前言

CYPRESS的PSOC BLE和PROC BLE芯片内部有个512Bytes的SFLash，用于保存用户指定的数据，接下来分享下如何对该区域进行读写
SFLASH的内部结构

从上图可以看出，SFLASH共有4行，每行128Bytes，其中第0行的前6个字节是存放BLE的MAC地址用的，用户不能修改否则MAC地址就会被篡改了。同时，SFLASH地址从0x0FFF F200_0x0FFF F380.

写SFLASH的关键代码实现
根据《cy_boot Component v5.30》手册的第8章所说，写SFLASH都是一次性写入128Bytes数据，不能一个Bytes一个Bytes地写入SFlash，但是我进行了相应的修改，一行可以在SFLASH地址范围指定的地方写入数据，代码如下：

1. 使用到的宏定义：
/*****************************************************
*                  Enums and macros
*****************************************************/  
#define SWITCH_PRESSED                  (0u)   /* Active low user switch on BLE Pioneer kit */
#define USER_SFLASH_ROW_SIZE            (128u) /* SFlash row size for 128KB flash BLE device. For other PSoC 4 BLE devices
                                                * with higher flash size, this example project might need some modification.
                                                * Please check the device datasheet and TRM before using this code on non 128KB
                                                * flash devices */
#define SFLASH_STARTING_VALUE           (0x00) /* Starting value to be stored in user SFlash to demonstrate SFlash write API */
#define USER_SFLASH_ROWS                (4u)   /* Total number of user SFlash rows supported by the device */
#define USER_SFLASH_BASE_ADDRESS        (0x0FFFF200u) /* Starting address of user SFlash row for 128KB PSoC 4 BLE device */   
   
#define LOAD_FLASH                                         0x80000004
#define WRITE_USER_SFLASH_ROW                 0x80000018
#define USER_SFLASH_WRITE_SUCCESSFUL     0xA0000000     

2. 关键代码的实现：

/*******************************************************************************
* Function Name: WriteUserSFlashRow
********************************************************************************
* Summary:
*        This routine calls the PSoC 4 BLE device supervisory ROM APIs to update
* the user configuration area of Supervisory Flash (SFlash).  
*
* Parameters:
*  userRowNUmber - User config SFlash row number to which data is to be written
*  dataPointer - Pointer to the data to be written. This API writes one row of
*                user config SFlash row at a time.
*
* Return:
*  uint32 - state of the user config SFlash write operation.
*
*******************************************************************************/
#if defined (__GNUC__)
#pragma GCC optimize ("O0")
#endif /* End of #if defined (__GNUC__) */
uint32 WriteUserSFlashRow(uint8 userRowNUmber, uint32 *dataPointer,uint8_t datalength,uint8_t address)
{
    uint8 localCount;
        volatile uint32 retValue=0;
//        volatile uint32 cmdDataBuffer[(CY_FLASH_SIZEOF_ROW/4) + 2];
    volatile uint32 cmdDataBuffer[datalength+2];
        volatile uint32 reg1,reg2,reg3,reg4,reg5,reg6;
        
        /* Store the clock settings temporarily */
    reg1 =        CY_GET_XTND_REG32((void CYFAR *)(CYREG_CLK_SELECT));
    reg2 =  CY_GET_XTND_REG32((void CYFAR *)(CYREG_CLK_IMO_CONFIG));
    reg3 =  CY_GET_XTND_REG32((void CYFAR *)(CYREG_PWR_BG_TRIM4));
    reg4 =  CY_GET_XTND_REG32((void CYFAR *)(CYREG_PWR_BG_TRIM5));
    reg5 =  CY_GET_XTND_REG32((void CYFAR *)(CYREG_CLK_IMO_TRIM1));
    reg6 =  CY_GET_XTND_REG32((void CYFAR *)(CYREG_CLK_IMO_TRIM2));
        
        /* Initialize the clock necessary for flash programming */
        CY_SET_REG32(CYREG_CPUSS_SYSARG, 0x0000e8b6);
        CY_SET_REG32(CYREG_CPUSS_SYSREQ, 0x80000015);
        
        /******* Initialize SRAM parameters for the LOAD FLASH command ******/
        /* byte 3 (i.e. 00) is the Macro_select */
        /* byte 2 (i.e. 00) is the Start addr of page latch */
        /* byte 1 (i.e. d7) is the key 2  */
        /* byte 0 (i.e. b6) is the key 1  */
          cmdDataBuffer[0]=0x0000d7b6|(address<<16);
        /****** Initialize SRAM parameters for the LOAD FLASH command ******/
        /* byte 3,2 and 1 are null */
        /* byte 0 (i.e. 7F) is the number of bytes to be written */
        cmdDataBuffer[1]=0x00000000|datalength-1;            
        /* Initialize the SRAM buffer with data bytes */
//    cmdDataBuffer[2] = *dataPointer;
    for(localCount = 0; localCount < datalength; localCount++)   
        {
                cmdDataBuffer[localCount + 2 = dataPointer[localCount];
        }
        
        /* Write the following to registers to execute a LOAD FLASH bytes */
        CY_SET_REG32(CYREG_CPUSS_SYSARG, &cmdDataBuffer[0]);
        CY_SET_REG32(CYREG_CPUSS_SYSREQ, LOAD_FLASH);
        
    /****** Initialize SRAM parameters for the WRITE ROW command ******/
        /* byte 3 & 2 are null */
        /* byte 1 (i.e. 0xeb) is the key 2  */
        /* byte 0 (i.e. 0xb6) is the key 1  */
        cmdDataBuffer[0 = 0x0000ebb6;
   
        /* byte 7,6 and 5 are null */
        /* byte 4 is desired SFlash user row
         * Allowed values 0 - row 4
                          1 - row 5
                                          2 - row 6
                                          3 - row 7 */
        cmdDataBuffer[1 = (uint32) userRowNUmber;
        
        /* Write the following to registers to execute a WRITE USER SFlash ROW command */
        CY_SET_REG32(CYREG_CPUSS_SYSARG, &cmdDataBuffer[0]);
        CY_SET_REG32(CYREG_CPUSS_SYSREQ, WRITE_USER_SFLASH_ROW);
   
        /* Read back SYSARG for the result. 0xA0000000 = SUCCESS; */
        retValue = CY_GET_REG32(CYREG_CPUSS_SYSARG);
        
        /* Restore the clock settings after the flash programming is done */
    CY_SET_XTND_REG32((void CYFAR *)(CYREG_CLK_SELECT),reg1);
    CY_SET_XTND_REG32((void CYFAR *)(CYREG_CLK_IMO_CONFIG),reg2);
    CY_SET_XTND_REG32((void CYFAR *)(CYREG_PWR_BG_TRIM4),reg3);
    CY_SET_XTND_REG32((void CYFAR *)(CYREG_PWR_BG_TRIM5),reg4);
    CY_SET_XTND_REG32((void CYFAR *)(CYREG_CLK_IMO_TRIM1),reg5);
    CY_SET_XTND_REG32((void CYFAR *)(CYREG_CLK_IMO_TRIM2),reg6);  
        
        return retValue;
}
#if defined (__GNUC__)
#pragma GCC reset_options
#endif /* End of #if defined (__GNUC__) */

3. 读SFLASH的内容

直接读x0FFF F200~0x0FFF F380地址的内容即可，代码实现如下:

/*******************************************************************************
* Function Name: ReadDataFromSFlash
********************************************************************************
*
*
*
*  读取SFlash中的数据
* \param  none
* \return
*  None
*       SFlash中有506Bytes字节的用户可配置的空间
******************************************************************************/
uint8_t ReadDataFromSFlash()
{
   
    uint8_t FlashData=0;
    uint8_t *sflashPtr=(uint8_t *)USER_SFLASH_BASE_ADDRESS;//SFlash的首地址
    sflashPtr=sflashPtr+6;//前6字节是保存MAC地址，不能修改
    FlashData=*sflashPtr;
    return FlashData;   
}

cypress-blesflash.pdf

363kB