我在SDK里ble_app_ota创建了定时器回调，在回调内无法读取Flash，但在app_init里Flash读写擦都正常

数据是先放在0x20000,0x21000是备份区，0x22000是修改区

static void timer_cb(void)
{

// Disable HW RST on P0_0 so it can be used as SPI MOSI.
GPIO_Disable_HW_Reset();
int8_t ret;
uint32_t bytes_read;
uint32_t bytes_written;
uint8_t data_write[4] = { 0 };
ret = spi_flash_block_erase(0x20000, SPI_FLASH_OP_SE);//
ret = spi_flash_read_data(data_write, 0x20000, 4, &bytes_read);// ȡ
ret = spi_flash_block_erase(0x22000, SPI_FLASH_OP_SE);//
ret = spi_flash_write_data(data_write, 0x22000, 4, &bytes_written);//


// Reduce power consumption by putting flash into sleep mode */
spi_flash_power_down();

// Re-enable HW reset input (must be disabled if/when further operation on
// external flash are performed) - must set as input first!
GPIO_ConfigurePin(GPIO_PORT_0, GPIO_PIN_0, INPUT_PULLDOWN, PID_GPIO, false);
GPIO_Enable_HW_Reset();

/* Restart the timer */
timer_id = app_easy_timer(100, timer_cb);
//}

void user_app_init(void)
{
// Disable HW RST on P0_0 so it can be used as SPI MOSI.
GPIO_Disable_HW_Reset();
int8_t ret;
uint32_t bytes_read;
ret = spi_flash_read_data(val, 0x20000, 1, &bytes_read);// ȡ
if(val[0]==0xFF)//flashȫ
{
uint32_t bytes_written;
uint8_t data_write[101][4] = { 0 };
ret = spi_flash_block_erase(0x20000, SPI_FLASH_OP_SE);//
for(uint8_t i=0;i<101;i++)
convert_to_8bit(NTC[i],i,data_write,false);// ȡԭʼ
ret = spi_flash_write_data((uint8_t*)data_write, 0x20000, 404, &bytes_written);// ¹
ret = spi_flash_read_data(val, 0x20000, 404, &bytes_read);// ȡ

ret = spi_flash_block_erase(0x21000, SPI_FLASH_OP_SE);//
ret = spi_flash_write_data(val, 0x21000, 404, &bytes_written);// ±
}

// Reduce power consumption by putting flash into sleep mode */
spi_flash_power_down();

// Re-enable HW reset input (must be disabled if/when further operation on
// external flash are performed) - must set as input first!
GPIO_ConfigurePin(GPIO_PORT_0, GPIO_PIN_0, INPUT_PULLDOWN, PID_GPIO, false);
GPIO_Enable_HW_Reset();

app_param_update_request_timer_used = EASY_TIMER_INVALID_TIMER;
my_led_state = false;
// Initialize Manufacturer Specific Data
mnf_data_init();

// Initialize Advertising and Scan Response Data
memcpy(stored_adv_data, USER_ADVERTISE_DATA, USER_ADVERTISE_DATA_LEN);
stored_adv_data_len = USER_ADVERTISE_DATA_LEN;
memcpy(stored_scan_rsp_data, USER_ADVERTISE_SCAN_RESPONSE_DATA, USER_ADVERTISE_SCAN_RESPONSE_DATA_LEN);
stored_scan_rsp_data_len = USER_ADVERTISE_SCAN_RESPONSE_DATA_LEN;

default_app_on_init();
}