MSPM0G3507: 片上flash在完成写入后，再次读取时会进入Default_Handler函数

测试程序是在芯片的0x1fc00地址处写入8个字节，在写入成功后读取flash就会Default_Handler函数，我自己封装了读写函数。请问片上flash读写是有什么注意事项么？

  OnChipFlashRead(0x1fc00, onchip_flash_read_data_buf, 0x08);

  for (int i = 0; i < 8; i++) {
    uart0_send_char(onchip_flash_read_data_buf[i]);
  }

  if (onchip_flash_read_data_buf[0] == 0xFF) {

    bool ret = OnChipFlashWrite(0x1fc00, onchip_flash_write_data_buf, 8);

    if (ret == false) {
      uart0_send_string("OnChip Flash Write Faile\r\n");
    } else {
      uart0_send_string("OnChip Flash Write Success\r\n");

      OnChipFlashRead(0x1fc00, onchip_flash_read_data_buf, 0x08);

      for (int i = 0; i < 8; i++) {
        uart0_send_char(onchip_flash_read_data_buf[i]);
      }
    }
  }

bool OnChipFlashWrite(uint32_t sector_addr, uint8_t buf[], uint16_t len) {

  DL_FLASHCTL_COMMAND_STATUS FlashAPIState;

  if ((len == 0) || (len % 8 != 0)) {
    return false;
  }

  uint32_t *write_ptr = NULL;

  DL_FlashCTL_executeClearStatus(FLASHCTL);
  DL_FlashCTL_unprotectSector(FLASHCTL, sector_addr,
                              DL_FLASHCTL_REGION_SELECT_MAIN);

  for (int i = 0; i < len; i += 8) {

    write_ptr = (uint32_t *)(&buf[i]);
    sector_addr += i;

    FlashAPIState =
        DL_FlashCTL_programMemoryFromRAM64(FLASHCTL, sector_addr, write_ptr);

    if (FlashAPIState == DL_FLASHCTL_COMMAND_STATUS_FAILED) {
      return false;
    }
  }

  return true;
}

static volatile uint32_t tmp[16] = {0};

uint8_t OnChipFlashRead(uint32_t addr, uint8_t buf[], uint16_t len) {
  uint32_t *read_ptr = (uint32_t *)addr;

  for (uint16_t i = 0; i < len; i += 4) {

    tmp[i / 4] = *read_ptr;

    buf[i] = (uint8_t)(tmp[i / 4] >> 24) & 0xFF;
    buf[i + 1] = (uint8_t)((tmp[i / 4] >> 16) & 0xff);
    buf[i + 2] = (uint8_t)((tmp[i / 4] >> 8) & 0xff);
    buf[i + 3] = (uint8_t)(tmp[i / 4] & 0xff);

    read_ptr += 1;
  }

  return len;
}