diff --git a/xs_flash.h b/xs_flash.h
index e08af76..5c7bd57 100644
--- a/xs_flash.h
+++ b/xs_flash.h
@@ -28,7 +28,7 @@
  *      3. rawstartadd第一位必须是0xABCD,最后一位是校验和
  */
 
-#define FLASH_MASK_VAL     0xABCD
+#define FLASH_MASK_VAL     0xDCBA
 #define FLASH_START_ADD    0x080C0000  //
 #define FLASH_EARSE_SECTOR FLASH_SECTOR_10