STM32内部flash详解（1）_操作_存放器

主存储器：在STM32F4中共有12个主存储器扇区，这12个扇区分为4个16KB、1个64KB以及7个128KB扇区。
系统存储器：器件在系统存储器自举模式下从该存储器启动（便是boot代码，出厂就已经存在的，专门给主存储器下载代码用的，这时候B0外接3.3V,B1接GND的时候从写个存储器启动（像CAN、串口下载就用这个）。
OTP 区域：即一次性可编程区域，共 528 字节，被分成两个部分，前面 512 字节（32 字节为 1 块，分成 16 块），可以用来存储一些用户数据（一次性的，写完一次，永久不可以擦除），后面 16 字节，用于锁定对应块。
如图：选项字节：选项字节用于配置 FLASH 的读写保护、电源管理中的 BOR 级别、软件/硬件看门狗等功能，这部分共 32 字节。
可以通过修正 FLASH 的选项掌握寄存器修正。
STM32读写在对FLASH读写之前首先须要对flash解锁。
紧张流程如下：1-解锁

因芯片内flash存储的是核心程序，因此默认是上锁的，须要通过软件编写进行解锁（有对应的解锁寄存器和库函数）。

复位后，Flash 掌握寄存器 (FLASH_CR) 不许可实行写操作，以防因电气滋扰等缘故原由涌现对Flash 的意外操作。
此寄存器的解锁顺序如下：

1-第一步在 Flash 密钥寄存器 (FLASH_KEYR) 中写入 KEY1 = 0x45670123

2-第二部在 Flash 密钥寄存器 (FLASH_KEYR) 中写入 KEY2 = 0xCDEF89AB

（把稳：如果flash解锁顺序涌现缺点，将返回总线缺点并锁定 FLASH_CR 寄存器，直到下一次复位。
也可通过软件将 FLASH_CR 寄存器中的 LOCK 位置为 1 来锁定 FLASH_CR 寄存器。
当 FLASH_SR 寄存器中的 BSY 位为 1 时，将不能在写模式下访问 FLASH_CR 寄存器。
BSY 位为 1 时，对该寄存器的任何写操作考试测验都会导致 AHB 总线壅塞，直到 BSY 位清零。
）

最大操作位数会影响擦除和写入的速率，个中 64 位宽度的操作除了配置寄存器位外，还须要在 Vpp 引脚外加一个 8-9V 的电压源，且其供电韶光不得超过一小时，否则 FLASH可能破坏，以是 64 位宽度的操作一样平常是在量产时对 FLASH 写入运用程序时才利用，大部分运用处所都是用 32 位的宽度。

再下入一块新数据之前，我们须要把之前的数据给擦出掉。
步骤如下：

当flash擦除完毕后，我们对其进行数据的写入（写入flash便是操作指针、地址这些）。
步骤如下：

Flash 编程顺序如下：

不许可针对 Flash 实行超过 128 位行界线的数据编程操作。
如果涌现这种情形，写操作将不会实行，并且 FLASH_SR 寄存器中的编程对齐缺点标志位 (PGAERR) 将置 1。
写访问宽度（字节、半字、字或双字）必须与所选并行位数类型（x8、x16、x32 或 x64）符合。
否则，写操作将不会实行，并且 FLASH_SR 寄存器中的编程并行位数缺点标志位(PGPERR) 将置 1。
如果未遵照标准的编程顺序（例如，在 PG 位未置 1 时考试测验向 Flash 地址写入数据），则操作将中止并且 FLASH_SR 寄存器中的编程顺序缺点标志位 (PGSERR) 将置 1。
说白了就两点：一是不能越界，而是按照顺序编写

如果 Flash 写访问涉及数据缓存中的某些数据，Flash 写访问将修正 Flash 中的数据和缓存中的数据。

如果 Flash 中的擦除操作也涉及数据或指令缓存中的数据，则必须确保在代码实行期间访问这些数据之前将它们重新写入缓存。
如果无法可靠实行这一操作，建议将 FLASH_CR 寄存器中的 DCRST 和 ICRST 位置 1，以刷新缓存把稳：I/D 缓存只有在被禁止 (I/DCEN = 0) 的情形下才能刷新

我们打开MDK可以看到代码霸占了多少flash如下两幅图:

1-Flash解锁的操作（操作库函数，也可以操作寄存器看个人）

文件：stm32f4xx_flash.cstm32f4xx_flash.h

我们想要把数据写入flash之前一定要先解锁，否则数据无法写入成功。

#define RDP_KEY ((uint16_t)0x00A5)#define FLASH_KEY1 ((uint32_t)0x45670123)#define FLASH_KEY2 ((uint32_t)0xCDEF89AB)#define FLASH_OPT_KEY1 ((uint32_t)0x08192A3B)#define FLASH_OPT_KEY2 ((uint32_t)0x4C5D6E7F)//解锁FLASH控件寄存器访问void FLASH_Unlock(void){if((FLASH->CR & FLASH_CR_LOCK) != RESET){/ Authorize the FLASH Registers access /FLASH->KEYR = FLASH_KEY1;FLASH->KEYR = FLASH_KEY2;} }2-打消标志位

@brief Clears the FLASH's pending flags. @param FLASH_FLAG: specifies the FLASH flags to clear. This parameter can be any combination of the following values: @arg FLASH_FLAG_EOP: FLASH End of Operation flag @arg FLASH_FLAG_OPERR: FLASH operation Error flag @arg FLASH_FLAG_WRPERR: FLASH Write protected error flag @arg FLASH_FLAG_PGAERR: FLASH Programming Alignment error flag @arg FLASH_FLAG_PGPERR: FLASH Programming Parallelism error flag @arg FLASH_FLAG_PGSERR: FLASH Programming Sequence error flag @arg FLASH_FLAG_RDERR: FLASH Read Protection error flag (STM32F42xx/43xxx and STM32F401xx/411xE devices) @retval None/void FLASH_ClearFlag(uint32_t FLASH_FLAG){/ Check the parameters /assert_param(IS_FLASH_CLEAR_FLAG(FLASH_FLAG));/ Clear the flags /FLASH->SR = FLASH_FLAG;}3-擦除

STM32 擦除可以按照块擦除、扇区擦除、擦除全部扇区这三种情形，从上面就能理解这三个的不同

/ @brief Erases a specified FLASH Sector. @note If an erase and a program operations are requested simultaneously, the erase operation is performed before the program one. @param FLASH_Sector: The Sector number to be erased. @note For STM32F405xx/407xx and STM32F415xx/417xx devices this parameter can be a value between FLASH_Sector_0 and FLASH_Sector_11. For STM32F42xxx/43xxx devices this parameter can be a value between FLASH_Sector_0 and FLASH_Sector_23. For STM32F401xx devices this parameter can be a value between FLASH_Sector_0 and FLASH_Sector_5. For STM32F411xE devices this parameter can be a value between FLASH_Sector_0 and FLASH_Sector_7. @param VoltageRange: The device voltage range which defines the erase parallelism. This parameter can be one of the following values: @arg VoltageRange_1: when the device voltage range is 1.8V to 2.1V, the operation will be done by byte (8-bit) @arg VoltageRange_2: when the device voltage range is 2.1V to 2.7V, the operation will be done by half word (16-bit) @arg VoltageRange_3: when the device voltage range is 2.7V to 3.6V, the operation will be done by word (32-bit) @arg VoltageRange_4: when the device voltage range is 2.7V to 3.6V + External Vpp, the operation will be done by double word (64-bit) @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_ERROR_OPERATION or FLASH_COMPLETE./FLASH_Status FLASH_EraseSector(uint32_t FLASH_Sector, uint8_t VoltageRange){uint32_t tmp_psize = 0x0;FLASH_Status status = FLASH_COMPLETE;/ Check the parameters /assert_param(IS_FLASH_SECTOR(FLASH_Sector));assert_param(IS_VOLTAGERANGE(VoltageRange));if(VoltageRange == VoltageRange_1){tmp_psize = FLASH_PSIZE_BYTE;}else if(VoltageRange == VoltageRange_2){tmp_psize = FLASH_PSIZE_HALF_WORD;}else if(VoltageRange == VoltageRange_3){tmp_psize = FLASH_PSIZE_WORD;}else{tmp_psize = FLASH_PSIZE_DOUBLE_WORD;}/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();if(status == FLASH_COMPLETE){ / if the previous operation is completed, proceed to erase the sector /FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= tmp_psize;FLASH->CR &= SECTOR_MASK;FLASH->CR |= FLASH_CR_SER | FLASH_Sector;FLASH->CR |= FLASH_CR_STRT;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the erase operation is completed, disable the SER Bit /FLASH->CR &= (~FLASH_CR_SER);FLASH->CR &= SECTOR_MASK; }/ Return the Erase Status /return status;}/ @brief Erases all FLASH Sectors. @note If an erase and a program operations are requested simultaneously, the erase operation is performed before the program one. @param VoltageRange: The device voltage range which defines the erase parallelism. This parameter can be one of the following values: @arg VoltageRange_1: when the device voltage range is 1.8V to 2.1V, the operation will be done by byte (8-bit) @arg VoltageRange_2: when the device voltage range is 2.1V to 2.7V, the operation will be done by half word (16-bit) @arg VoltageRange_3: when the device voltage range is 2.7V to 3.6V, the operation will be done by word (32-bit) @arg VoltageRange_4: when the device voltage range is 2.7V to 3.6V + External Vpp, the operation will be done by double word (64-bit) @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_ERROR_OPERATION or FLASH_COMPLETE./FLASH_Status FLASH_EraseAllSectors(uint8_t VoltageRange){uint32_t tmp_psize = 0x0;FLASH_Status status = FLASH_COMPLETE;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();assert_param(IS_VOLTAGERANGE(VoltageRange));if(VoltageRange == VoltageRange_1){tmp_psize = FLASH_PSIZE_BYTE;}else if(VoltageRange == VoltageRange_2){tmp_psize = FLASH_PSIZE_HALF_WORD;}else if(VoltageRange == VoltageRange_3){tmp_psize = FLASH_PSIZE_WORD;}else{tmp_psize = FLASH_PSIZE_DOUBLE_WORD;} if(status == FLASH_COMPLETE){/ if the previous operation is completed, proceed to erase all sectors /#if defined(STM32F427_437xx) || defined(STM32F429_439xx) FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= tmp_psize;FLASH->CR |= (FLASH_CR_MER1 | FLASH_CR_MER2);FLASH->CR |= FLASH_CR_STRT;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the erase operation is completed, disable the MER Bit /FLASH->CR &= ~(FLASH_CR_MER1 | FLASH_CR_MER2);#endif / STM32F427_437xx || STM32F429_439xx /#if defined(STM32F40_41xxx) || defined(STM32F401xx) || defined(STM32F411xE) || defined(STM32F446xx)FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= tmp_psize;FLASH->CR |= FLASH_CR_MER;FLASH->CR |= FLASH_CR_STRT;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the erase operation is completed, disable the MER Bit /FLASH->CR &= (~FLASH_CR_MER);#endif / STM32F40_41xxx || STM32F401xx || STM32F411xE || STM32F446xx /} / Return the Erase Status /return status;}/ @brief Erases all FLASH Sectors in Bank 1. @note This function can be used only for STM32F42xxx/43xxx devices. @note If an erase and a program operations are requested simultaneously, the erase operation is performed before the program one. @param VoltageRange: The device voltage range which defines the erase parallelism. This parameter can be one of the following values: @arg VoltageRange_1: when the device voltage range is 1.8V to 2.1V, the operation will be done by byte (8-bit) @arg VoltageRange_2: when the device voltage range is 2.1V to 2.7V, the operation will be done by half word (16-bit) @arg VoltageRange_3: when the device voltage range is 2.7V to 3.6V, the operation will be done by word (32-bit) @arg VoltageRange_4: when the device voltage range is 2.7V to 3.6V + External Vpp, the operation will be done by double word (64-bit) @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_ERROR_OPERATION or FLASH_COMPLETE./FLASH_Status FLASH_EraseAllBank1Sectors(uint8_t VoltageRange){uint32_t tmp_psize = 0x0;FLASH_Status status = FLASH_COMPLETE;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();assert_param(IS_VOLTAGERANGE(VoltageRange));if(VoltageRange == VoltageRange_1){tmp_psize = FLASH_PSIZE_BYTE;}else if(VoltageRange == VoltageRange_2){tmp_psize = FLASH_PSIZE_HALF_WORD;}else if(VoltageRange == VoltageRange_3){tmp_psize = FLASH_PSIZE_WORD;}else{tmp_psize = FLASH_PSIZE_DOUBLE_WORD;} if(status == FLASH_COMPLETE){/ if the previous operation is completed, proceed to erase all sectors /FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= tmp_psize;FLASH->CR |= FLASH_CR_MER1;FLASH->CR |= FLASH_CR_STRT;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the erase operation is completed, disable the MER Bit /FLASH->CR &= (~FLASH_CR_MER1);} / Return the Erase Status /return status;}/ @brief Erases all FLASH Sectors in Bank 2. @note This function can be used only for STM32F42xxx/43xxx devices. @note If an erase and a program operations are requested simultaneously, the erase operation is performed before the program one. @param VoltageRange: The device voltage range which defines the erase parallelism. This parameter can be one of the following values: @arg VoltageRange_1: when the device voltage range is 1.8V to 2.1V, the operation will be done by byte (8-bit) @arg VoltageRange_2: when the device voltage range is 2.1V to 2.7V, the operation will be done by half word (16-bit) @arg VoltageRange_3: when the device voltage range is 2.7V to 3.6V, the operation will be done by word (32-bit) @arg VoltageRange_4: when the device voltage range is 2.7V to 3.6V + External Vpp, the operation will be done by double word (64-bit) @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_ERROR_OPERATION or FLASH_COMPLETE./FLASH_Status FLASH_EraseAllBank2Sectors(uint8_t VoltageRange){uint32_t tmp_psize = 0x0;FLASH_Status status = FLASH_COMPLETE;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();assert_param(IS_VOLTAGERANGE(VoltageRange));if(VoltageRange == VoltageRange_1){tmp_psize = FLASH_PSIZE_BYTE;}else if(VoltageRange == VoltageRange_2){tmp_psize = FLASH_PSIZE_HALF_WORD;}else if(VoltageRange == VoltageRange_3){tmp_psize = FLASH_PSIZE_WORD;}else{tmp_psize = FLASH_PSIZE_DOUBLE_WORD;} if(status == FLASH_COMPLETE){/ if the previous operation is completed, proceed to erase all sectors /FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= tmp_psize;FLASH->CR |= FLASH_CR_MER2;FLASH->CR |= FLASH_CR_STRT;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the erase operation is completed, disable the MER Bit /FLASH->CR &= (~FLASH_CR_MER2);} / Return the Erase Status /return status;}4-编程（数据写入）

把稳：STM32写入可以按照字、半字、字节单位写入（这点记住每个厂商写入的字节数有的并不相同，像华大的就和这不太一样）

@brief 在指定地址上编程双字(64位)。
@note This function must be used when the device voltage range is from 2.7V to 3.6V and an External Vpp is present. @note If an erase and a program operations are requested simultaneously, the erase operation is performed before the program one. @param Address: specifies the address to be programmed. @param Data: specifies the data to be programmed. @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_ERROR_OPERATION or FLASH_COMPLETE./FLASH_Status FLASH_ProgramDoubleWord(uint32_t Address, uint64_t Data){FLASH_Status status = FLASH_COMPLETE;/ Check the parameters /assert_param(IS_FLASH_ADDRESS(Address));/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();if(status == FLASH_COMPLETE){/ if the previous operation is completed, proceed to program the new data /FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= FLASH_PSIZE_DOUBLE_WORD;FLASH->CR |= FLASH_CR_PG;(__IO uint64_t)Address = Data;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the program operation is completed, disable the PG Bit /FLASH->CR &= (~FLASH_CR_PG);} / Return the Program Status /return status;}/ @brief 在指定地址编程一个字(32位)。
@note This function must be used when the device voltage range is from 2.7V to 3.6V. @note If an erase and a program operations are requested simultaneously, the erase operation is performed before the program one. @param Address: specifies the address to be programmed. This parameter can be any address in Program memory zone or in OTP zone. @param Data: specifies the data to be programmed. @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_ERROR_OPERATION or FLASH_COMPLETE./FLASH_Status FLASH_ProgramWord(uint32_t Address, uint32_t Data){FLASH_Status status = FLASH_COMPLETE;/ Check the parameters /assert_param(IS_FLASH_ADDRESS(Address));/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();if(status == FLASH_COMPLETE){/ if the previous operation is completed, proceed to program the new data /FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= FLASH_PSIZE_WORD;FLASH->CR |= FLASH_CR_PG;(__IO uint32_t)Address = Data;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the program operation is completed, disable the PG Bit /FLASH->CR &= (~FLASH_CR_PG);} / Return the Program Status /return status;}/ @brief 在指定地址上编程半字(16位)。
@note This function must be used when the device voltage range is from 2.1V to 3.6V. @note If an erase and a program operations are requested simultaneously, the erase operation is performed before the program one. @param Address: specifies the address to be programmed. This parameter can be any address in Program memory zone or in OTP zone. @param Data: specifies the data to be programmed. @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_ERROR_OPERATION or FLASH_COMPLETE./FLASH_Status FLASH_ProgramHalfWord(uint32_t Address, uint16_t Data){FLASH_Status status = FLASH_COMPLETE;/ Check the parameters /assert_param(IS_FLASH_ADDRESS(Address));/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();if(status == FLASH_COMPLETE){/ if the previous operation is completed, proceed to program the new data /FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= FLASH_PSIZE_HALF_WORD;FLASH->CR |= FLASH_CR_PG;(__IO uint16_t)Address = Data;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the program operation is completed, disable the PG Bit /FLASH->CR &= (~FLASH_CR_PG);} / Return the Program Status /return status;}/ @brief 在指定地址编程序一个字节(8位)。
@note This function can be used within all the device supply voltage ranges. @note If an erase and a program operations are requested simultaneously, the erase operation is performed before the program one. @param Address: specifies the address to be programmed. This parameter can be any address in Program memory zone or in OTP zone. @param Data: specifies the data to be programmed. @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PROGRAM, FLASH_ERROR_WRP, FLASH_ERROR_OPERATION or FLASH_COMPLETE./FLASH_Status FLASH_ProgramByte(uint32_t Address, uint8_t Data){FLASH_Status status = FLASH_COMPLETE;/ Check the parameters /assert_param(IS_FLASH_ADDRESS(Address));/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();if(status == FLASH_COMPLETE){/ if the previous operation is completed, proceed to program the new data /FLASH->CR &= CR_PSIZE_MASK;FLASH->CR |= FLASH_PSIZE_BYTE;FLASH->CR |= FLASH_CR_PG;(__IO uint8_t)Address = Data;/ Wait for last operation to be completed /status = FLASH_WaitForLastOperation();/ if the program operation is completed, disable the PG Bit /FLASH->CR &= (~FLASH_CR_PG);} / Return the Program Status /return status;}5- 上锁

@brief Locks the FLASH control register access @param None @retval None/void FLASH_Lock(void){/ Set the LOCK Bit to lock the FLASH Registers access /FLASH->CR |= FLASH_CR_LOCK;}

以是根据以上总结如下步骤（严格来说中间还有一些过程，但是常用的就这几步骤，当然库函数不知这几个，还有得到标志位什么的，这点后面再讲）。

(1) 调用 FLASH_Unlock 解锁；

(2) 调用 FLASH_ClearFlag 打消各种标志位；

(3) 根据起始地址及结束地址打算要擦除的扇区；

(4) 调用 FLASH_EraseSector （或FLASH_EraseAllSectors、FLASH_EraseAllBank1Sectors、FLASH_EraseAllBank2Sectors，一样平常情形下都是按照扇区删除，有时也会按照块删除）擦除扇区，擦除时按字为单位进行操作；

(5) 调用 FLASH_ProgramWord（或其他都可以） 函数向起始地址至结束地址的存储区域都写入数值

(6) 调用 FLASH_Lock 上锁；

(7) 利用指针读取数据内容并校验。

咱们来看一下官网给出的例子

/ 解锁Flash // 启用flash掌握寄存器访问 /FLASH_Unlock();/ 擦除用户Flash区域// area defined by FLASH_USER_START_ADDR and FLASH_USER_END_ADDR // 打消挂起的标志(如果有) / FLASH_ClearFlag(FLASH_FLAG_EOP | FLASH_FLAG_OPERR | FLASH_FLAG_WRPERR | FLASH_FLAG_PGAERR | FLASH_FLAG_PGPERR|FLASH_FLAG_PGSERR); / 获取开始扇区和结束扇区的数量 /uwStartSector = GetSector(FLASH_USER_START_ADDR);uwEndSector = GetSector(FLASH_USER_END_ADDR);/开始擦除操作 /uwSectorCounter = uwStartSector;while (uwSectorCounter <= uwEndSector) {/ 设备电压范围假定为[2.7V ~ 3.6V]，操作将通过字完成/ if (FLASH_EraseSector(uwSectorCounter, VoltageRange_3) != FLASH_COMPLETE){ / 扇区擦除时发生缺点。
. 用户可以在这里添加一些代码来处理这个缺点 /while (1){}}/ 跳到下一个扇区 /if (uwSectorCounter == FLASH_Sector_11){uwSectorCounter += 40;} else {uwSectorCounter += 8;}}/ 按照字写入Flash区 // area defined by FLASH_USER_START_ADDR and FLASH_USER_END_ADDR /uwAddress = FLASH_USER_START_ADDR;while (uwAddress < FLASH_USER_END_ADDR){if (FLASH_ProgramWord(uwAddress, DATA_32) == FLASH_COMPLETE){uwAddress = uwAddress + 4;}else{ / Error occurred while writing data in Flash memory. User can add here some code to deal with this error /while (1){}}}/ Lock the Flash to disable the flash control register access (recommendedto protect the FLASH memory against possible unwanted operation) /FLASH_Lock();

还有一些下章先容。