EEPW论坛

    之前使用STM32的F系列时一直没有内部EEPROM，后来听说L0系列才有内部EEPROM，第一次使用L0，就先测试下内部EEPROM的读写。

   内部FLASH和EEPROM这种掉电后还能保存内容的内存统称为non-volatile memory（NVM）,STM32L053内部有2K的EEPROM.

内部EEPROM的页大小为一个Word为单位，擦除是必须以页为单位，所以库函数里的擦除函数也是每次擦除4个字节：

/**
  * @brief  Erase a word in data memory.
  * @param  Address: specifies the address to be erased.
  * @note   To correctly run this function, the HAL_FLASHEx_DATAEEPROM_Unlock() function
  *         must be called before.
  *         Call the HAL_FLASHEx_DATAEEPROM_Lock() to the data EEPROM access
  *         and Flash program erase control register access(recommended to protect 
  *         the DATA_EEPROM against possible unwanted operation).
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_FLASHEx_DATAEEPROM_Erase(uint32_t Address)
{
  HAL_StatusTypeDef status = HAL_OK;
  
  /* Check the parameters */
  assert_param(IS_FLASH_DATA_ADDRESS(Address));
  
  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(FLASH_TIMEOUT_VALUE);
  
  if(status == HAL_OK)
  {
    /* Clean the error context */
    ProcFlash.ErrorCode = HAL_FLASH_ERROR_NONE;

    /* Write "00000000h" to valid address in the data memory" */
      *(__IO uint32_t *) Address = 0x00000000;

    status = FLASH_WaitForLastOperation(FLASH_TIMEOUT_VALUE);
  }
  
  return status;
}  

 写EEPROM的顺序和使用flash类似，要先解锁（UNLOCK） 才能写，写的时候可以字节、半字、字为单位都可以。

写的时候可以不擦除，内部会自动擦除。需要注意的是写EEPROM会消耗固定的时间，所以需要在程序对时间要求严格时

正确安排写EEPROM的时机。

写EEPROM的函数如下：

void EEPROM_Write(uint16_t WriteAddr,uint8_t *pBuffer,uint16_t NumToWrite)
{
	uint16_t t;
	HAL_FLASHEx_DATAEEPROM_Unlock();	
	for(t = 0;t < NumToWrite;t++)
	{
		HAL_FLASHEx_DATAEEPROM_Program(FLASH_TYPEPROGRAMDATA_BYTE,DATA_EEPROM_BASE + WriteAddr + t,*(pBuffer + t));
	}
	HAL_FLASHEx_DATAEEPROM_Unlock();
}

#include "main.h"
uint8_t Test[25] = "http://www.eepw.com.cn/";
uint8_t Buff[25];
int main(void)
{
	uint8_t res;
	HAL_Init();
	SystemClock_Config();
	LED_Init();
	EEPROM_Write(0,Test,25);
	EEPROM_Read(0,Buff,25);
	res = strcmp((const char*)Buff,(const char*)Test);
	if(0 == res)
	{
		while(1)
		{	
			HAL_Delay(500);
			LED_TOG;			
		}
  }
}

 测试代码：EEPROM.rar