diff --git a/gat_stand_fw/usblib/config/hw_config.c b/gat_stand_fw/usblib/config/hw_config.c
index cdd2242..befecef 100644
--- a/gat_stand_fw/usblib/config/hw_config.c
+++ b/gat_stand_fw/usblib/config/hw_config.c
@@ -78,9 +78,9 @@ void usb_conf_clksource(void)
  *
  * @return    None
  */
-void Enter_LowPowerMode(void)
+void usb_enter_LowPowerMode(void)
 {  
- 	printf("usb enter low power mode\r\n");
+ 	printf_usb("usb enter low power mode\r\n");
 	bDeviceState = SUSPENDED;
 } 
 
@@ -91,10 +91,10 @@ void Enter_LowPowerMode(void)
  *
  * @return     None
  */
-void Leave_LowPowerMode(void)
+void usb_leave_LowPowerMode(void)
 {
 	DEVICE_INFO *pInfo = &Device_Info;
-	printf("usb leave low power mode\r\n"); 
+	printf_usb("usb leave low power mode\r\n");
 	if (pInfo->Current_Configuration != 0)
 	    bDeviceState = CONFIGURED;
 	else
@@ -141,7 +141,7 @@ void usb_intr_init(void)
  *
  * @return     None
  */
-void USB_Port_Set(FunctionalState NewState, FunctionalState Pin_In_IPU)
+void usb_gpio_init(FunctionalState NewState, FunctionalState Pin_In_IPU)
 {
 	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
 
diff --git a/gat_stand_fw/usblib/config/hw_config.h b/gat_stand_fw/usblib/config/hw_config.h
index 8e3d3ef..f6d3bbb 100644
--- a/gat_stand_fw/usblib/config/hw_config.h
+++ b/gat_stand_fw/usblib/config/hw_config.h
@@ -31,10 +31,10 @@
 void usb_conf_clksource(void);
 void usb_intr_init(void);
 
-void Enter_LowPowerMode(void);
-void Leave_LowPowerMode(void);
+void usb_enter_LowPowerMode(void);
+void usb_leave_LowPowerMode(void);
 
-void USB_Port_Set(FunctionalState NewState, FunctionalState Pin_In_IPU);
+void usb_gpio_init(FunctionalState NewState, FunctionalState Pin_In_IPU);
 
 
 
diff --git a/gat_stand_fw/usblib/config/usb_prop.c b/gat_stand_fw/usblib/config/usb_prop.c
index a10e721..3b75481 100644
--- a/gat_stand_fw/usblib/config/usb_prop.c
+++ b/gat_stand_fw/usblib/config/usb_prop.c
@@ -194,7 +194,7 @@ void USBD_Status_Out(void)
 void USBD_init(void)
 {
     uint8_t	i;
-    uint32_t timeout;
+    volatile uint32_t timeout;
 
     pInformation->Current_Configuration = 0;
     PowerOn();
@@ -206,9 +206,9 @@ void USBD_init(void)
     USB_SIL_Init();
     bDeviceState = UNCONNECTED;
     
-    USB_Port_Set(DISABLE, DISABLE);
+    usb_gpio_init(DISABLE, DISABLE);
     for (timeout = SystemCoreClock >> 5; timeout; timeout--);
-    USB_Port_Set(ENABLE, ENABLE);
+    usb_gpio_init(ENABLE, ENABLE);
 }
 
 /*******************************************************************************
diff --git a/gat_stand_fw/usblib/config/usb_pwr.c b/gat_stand_fw/usblib/config/usb_pwr.c
index 2da7f0e..3e5d268 100644
--- a/gat_stand_fw/usblib/config/usb_pwr.c
+++ b/gat_stand_fw/usblib/config/usb_pwr.c
@@ -115,7 +115,7 @@ void Suspend(void)
 	wCNTR |= CNTR_LPMODE;
 	_SetCNTR(wCNTR);
 
-	Enter_LowPowerMode();
+	usb_enter_LowPowerMode();
 }
 
 /*******************************************************************************
@@ -132,7 +132,7 @@ void Resume_Init(void)
     wCNTR = _GetCNTR();
     wCNTR &= (~CNTR_LPMODE);
     _SetCNTR(wCNTR);
-    Leave_LowPowerMode();
+    usb_leave_LowPowerMode();
     _SetCNTR(IMR_MSK);
 }