[嵌入式]STM32F4—Flash读写

STM32F40–Flash读写操作

一般在代码调节参数时，比如在调PID的时候，如果每次改参数就重新烧写代码就十分的麻烦。我们可以利用stm32内部flash的读写功能，实现数据保存。

可以从数据手册中查找Flash内存地址

可以看到F4的主存储器基地址位0x0800 0000，有12个扇区，我们可以在头文件中宏定义这些扇区。

flash.h

#ifndef _flash_H
#define _flash_H

#include "stm32f4xx.h"

#define  TEST_ERROR    -1
#define  TEST_SUCCESS  0 

#define DATA_FLASH_SAVE_NUM 2   //存储数据个数
 
#define FLASH_SAVE_ADDR  ADDR_FLASH_SECTOR_4    //扇区有64kb的大小 一般寸几个数据已经足够
//FLASH 扇区的起始地址
#define ADDR_FLASH_SECTOR_0     ((u32)0x08000000) 	//扇区0起始地址, 16 Kbytes  
#define ADDR_FLASH_SECTOR_1     ((u32)0x08004000) 	//扇区1起始地址, 16 Kbytes  
#define ADDR_FLASH_SECTOR_2     ((u32)0x08008000) 	//扇区2起始地址, 16 Kbytes  
#define ADDR_FLASH_SECTOR_3     ((u32)0x0800C000) 	//扇区3起始地址, 16 Kbytes  
#define ADDR_FLASH_SECTOR_4     ((u32)0x08010000) 	//扇区4起始地址, 64 Kbytes  
#define ADDR_FLASH_SECTOR_5     ((u32)0x08020000) 	//扇区5起始地址, 128 Kbytes  
#define ADDR_FLASH_SECTOR_6     ((u32)0x08040000) 	//扇区6起始地址, 128 Kbytes  
#define ADDR_FLASH_SECTOR_7     ((u32)0x08060000) 	//扇区7起始地址, 128 Kbytes  
#define ADDR_FLASH_SECTOR_8     ((u32)0x08080000) 	//扇区8起始地址, 128 Kbytes  
#define ADDR_FLASH_SECTOR_9     ((u32)0x080A0000) 	//扇区9起始地址, 128 Kbytes  
#define ADDR_FLASH_SECTOR_10    ((u32)0x080C0000) 	//扇区10起始地址,128 Kbytes  
#define ADDR_FLASH_SECTOR_11    ((u32)0x080E0000) 	//扇区11起始地址,128 Kbytes  

uint16_t STMFLASH_GetFlashSector(u32 addr);  

void write_to_flash(void);			
void read_from_flash(void);   		

void read_flash(uint16_t *FlashReadBuf);
int write_flash(uint16_t *FlashWriteBuf);

#endif

flash.c

#include "flash.h"

uint16_t write_data[DATA_FLASH_SAVE_NUM];
uint16_t read_data[DATA_FLASH_SAVE_NUM];

//通过地址获取扇区位置
uint16_t STMFLASH_GetFlashSector(u32 addr)
{
	if(addr<ADDR_FLASH_SECTOR_1)return FLASH_Sector_0;
	else if(addr<ADDR_FLASH_SECTOR_2)return FLASH_Sector_1;
	else if(addr<ADDR_FLASH_SECTOR_3)return FLASH_Sector_2;
	else if(addr<ADDR_FLASH_SECTOR_4)return FLASH_Sector_3;
	else if(addr<ADDR_FLASH_SECTOR_5)return FLASH_Sector_4;
	else if(addr<ADDR_FLASH_SECTOR_6)return FLASH_Sector_5;
	else if(addr<ADDR_FLASH_SECTOR_7)return FLASH_Sector_6;
	else if(addr<ADDR_FLASH_SECTOR_8)return FLASH_Sector_7;
	else if(addr<ADDR_FLASH_SECTOR_9)return FLASH_Sector_8;
	else if(addr<ADDR_FLASH_SECTOR_10)return FLASH_Sector_9;
	else if(addr<ADDR_FLASH_SECTOR_11)return FLASH_Sector_10; 
	return FLASH_Sector_11;	
}

//将数据写入内存 16位数据
int write_flash(uint16_t *FlashWriteBuf)
{
	
	uint32_t StartAddr;
	StartAddr = FLASH_SAVE_ADDR;

	FLASH_Unlock();	//解锁
    FLASH_ClearFlag(FLASH_FLAG_EOP | FLASH_FLAG_OPERR | FLASH_FLAG_WRPERR | 
                  FLASH_FLAG_PGAERR | FLASH_FLAG_PGPERR|FLASH_FLAG_PGSERR);

	if (FLASH_COMPLETE != FLASH_EraseSector(STMFLASH_GetFlashSector(StartAddr),VoltageRange_2)) //擦除扇区内容
    {		
		return TEST_ERROR;
	}
	
	for (int i = 0; i < DATA_FLASH_SAVE_NUM; i++)
	{
		if (FLASH_COMPLETE != FLASH_ProgramHalfWord(StartAddr, FlashWriteBuf[i]))	//写入16位数据
		{			
			return TEST_ERROR;
		}
		StartAddr += 2;	//16位数据偏移两个位置
	}

	FLASH_Lock();	//上锁
     
	return TEST_SUCCESS;
}

//从内存读数据 16位数据
void read_flash(uint16_t *FlashReadBuf)
{
	uint32_t StartAddr = FLASH_SAVE_ADDR;
	for (int i = 0; i < DATA_FLASH_SAVE_NUM; i++)
	{
		FlashReadBuf[i] = *(__IO uint16_t*)StartAddr;
		StartAddr += 2;
	}
}

void write_to_flash(void)
{
	memset(write_data, 0, sizeof(write_data));
	/*
		//这里就可以写入一些参数 如kp、ki
		write_data[0] = kp;
		write_data[1] = ki;
	*/
	if(TEST_SUCCESS!=write_flash(write_data))	
		return;  //写入错误

}


void read_from_flash(void)
{
	memset(read_data, 0, sizeof(read_data));
	read_flash(read_data);
	/*
		//这里读取数据
		kp = read_data[0];
		ki = read_data[1];
	*/
}

main.c

#include "stm32f4xx.h"
#include "delay.h"
#include "flash.h"

int main(void)
{
  delay_init(84);
  LED_Init();
  read_from_flash();	//这个函数必须在执行一次 write_to_flash() 后在加入这行，否则可能读取到内存一些不正常的数据
  
  while (1)
  {
  		//...
  		write_to_flash();  //可在修改完参数后执行
  		//...
  }
}
//每次重新启动32后，参数数据就是从内存读取的数据