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE) {
    /* Enable the interrupt sources */
    FLASH->CR |= FLASH_IT;
  } else { /* if (NewState != DISABLE) */
    /* Disable the interrupt sources */
    FLASH->CR &= ~(uint32_t)FLASH_IT;
  }  /* if (NewState != DISABLE) */
}

/*
 * Checks whether the specified FLASH flag is set or not.
 * @param FLASH_FLAG: specifies the FLASH flag to check.
 *   This parameter can be one of the following values:
 * @arg FLASH_FLAG_BSY: FLASH Busy flag           
 * @arg FLASH_FLAG_PGERR: FLASH Program error flag       
 * @arg FLASH_FLAG_WRPRTERR: FLASH Write protected error flag      
 * @arg FLASH_FLAG_EOP: FLASH End of Operation flag           
 * @arg FLASH_FLAG_OPTERR:  FLASH Option Byte error flag     
 * @retval : The new state of FLASH_FLAG (SET or RESET).
 */
FlagStatus FLASH_GetFlagStatus(uint16_t FLASH_FLAG)
{
  FlagStatus bitstatus = RESET;

  /* Check the parameters */
  assert_param(IS_FLASH_GET_FLAG(FLASH_FLAG)) ;

  if (FLASH_FLAG == FLASH_FLAG_OPTERR) {

    if ((FLASH->OBR & FLASH_FLAG_OPTERR) != (uint32_t)RESET) {
      bitstatus = SET;
    } else { /* if ((FLASH->OBR & FLASH_FLAG_OPTERR) != (uint32_t)RESET) */
      bitstatus = RESET;
    } /* if ((FLASH->OBR & FLASH_FLAG_OPTERR) != (uint32_t)RESET) */

  } else { /* if (FLASH_FLAG == FLASH_FLAG_OPTERR) */

    if ((FLASH->SR & FLASH_FLAG) != (uint32_t)RESET) {
      bitstatus = SET;
    } else { /* if ((FLASH->SR & FLASH_FLAG) != (uint32_t)RESET) */
      bitstatus = RESET;
    } /* if ((FLASH->SR & FLASH_FLAG) != (uint32_t)RESET) */

  } /* if (FLASH_FLAG == FLASH_FLAG_OPTERR) */

  /* Return the new state of FLASH_FLAG (SET or RESET) */
  return bitstatus;
}

/*
 * Clears the FLASHs pending flags.
 * @param FLASH_FLAG: specifies the FLASH flags to clear.
 *   This parameter can be any combination of the following values:
 * @arg FLASH_FLAG_BSY: FLASH Busy flag           
 * @arg FLASH_FLAG_PGERR: FLASH Program error flag       
 * @arg FLASH_FLAG_WRPRTERR: FLASH Write protected error flag      
 * @arg FLASH_FLAG_EOP: FLASH End of Operation flag           
 * @retval : None
 */
void FLASH_ClearFlag(uint16_t FLASH_FLAG)
{
  /* Check the parameters */
  assert_param(IS_FLASH_CLEAR_FLAG(FLASH_FLAG)) ;
  
  /* Clear the flags */
  FLASH->SR = FLASH_FLAG;
}

/*
 * Returns the FLASH Status.
 * @param  None
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   FLASH_ERROR_PG, FLASH_ERROR_WRP or FLASH_COMPLETE
 */
FLASH_Status FLASH_GetStatus(void)
{
  FLASH_Status flashstatus = FLASH_COMPLETE;
  
  if ((FLASH->SR & FLASH_FLAG_BSY) == FLASH_FLAG_BSY) {

    flashstatus = FLASH_BUSY;

  } else { /* if ((FLASH->SR & FLASH_FLAG_BSY) == FLASH_FLAG_BSY) */
  
    if (FLASH->SR & FLASH_FLAG_PGERR) { 
      flashstatus = FLASH_ERROR_PG;
    } else { /* if (FLASH->SR & FLASH_FLAG_PGERR) */

      if (FLASH->SR & FLASH_FLAG_WRPRTERR) {
        flashstatus = FLASH_ERROR_WRP;
      } else { /* if (FLASH->SR & FLASH_FLAG_WRPRTERR) */
        flashstatus = FLASH_COMPLETE;
      } /* if (FLASH->SR & FLASH_FLAG_WRPRTERR) */

    } /* if (FLASH->SR & FLASH_FLAG_PGERR) */

  } /* if ((FLASH->SR & FLASH_FLAG_BSY) == FLASH_FLAG_BSY) */

  /* Return the Flash Status */
  return flashstatus;
}

/*
 * Waits for a Flash operation to complete or a TIMEOUT to occur.
 * @param Timeout: FLASH progamming Timeout
 * @retval : FLASH Status: The returned value can be: FLASH_BUSY, 
 *   FLASH_ERROR_PG, FLASH_ERROR_WRP, FLASH_COMPLETE or 
 *   FLASH_TIMEOUT.
 */
FLASH_Status FLASH_WaitForLastOperation(uint32_t Timeout)
{ 
  FLASH_Status status = FLASH_COMPLETE;
   
  /* Check for the Flash Status */
  status = FLASH_GetStatus();
 
  /* Wait for a Flash operation to complete or a TIMEOUT to occur */
  while ((status == FLASH_BUSY) && (Timeout != 0x00)) {
    delay();
    status = FLASH_GetStatus();
    Timeout--;
  } /* while ((status == FLASH_BUSY) && (Timeout != 0x00)) */
  
  if (Timeout == 0x00 ) {
    status = FLASH_TIMEOUT;
  } /* if (Timeout == 0x00 ) */

  /* Return the operation status */
  return status;
}

/**
  * @brief  Inserts a time delay.
  * @param  None
  * @retval : None
  */
static void delay(void)
{
  __IO uint32_t i = 0;

  for(i = 0xFF; i != 0; i--) {
  }

}