Diff: eeprom.cpp

Revision:

0:bbe849f641a8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/eeprom.cpp	Sun May 29 01:22:48 2016 +0000
@@ -0,0 +1,730 @@
+/**
+  ******************************************************************************
+  * @file    EEPROM/EEPROM_Emulation/src/eeprom.c 
+  * @author  MCD Application Team
+  * @version V1.0.1
+  * @date    29-January-2016
+  * @brief   This file provides all the EEPROM emulation firmware functions.
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; COPYRIGHT(c) 2016 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 EEPROM_Emulation
+  * @{
+  */ 
+
+/* Includes ------------------------------------------------------------------*/
+#include "eeprom.h"
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+
+/* Global variable used to store variable value in read sequence */
+uint16_t DataVar = 0;
+
+/* Virtual address defined by the user: 0xFFFF value is prohibited */
+extern uint16_t VirtAddVarTab[NB_OF_VAR];
+
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+static HAL_StatusTypeDef EE_Format(void);
+static uint16_t EE_FindValidPage(uint8_t Operation);
+static uint16_t EE_VerifyPageFullWriteVariable(uint16_t VirtAddress, uint16_t Data);
+static uint16_t EE_PageTransfer(uint16_t VirtAddress, uint16_t Data);
+static uint16_t EE_VerifyPageFullyErased(uint32_t Address);
+
+/**
+  * @brief  Restore the pages to a known good state in case of page's status
+  *   corruption after a power loss.
+  * @param  None.
+  * @retval - Flash error code: on write Flash error
+  *         - FLASH_COMPLETE: on success
+  */
+uint16_t EE_Init(void)
+{
+  uint16_t PageStatus0 = 6, PageStatus1 = 6;
+  uint16_t VarIdx = 0;
+  uint16_t EepromStatus = 0, ReadStatus = 0;
+  int16_t x = -1;
+  HAL_StatusTypeDef  FlashStatus;
+  uint32_t SectorError = 0;
+  FLASH_EraseInitTypeDef pEraseInit;
+
+
+  /* Get Page0 status */
+  PageStatus0 = (*(__IO uint16_t*)PAGE0_BASE_ADDRESS);
+  /* Get Page1 status */
+  PageStatus1 = (*(__IO uint16_t*)PAGE1_BASE_ADDRESS);
+
+  pEraseInit.TypeErase = TYPEERASE_SECTORS;
+  pEraseInit.Sector = PAGE0_ID;
+  pEraseInit.NbSectors = 1;
+  pEraseInit.VoltageRange = VOLTAGE_RANGE;
+  
+  /* Check for invalid header states and repair if necessary */
+  switch (PageStatus0)
+  {
+    case ERASED:
+      if (PageStatus1 == VALID_PAGE) /* Page0 erased, Page1 valid */
+      {
+          /* Erase Page0 */
+        if(!EE_VerifyPageFullyErased(PAGE0_BASE_ADDRESS))
+        {
+          FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError);
+          /* If erase operation was failed, a Flash error code is returned */
+          if (FlashStatus != HAL_OK)
+          {
+            return FlashStatus;
+          }
+        }
+      }
+      else if (PageStatus1 == RECEIVE_DATA) /* Page0 erased, Page1 receive */
+      {
+        /* Erase Page0 */
+        if(!EE_VerifyPageFullyErased(PAGE0_BASE_ADDRESS))
+        { 
+          FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError);
+          /* If erase operation was failed, a Flash error code is returned */
+          if (FlashStatus != HAL_OK)
+          {
+            return FlashStatus;
+          }
+        }
+        /* Mark Page1 as valid */
+        FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, PAGE1_BASE_ADDRESS, VALID_PAGE);
+        /* If program operation was failed, a Flash error code is returned */
+        if (FlashStatus != HAL_OK)
+        {
+          return FlashStatus;
+        }
+      }
+      else /* First EEPROM access (Page0&1 are erased) or invalid state -> format EEPROM */
+      {
+        /* Erase both Page0 and Page1 and set Page0 as valid page */
+        FlashStatus = EE_Format();
+        /* If erase/program operation was failed, a Flash error code is returned */
+        if (FlashStatus != HAL_OK)
+        {
+          return FlashStatus;
+        }
+      }
+      break;
+
+    case RECEIVE_DATA:
+      if (PageStatus1 == VALID_PAGE) /* Page0 receive, Page1 valid */
+      {
+        /* Transfer data from Page1 to Page0 */
+        for (VarIdx = 0; VarIdx < NB_OF_VAR; VarIdx++)
+        {
+          if (( *(__IO uint16_t*)(PAGE0_BASE_ADDRESS + 6)) == VirtAddVarTab[VarIdx])
+          {
+            x = VarIdx;
+          }
+          if (VarIdx != x)
+          {
+            /* Read the last variables' updates */
+            ReadStatus = EE_ReadVariable(VirtAddVarTab[VarIdx], &DataVar);
+            /* In case variable corresponding to the virtual address was found */
+            if (ReadStatus != 0x1)
+            {
+              /* Transfer the variable to the Page0 */
+              EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddVarTab[VarIdx], DataVar);
+              /* If program operation was failed, a Flash error code is returned */
+              if (EepromStatus != HAL_OK)
+              {
+                return EepromStatus;
+              }
+            }
+          }
+        }
+        /* Mark Page0 as valid */
+        FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, PAGE0_BASE_ADDRESS, VALID_PAGE);
+        /* If program operation was failed, a Flash error code is returned */
+        if (FlashStatus != HAL_OK)
+        {
+          return FlashStatus;
+        }
+        pEraseInit.Sector = PAGE1_ID;
+        pEraseInit.NbSectors = 1;
+        pEraseInit.VoltageRange = VOLTAGE_RANGE;
+        /* Erase Page1 */
+        if(!EE_VerifyPageFullyErased(PAGE1_BASE_ADDRESS))
+        { 
+          FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError);
+          /* If erase operation was failed, a Flash error code is returned */
+          if (FlashStatus != HAL_OK)
+          {
+            return FlashStatus;
+          }
+        }
+      }
+      else if (PageStatus1 == ERASED) /* Page0 receive, Page1 erased */
+      {
+        pEraseInit.Sector = PAGE1_ID;
+        pEraseInit.NbSectors = 1;
+        pEraseInit.VoltageRange = VOLTAGE_RANGE;
+        /* Erase Page1 */
+        if(!EE_VerifyPageFullyErased(PAGE1_BASE_ADDRESS))
+        { 
+          FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError);
+          /* If erase operation was failed, a Flash error code is returned */
+          if (FlashStatus != HAL_OK)
+          {
+            return FlashStatus;
+          }
+        }
+        /* Mark Page0 as valid */
+        FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, PAGE0_BASE_ADDRESS, VALID_PAGE);
+        /* If program operation was failed, a Flash error code is returned */
+        if (FlashStatus != HAL_OK)
+        {
+          return FlashStatus;
+        }
+      }
+      else /* Invalid state -> format eeprom */
+      {
+        /* Erase both Page0 and Page1 and set Page0 as valid page */
+        FlashStatus = EE_Format();
+        /* If erase/program operation was failed, a Flash error code is returned */
+        if (FlashStatus != HAL_OK)
+        {
+          return FlashStatus;
+        }
+      }
+      break;
+
+    case VALID_PAGE:
+      if (PageStatus1 == VALID_PAGE) /* Invalid state -> format eeprom */
+      {
+        /* Erase both Page0 and Page1 and set Page0 as valid page */
+        FlashStatus = EE_Format();
+        /* If erase/program operation was failed, a Flash error code is returned */
+        if (FlashStatus != HAL_OK)
+        {
+          return FlashStatus;
+        }
+      }
+      else if (PageStatus1 == ERASED) /* Page0 valid, Page1 erased */
+      {
+        pEraseInit.Sector = PAGE1_ID;
+        pEraseInit.NbSectors = 1;
+        pEraseInit.VoltageRange = VOLTAGE_RANGE;
+        /* Erase Page1 */
+        if(!EE_VerifyPageFullyErased(PAGE1_BASE_ADDRESS))
+        { 
+          FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError);
+          /* If erase operation was failed, a Flash error code is returned */
+          if (FlashStatus != HAL_OK)
+          {
+            return FlashStatus;
+          }
+        }
+      }
+      else /* Page0 valid, Page1 receive */
+      {
+        /* Transfer data from Page0 to Page1 */
+        for (VarIdx = 0; VarIdx < NB_OF_VAR; VarIdx++)
+        {
+          if ((*(__IO uint16_t*)(PAGE1_BASE_ADDRESS + 6)) == VirtAddVarTab[VarIdx])
+          {
+            x = VarIdx;
+          }
+          if (VarIdx != x)
+          {
+            /* Read the last variables' updates */
+            ReadStatus = EE_ReadVariable(VirtAddVarTab[VarIdx], &DataVar);
+            /* In case variable corresponding to the virtual address was found */
+            if (ReadStatus != 0x1)
+            {
+              /* Transfer the variable to the Page1 */
+              EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddVarTab[VarIdx], DataVar);
+              /* If program operation was failed, a Flash error code is returned */
+              if (EepromStatus != HAL_OK)
+              {
+                return EepromStatus;
+              }
+            }
+          }
+        }
+        /* Mark Page1 as valid */
+        FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, PAGE1_BASE_ADDRESS, VALID_PAGE);        
+        /* If program operation was failed, a Flash error code is returned */
+        if (FlashStatus != HAL_OK)
+        {
+          return FlashStatus;
+        }
+        pEraseInit.Sector = PAGE0_ID;
+        pEraseInit.NbSectors = 1;
+        pEraseInit.VoltageRange = VOLTAGE_RANGE;
+        /* Erase Page0 */
+        if(!EE_VerifyPageFullyErased(PAGE0_BASE_ADDRESS))
+        { 
+          FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError);
+          /* If erase operation was failed, a Flash error code is returned */
+          if (FlashStatus != HAL_OK)
+          {
+            return FlashStatus;
+          }
+        }
+      }
+      break;
+
+    default:  /* Any other state -> format eeprom */
+      /* Erase both Page0 and Page1 and set Page0 as valid page */
+      FlashStatus = EE_Format();
+      /* If erase/program operation was failed, a Flash error code is returned */
+      if (FlashStatus != HAL_OK)
+      {
+        return FlashStatus;
+      }
+      break;
+  }
+
+  return HAL_OK;
+}
+
+/**
+  * @brief  Verify if specified page is fully erased.
+  * @param  Address: page address
+  *   This parameter can be one of the following values:
+  *     @arg PAGE0_BASE_ADDRESS: Page0 base address
+  *     @arg PAGE1_BASE_ADDRESS: Page1 base address
+  * @retval page fully erased status:
+  *           - 0: if Page not erased
+  *           - 1: if Page erased
+  */
+uint16_t EE_VerifyPageFullyErased(uint32_t Address)
+{
+  uint32_t ReadStatus = 1;
+  uint16_t AddressValue = 0x5555;
+    
+  /* Check each active page address starting from end */
+  while (Address <= PAGE0_END_ADDRESS)
+  {
+    /* Get the current location content to be compared with virtual address */
+    AddressValue = (*(__IO uint16_t*)Address);
+
+    /* Compare the read address with the virtual address */
+    if (AddressValue != ERASED)
+    {
+      
+      /* In case variable value is read, reset ReadStatus flag */
+      ReadStatus = 0;
+
+      break;
+    }
+    /* Next address location */
+    Address = Address + 4;
+  }
+  
+  /* Return ReadStatus value: (0: Page not erased, 1: Sector erased) */
+  return ReadStatus;
+}
+
+/**
+  * @brief  Returns the last stored variable data, if found, which correspond to
+  *   the passed virtual address
+  * @param  VirtAddress: Variable virtual address
+  * @param  Data: Global variable contains the read variable value
+  * @retval Success or error status:
+  *           - 0: if variable was found
+  *           - 1: if the variable was not found
+  *           - NO_VALID_PAGE: if no valid page was found.
+  */
+uint16_t EE_ReadVariable(uint16_t VirtAddress, uint16_t* Data)
+{
+  uint16_t ValidPage = PAGE0;
+  uint16_t AddressValue = 0x5555, ReadStatus = 1;
+  uint32_t Address = EEPROM_START_ADDRESS, PageStartAddress = EEPROM_START_ADDRESS;
+
+  /* Get active Page for read operation */
+  ValidPage = EE_FindValidPage(READ_FROM_VALID_PAGE);
+
+  /* Check if there is no valid page */
+  if (ValidPage == NO_VALID_PAGE)
+  {
+    return  NO_VALID_PAGE;
+  }
+
+  /* Get the valid Page start Address */
+  PageStartAddress = (uint32_t)(EEPROM_START_ADDRESS + (uint32_t)(ValidPage * PAGE_SIZE));
+
+  /* Get the valid Page end Address */
+  Address = (uint32_t)((EEPROM_START_ADDRESS - 2) + (uint32_t)((1 + ValidPage) * PAGE_SIZE));
+
+  /* Check each active page address starting from end */
+  while (Address > (PageStartAddress + 2))
+  {
+    /* Get the current location content to be compared with virtual address */
+    AddressValue = (*(__IO uint16_t*)Address);
+
+    /* Compare the read address with the virtual address */
+    if (AddressValue == VirtAddress)
+    {
+      /* Get content of Address-2 which is variable value */
+      *Data = (*(__IO uint16_t*)(Address - 2));
+
+      /* In case variable value is read, reset ReadStatus flag */
+      ReadStatus = 0;
+
+      break;
+    }
+    else
+    {
+      /* Next address location */
+      Address = Address - 4;
+    }
+  }
+
+  /* Return ReadStatus value: (0: variable exist, 1: variable doesn't exist) */
+  return ReadStatus;
+}
+
+/**
+  * @brief  Writes/upadtes variable data in EEPROM.
+  * @param  VirtAddress: Variable virtual address
+  * @param  Data: 16 bit data to be written
+  * @retval Success or error status:
+  *           - FLASH_COMPLETE: on success
+  *           - PAGE_FULL: if valid page is full
+  *           - NO_VALID_PAGE: if no valid page was found
+  *           - Flash error code: on write Flash error
+  */
+uint16_t EE_WriteVariable(uint16_t VirtAddress, uint16_t Data)
+{
+  uint16_t Status = 0;
+
+  /* Write the variable virtual address and value in the EEPROM */
+  Status = EE_VerifyPageFullWriteVariable(VirtAddress, Data);
+
+  /* In case the EEPROM active page is full */
+  if (Status == PAGE_FULL)
+  {
+    /* Perform Page transfer */
+    Status = EE_PageTransfer(VirtAddress, Data);
+  }
+
+  /* Return last operation status */
+  return Status;
+}
+
+/**
+  * @brief  Erases PAGE and PAGE1 and writes VALID_PAGE header to PAGE
+  * @param  None
+  * @retval Status of the last operation (Flash write or erase) done during
+  *         EEPROM formating
+  */
+static HAL_StatusTypeDef EE_Format(void)
+{
+  HAL_StatusTypeDef FlashStatus = HAL_OK;
+  uint32_t SectorError = 0;
+  FLASH_EraseInitTypeDef pEraseInit;
+
+  pEraseInit.TypeErase = FLASH_TYPEERASE_SECTORS;  
+  pEraseInit.Sector = PAGE0_ID;
+  pEraseInit.NbSectors = 1;
+  pEraseInit.VoltageRange = VOLTAGE_RANGE;
+  /* Erase Page0 */
+  if(!EE_VerifyPageFullyErased(PAGE0_BASE_ADDRESS))
+  {
+    FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError); 
+    /* If erase operation was failed, a Flash error code is returned */
+    if (FlashStatus != HAL_OK)
+    {
+      return FlashStatus;
+    }
+  }
+  /* Set Page0 as valid page: Write VALID_PAGE at Page0 base address */
+  FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, PAGE0_BASE_ADDRESS, VALID_PAGE); 
+  /* If program operation was failed, a Flash error code is returned */
+  if (FlashStatus != HAL_OK)
+  {
+    return FlashStatus;
+  }
+
+  pEraseInit.Sector = PAGE1_ID;
+  /* Erase Page1 */
+  if(!EE_VerifyPageFullyErased(PAGE1_BASE_ADDRESS))
+  {  
+    FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError); 
+    /* If erase operation was failed, a Flash error code is returned */
+    if (FlashStatus != HAL_OK)
+    {
+      return FlashStatus;
+    }
+  }
+  
+  return HAL_OK;
+}
+
+/**
+  * @brief  Find valid Page for write or read operation
+  * @param  Operation: operation to achieve on the valid page.
+  *   This parameter can be one of the following values:
+  *     @arg READ_FROM_VALID_PAGE: read operation from valid page
+  *     @arg WRITE_IN_VALID_PAGE: write operation from valid page
+  * @retval Valid page number (PAGE or PAGE1) or NO_VALID_PAGE in case
+  *   of no valid page was found
+  */
+static uint16_t EE_FindValidPage(uint8_t Operation)
+{
+  uint16_t PageStatus0 = 6, PageStatus1 = 6;
+
+  /* Get Page0 actual status */
+  PageStatus0 = (*(__IO uint16_t*)PAGE0_BASE_ADDRESS);
+
+  /* Get Page1 actual status */
+  PageStatus1 = (*(__IO uint16_t*)PAGE1_BASE_ADDRESS);
+
+  /* Write or read operation */
+  switch (Operation)
+  {
+    case WRITE_IN_VALID_PAGE:   /* ---- Write operation ---- */
+      if (PageStatus1 == VALID_PAGE)
+      {
+        /* Page0 receiving data */
+        if (PageStatus0 == RECEIVE_DATA)
+        {
+          return PAGE0;         /* Page0 valid */
+        }
+        else
+        {
+          return PAGE1;         /* Page1 valid */
+        }
+      }
+      else if (PageStatus0 == VALID_PAGE)
+      {
+        /* Page1 receiving data */
+        if (PageStatus1 == RECEIVE_DATA)
+        {
+          return PAGE1;         /* Page1 valid */
+        }
+        else
+        {
+          return PAGE0;         /* Page0 valid */
+        }
+      }
+      else
+      {
+        return NO_VALID_PAGE;   /* No valid Page */
+      }
+
+    case READ_FROM_VALID_PAGE:  /* ---- Read operation ---- */
+      if (PageStatus0 == VALID_PAGE)
+      {
+        return PAGE0;           /* Page0 valid */
+      }
+      else if (PageStatus1 == VALID_PAGE)
+      {
+        return PAGE1;           /* Page1 valid */
+      }
+      else
+      {
+        return NO_VALID_PAGE ;  /* No valid Page */
+      }
+
+    default:
+      return PAGE0;             /* Page0 valid */
+  }
+}
+
+/**
+  * @brief  Verify if active page is full and Writes variable in EEPROM.
+  * @param  VirtAddress: 16 bit virtual address of the variable
+  * @param  Data: 16 bit data to be written as variable value
+  * @retval Success or error status:
+  *           - FLASH_COMPLETE: on success
+  *           - PAGE_FULL: if valid page is full
+  *           - NO_VALID_PAGE: if no valid page was found
+  *           - Flash error code: on write Flash error
+  */
+static uint16_t EE_VerifyPageFullWriteVariable(uint16_t VirtAddress, uint16_t Data)
+{
+  HAL_StatusTypeDef FlashStatus = HAL_OK;
+  uint16_t ValidPage = PAGE0;
+  uint32_t Address = EEPROM_START_ADDRESS, PageEndAddress = EEPROM_START_ADDRESS+PAGE_SIZE;
+
+  /* Get valid Page for write operation */
+  ValidPage = EE_FindValidPage(WRITE_IN_VALID_PAGE);
+  
+  /* Check if there is no valid page */
+  if (ValidPage == NO_VALID_PAGE)
+  {
+    return  NO_VALID_PAGE;
+  }
+
+  /* Get the valid Page start Address */
+  Address = (uint32_t)(EEPROM_START_ADDRESS + (uint32_t)(ValidPage * PAGE_SIZE));
+
+  /* Get the valid Page end Address */
+  PageEndAddress = (uint32_t)((EEPROM_START_ADDRESS - 1) + (uint32_t)((ValidPage + 1) * PAGE_SIZE));
+
+  /* Check each active page address starting from begining */
+  while (Address < PageEndAddress)
+  {
+    /* Verify if Address and Address+2 contents are 0xFFFFFFFF */
+    if ((*(__IO uint32_t*)Address) == 0xFFFFFFFF)
+    {
+      /* Set variable data */
+      FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, Address, Data);       
+      /* If program operation was failed, a Flash error code is returned */
+      if (FlashStatus != HAL_OK)
+      {
+        return FlashStatus;
+      }
+      /* Set variable virtual address */
+      FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, Address + 2, VirtAddress);       
+      /* Return program operation status */
+      return FlashStatus;
+    }
+    else
+    {
+      /* Next address location */
+      Address = Address + 4;
+    }
+  }
+
+  /* Return PAGE_FULL in case the valid page is full */
+  return PAGE_FULL;
+}
+
+/**
+  * @brief  Transfers last updated variables data from the full Page to
+  *   an empty one.
+  * @param  VirtAddress: 16 bit virtual address of the variable
+  * @param  Data: 16 bit data to be written as variable value
+  * @retval Success or error status:
+  *           - FLASH_COMPLETE: on success
+  *           - PAGE_FULL: if valid page is full
+  *           - NO_VALID_PAGE: if no valid page was found
+  *           - Flash error code: on write Flash error
+  */
+static uint16_t EE_PageTransfer(uint16_t VirtAddress, uint16_t Data)
+{
+  HAL_StatusTypeDef FlashStatus = HAL_OK;
+  uint32_t NewPageAddress = EEPROM_START_ADDRESS;
+  uint16_t OldPageId=0;
+  uint16_t ValidPage = PAGE0, VarIdx = 0;
+  uint16_t EepromStatus = 0, ReadStatus = 0;
+  uint32_t SectorError = 0;
+  FLASH_EraseInitTypeDef pEraseInit;
+
+  /* Get active Page for read operation */
+  ValidPage = EE_FindValidPage(READ_FROM_VALID_PAGE);
+
+  if (ValidPage == PAGE1)       /* Page1 valid */
+  {
+    /* New page address where variable will be moved to */
+    NewPageAddress = PAGE0_BASE_ADDRESS;
+
+    /* Old page ID where variable will be taken from */
+    OldPageId = PAGE1_ID;
+  }
+  else if (ValidPage == PAGE0)  /* Page0 valid */
+  {
+    /* New page address  where variable will be moved to */
+    NewPageAddress = PAGE1_BASE_ADDRESS;
+
+    /* Old page ID where variable will be taken from */
+    OldPageId = PAGE0_ID;
+  }
+  else
+  {
+    return NO_VALID_PAGE;       /* No valid Page */
+  }
+
+  /* Set the new Page status to RECEIVE_DATA status */
+  FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, NewPageAddress, RECEIVE_DATA);  
+  /* If program operation was failed, a Flash error code is returned */
+  if (FlashStatus != HAL_OK)
+  {
+    return FlashStatus;
+  }
+  
+  /* Write the variable passed as parameter in the new active page */
+  EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddress, Data);
+  /* If program operation was failed, a Flash error code is returned */
+  if (EepromStatus != HAL_OK)
+  {
+    return EepromStatus;
+  }
+
+  /* Transfer process: transfer variables from old to the new active page */
+  for (VarIdx = 0; VarIdx < NB_OF_VAR; VarIdx++)
+  {
+    if (VirtAddVarTab[VarIdx] != VirtAddress)  /* Check each variable except the one passed as parameter */
+    {
+      /* Read the other last variable updates */
+      ReadStatus = EE_ReadVariable(VirtAddVarTab[VarIdx], &DataVar);
+      /* In case variable corresponding to the virtual address was found */
+      if (ReadStatus != 0x1)
+      {
+        /* Transfer the variable to the new active page */
+        EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddVarTab[VarIdx], DataVar);
+        /* If program operation was failed, a Flash error code is returned */
+        if (EepromStatus != HAL_OK)
+        {
+          return EepromStatus;
+        }
+      }
+    }
+  }
+
+  pEraseInit.TypeErase = TYPEERASE_SECTORS;
+  pEraseInit.Sector = OldPageId;
+  pEraseInit.NbSectors = 1;
+  pEraseInit.VoltageRange = VOLTAGE_RANGE;
+  
+  /* Erase the old Page: Set old Page status to ERASED status */
+  FlashStatus = HAL_FLASHEx_Erase(&pEraseInit, &SectorError);  
+  /* If erase operation was failed, a Flash error code is returned */
+  if (FlashStatus != HAL_OK)
+  {
+    return FlashStatus;
+  }
+
+  /* Set new Page status to VALID_PAGE status */
+  FlashStatus = HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, NewPageAddress, VALID_PAGE);   
+  /* If program operation was failed, a Flash error code is returned */
+  if (FlashStatus != HAL_OK)
+  {
+    return FlashStatus;
+  }
+
+  /* Return last operation flash status */
+  return FlashStatus;
+}
+
+/**
+  * @}
+  */ 
+
+/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/