STM32 內部Flash帶緩存讀寫 程序源碼
由於STM32 系列Flash的Erase操作很多是按Page擦除，如果往Flash寫入的數據或餘數不夠一個整Page，那麼該Page其他數據也會被擦除掉。
所以這種情況想保持其他未操作數據不變的話，就要做緩存讀寫，既將要擦除Page的數據全讀出來，與新寫入的數據Merge後，再寫入。這一塊目前ST沒有給出Demo，需要現寫。
注意到Programming in the Flash memory performed by word or half-page 所以，Write API使用了按Word寫入
測試程序使用的單片機爲STM32L0系列，PageSize爲128B，
Memory map如下：
下面是我以前寫的API，首先是相關宏定義：
0 Macro
讀寫API內部調用的是STM32xx_hal_flash.c中的HAL_FLASH_Program API，如果使用不一樣的Hal庫，可以直接替換下方的Flash_WriteOneWord宏定義：
#define TRUE 1
#define FALSE 0
typedef unsigned char BOOL; /* boolean data */
typedef unsigned char FLAG; /* boolean data */
typedef unsigned char U8BIT; /* unsigned 8 bit data */
typedef unsigned short U16BIT; /* unsigned 16 bit data */
typedef unsigned long U32BIT; /* unsigned 32 bit data */
typedef unsigned long WORD; /* unsigned 32 bit data */
#define PAGE_SIZE FLASH_PAGE_SIZE
#define Flash_WriteOneWord(a, b) HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, a, b)
#define Flash_WriteOneHalfWord(a, b) HAL_FLASH_Program(FLASH_TYPEPROGRAM_HALFWORD, a, b)
1.Flash_Erase
Erase主要負責寫入之前清空的操作，由Wirte API判斷要Erase多少Page
/*****************************************************************************
@Name : Flash_Erase
@Brief : Erase the whole page by NumtoErase
@Param In : U32BIT StartAddr
uint16_t PageNumtoErase
@Param Out :
@Return : TURE for Success, FALSE for Failed
History :
1.Date : Tuesday, June 04, 2018
Author : Howard Xue
*****************************************************************************/
BOOL Flash_Erase(uint32_t StartAddr, uint16_t PageNumtoErase)
{
if(HAL_FLASH_Unlock() != HAL_OK)
return FALSE;
uint32_t PageError_Tmp = 0;
FLASH_EraseInitTypeDef Eras;
Eras.NbPages = PageNumtoErase;
Eras.PageAddress = StartAddr;
Eras.TypeErase = FLASH_TYPEERASE_PAGES;
if(HAL_FLASHEx_Erase(&Eras , &PageError_Tmp) != HAL_OK)
return FALSE;
if(HAL_FLASH_Lock() != HAL_OK)
return FALSE;
return TRUE;
}
2. Flash_Read_Byte
/*****************************************************************************
@Name : Flash_Read_Byte
@Brief : Read Internal Falsh data by address
@Param In : uint32_t StartAddr
uint8_t *ReadBuf
uint32_t NumToRead
@Param Out : uint8_t *ReadBuf
@Return : TURE for Success, FALSE for Failed
History :
1.Date : Tuesday, June 04, 2018
Author : Howard Xue
*****************************************************************************/
BOOL Flash_Read_Byte(uint32_t StartAddr, uint8_t *ReadBuf, uint32_t NumToRead)
{
if(NumToRead== 0)
return FALSE;
uint32_t DataNum = 0;
uint32_t ReadAddress = StartAddr;
while(DataNum < NumToRead)
{
*(ReadBuf + DataNum) = *(__IO uint8_t *)ReadAddress++;
DataNum++;
}
return TRUE;
}
3.Flash_Write_WithBuffer
BufferWrite其實就是先根據要寫多少數據，算出相應需Erase的page數，之後將這些Page的數據全讀出來，與新要寫入的數據合併覆蓋後，再寫入。 這樣就實現除了要寫入的地址數據，其他的數據不被Erase更改。
注意Wite傳入參數如果是U8的需要強制轉換成U32
/*****************************************************************************
@Name : Flash_Write_WithBuffer
@Brief : Read Buffer from Flash ,Then Merge New Data and Write
@Param In : uint32_t StartAddr
uint32_t *pBufferToWrite
uint32_t NumToWrite
@Param Out : uint32_t *pBufferToWrite
@Return : TURE for Success, FALSE for Failed
History :
1.Date : Tuesday, June 04, 2018
Author : Howard Xue
*****************************************************************************/
BOOL Flash_Write_WithBuffer(uint32_t StartAddr, uint32_t *pBufferToWrite, uint32_t NumToWrite)
{
uint8_t PageNumtoErase = 1;//default is erase 1 page.
uint32_t i;
uint32_t ReadBuffer_Length = 0;
// uint8_t ReadBuffer[FLASH_PAGE_SIZE] = {0};
if(NumToWrite == 0)
return FALSE;
//GetPageNum to erase
if(NumToWrite > FLASH_PAGE_SIZE)
{
PageNumtoErase = NumToWrite/FLASH_PAGE_SIZE + 1;
}
ReadBuffer_Length = PageNumtoErase*FLASH_PAGE_SIZE;
U32BIT *pReadBuffer = (U32BIT *)calloc(1, ReadBuffer_Length);
U32BIT *pReadBufferCount = pReadBuffer;
//1.Read orginal data from flash
Flash_Read_Byte(StartAddr,(U8BIT *)pReadBuffer,ReadBuffer_Length);
//2.Merge New Data for Write
memcpy(pReadBufferCount,pBufferToWrite,NumToWrite);
//3.Erase whole page
if(Flash_Erase(StartAddr, PageNumtoErase) != TRUE)
return FALSE;
//4.Write Buffer to Flash, Unlock -> write -> lock
if(HAL_FLASH_Unlock() != HAL_OK)
return FALSE;
for ( i = 0 ; i < (ReadBuffer_Length/4) ; i++ )
{
if(Flash_WriteOneWord(StartAddr + i * sizeof(uint32_t ), *pReadBufferCount) != HAL_OK)
return FALSE;
pReadBufferCount++;
}
if(HAL_FLASH_Lock() != HAL_OK)
return FALSE;
free(pReadBuffer);
return TRUE;
}
4.Flash_Write_NoBuffer
/*****************************************************************************
@Name : Flash_Write_NoBuffer
@Brief : Write Flash without Buffer
@Param In : uint32_t StartAddr
uint32_t *pBufferToWrite
uint32_t NumToWrite
@Param Out : uint32_t *pBufferToWrite
@Return : TURE for Success, FALSE for Failed
History :
1.Date : Tuesday, June 04, 2018
Author : Howard Xue
*****************************************************************************/
BOOL Flash_Write_NoBuffer(uint32_t StartAddr, uint32_t *pBufferToWrite, uint32_t NumToWrite)
{
uint32_t PageNumtoErase = 1;//default
uint32_t i;
if(NumToWrite == 0)
return FALSE;
//GetPageNum to erase
if(NumToWrite > FLASH_PAGE_SIZE)
{
PageNumtoErase = NumToWrite/FLASH_PAGE_SIZE + 1;
}
//Erase whole page
if(Flash_Erase(StartAddr, PageNumtoErase) != TRUE)
return FALSE;
//4.Write Buffer to Flash, Unlock -> write -> lock
if(HAL_FLASH_Unlock() != HAL_OK)
return FALSE;
for ( i = 0 ; i < (NumToWrite/4) ; i++ )
{
if(Flash_WriteOneWord(StartAddr + i * sizeof(uint32_t ), *pBufferToWrite) != HAL_OK)
return FALSE;
pBufferToWrite++;
}
if(HAL_FLASH_Lock() != HAL_OK)
return FALSE;
return TRUE;
}
5. Test
Test程序中，先Flash_Write_NoBuffer將Data全部寫入Flash，然後更改幾個下次要寫入的數值，只寫入更改的數據，這樣FlashBufferWrite就會僅更新更改的數值，其他數值不變（如果不使用BufferWrite，Flash同一Page其他數據都會被Erase）
注意Wite傳入參數如果是U8的需要強制轉換成U32
void FlashTest()
{
U8BIT Data_W[64] = {0xFA,0xFA,0xFE,0xFE,0xFA,0xFA,0xFE,0xFE,0xFA,0xFA,0xFE,0xFE,0xFA,0xFA,0xFE,0xFE,0xFA,0xFA,0xFE,0xFE,0xFA,0xFA,0xFE,0xFE};
U8BIT Data_R[64] = {0};
U32BIT FLASH_DATAZONE_BASE_ADDR = 0x08028000; //Address for test
Flash_Read_Byte（FLASH_DATAZONE_BASE_ADDR, Data_R,sizeof(Data_R));
Flash_Write_NoBuffer(FLASH_DATAZONE_BASE_ADDR,(U32BIT *)&Data_W[0],sizeof(Data_W));
Flash_Read_Byte(FLASH_DATAZONE_BASE_ADDR, Data_R,sizeof(Data_R));
Data_W[0] = 0;
Data_W[1] = 1;
//Merge new data and write, ohter data will contained
Flash_Write_WithBuffer(FLASH_DATAZONE_BASE_ADDR,(U32BIT *)&Data_W[0],4);
Flash_Read_Byte(FLASH_DATAZONE_BASE_ADDR, Data_R,sizeof(Data_R));
}