STM32小白入门（第14天）-------Flash

一、Flash概述

    闪存（Flash Memory）是一种长寿命的非易失性（在断电情况下仍能保持所存储的数据信息）的存储器。

用途：SD卡、固态硬盘、芯片内存存储单元存储代码。

二、内部FLASH特征

1、以分区形式进行规划，配置数据最好从最后扇区进行操作，防止覆盖扇区0的代码。

2、写入数据之前得先擦除数据，类似与读书时的黑板原理。

思考题1：擦除完之后，扇区里面所有的数据是什么？

答：所有的数据都是为0xFF，所有bit位都是1.

思考题2：假如说现在已经擦除完扇区，先写入了1个字节，然后在下一个偏移地址再次写入新的字节是否在需要擦除扇区？

答案：不需要的。

思考题3：假如说现在已经擦除完扇区，先写了1个字节，然后在同一个地址再次写入新的字节是否在需要擦除扇区？

答案：需要进行擦除！

例子，已经写入数据为0x12345678，然后再写入新的数据为0x1111111，最后得到的数据居然是0x101010.

#define FLASH_USER_START_ADDR   ADDR_FLASH_SECTOR_6   /* Start address of user Flash area */

#define FLASH_USER_END_ADDR     ADDR_FLASH_SECTOR_7   /* End address of user Flash area */

/* Base address of the Flash sectors */ 

#define ADDR_FLASH_SECTOR_0     ((uint32_t)0x08000000) /* Base address of Sector 0, 16 Kbytes   */

#define ADDR_FLASH_SECTOR_1     ((uint32_t)0x08004000) /* Base address of Sector 1, 16 Kbytes   */

#define ADDR_FLASH_SECTOR_2     ((uint32_t)0x08008000) /* Base address of Sector 2, 16 Kbytes   */

#define ADDR_FLASH_SECTOR_3     ((uint32_t)0x0800C000) /* Base address of Sector 3, 16 Kbytes   */

#define ADDR_FLASH_SECTOR_4     ((uint32_t)0x08010000) /* Base address of Sector 4, 64 Kbytes   */

#define ADDR_FLASH_SECTOR_5     ((uint32_t)0x08020000) /* Base address of Sector 5, 128 Kbytes  */

#define ADDR_FLASH_SECTOR_6     ((uint32_t)0x08040000) /* Base address of Sector 6, 128 Kbytes  */

#define ADDR_FLASH_SECTOR_7     ((uint32_t)0x08060000) /* Base address of Sector 7, 128 Kbytes  */

#define ADDR_FLASH_SECTOR_8     ((uint32_t)0x08080000) /* Base address of Sector 8, 128 Kbytes  */

#define ADDR_FLASH_SECTOR_9     ((uint32_t)0x080A0000) /* Base address of Sector 9, 128 Kbytes  */

#define ADDR_FLASH_SECTOR_10    ((uint32_t)0x080C0000) /* Base address of Sector 10, 128 Kbytes */

#define ADDR_FLASH_SECTOR_11    ((uint32_t)0x080E0000) /* Base address of Sector 11, 128 Kbytes */

uint32_t uwStartSector = 0;

uint32_t uwEndSector = 0;

uint32_t uwAddress = 0;

uint32_t uwSectorCounter = 0;

__IO uint32_t uwData32 = 0;

//获取所在扇区

static uint32_t GetSector(uint32_t Address)

{

  uint32_t sector = 0;

  if((Address < ADDR_FLASH_SECTOR_1) && (Address >= ADDR_FLASH_SECTOR_0))

  {

    sector = FLASH_Sector_0;  

  }

  else if((Address < ADDR_FLASH_SECTOR_2) && (Address >= ADDR_FLASH_SECTOR_1))

  {

    sector = FLASH_Sector_1;  

  }

  else if((Address < ADDR_FLASH_SECTOR_3) && (Address >= ADDR_FLASH_SECTOR_2))

  {

    sector = FLASH_Sector_2;  

  }

  else if((Address < ADDR_FLASH_SECTOR_4) && (Address >= ADDR_FLASH_SECTOR_3))

  {

    sector = FLASH_Sector_3;  

  }

  else if((Address < ADDR_FLASH_SECTOR_5) && (Address >= ADDR_FLASH_SECTOR_4))

  {

    sector = FLASH_Sector_4;  

  }

  else if((Address < ADDR_FLASH_SECTOR_6) && (Address >= ADDR_FLASH_SECTOR_5))

  {

    sector = FLASH_Sector_5;  

  }

  else if((Address < ADDR_FLASH_SECTOR_7) && (Address >= ADDR_FLASH_SECTOR_6))

  {

    sector = FLASH_Sector_6;  

  }

  else if((Address < ADDR_FLASH_SECTOR_8) && (Address >= ADDR_FLASH_SECTOR_7))

  {

    sector = FLASH_Sector_7;  

  }

  else if((Address < ADDR_FLASH_SECTOR_9) && (Address >= ADDR_FLASH_SECTOR_8))

  {

    sector = FLASH_Sector_8;  

  }

  else if((Address < ADDR_FLASH_SECTOR_10) && (Address >= ADDR_FLASH_SECTOR_9))

  {

    sector = FLASH_Sector_9;  

  }

  else if((Address < ADDR_FLASH_SECTOR_11) && (Address >= ADDR_FLASH_SECTOR_10))

  {

    sector = FLASH_Sector_10;  

  }

  else/*(Address < FLASH_END_ADDR) && (Address >= ADDR_FLASH_SECTOR_11))*/

  {

    sector = FLASH_Sector_11;  

  }

  return sector;

}

//擦除扇区

void FLASH_Eraze(void)

{

//解锁闪存

/* Enable the flash control register access ，使能闪存控制寄存器的访问*/

FLASH_Unlock();

/* Clear pending flags (if any) ，清空所有相关的标志位*/  

FLASH_ClearFlag(FLASH_FLAG_EOP | FLASH_FLAG_OPERR | FLASH_FLAG_WRPERR | 

FLASH_FLAG_PGAERR | FLASH_FLAG_PGPERR|FLASH_FLAG_PGSERR); 

/* Get the number of the start and end sectors，将扇区地址转换为扇区号 */

uwStartSector = GetSector(FLASH_USER_START_ADDR); //起始扇区为扇区6

uwEndSector = GetSector(FLASH_USER_END_ADDR); //结束扇区为扇区7

/* start the erase operation */

uwSectorCounter = uwStartSector;

//判断擦除是否已经到达结束扇区

while (uwSectorCounter <= uwEndSector) 

{

/* Device voltage range supposed to be [2.7V to 3.6V], the operation will

be done by word 

像手机升级的一样，必须保证电压稳定，同时看到如果擦除扇区，供电的电压必须为2.7V~3.6V

*/ 

if (FLASH_EraseSector(uwSectorCounter, VoltageRange_3) != FLASH_COMPLETE)

{ 

//擦除失败

printf("FLASH_EraseSector errorrn");

while (1);

}

/* jump to the next sector ，切换到下一个扇区*/

if (uwSectorCounter == FLASH_Sector_11)

{

uwSectorCounter += 40;

} 

else 

{

uwSectorCounter += 8;

}

}

}

void FLASH_Wirte_Data(uint32_t data)

{

//对对应的地址写入数据，从扇区6开始写入数据

uwAddress = FLASH_USER_START_ADDR; //扇区6的起始地址

//判断当前的写入地址是否已经到达结束扇区地址

while (uwAddress < FLASH_USER_END_ADDR)

{

//对对应的地址写入4字节数据,全部数据位0x12345678

if (FLASH_ProgramWord(uwAddress, data) == FLASH_COMPLETE)

{

//写入成功后，地址偏移4个字节

uwAddress = uwAddress + 4;

}

else

{ 

//写入数据出问题，则将错误的地址进行打印

printf("FLASH_ProgramWord at %x errorrn",uwAddress);

while (1);

}

}

//写入完毕后，则进行锁定闪存，不允许任何的修改

FLASH_Lock(); 

}

void FLASH_Read_Data(void)

{

//从起始扇区开始读取

uwAddress = FLASH_USER_START_ADDR;

//判断读取数据的地址是否已经到达结束扇区

while (uwAddress < FLASH_USER_END_ADDR)

{

//读取数据

uwData32 = *(__IO uint32_t*)uwAddress;

if (uwData32 != 0x12345678)

{

printf("flash read at %X,val=%Xrn",uwAddress,uwData32);

}

//地址偏移4个字节

uwAddress = uwAddress + 4;

}

}

//在6扇区记录

void FLASH_Record(uint32_t data, uint32_t record_count)

{

//对对应的地址写入数据，从扇区6开始写入数据

//uwAddress = FLASH_USER_START_ADDR; //扇区6的起始地址

//一系列的字节数40

uwAddress = FLASH_USER_START_ADDR + uwRecordCounter + record_count*40;

//判断当前的写入地址是否已经到达结束扇区地址

if(uwAddress < FLASH_USER_END_ADDR)

{

uwRecordCounter = uwRecordCounter + 4;

//对对应的地址写入4字节数据

if (FLASH_ProgramWord(uwAddress, data) != FLASH_COMPLETE)

{

//写入数据出问题，则将错误的地址进行打印

printf("FLASH_ProgramWord at %x errorrn",uwAddress);

while (1);

}

while(uwRecordCounter == 40)

{

uwRecordCounter = 0;

}

}

//写入完毕后，则进行锁定闪存，不允许任何的修改

//FLASH_Lock(); 

}

//读取出记录

void Record_DataRead(uint32_t record_count)

{

uint32_t Read_buf[10] = {0};

uint32_t Read_buf_count = 0;

uint32_t times = 0;

//从起始扇区开始读取

uwAddress = FLASH_USER_START_ADDR;

//判断读取数据的地址是否已经count条记录 每条记录40字节

while (uwAddress < (FLASH_USER_START_ADDR+record_count*40))

{

for(Read_buf_count = 0; Read_buf_count < 10; Read_buf_count++)

{

//读取数据

Read_buf[Read_buf_count] = *(__IO uint32_t*)uwAddress;

//地址偏移4字节

uwAddress = uwAddress + 4;

}

times++;

//格式：[001]2017/10/14  9:40:12 Temp=30.0 Humi=92.0

printf("[%03d]20%x/%x/%x  %x:%x:%x Temp=%d.%d℃ Humi=%d.%drn",times,Read_buf[0],Read_buf[1],

Read_buf[2],Read_buf[3],Read_buf[4],

Read_buf[5],Read_buf[6],Read_buf[7],

Read_buf[8],Read_buf[9]);

}

printf("读取完毕rn");

}