diff --git a/libcpu/arm/am335x/mmu.c b/libcpu/arm/am335x/mmu.c
index 46f2d6afd7e247a3df8360d5030bb5f8064144bd..d3e505e76a0e3f1e76c0ac5f2d4af206db30b60e 100644
--- a/libcpu/arm/am335x/mmu.c
+++ b/libcpu/arm/am335x/mmu.c
@@ -15,7 +15,7 @@
 #include <rtthread.h>
 #include "am33xx.h"
 
-#define DESC_SEC		(0x2|(1<<4))
+#define DESC_SEC		(0x2)
 #define CB				(3<<2)  //cache_on, write_back
 #define CNB				(2<<2)  //cache_on, write_through
 #define NCB				(1<<2)  //cache_off,WR_BUF on