在FreeRTOS環境下，如果外部擦寫 Flash，禁用指令緩存以避免在多個任務中使用來自Flash 的分支預測和應用程序同步操作 Flash的緩存預加載指令。因為代碼是XIP，所以向量表也在Flash 中。所以，當發生中斷時，內核將讀取此中斷向量表。如果同時，Flash閃存被編程寫入，讀取操作將失敗。用戶通過禁用中斷來保護關鍵代碼，以避免這種情況。

使用 "taskENTER/EXIT_CRITICAL()" 函數，最后它會調用如下圖這個函數vPortRaiseBASEPRI。該函數只能禁用優先級低于configMAX_SYSCALL_INTERRUPT_priority的中斷，這可以確保系統仍然可以工作。因此，需要檢查所有其他外設中斷的優先級，比如LCDIPv2_IRQn，LPUART，LPSPI 等等。要確保優先級低于configMAX_SYSCALL_INTERRUPT_priority，或將configMAX_SYSCALL_INTERROPT_priority配置為更高的優先級。

不需要逐一禁用所有IRQ。因此，如果使用上述方式還有問題，請嘗試如下API：

__set_PRIMASK(1);//關閉總中斷

//擦，寫，讀 Flash//

__set_PRIMASK(0);//開啟總中斷

參考示例代碼：

/* FreeRTOS kernel includes. */

#include "FreeRTOS.h"

#include "task.h"

#include "queue.h"

#include "timers.h"

/* Freescale includes. */

#include "fsl_device_registers.h"

#include "fsl_debug_console.h"

#include "fsl_flexspi.h"

#include "pin_mux.h"

#include "clock_config.h"

#include "board.h"

#include "app.h"

#include "fsl_common.h"

/* Task priorities. */

#define hello_task_PRIORITY (configMAX_PRIORITIES - 2)

#define flash_operation_task_PRIORITY (configMAX_PRIORITIES - 1)

static void hello_task(void *pvParameters);

static void flash_operation_task(void *pvParameters);

status_t flexspi_nor_flash_read_sector(FLEXSPI_Type *base, uint32_t address, const uint32_t *src, size_t leng);

extern status_t flexspi_nor_flash_erase_sector(FLEXSPI_Type *base, uint32_t address);

extern status_t flexspi_nor_flash_page_program(FLEXSPI_Type *base, uint32_t dstAddr, const uint32_t *src);

extern status_t flexspi_nor_get_vendor_id(FLEXSPI_Type *base, uint8_t *vendorId);

extern status_t flexspi_nor_enable_quad_mode(FLEXSPI_Type *base);

extern void flexspi_nor_flash_init(FLEXSPI_Type *base);

extern void flexspi_clear_buffer(FLEXSPI_Type *base);

flexspi_device_config_t deviceconfig = {

.flexspiRootClk = 12000000,

.flashSize = FLASH_SIZE,

.CSIntervalUnit = kFLEXSPI_CsIntervalUnit1SckCycle,

.CSInterval = 2,

.CSHoldTime = 3,

.CSSetupTime = 3,

.dataValidTime = 0,

.columnspace = 0,

.enableWordAddress = 0,

.AWRSeqIndex = 0,

.AWRSeqNumber = 0,

.ARDSeqIndex = NOR_CMD_LUT_SEQ_IDX_READ_FAST_QUAD,

.ARDSeqNumber = 1,

.AHBWriteWaitUnit = kFLEXSPI_AhbWriteWaitUnit2AhbCycle,

.AHBWriteWaitInterval = 0,

};

constuint32_tcustomLUT[CUSTOM_LUT_LENGTH]={

/* Normal read mode -SDR */

[4 * NOR_CMD_LUT_SEQ_IDX_READ_NORMAL] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x03, kFLEXSPI_Command_RADDR_SDR, kFLEXSPI_1PAD, 0x18),

[4 * NOR_CMD_LUT_SEQ_IDX_READ_NORMAL + 1] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_READ_SDR, kFLEXSPI_1PAD, 0x04, kFLEXSPI_Command_STOP, kFLEXSPI_1PAD, 0),

/* Fast read mode - SDR */

[4 * NOR_CMD_LUT_SEQ_IDX_READ_FAST] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x0B, kFLEXSPI_Command_RADDR_SDR, kFLEXSPI_1PAD, 0x18),

[4 * NOR_CMD_LUT_SEQ_IDX_READ_FAST + 1] = FLEXSPI_LUT_SEQ(

kFLEXSPI_Command_DUMMY_SDR, kFLEXSPI_1PAD, 0x08, kFLEXSPI_Command_READ_SDR, kFLEXSPI_1PAD, 0x04),

/* Fast read quad mode - SDR */

[4 * NOR_CMD_LUT_SEQ_IDX_READ_FAST_QUAD] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0xEB, kFLEXSPI_Command_RADDR_SDR, kFLEXSPI_4PAD, 0x18),

[4 * NOR_CMD_LUT_SEQ_IDX_READ_FAST_QUAD + 1] = FLEXSPI_LUT_SEQ(

kFLEXSPI_Command_DUMMY_SDR, kFLEXSPI_4PAD, 0x06, kFLEXSPI_Command_READ_SDR, kFLEXSPI_4PAD, 0x04),

/* Read extend parameters */

[4 * NOR_CMD_LUT_SEQ_IDX_READSTATUS] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x81, kFLEXSPI_Command_READ_SDR, kFLEXSPI_1PAD, 0x04),

/* Write Enable */

[4 * NOR_CMD_LUT_SEQ_IDX_WRITEENABLE] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x06, kFLEXSPI_Command_STOP, kFLEXSPI_1PAD, 0),

/* Erase Sector */

[4 * NOR_CMD_LUT_SEQ_IDX_ERASESECTOR] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0xD7, kFLEXSPI_Command_RADDR_SDR, kFLEXSPI_1PAD, 0x18),

/* Page Program - single mode */

[4 * NOR_CMD_LUT_SEQ_IDX_PAGEPROGRAM_SINGLE] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x02, kFLEXSPI_Command_RADDR_SDR, kFLEXSPI_1PAD, 0x18),

[4 * NOR_CMD_LUT_SEQ_IDX_PAGEPROGRAM_SINGLE + 1] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_WRITE_SDR, kFLEXSPI_1PAD, 0x04, kFLEXSPI_Command_STOP, kFLEXSPI_1PAD, 0),

/* Page Program - quad mode */

[4 * NOR_CMD_LUT_SEQ_IDX_PAGEPROGRAM_QUAD] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x32, kFLEXSPI_Command_RADDR_SDR, kFLEXSPI_1PAD, 0x18),

[4 * NOR_CMD_LUT_SEQ_IDX_PAGEPROGRAM_QUAD + 1] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_WRITE_SDR, kFLEXSPI_4PAD, 0x04, kFLEXSPI_Command_STOP, kFLEXSPI_1PAD, 0),

/* Read ID */

[4 * NOR_CMD_LUT_SEQ_IDX_READID] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x9F, kFLEXSPI_Command_READ_SDR, kFLEXSPI_1PAD, 0x04),

/* Enable Quad mode */

[4 * NOR_CMD_LUT_SEQ_IDX_WRITESTATUSREG] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x01, kFLEXSPI_Command_WRITE_SDR, kFLEXSPI_1PAD, 0x04),

/* Enter QPI mode */

[4 * NOR_CMD_LUT_SEQ_IDX_ENTERQPI] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x35, kFLEXSPI_Command_STOP, kFLEXSPI_1PAD, 0),

/* Exit QPI mode */

[4 * NOR_CMD_LUT_SEQ_IDX_EXITQPI] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_4PAD, 0xF5, kFLEXSPI_Command_STOP, kFLEXSPI_1PAD, 0),

/* Read status register */

[4 * NOR_CMD_LUT_SEQ_IDX_READSTATUSREG] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x05, kFLEXSPI_Command_READ_SDR, kFLEXSPI_1PAD, 0x04),

/* Erase whole chip */

[4 * NOR_CMD_LUT_SEQ_IDX_ERASECHIP] =

FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0xC7, kFLEXSPI_Command_STOP, kFLEXSPI_1PAD, 0),

};

int main(void)

{

/* Init board hardware. */

BOARD_ConfigMPU();

BOARD_InitPins();

BOARD_BootClockRUN();

BOARD_InitDebugConsole();

PRINTF("Flash Operation on FreeRTOS in XIP Mode! ");

if (xTaskCreate(hello_task, "Hello_task", configMINIMAL_STACK_SIZE + 100, NULL, hello_task_PRIORITY, NULL) !=

pdPASS)

{

PRINTF("Task creation failed!. ");

while (1)

;

}

if (xTaskCreate(flash_operation_task, "flash_operation_task", configMINIMAL_STACK_SIZE + 800, NULL,

flash_operation_task_PRIORITY, NULL) != pdPASS)

{

PRINTF("Task creation failed!. ");

while (1)

;

}

vTaskStartScheduler();

for (;;)

;

}

static void hello_task(void *pvParameters)

{

for (;;)

{

PRINTF("Hello world. ");

/* delay 2s */

vTaskDelay(2 * configTICK_RATE_HZ);

}

}

static void flash_operation_task(void *pvParameters)

{

status_t status;

uint8_t vendorID = 0;

/*Programe Buffer must be 4 and 4's multiplier bytes alignment */

uint8_t *nor_program_buffer = pvPortMalloc(256);

if (NULL == nor_program_buffer)

{

PRINTF("nor_program_buffer memory allocation failed! ");

configASSERT(NULL);

}

uint8_t *nor_read_buffer = pvPortMalloc(256);

if (NULL == nor_read_buffer)

{

PRINTF("nor_read_buffer memory allocation failed! ");

configASSERT(NULL);

}

taskENTER_CRITICAL();

flexspi_nor_flash_init(EXAMPLE_FLEXSPI);

taskEXIT_CRITICAL();

/* Get vendor ID. */

status = flexspi_nor_get_vendor_id(EXAMPLE_FLEXSPI, &vendorID);

if (status != kStatus_Success)

{

PRINTF("Get Vendor ID Failure!");

configASSERT(NULL);

}

PRINTF("Flash Vendor ID: 0x%x ", vendorID);

/* Disable I cache to avoid cache pre-fatch instruction with branch prediction from flash and application operate flash synchronously in multi-tasks. */

#if defined(__ICACHE_PRESENT) && (__ICACHE_PRESENT == 1U)

volatile bool ICacheEnableFlag = false;

/* Disable I cache. */

if (SCB_CCR_IC_Msk == (SCB_CCR_IC_Msk & SCB->CCR))

{

SCB_DisableICache();

ICacheEnableFlag = true;

}

#endif /* __ICACHE_PRESENT */

/* Enter quad mode. */

taskENTER_CRITICAL();

status = flexspi_nor_enable_quad_mode(EXAMPLE_FLEXSPI);

taskEXIT_CRITICAL();

#if defined(__ICACHE_PRESENT) && (__ICACHE_PRESENT == 1U)

if (ICacheEnableFlag)

{

/* Enable I cache. */

SCB_EnableICache();

ICacheEnableFlag = false;

}

#endif /* __ICACHE_PRESENT */

if (status != kStatus_Success)

{

configASSERT(NULL);

}

/* Erase sectors. */

PRINTF("Erasing Serial NOR over FlexSPI... ");

/* Disable I cache to avoid cache pre-fatch instruction with branch prediction from flash and application operae flash synchronously inmulti-tasks.*/

#if defined(__ICACHE_PRESENT) && (__ICACHE_PRESENT == 1U)

/* Disable I cache. */

if (SCB_CCR_IC_Msk == (SCB_CCR_IC_Msk & SCB->CCR))

{

SCB_DisableICache();

ICacheEnableFlag = true;

}

#endif /* __ICACHE_PRESENT */

taskENTER_CRITICAL();

status = flexspi_nor_flash_erase_sector(EXAMPLE_FLEXSPI, EXAMPLE_SECTOR * SECTOR_SIZE);

taskEXIT_CRITICAL();

#if defined(__ICACHE_PRESENT) && (__ICACHE_PRESENT == 1U)

if (ICacheEnableFlag)

{

/* Enable I cache. */

SCB_EnableICache();

ICacheEnableFlag = false;

}

#endif /* __ICACHE_PRESENT */

if (status != kStatus_Success)

{

PRINTF("Erase sector failure ! ");

configASSERT(NULL);

}

/* Invalidate the D cache before reading data from QSPI Flash */

#if defined(CACHE_MAINTAIN) && CACHE_MAINTAIN

DCACHE_InvalidateByRange(EXAMPLE_FLEXSPI_AMBA_BASE + EXAMPLE_SECTOR * SECTOR_SIZE, FLASH_PAGE_SIZE);

#endif

memcpy(nor_read_buffer, (void *)(EXAMPLE_FLEXSPI_AMBA_BASE + EXAMPLE_SECTOR * SECTOR_SIZE), FLASH_PAGE_SIZE);

for (uint16_t i = 0; i < FLASH_PAGE_SIZE; i++)

{

if (0xFF != nor_read_buffer[i])

{

PRINTF("Erase data - read out data value incorrect ! ");

configASSERT(NULL);

}

}

PRINTF("Sector Erase successfully ! ");

/* Program Sector */

for (uint16_t i = 0U; i < FLASH_PAGE_SIZE; i++)

{

nor_program_buffer[i] = i;

}

/* Clean program buffer to maker sure program data is valid before program execution for SDRAM target, because heap is cacheabe in SDRAM target.*/

#if defined(USE_SDRAM) && USE_SDRAM

#if defined(CACHE_MAINTAIN) && CACHE_MAINTAIN

DCACHE_CleanByRange((uint32_t)nor_program_buffer, FLASH_PAGE_SIZE);

#endif

#endif

/* Disable I cache to avoid cache pre-fatch instruction with branch prediction from flash andapplication operate flash synchronously inmulti-tasks.*/

#if defined(__ICACHE_PRESENT) && (__ICACHE_PRESENT == 1U)

/* Disable I cache. */

if (SCB_CCR_IC_Msk == (SCB_CCR_IC_Msk & SCB->CCR))

{

SCB_DisableICache();

ICacheEnableFlag = true;

}

#endif /* __ICACHE_PRESENT */

taskENTER_CRITICAL();

status = flexspi_nor_flash_page_program(EXAMPLE_FLEXSPI, EXAMPLE_SECTOR * SECTOR_SIZE, (void *)nor_program_buffer);

taskEXIT_CRITICAL();

#if defined(__ICACHE_PRESENT) && (__ICACHE_PRESENT == 1U)

if (ICacheEnableFlag)

{

/* Enable I cache. */

SCB_EnableICache();

ICacheEnableFlag = false;

}

#endif /* __ICACHE_PRESENT */

if (status != kStatus_Success)

{

PRINTF("Page program failure ! ");

configASSERT(NULL);

}

PRINTF("Page program successfully ! ");

/* clean the D cache before reading data from QSPI Flash */

#if defined(CACHE_MAINTAIN) && CACHE_MAINTAIN

DCACHE_InvalidateByRange(EXAMPLE_FLEXSPI_AMBA_BASE + EXAMPLE_SECTOR * SECTOR_SIZE, FLASH_PAGE_SIZE);

#endif

/* the below read sector API can be used in both Code in QSPI mode and Code in SRAM mode */

taskENTER_CRITICAL();

memcpy(nor_read_buffer, (void *)(EXAMPLE_FLEXSPI_AMBA_BASE + EXAMPLE_SECTOR * SECTOR_SIZE), FLASH_PAGE_SIZE);

taskEXIT_CRITICAL();

PRINTF("Read Sector Content: ");

for (uint16_t i = 0; i < FLASH_PAGE_SIZE; i++)

{

PRINTF("%d, ", nor_read_buffer[i]);

}

PRINTF(" Flash operation done, suspend this task now. ");

/* Suspend itself */

vTaskSuspend(NULL);

}

審核編輯：湯梓紅