Posted on January 19, 2017 at 13:27Hi Patil
This works for the STM32l051 on Eclipse, just migrating to Keil so haven't tried it on that yet:
#define DATA_EEPROM_BASE_ADDR ((uint32_t)0x08080000) /* Data EEPROM base address */
#define DATA_EEPROM_END_ADDR ((uint32_t)0x080807FF) /* Data EEPROM end address */
Simple write sequence:
void Write_Registers_to_Eeprom(void)
{
uint32_t i;
uint32_t* p_tFlashRegs;
i = 0;
p_tFlashRegs = (uint32_t*)&data_to_write; /* Point to data to write */
UnlockEeprom(); /* Unlock the EEPROM and enable flash interrupts */
FLASH->PECR = FLASH->PECR & ~(FLASH_PECR_ERASE | FLASH_PECR_DATA); /* Reset the ERASE and DATA bits in the FLASH_PECR register to disable any residual erase */
/* Put the next line in a loop if sequential bits to be written with i as loop counter */
EepromProgram(DATA_EEPROM_BASE_ADDR + (4 * i), *(p_tFlashRegs + i)); /* Increase eeprom address by 4 for each word to write. */
LockEeprom(); /* Lock the EEPROM */
}
Called routines:
/* Unlock the EEPROM: */
void UnlockEeprom(void)
{
while ((FLASH->SR & FLASH_SR_BSY) != 0) /* Wait for FLASH to be free */
{
/* insert timeout test */
}
if ((FLASH->PECR & FLASH_PECR_PELOCK) != 0) /* If PELOCK is locked */
{
FLASH->PEKEYR = FLASH_PEKEY1; /* Unlock PELOCK */
FLASH->PEKEYR = FLASH_PEKEY2;
}
FLASH->PECR = FLASH->PECR | (FLASH_PECR_ERRIE | FLASH_PECR_EOPIE); /* enable flash interrupts */
}
/**
* Brief This function programs a word of data EEPROM.
* The ERASE bit and DATA bit are cleared in PECR at the beginning
* words are automatically erased if required before programming
* Param addr is the 32-bit EEPROM address to program, data is the 32 bit word to program
* Retval None
*/
void EepromProgram(uint32_t addr, uint32_t ee_data)
{
/* NOTE: The EEPROM must be unlocked and the flash interrupts must have been enabled prior to calling this function.*/
*(uint32_t *)(addr) = ee_data; /* write data to EEPROM */
__WFI();
if (*(uint32_t *)(addr) != ee_data)
{
error |= ERROR_PROG_32B_WORD;
}
}
/* Lock the EEPROM: */
void LockEeprom(void)
{
while ((FLASH->SR & FLASH_SR_BSY) != 0) /* Wait for FLASH to be free */
{
/* insert timeout test */
}
FLASH->PECR = FLASH->PECR & ~(FLASH_PECR_ERRIE | FLASH_PECR_EOPIE); /* disable flash interrupts */
FLASH->PECR = FLASH->PECR | FLASH_PECR_PELOCK; /* Lock memory with PELOCK */
}
To read you can use a simple structure (eg called Eeprom_registers) and have something like:
#define CONFIG ((Eeprom_registers *) DATA_EEPROM_BASE_ADDR)
then get data using something like
Eeprom_data1 = CONFIG-> xxxx ; /* where xxxx is the entry in the Eeprom registers */
either that or something like
Eeprom_data1 = *(uint32_t *)(addr); /* where addr is the EEPROM address you want to read */
Hope this helps.
