Erasing my Flash on STM32L1

Question

I'm facing a problem with my erasing function. I try to erase 15 sectors of my Flash in order to put a new binary file. I don't understand why but my function freeze and i cannot erase all memory i need.

Here is my code if you want to give a try

/*
 * bootloader.c
 *
 *  Created on: 9 juin 2015
 *      Author: tgloaguen
 */
#include "usart.h"
#include "stm32l1xx_flash.h"
#define WRITE_START_ADDR 0x08000000
#define WRITE_END_ADDR 0x0800FFFF
#define FLASH_PAGE_SIZE    ((uint16_t)0x100) //If a page is 256 bits
#define MY_BL_FUNCTIONS __attribute__((section(".bootsection")))

void BootLoader(void) MY_BL_FUNCTIONS;
FLASH_Status Flash_Write ( uint32_t StartAddress, uint8_t *p, uint32_t Size ) MY_BL_FUNCTIONS;
uint8_t Flash_Erase() MY_BL_FUNCTIONS;
void Receive_Data(char * buffer,int size)MY_BL_FUNCTIONS;
void Receive_Size(char * buffer, int *sizeData)MY_BL_FUNCTIONS;

void BootLoader(void) {

    //clear all ITs
    USART_ITConfig( USART1, USART_IT_RXNE, DISABLE );
    //SendString("HELLO",USART2);
    uint8_t status,i;
    char buffer[33];
    //en dur
    uint16_t *adr = WRITE_START_ADDR;
    uint16_t sizeBin = 51400,k = 0,k_hexa = 0x20;
    SendString("BOOTLOADER",USART2);


    Flash_Erase();
    SendString("ERASEOK",USART2);
    //if sizeBin ok
}

and the erase function

uint8_t Flash_Erase() {

    uint32_t EraseCounter = 0x00, Address = 0x00;//Erase count, write address
    uint32_t NbrOfPage = 0x00;//Recording to erase the pages
    volatile FLASH_Status FLASHStatus = FLASH_COMPLETE;/*FLASH complete erasure marks*/
      /*Unlock FLASH*/

    FLASH_Unlock();
      /*Calculate the number of FLASH pages need to erase */
    NbrOfPage = (WRITE_END_ADDR - WRITE_START_ADDR) / FLASH_PAGE_SIZE;
      /* Remove all hang flags */
    FLASH_ClearFlag ( FLASH_FLAG_EOP     |
                            FLASH_FLAG_WRPERR  |
                            FLASH_FLAG_PGAERR  |
                            FLASH_FLAG_SIZERR  |
                            FLASH_FLAG_OPTVERR );
      /* Erase the FLASH page*/
    for(EraseCounter = 0; (EraseCounter <NbrOfPage) && (FLASHStatus == FLASH_COMPLETE); EraseCounter++)
      {
        SendString("ok |",USART2);
        FLASHStatus = FLASH_ErasePage(WRITE_START_ADDR + (FLASH_PAGE_SIZE * EraseCounter));

      }
      FLASH_Lock ( );

    return (uint8_t)FLASHStatus;
}

Answer 1

In your code you are tring to erase the whole flash, but you are executing your bootloader from flash from final sectors.

As reported by th REF man

During a write/erase operation to the NVM (except Half Page programming or Double-word erase/write), any attempt to read the same bank of NVM stalls the bus.

Then you have to preserve the space of bootloader changing WRITE_END_ADDR define according to your memory map.

Example: if your bootloader is 4K long and belongs to the last sector (0x0801 F000 - 0x0801 FFFF) then WRITE_END_ADDR must be 0x0801 EFFF.

EDIT As @Olaf wrote take care about your ISP (Initial Stack Pointer) and IPC (Initial Program Counter) that belong to first 8 bytes in your flash at address 0.