diff --git a/usb_int.c b/usb_int.c
new file mode 100644
--- /dev/null
+++ b/usb_int.c
@@ -0,0 +1,195 @@
+/**
+  ******************************************************************************
+  * @file    usb_int.c
+  * @author  MCD Application Team
+  * @version V4.0.0
+  * @date    28-August-2012
+  * @brief   Endpoint CTR (Low and High) interrupt's service routines
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; COPYRIGHT 2012 STMicroelectronics</center></h2>
+  *
+  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
+  * You may not use this file except in compliance with the License.
+  * You may obtain a copy of the License at:
+  *
+  *        http://www.st.com/software_license_agreement_liberty_v2
+  *
+  * Unless required by applicable law or agreed to in writing, software 
+  * distributed under the License is distributed on an "AS IS" BASIS, 
+  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  * See the License for the specific language governing permissions and
+  * limitations under the License.
+  *
+  ******************************************************************************
+  */
+
+/* Includes ------------------------------------------------------------------*/
+#include "usb_lib.h"
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+__IO uint16_t SaveRState;
+__IO uint16_t SaveTState;
+
+/* Extern variables ----------------------------------------------------------*/
+extern void (*pEpInt_IN[7])(void);    /*  Handles IN  interrupts   */
+extern void (*pEpInt_OUT[7])(void);   /*  Handles OUT interrupts   */
+
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+
+/*******************************************************************************
+* Function Name  : CTR_LP.
+* Description    : Low priority Endpoint Correct Transfer interrupt's service
+*                  routine.
+* Input          : None.
+* Output         : None.
+* Return         : None.
+*******************************************************************************/
+void CTR_LP(void)
+{
+  __IO uint16_t wEPVal = 0;
+  /* stay in loop while pending interrupts */
+  while (((wIstr = _GetISTR()) & ISTR_CTR) != 0)
+  {
+    /* extract highest priority endpoint number */
+    EPindex = (uint8_t)(wIstr & ISTR_EP_ID);
+    if (EPindex == 0)
+    {
+      /* Decode and service control endpoint interrupt */
+      /* calling related service routine */
+      /* (Setup0_Process, In0_Process, Out0_Process) */
+
+      /* save RX & TX status */
+      /* and set both to NAK */
+      
+	    SaveRState = _GetENDPOINT(ENDP0);
+	    SaveTState = SaveRState & EPTX_STAT;
+	    SaveRState &=  EPRX_STAT;	
+
+	    _SetEPRxTxStatus(ENDP0,EP_RX_NAK,EP_TX_NAK);
+
+      /* DIR bit = origin of the interrupt */
+
+      if ((wIstr & ISTR_DIR) == 0)
+      {
+        /* DIR = 0 */
+
+        /* DIR = 0      => IN  int */
+        /* DIR = 0 implies that (EP_CTR_TX = 1) always  */
+
+        _ClearEP_CTR_TX(ENDP0);
+        In0_Process();
+
+           /* before terminate set Tx & Rx status */
+
+            _SetEPRxTxStatus(ENDP0,SaveRState,SaveTState);
+		  return;
+      }
+      else
+      {
+        /* DIR = 1 */
+
+        /* DIR = 1 & CTR_RX       => SETUP or OUT int */
+        /* DIR = 1 & (CTR_TX | CTR_RX) => 2 int pending */
+
+        wEPVal = _GetENDPOINT(ENDP0);
+        
+        if ((wEPVal &EP_SETUP) != 0)
+        {
+          _ClearEP_CTR_RX(ENDP0); /* SETUP bit kept frozen while CTR_RX = 1 */
+          Setup0_Process();
+          /* before terminate set Tx & Rx status */
+
+		      _SetEPRxTxStatus(ENDP0,SaveRState,SaveTState);
+          return;
+        }
+
+        else if ((wEPVal & EP_CTR_RX) != 0)
+        {
+          _ClearEP_CTR_RX(ENDP0);
+          Out0_Process();
+          /* before terminate set Tx & Rx status */
+     
+		     _SetEPRxTxStatus(ENDP0,SaveRState,SaveTState);
+          return;
+        }
+      }
+    }/* if(EPindex == 0) */
+    else
+    {
+      /* Decode and service non control endpoints interrupt  */
+
+      /* process related endpoint register */
+      wEPVal = _GetENDPOINT(EPindex);
+      if ((wEPVal & EP_CTR_RX) != 0)
+      {
+        /* clear int flag */
+        _ClearEP_CTR_RX(EPindex);
+
+        /* call OUT service function */
+        (*pEpInt_OUT[EPindex-1])();
+
+      } /* if((wEPVal & EP_CTR_RX) */
+
+      if ((wEPVal & EP_CTR_TX) != 0)
+      {
+        /* clear int flag */
+        _ClearEP_CTR_TX(EPindex);
+
+        /* call IN service function */
+        (*pEpInt_IN[EPindex-1])();
+      } /* if((wEPVal & EP_CTR_TX) != 0) */
+
+    }/* if(EPindex == 0) else */
+
+  }/* while(...) */
+}
+
+/*******************************************************************************
+* Function Name  : CTR_HP.
+* Description    : High Priority Endpoint Correct Transfer interrupt's service 
+*                  routine.
+* Input          : None.
+* Output         : None.
+* Return         : None.
+*******************************************************************************/
+void CTR_HP(void)
+{
+  uint32_t wEPVal = 0;
+
+  while (((wIstr = _GetISTR()) & ISTR_CTR) != 0)
+  {
+    _SetISTR((uint16_t)CLR_CTR); /* clear CTR flag */
+    /* extract highest priority endpoint number */
+    EPindex = (uint8_t)(wIstr & ISTR_EP_ID);
+    /* process related endpoint register */
+    wEPVal = _GetENDPOINT(EPindex);
+    if ((wEPVal & EP_CTR_RX) != 0)
+    {
+      /* clear int flag */
+      _ClearEP_CTR_RX(EPindex);
+
+      /* call OUT service function */
+      (*pEpInt_OUT[EPindex-1])();
+
+    } /* if((wEPVal & EP_CTR_RX) */
+    else if ((wEPVal & EP_CTR_TX) != 0)
+    {
+      /* clear int flag */
+      _ClearEP_CTR_TX(EPindex);
+
+      /* call IN service function */
+      (*pEpInt_IN[EPindex-1])();
+
+
+    } /* if((wEPVal & EP_CTR_TX) != 0) */
+
+  }/* while(...) */
+}
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/