diff --git a/build/libraries/cdc/ARM7/src/cdc_api.c b/build/libraries/cdc/ARM7/src/cdc_api.c
index 9e9b77a..a2dfd39 100644
--- a/build/libraries/cdc/ARM7/src/cdc_api.c
+++ b/build/libraries/cdc/ARM7/src/cdc_api.c
@@ -18,6 +18,8 @@
 
 #include "pm_pmic.h"
 
+#define OS_Sleep(msec)  OS_SpinWait(((msec)*(HW_CPU_CLOCK/1000))&~3)
+
 //#define MEASUREMENT_BY_TICK
 #ifdef  MEASUREMENT_BY_TICK
 #include <twl/vlink.h>